A2A Definition/Schema¶
Protobuf
The normative A2A protocol definition in Protocol Buffers (proto3 syntax). This is the source of truth for the A2A protocol specification.Download
You can download the proto file directly: a2a.proto
Definition
// Older protoc compilers don't understand edition yet.
syntax = "proto3";
package lf.a2a.v1;
import "google/api/annotations.proto";
import "google/api/client.proto";
import "google/api/field_behavior.proto";
import "google/protobuf/empty.proto";
import "google/protobuf/struct.proto";
import "google/protobuf/timestamp.proto";
option csharp_namespace = "Lf.A2a.V1";
option go_package = "google.golang.org/lf/a2a/v1";
option java_multiple_files = true;
option java_outer_classname = "A2A";
option java_package = "com.google.lf.a2a.v1";
// Provides operations for interacting with agents using the A2A protocol.
service A2AService {
// Sends a message to an agent.
rpc SendMessage(SendMessageRequest) returns (SendMessageResponse) {
option (google.api.http) = {
post: "/message:send"
body: "*"
additional_bindings: {
post: "/{tenant}/message:send"
body: "*"
}
};
}
// Sends a streaming message to an agent, allowing for real-time interaction and status updates.
// Streaming version of `SendMessage`
rpc SendStreamingMessage(SendMessageRequest) returns (stream StreamResponse) {
option (google.api.http) = {
post: "/message:stream"
body: "*"
additional_bindings: {
post: "/{tenant}/message:stream"
body: "*"
}
};
}
// Gets the latest state of a task.
rpc GetTask(GetTaskRequest) returns (Task) {
option (google.api.http) = {
get: "/tasks/{id=*}"
additional_bindings: {
get: "/{tenant}/tasks/{id=*}"
}
};
option (google.api.method_signature) = "id";
}
// Lists tasks that match the specified filter.
rpc ListTasks(ListTasksRequest) returns (ListTasksResponse) {
option (google.api.http) = {
get: "/tasks"
additional_bindings: {
get: "/{tenant}/tasks"
}
};
}
// Cancels a task in progress.
rpc CancelTask(CancelTaskRequest) returns (Task) {
option (google.api.http) = {
post: "/tasks/{id=*}:cancel"
body: "*"
additional_bindings: {
post: "/{tenant}/tasks/{id=*}:cancel"
body: "*"
}
};
}
// Subscribes to task updates for tasks not in a terminal state.
// Returns `UnsupportedOperationError` if the task is already in a terminal state (completed, failed, canceled, rejected).
rpc SubscribeToTask(SubscribeToTaskRequest) returns (stream StreamResponse) {
option (google.api.http) = {
get: "/tasks/{id=*}:subscribe"
additional_bindings: {
get: "/{tenant}/tasks/{id=*}:subscribe"
}
};
}
// (-- api-linter: client-libraries::4232::required-fields=disabled
// api-linter: core::0133::method-signature=disabled
// aip.dev/not-precedent: method_signature preserved for backwards compatibility --)
// Creates a push notification config for a task.
rpc CreateTaskPushNotificationConfig(CreateTaskPushNotificationConfigRequest) returns (TaskPushNotificationConfig) {
option (google.api.http) = {
post: "/tasks/{task_id=*}/pushNotificationConfigs"
body: "config"
additional_bindings: {
post: "/{tenant}/tasks/{task_id=*}/pushNotificationConfigs"
body: "config"
}
};
option (google.api.method_signature) = "task_id,config";
}
// Gets a push notification config for a task.
rpc GetTaskPushNotificationConfig(GetTaskPushNotificationConfigRequest) returns (TaskPushNotificationConfig) {
option (google.api.http) = {
get: "/tasks/{task_id=*}/pushNotificationConfigs/{id=*}"
additional_bindings: {
get: "/{tenant}/tasks/{task_id=*}/pushNotificationConfigs/{id=*}"
}
};
option (google.api.method_signature) = "task_id,id";
}
// Get a list of push notifications configured for a task.
rpc ListTaskPushNotificationConfigs(ListTaskPushNotificationConfigsRequest) returns (ListTaskPushNotificationConfigsResponse) {
option (google.api.http) = {
get: "/tasks/{task_id=*}/pushNotificationConfigs"
additional_bindings: {
get: "/{tenant}/tasks/{task_id=*}/pushNotificationConfigs"
}
};
option (google.api.method_signature) = "task_id";
}
// Gets the extended agent card for the authenticated agent.
rpc GetExtendedAgentCard(GetExtendedAgentCardRequest) returns (AgentCard) {
option (google.api.http) = {
get: "/extendedAgentCard"
additional_bindings: {
get: "/{tenant}/extendedAgentCard"
}
};
}
// Deletes a push notification config for a task.
rpc DeleteTaskPushNotificationConfig(DeleteTaskPushNotificationConfigRequest) returns (google.protobuf.Empty) {
option (google.api.http) = {
delete: "/tasks/{task_id=*}/pushNotificationConfigs/{id=*}"
additional_bindings: {
delete: "/{tenant}/tasks/{task_id=*}/pushNotificationConfigs/{id=*}"
}
};
option (google.api.method_signature) = "task_id,id";
}
}
// Configuration of a send message request.
message SendMessageConfiguration {
// A list of media types the client is prepared to accept for response parts.
// Agents SHOULD use this to tailor their output.
repeated string accepted_output_modes = 1;
// Configuration for the agent to send push notifications for task updates.
PushNotificationConfig push_notification_config = 2;
// The maximum number of most recent messages from the task's history to retrieve in
// the response. An unset value means the client does not impose any limit. A
// value of zero is a request to not include any messages. The server MUST NOT
// return more messages than the provided value, but MAY apply a lower limit.
optional int32 history_length = 3;
// If `true`, the operation MUST wait until the task reaches a terminal state
// (`COMPLETED`, `FAILED`, `CANCELED`, `REJECTED`) or an interrupted state
// (`INPUT_REQUIRED`, `AUTH_REQUIRED`) before returning. Default is `false`.
bool blocking = 4;
}
// `Task` is the core unit of action for A2A. It has a current status
// and when results are created for the task they are stored in the
// artifact. If there are multiple turns for a task, these are stored in
// history.
message Task {
// Unique identifier (e.g. UUID) for the task, generated by the server for a
// new task.
string id = 1 [(google.api.field_behavior) = REQUIRED];
// Unique identifier (e.g. UUID) for the contextual collection of interactions
// (tasks and messages). Created by the A2A server.
string context_id = 2 [(google.api.field_behavior) = REQUIRED];
// The current status of a `Task`, including `state` and a `message`.
TaskStatus status = 3 [(google.api.field_behavior) = REQUIRED];
// A set of output artifacts for a `Task`.
repeated Artifact artifacts = 4;
// protolint:disable REPEATED_FIELD_NAMES_PLURALIZED
// The history of interactions from a `Task`.
repeated Message history = 5;
// protolint:enable REPEATED_FIELD_NAMES_PLURALIZED
// A key/value object to store custom metadata about a task.
google.protobuf.Struct metadata = 6;
}
// Defines the possible lifecycle states of a `Task`.
enum TaskState {
// The task is in an unknown or indeterminate state.
TASK_STATE_UNSPECIFIED = 0;
// Indicates that a task has been successfully submitted and acknowledged.
TASK_STATE_SUBMITTED = 1;
// Indicates that a task is actively being processed by the agent.
TASK_STATE_WORKING = 2;
// Indicates that a task has finished successfully. This is a terminal state.
TASK_STATE_COMPLETED = 3;
// Indicates that a task has finished with an error. This is a terminal state.
TASK_STATE_FAILED = 4;
// Indicates that a task was canceled before completion. This is a terminal state.
TASK_STATE_CANCELED = 5;
// Indicates that the agent requires additional user input to proceed. This is an interrupted state.
TASK_STATE_INPUT_REQUIRED = 6;
// Indicates that the agent has decided to not perform the task.
// This may be done during initial task creation or later once an agent
// has determined it can't or won't proceed. This is a terminal state.
TASK_STATE_REJECTED = 7;
// Indicates that authentication is required to proceed. This is an interrupted state.
TASK_STATE_AUTH_REQUIRED = 8;
}
// A container for the status of a task
message TaskStatus {
// The current state of this task.
TaskState state = 1 [(google.api.field_behavior) = REQUIRED];
// A message associated with the status.
Message message = 2;
// ISO 8601 Timestamp when the status was recorded.
// Example: "2023-10-27T10:00:00Z"
google.protobuf.Timestamp timestamp = 3;
}
// `Part` represents a container for a section of communication content.
// Parts can be purely textual, some sort of file (image, video, etc) or
// a structured data blob (i.e. JSON).
message Part {
oneof content {
// The string content of the `text` part.
string text = 1;
// The `raw` byte content of a file. In JSON serialization, this is encoded as a base64 string.
bytes raw = 2;
// A `url` pointing to the file's content.
string url = 3;
// Arbitrary structured `data` as a JSON value (object, array, string, number, boolean, or null).
google.protobuf.Value data = 4;
}
// Optional. metadata associated with this part.
google.protobuf.Struct metadata = 5;
// An optional `filename` for the file (e.g., "document.pdf").
string filename = 6;
// The `media_type` (MIME type) of the part content (e.g., "text/plain", "application/json", "image/png").
// This field is available for all part types.
string media_type = 7;
}
// Defines the sender of a message in A2A protocol communication.
enum Role {
// The role is unspecified.
ROLE_UNSPECIFIED = 0;
// The message is from the client to the server.
ROLE_USER = 1;
// The message is from the server to the client.
ROLE_AGENT = 2;
}
// `Message` is one unit of communication between client and server. It can be
// associated with a context and/or a task. For server messages, `context_id` must
// be provided, and `task_id` only if a task was created. For client messages, both
// fields are optional, with the caveat that if both are provided, they have to
// match (the `context_id` has to be the one that is set on the task). If only
// `task_id` is provided, the server will infer `context_id` from it.
message Message {
// The unique identifier (e.g. UUID) of the message. This is created by the message creator.
string message_id = 1 [(google.api.field_behavior) = REQUIRED];
// Optional. The context id of the message. If set, the message will be associated with the given context.
string context_id = 2;
// Optional. The task id of the message. If set, the message will be associated with the given task.
string task_id = 3;
// Identifies the sender of the message.
Role role = 4 [(google.api.field_behavior) = REQUIRED];
// Parts is the container of the message content.
repeated Part parts = 5 [(google.api.field_behavior) = REQUIRED];
// Optional. Any metadata to provide along with the message.
google.protobuf.Struct metadata = 6;
// The URIs of extensions that are present or contributed to this Message.
repeated string extensions = 7;
// A list of task IDs that this message references for additional context.
repeated string reference_task_ids = 8;
}
// Artifacts represent task outputs.
message Artifact {
// Unique identifier (e.g. UUID) for the artifact. It must be unique within a task.
string artifact_id = 1 [(google.api.field_behavior) = REQUIRED];
// A human readable name for the artifact.
string name = 2;
// Optional. A human readable description of the artifact.
string description = 3;
// The content of the artifact. Must contain at least one part.
repeated Part parts = 4 [(google.api.field_behavior) = REQUIRED];
// Optional. Metadata included with the artifact.
google.protobuf.Struct metadata = 5;
// The URIs of extensions that are present or contributed to this Artifact.
repeated string extensions = 6;
}
// An event sent by the agent to notify the client of a change in a task's status.
message TaskStatusUpdateEvent {
// The ID of the task that has changed.
string task_id = 1 [(google.api.field_behavior) = REQUIRED];
// The ID of the context that the task belongs to.
string context_id = 2 [(google.api.field_behavior) = REQUIRED];
// The new status of the task.
TaskStatus status = 3 [(google.api.field_behavior) = REQUIRED];
// Optional. Metadata associated with the task update.
google.protobuf.Struct metadata = 4;
}
// A task delta where an artifact has been generated.
message TaskArtifactUpdateEvent {
// The ID of the task for this artifact.
string task_id = 1 [(google.api.field_behavior) = REQUIRED];
// The ID of the context that this task belongs to.
string context_id = 2 [(google.api.field_behavior) = REQUIRED];
// The artifact that was generated or updated.
Artifact artifact = 3 [(google.api.field_behavior) = REQUIRED];
// If true, the content of this artifact should be appended to a previously
// sent artifact with the same ID.
bool append = 4;
// If true, this is the final chunk of the artifact.
bool last_chunk = 5;
// Optional. Metadata associated with the artifact update.
google.protobuf.Struct metadata = 6;
}
// Configuration for setting up push notifications for task updates.
message PushNotificationConfig {
// A unique identifier (e.g. UUID) for this push notification configuration.
string id = 1;
// The URL where the notification should be sent.
string url = 2 [(google.api.field_behavior) = REQUIRED];
// A token unique for this task or session.
string token = 3;
// Authentication information required to send the notification.
AuthenticationInfo authentication = 4;
}
// Defines authentication details, used for push notifications.
message AuthenticationInfo {
// HTTP Authentication Scheme from the [IANA registry](https://www.iana.org/assignments/http-authschemes/).
// Examples: `Bearer`, `Basic`, `Digest`.
// Scheme names are case-insensitive per [RFC 9110 Section 11.1](https://www.rfc-editor.org/rfc/rfc9110#section-11.1).
string scheme = 1 [(google.api.field_behavior) = REQUIRED];
// Push Notification credentials. Format depends on the scheme (e.g., token for Bearer).
string credentials = 2;
}
// Declares a combination of a target URL, transport and protocol version for interacting with the agent.
// This allows agents to expose the same functionality over multiple protocol binding mechanisms.
message AgentInterface {
// The URL where this interface is available. Must be a valid absolute HTTPS URL in production.
// Example: "https://api.example.com/a2a/v1", "https://grpc.example.com/a2a"
string url = 1 [(google.api.field_behavior) = REQUIRED];
// The protocol binding supported at this URL. This is an open form string, to be
// easily extended for other protocol bindings. The core ones officially
// supported are `JSONRPC`, `GRPC` and `HTTP+JSON`.
string protocol_binding = 2 [(google.api.field_behavior) = REQUIRED];
// Tenant ID to be used in the request when calling the agent.
string tenant = 3;
// The version of the A2A protocol this interface exposes.
// Use the latest supported minor version per major version.
// Examples: "0.3", "1.0"
string protocol_version = 4 [(google.api.field_behavior) = REQUIRED];
}
// A self-describing manifest for an agent. It provides essential
// metadata including the agent's identity, capabilities, skills, supported
// communication methods, and security requirements.
// Next ID: 20
message AgentCard {
// A human readable name for the agent.
// Example: "Recipe Agent"
string name = 1 [(google.api.field_behavior) = REQUIRED];
// A human-readable description of the agent, assisting users and other agents
// in understanding its purpose.
// Example: "Agent that helps users with recipes and cooking."
string description = 2 [(google.api.field_behavior) = REQUIRED];
// Ordered list of supported interfaces. The first entry is preferred.
repeated AgentInterface supported_interfaces = 3 [(google.api.field_behavior) = REQUIRED];
// The service provider of the agent.
AgentProvider provider = 4;
// The version of the agent.
// Example: "1.0.0"
string version = 5 [(google.api.field_behavior) = REQUIRED];
// A URL providing additional documentation about the agent.
optional string documentation_url = 6;
// A2A Capability set supported by the agent.
AgentCapabilities capabilities = 7 [(google.api.field_behavior) = REQUIRED];
// The security scheme details used for authenticating with this agent.
map<string, SecurityScheme> security_schemes = 8;
// Security requirements for contacting the agent.
repeated SecurityRequirement security_requirements = 9;
// protolint:enable REPEATED_FIELD_NAMES_PLURALIZED
// The set of interaction modes that the agent supports across all skills.
// This can be overridden per skill. Defined as media types.
repeated string default_input_modes = 10 [(google.api.field_behavior) = REQUIRED];
// The media types supported as outputs from this agent.
repeated string default_output_modes = 11 [(google.api.field_behavior) = REQUIRED];
// Skills represent the abilities of an agent.
// It is largely a descriptive concept but represents a more focused set of behaviors that the
// agent is likely to succeed at.
repeated AgentSkill skills = 12 [(google.api.field_behavior) = REQUIRED];
// JSON Web Signatures computed for this `AgentCard`.
repeated AgentCardSignature signatures = 13;
// Optional. A URL to an icon for the agent.
optional string icon_url = 14;
}
// Represents the service provider of an agent.
message AgentProvider {
// A URL for the agent provider's website or relevant documentation.
// Example: "https://ai.google.dev"
string url = 1 [(google.api.field_behavior) = REQUIRED];
// The name of the agent provider's organization.
// Example: "Google"
string organization = 2 [(google.api.field_behavior) = REQUIRED];
}
// Defines optional capabilities supported by an agent.
message AgentCapabilities {
// Indicates if the agent supports streaming responses.
optional bool streaming = 1;
// Indicates if the agent supports sending push notifications for asynchronous task updates.
optional bool push_notifications = 2;
// A list of protocol extensions supported by the agent.
repeated AgentExtension extensions = 3;
// Indicates if the agent supports providing an extended agent card when authenticated.
optional bool extended_agent_card = 4;
}
// A declaration of a protocol extension supported by an Agent.
message AgentExtension {
// The unique URI identifying the extension.
string uri = 1;
// A human-readable description of how this agent uses the extension.
string description = 2;
// If true, the client must understand and comply with the extension's requirements.
bool required = 3;
// Optional. Extension-specific configuration parameters.
google.protobuf.Struct params = 4;
}
// Represents a distinct capability or function that an agent can perform.
message AgentSkill {
// A unique identifier for the agent's skill.
string id = 1 [(google.api.field_behavior) = REQUIRED];
// A human-readable name for the skill.
string name = 2 [(google.api.field_behavior) = REQUIRED];
// A detailed description of the skill.
string description = 3 [(google.api.field_behavior) = REQUIRED];
// A set of keywords describing the skill's capabilities.
repeated string tags = 4 [(google.api.field_behavior) = REQUIRED];
// Example prompts or scenarios that this skill can handle.
repeated string examples = 5;
// The set of supported input media types for this skill, overriding the agent's defaults.
repeated string input_modes = 6;
// The set of supported output media types for this skill, overriding the agent's defaults.
repeated string output_modes = 7;
// Security schemes necessary for this skill.
repeated SecurityRequirement security_requirements = 8;
}
// AgentCardSignature represents a JWS signature of an AgentCard.
// This follows the JSON format of an RFC 7515 JSON Web Signature (JWS).
message AgentCardSignature {
// (-- api-linter: core::0140::reserved-words=disabled
// aip.dev/not-precedent: Backwards compatibility --)
// Required. The protected JWS header for the signature. This is always a
// base64url-encoded JSON object.
string protected = 1 [(google.api.field_behavior) = REQUIRED];
// Required. The computed signature, base64url-encoded.
string signature = 2 [(google.api.field_behavior) = REQUIRED];
// The unprotected JWS header values.
google.protobuf.Struct header = 3;
}
// A container associating a push notification configuration with a specific task.
message TaskPushNotificationConfig {
// Optional. Tenant ID.
string tenant = 1;
// The ID of the task this configuration is associated with.
string task_id = 2 [(google.api.field_behavior) = REQUIRED];
// The push notification configuration details.
PushNotificationConfig push_notification_config = 3 [(google.api.field_behavior) = REQUIRED];
}
// protolint:disable REPEATED_FIELD_NAMES_PLURALIZED
// A list of strings.
message StringList {
// The individual string values.
repeated string list = 1;
}
// protolint:enable REPEATED_FIELD_NAMES_PLURALIZED
// Defines the security requirements for an agent.
message SecurityRequirement {
// A map of security schemes to the required scopes.
map<string, StringList> schemes = 1;
}
// Defines a security scheme that can be used to secure an agent's endpoints.
// This is a discriminated union type based on the OpenAPI 3.2 Security Scheme Object.
// See: https://spec.openapis.org/oas/v3.2.0.html#security-scheme-object
message SecurityScheme {
oneof scheme {
// API key-based authentication.
APIKeySecurityScheme api_key_security_scheme = 1;
// HTTP authentication (Basic, Bearer, etc.).
HTTPAuthSecurityScheme http_auth_security_scheme = 2;
// OAuth 2.0 authentication.
OAuth2SecurityScheme oauth2_security_scheme = 3;
// OpenID Connect authentication.
OpenIdConnectSecurityScheme open_id_connect_security_scheme = 4;
// Mutual TLS authentication.
MutualTlsSecurityScheme mtls_security_scheme = 5;
}
}
// Defines a security scheme using an API key.
message APIKeySecurityScheme {
// An optional description for the security scheme.
string description = 1;
// The location of the API key. Valid values are "query", "header", or "cookie".
string location = 2 [(google.api.field_behavior) = REQUIRED];
// The name of the header, query, or cookie parameter to be used.
string name = 3 [(google.api.field_behavior) = REQUIRED];
}
// Defines a security scheme using HTTP authentication.
message HTTPAuthSecurityScheme {
// An optional description for the security scheme.
string description = 1;
// The name of the HTTP Authentication scheme to be used in the Authorization header,
// as defined in RFC7235 (e.g., "Bearer").
// This value should be registered in the IANA Authentication Scheme registry.
string scheme = 2 [(google.api.field_behavior) = REQUIRED];
// A hint to the client to identify how the bearer token is formatted (e.g., "JWT").
// Primarily for documentation purposes.
string bearer_format = 3;
}
// Defines a security scheme using OAuth 2.0.
message OAuth2SecurityScheme {
// An optional description for the security scheme.
string description = 1;
// An object containing configuration information for the supported OAuth 2.0 flows.
OAuthFlows flows = 2 [(google.api.field_behavior) = REQUIRED];
// URL to the OAuth2 authorization server metadata [RFC 8414](https://datatracker.ietf.org/doc/html/rfc8414).
// TLS is required.
string oauth2_metadata_url = 3;
}
// Defines a security scheme using OpenID Connect.
message OpenIdConnectSecurityScheme {
// An optional description for the security scheme.
string description = 1;
// The [OpenID Connect Discovery URL](https://openid.net/specs/openid-connect-discovery-1_0.html) for the OIDC provider's metadata.
string open_id_connect_url = 2 [(google.api.field_behavior) = REQUIRED];
}
// Defines a security scheme using mTLS authentication.
message MutualTlsSecurityScheme {
// An optional description for the security scheme.
string description = 1;
}
// Defines the configuration for the supported OAuth 2.0 flows.
message OAuthFlows {
oneof flow {
// Configuration for the OAuth Authorization Code flow.
AuthorizationCodeOAuthFlow authorization_code = 1;
// Configuration for the OAuth Client Credentials flow.
ClientCredentialsOAuthFlow client_credentials = 2;
// Deprecated: Use Authorization Code + PKCE instead.
ImplicitOAuthFlow implicit = 3 [deprecated = true];
// Deprecated: Use Authorization Code + PKCE or Device Code.
PasswordOAuthFlow password = 4 [deprecated = true];
// Configuration for the OAuth Device Code flow.
DeviceCodeOAuthFlow device_code = 5;
}
}
// Defines configuration details for the OAuth 2.0 Authorization Code flow.
message AuthorizationCodeOAuthFlow {
// The authorization URL to be used for this flow.
string authorization_url = 1 [(google.api.field_behavior) = REQUIRED];
// The token URL to be used for this flow.
string token_url = 2 [(google.api.field_behavior) = REQUIRED];
// The URL to be used for obtaining refresh tokens.
string refresh_url = 3;
// The available scopes for the OAuth2 security scheme.
map<string, string> scopes = 4 [(google.api.field_behavior) = REQUIRED];
// Indicates if PKCE (RFC 7636) is required for this flow.
// PKCE should always be used for public clients and is recommended for all clients.
bool pkce_required = 5;
}
// Defines configuration details for the OAuth 2.0 Client Credentials flow.
message ClientCredentialsOAuthFlow {
// The token URL to be used for this flow.
string token_url = 1 [(google.api.field_behavior) = REQUIRED];
// The URL to be used for obtaining refresh tokens.
string refresh_url = 2;
// The available scopes for the OAuth2 security scheme.
map<string, string> scopes = 3 [(google.api.field_behavior) = REQUIRED];
}
// Deprecated: Use Authorization Code + PKCE instead.
message ImplicitOAuthFlow {
// The authorization URL to be used for this flow. This MUST be in the
// form of a URL. The OAuth2 standard requires the use of TLS
string authorization_url = 1;
// The URL to be used for obtaining refresh tokens. This MUST be in the
// form of a URL. The OAuth2 standard requires the use of TLS.
string refresh_url = 2;
// The available scopes for the OAuth2 security scheme. A map between the
// scope name and a short description for it. The map MAY be empty.
map<string, string> scopes = 3;
}
// Deprecated: Use Authorization Code + PKCE or Device Code.
message PasswordOAuthFlow {
// The token URL to be used for this flow. This MUST be in the form of a URL.
// The OAuth2 standard requires the use of TLS.
string token_url = 1;
// The URL to be used for obtaining refresh tokens. This MUST be in the
// form of a URL. The OAuth2 standard requires the use of TLS.
string refresh_url = 2;
// The available scopes for the OAuth2 security scheme. A map between the
// scope name and a short description for it. The map MAY be empty.
map<string, string> scopes = 3;
}
// Defines configuration details for the OAuth 2.0 Device Code flow (RFC 8628).
// This flow is designed for input-constrained devices such as IoT devices,
// and CLI tools where the user authenticates on a separate device.
message DeviceCodeOAuthFlow {
// The device authorization endpoint URL.
string device_authorization_url = 1 [(google.api.field_behavior) = REQUIRED];
// The token URL to be used for this flow.
string token_url = 2 [(google.api.field_behavior) = REQUIRED];
// The URL to be used for obtaining refresh tokens.
string refresh_url = 3;
// The available scopes for the OAuth2 security scheme.
map<string, string> scopes = 4 [(google.api.field_behavior) = REQUIRED];
}
// Represents a request for the `SendMessage` method.
message SendMessageRequest {
// Optional. Tenant ID, provided as a path parameter.
string tenant = 1;
// The message to send to the agent.
Message message = 2 [(google.api.field_behavior) = REQUIRED];
// Configuration for the send request.
SendMessageConfiguration configuration = 3;
// A flexible key-value map for passing additional context or parameters.
google.protobuf.Struct metadata = 4;
}
// Represents a request for the `GetTask` method.
message GetTaskRequest {
// Optional. Tenant ID, provided as a path parameter.
string tenant = 1;
// The resource ID of the task to retrieve.
string id = 2 [(google.api.field_behavior) = REQUIRED];
// The maximum number of most recent messages from the task's history to retrieve. An
// unset value means the client does not impose any limit. A value of zero is
// a request to not include any messages. The server MUST NOT return more
// messages than the provided value, but MAY apply a lower limit.
optional int32 history_length = 3;
}
// Parameters for listing tasks with optional filtering criteria.
message ListTasksRequest {
// Tenant ID, provided as a path parameter.
string tenant = 1;
// Filter tasks by context ID to get tasks from a specific conversation or session.
string context_id = 2;
// Filter tasks by their current status state.
TaskState status = 3;
// The maximum number of tasks to return. The service may return fewer than this value.
// If unspecified, at most 50 tasks will be returned.
// The minimum value is 1.
// The maximum value is 100.
optional int32 page_size = 4;
// A page token, received from a previous `ListTasks` call.
// `ListTasksResponse.next_page_token`.
// Provide this to retrieve the subsequent page.
string page_token = 5;
// The maximum number of messages to include in each task's history.
optional int32 history_length = 6;
// Filter tasks which have a status updated after the provided timestamp in ISO 8601 format (e.g., "2023-10-27T10:00:00Z").
// Only tasks with a status timestamp time greater than or equal to this value will be returned.
google.protobuf.Timestamp status_timestamp_after = 7;
// Whether to include artifacts in the returned tasks.
// Defaults to false to reduce payload size.
optional bool include_artifacts = 8;
}
// Result object for `ListTasks` method containing an array of tasks and pagination information.
message ListTasksResponse {
// Array of tasks matching the specified criteria.
repeated Task tasks = 1 [(google.api.field_behavior) = REQUIRED];
// A token to retrieve the next page of results, or empty if there are no more results in the list.
string next_page_token = 2 [(google.api.field_behavior) = REQUIRED];
// The page size used for this response.
int32 page_size = 3 [(google.api.field_behavior) = REQUIRED];
// Total number of tasks available (before pagination).
int32 total_size = 4 [(google.api.field_behavior) = REQUIRED];
}
// Represents a request for the `CancelTask` method.
message CancelTaskRequest {
// Optional. Tenant ID, provided as a path parameter.
string tenant = 1;
// The resource ID of the task to cancel.
string id = 2 [(google.api.field_behavior) = REQUIRED];
// A flexible key-value map for passing additional context or parameters.
google.protobuf.Struct metadata = 3;
}
// Represents a request for the `GetTaskPushNotificationConfig` method.
message GetTaskPushNotificationConfigRequest {
// Optional. Tenant ID, provided as a path parameter.
string tenant = 1;
// The parent task resource ID.
string task_id = 2 [(google.api.field_behavior) = REQUIRED];
// The resource ID of the configuration to retrieve.
string id = 3 [(google.api.field_behavior) = REQUIRED];
}
// Represents a request for the `DeleteTaskPushNotificationConfig` method.
message DeleteTaskPushNotificationConfigRequest {
// Optional. Tenant ID, provided as a path parameter.
string tenant = 1;
// The parent task resource ID.
string task_id = 2 [(google.api.field_behavior) = REQUIRED];
// The resource ID of the configuration to delete.
string id = 3 [(google.api.field_behavior) = REQUIRED];
}
// Represents a request for the `CreateTaskPushNotificationConfig` method.
message CreateTaskPushNotificationConfigRequest {
// Optional. Tenant ID, provided as a path parameter.
string tenant = 1;
// The parent task resource ID.
string task_id = 2 [(google.api.field_behavior) = REQUIRED];
// The configuration to create.
PushNotificationConfig config = 3 [(google.api.field_behavior) = REQUIRED];
}
// Represents a request for the `SubscribeToTask` method.
message SubscribeToTaskRequest {
// Optional. Tenant ID, provided as a path parameter.
string tenant = 1;
// The resource ID of the task to subscribe to.
string id = 2 [(google.api.field_behavior) = REQUIRED];
}
// Represents a request for the `ListTaskPushNotificationConfigs` method.
message ListTaskPushNotificationConfigsRequest {
// Optional. Tenant ID, provided as a path parameter.
string tenant = 4;
// The parent task resource ID.
string task_id = 1 [(google.api.field_behavior) = REQUIRED];
// The maximum number of configurations to return.
int32 page_size = 2;
// A page token received from a previous `ListTaskPushNotificationConfigsRequest` call.
string page_token = 3;
}
// Represents a request for the `GetExtendedAgentCard` method.
message GetExtendedAgentCardRequest {
// Optional. Tenant ID, provided as a path parameter.
string tenant = 1;
}
// Represents the response for the `SendMessage` method.
message SendMessageResponse {
// The payload of the response.
oneof payload {
// The task created or updated by the message.
Task task = 1;
// A message from the agent.
Message message = 2;
}
}
// A wrapper object used in streaming operations to encapsulate different types of response data.
message StreamResponse {
// The payload of the stream response.
oneof payload {
// A Task object containing the current state of the task.
Task task = 1;
// A Message object containing a message from the agent.
Message message = 2;
// An event indicating a task status update.
TaskStatusUpdateEvent status_update = 3;
// An event indicating a task artifact update.
TaskArtifactUpdateEvent artifact_update = 4;
}
}
// Represents a successful response for the `ListTaskPushNotificationConfigs`
// method.
message ListTaskPushNotificationConfigsResponse {
// The list of push notification configurations.
repeated TaskPushNotificationConfig configs = 1;
// A token to retrieve the next page of results, or empty if there are no more results in the list.
string next_page_token = 2;
}
JSON
The A2A protocol JSON Schema definition (JSON Schema 2020-12 compliant). This schema is automatically generated from the protocol buffer definitions and bundled into a single file with all message definitions.Download
You can download the schema file directly: a2a.json
Definition
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"title": "A2A Protocol Schemas",
"description": "Non-normative JSON Schema bundle extracted from proto definitions.",
"version": "v1",
"definitions": {
"Struct": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"title": "Struct",
"type": "object"
},
"Timestamp": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"format": "date-time",
"title": "Timestamp",
"type": "string"
},
"Value": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"title": "Value"
},
"API Key Security Scheme": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Defines a security scheme using an API key.",
"properties": {
"description": {
"default": "",
"description": "An optional description for the security scheme.",
"type": "string"
},
"location": {
"default": "",
"description": "The location of the API key. Valid values are \"query\", \"header\", or \"cookie\".",
"type": "string"
},
"name": {
"default": "",
"description": "The name of the header, query, or cookie parameter to be used.",
"type": "string"
}
},
"title": "API Key Security Scheme",
"type": "object"
},
"Agent Capabilities": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Defines optional capabilities supported by an agent.",
"patternProperties": {
"^(extended_agent_card)$": {
"description": "Indicates if the agent supports providing an extended agent card when authenticated.",
"type": "boolean"
},
"^(push_notifications)$": {
"description": "Indicates if the agent supports sending push notifications for asynchronous task updates.",
"type": "boolean"
}
},
"properties": {
"extendedAgentCard": {
"description": "Indicates if the agent supports providing an extended agent card when authenticated.",
"type": "boolean"
},
"extensions": {
"description": "A list of protocol extensions supported by the agent.",
"items": {
"$ref": "lf.a2a.v1.AgentExtension.jsonschema.json"
},
"type": "array"
},
"pushNotifications": {
"description": "Indicates if the agent supports sending push notifications for asynchronous task updates.",
"type": "boolean"
},
"streaming": {
"description": "Indicates if the agent supports streaming responses.",
"type": "boolean"
}
},
"title": "Agent Capabilities",
"type": "object"
},
"Agent Card": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "A self-describing manifest for an agent. It provides essential\n metadata including the agent's identity, capabilities, skills, supported\n communication methods, and security requirements.\n Next ID: 20",
"patternProperties": {
"^(default_input_modes)$": {
"description": "The set of interaction modes that the agent supports across all skills.\n This can be overridden per skill. Defined as media types.",
"items": {
"type": "string"
},
"type": "array"
},
"^(default_output_modes)$": {
"description": "The media types supported as outputs from this agent.",
"items": {
"type": "string"
},
"type": "array"
},
"^(documentation_url)$": {
"description": "A URL providing additional documentation about the agent.",
"type": "string"
},
"^(icon_url)$": {
"description": "Optional. A URL to an icon for the agent.",
"type": "string"
},
"^(security_requirements)$": {
"description": "Security requirements for contacting the agent.",
"items": {
"$ref": "lf.a2a.v1.SecurityRequirement.jsonschema.json"
},
"type": "array"
},
"^(security_schemes)$": {
"additionalProperties": {
"$ref": "lf.a2a.v1.SecurityScheme.jsonschema.json"
},
"description": "The security scheme details used for authenticating with this agent.",
"propertyNames": {
"type": "string"
},
"type": "object"
},
"^(supported_interfaces)$": {
"description": "Ordered list of supported interfaces. The first entry is preferred.",
"items": {
"$ref": "lf.a2a.v1.AgentInterface.jsonschema.json"
},
"type": "array"
}
},
"properties": {
"capabilities": {
"$ref": "lf.a2a.v1.AgentCapabilities.jsonschema.json",
"description": "A2A Capability set supported by the agent."
},
"defaultInputModes": {
"description": "The set of interaction modes that the agent supports across all skills.\n This can be overridden per skill. Defined as media types.",
"items": {
"type": "string"
},
"type": "array"
},
"defaultOutputModes": {
"description": "The media types supported as outputs from this agent.",
"items": {
"type": "string"
},
"type": "array"
},
"description": {
"default": "",
"description": "A human-readable description of the agent, assisting users and other agents\n in understanding its purpose.\n Example: \"Agent that helps users with recipes and cooking.\"",
"type": "string"
},
"documentationUrl": {
"description": "A URL providing additional documentation about the agent.",
"type": "string"
},
"iconUrl": {
"description": "Optional. A URL to an icon for the agent.",
"type": "string"
},
"name": {
"default": "",
"description": "A human readable name for the agent.\n Example: \"Recipe Agent\"",
"type": "string"
},
"provider": {
"$ref": "lf.a2a.v1.AgentProvider.jsonschema.json",
"description": "The service provider of the agent."
},
"securityRequirements": {
"description": "Security requirements for contacting the agent.",
"items": {
"$ref": "lf.a2a.v1.SecurityRequirement.jsonschema.json"
},
"type": "array"
},
"securitySchemes": {
"additionalProperties": {
"$ref": "lf.a2a.v1.SecurityScheme.jsonschema.json"
},
"description": "The security scheme details used for authenticating with this agent.",
"propertyNames": {
"type": "string"
},
"type": "object"
},
"signatures": {
"description": "JSON Web Signatures computed for this `AgentCard`.",
"items": {
"$ref": "lf.a2a.v1.AgentCardSignature.jsonschema.json"
},
"type": "array"
},
"skills": {
"description": "Skills represent the abilities of an agent.\n It is largely a descriptive concept but represents a more focused set of behaviors that the\n agent is likely to succeed at.",
"items": {
"$ref": "lf.a2a.v1.AgentSkill.jsonschema.json"
},
"type": "array"
},
"supportedInterfaces": {
"description": "Ordered list of supported interfaces. The first entry is preferred.",
"items": {
"$ref": "lf.a2a.v1.AgentInterface.jsonschema.json"
},
"type": "array"
},
"version": {
"default": "",
"description": "The version of the agent.\n Example: \"1.0.0\"",
"type": "string"
}
},
"title": "Agent Card",
"type": "object"
},
"Agent Card Signature": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "AgentCardSignature represents a JWS signature of an AgentCard.\n This follows the JSON format of an RFC 7515 JSON Web Signature (JWS).",
"properties": {
"header": {
"$ref": "google.protobuf.Struct.jsonschema.json",
"description": "The unprotected JWS header values."
},
"protected": {
"default": "",
"description": "(-- api-linter: core::0140::reserved-words=disabled\n aip.dev/not-precedent: Backwards compatibility --)\n Required. The protected JWS header for the signature. This is always a\n base64url-encoded JSON object.",
"type": "string"
},
"signature": {
"default": "",
"description": "Required. The computed signature, base64url-encoded.",
"type": "string"
}
},
"title": "Agent Card Signature",
"type": "object"
},
"Agent Extension": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "A declaration of a protocol extension supported by an Agent.",
"properties": {
"description": {
"default": "",
"description": "A human-readable description of how this agent uses the extension.",
"type": "string"
},
"params": {
"$ref": "google.protobuf.Struct.jsonschema.json",
"description": "Optional. Extension-specific configuration parameters."
},
"required": {
"default": false,
"description": "If true, the client must understand and comply with the extension's requirements.",
"type": "boolean"
},
"uri": {
"default": "",
"description": "The unique URI identifying the extension.",
"type": "string"
}
},
"title": "Agent Extension",
"type": "object"
},
"Agent Interface": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Declares a combination of a target URL, transport and protocol version for interacting with the agent.\n This allows agents to expose the same functionality over multiple protocol binding mechanisms.",
"patternProperties": {
"^(protocol_binding)$": {
"default": "",
"description": "The protocol binding supported at this URL. This is an open form string, to be\n easily extended for other protocol bindings. The core ones officially\n supported are `JSONRPC`, `GRPC` and `HTTP+JSON`.",
"type": "string"
},
"^(protocol_version)$": {
"default": "",
"description": "The version of the A2A protocol this interface exposes.\n Use the latest supported minor version per major version.\n Examples: \"0.3\", \"1.0\"",
"type": "string"
}
},
"properties": {
"protocolBinding": {
"default": "",
"description": "The protocol binding supported at this URL. This is an open form string, to be\n easily extended for other protocol bindings. The core ones officially\n supported are `JSONRPC`, `GRPC` and `HTTP+JSON`.",
"type": "string"
},
"protocolVersion": {
"default": "",
"description": "The version of the A2A protocol this interface exposes.\n Use the latest supported minor version per major version.\n Examples: \"0.3\", \"1.0\"",
"type": "string"
},
"tenant": {
"default": "",
"description": "Tenant ID to be used in the request when calling the agent.",
"type": "string"
},
"url": {
"default": "",
"description": "The URL where this interface is available. Must be a valid absolute HTTPS URL in production.\n Example: \"https://api.example.com/a2a/v1\", \"https://grpc.example.com/a2a\"",
"type": "string"
}
},
"title": "Agent Interface",
"type": "object"
},
"Agent Provider": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Represents the service provider of an agent.",
"properties": {
"organization": {
"default": "",
"description": "The name of the agent provider's organization.\n Example: \"Google\"",
"type": "string"
},
"url": {
"default": "",
"description": "A URL for the agent provider's website or relevant documentation.\n Example: \"https://ai.google.dev\"",
"type": "string"
}
},
"title": "Agent Provider",
"type": "object"
},
"Agent Skill": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Represents a distinct capability or function that an agent can perform.",
"patternProperties": {
"^(input_modes)$": {
"description": "The set of supported input media types for this skill, overriding the agent's defaults.",
"items": {
"type": "string"
},
"type": "array"
},
"^(output_modes)$": {
"description": "The set of supported output media types for this skill, overriding the agent's defaults.",
"items": {
"type": "string"
},
"type": "array"
},
"^(security_requirements)$": {
"description": "Security schemes necessary for this skill.",
"items": {
"$ref": "lf.a2a.v1.SecurityRequirement.jsonschema.json"
},
"type": "array"
}
},
"properties": {
"description": {
"default": "",
"description": "A detailed description of the skill.",
"type": "string"
},
"examples": {
"description": "Example prompts or scenarios that this skill can handle.",
"items": {
"type": "string"
},
"type": "array"
},
"id": {
"default": "",
"description": "A unique identifier for the agent's skill.",
"type": "string"
},
"inputModes": {
"description": "The set of supported input media types for this skill, overriding the agent's defaults.",
"items": {
"type": "string"
},
"type": "array"
},
"name": {
"default": "",
"description": "A human-readable name for the skill.",
"type": "string"
},
"outputModes": {
"description": "The set of supported output media types for this skill, overriding the agent's defaults.",
"items": {
"type": "string"
},
"type": "array"
},
"securityRequirements": {
"description": "Security schemes necessary for this skill.",
"items": {
"$ref": "lf.a2a.v1.SecurityRequirement.jsonschema.json"
},
"type": "array"
},
"tags": {
"description": "A set of keywords describing the skill's capabilities.",
"items": {
"type": "string"
},
"type": "array"
}
},
"title": "Agent Skill",
"type": "object"
},
"Artifact": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Artifacts represent task outputs.",
"patternProperties": {
"^(artifact_id)$": {
"default": "",
"description": "Unique identifier (e.g. UUID) for the artifact. It must be unique within a task.",
"type": "string"
}
},
"properties": {
"artifactId": {
"default": "",
"description": "Unique identifier (e.g. UUID) for the artifact. It must be unique within a task.",
"type": "string"
},
"description": {
"default": "",
"description": "Optional. A human readable description of the artifact.",
"type": "string"
},
"extensions": {
"description": "The URIs of extensions that are present or contributed to this Artifact.",
"items": {
"type": "string"
},
"type": "array"
},
"metadata": {
"$ref": "google.protobuf.Struct.jsonschema.json",
"description": "Optional. Metadata included with the artifact."
},
"name": {
"default": "",
"description": "A human readable name for the artifact.",
"type": "string"
},
"parts": {
"description": "The content of the artifact. Must contain at least one part.",
"items": {
"$ref": "lf.a2a.v1.Part.jsonschema.json"
},
"type": "array"
}
},
"title": "Artifact",
"type": "object"
},
"Authentication Info": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Defines authentication details, used for push notifications.",
"properties": {
"credentials": {
"default": "",
"description": "Push Notification credentials. Format depends on the scheme (e.g., token for Bearer).",
"type": "string"
},
"scheme": {
"default": "",
"description": "HTTP Authentication Scheme from the [IANA registry](https://www.iana.org/assignments/http-authschemes/).\n Examples: `Bearer`, `Basic`, `Digest`.\n Scheme names are case-insensitive per [RFC 9110 Section 11.1](https://www.rfc-editor.org/rfc/rfc9110#section-11.1).",
"type": "string"
}
},
"title": "Authentication Info",
"type": "object"
},
"Authorization CodeO Auth Flow": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Defines configuration details for the OAuth 2.0 Authorization Code flow.",
"patternProperties": {
"^(authorization_url)$": {
"default": "",
"description": "The authorization URL to be used for this flow.",
"type": "string"
},
"^(pkce_required)$": {
"default": false,
"description": "Indicates if PKCE (RFC 7636) is required for this flow.\n PKCE should always be used for public clients and is recommended for all clients.",
"type": "boolean"
},
"^(refresh_url)$": {
"default": "",
"description": "The URL to be used for obtaining refresh tokens.",
"type": "string"
},
"^(token_url)$": {
"default": "",
"description": "The token URL to be used for this flow.",
"type": "string"
}
},
"properties": {
"authorizationUrl": {
"default": "",
"description": "The authorization URL to be used for this flow.",
"type": "string"
},
"pkceRequired": {
"default": false,
"description": "Indicates if PKCE (RFC 7636) is required for this flow.\n PKCE should always be used for public clients and is recommended for all clients.",
"type": "boolean"
},
"refreshUrl": {
"default": "",
"description": "The URL to be used for obtaining refresh tokens.",
"type": "string"
},
"scopes": {
"additionalProperties": {
"type": "string"
},
"description": "The available scopes for the OAuth2 security scheme.",
"propertyNames": {
"type": "string"
},
"type": "object"
},
"tokenUrl": {
"default": "",
"description": "The token URL to be used for this flow.",
"type": "string"
}
},
"title": "Authorization CodeO Auth Flow",
"type": "object"
},
"Cancel Task Request": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Represents a request for the `CancelTask` method.",
"properties": {
"id": {
"default": "",
"description": "The resource ID of the task to cancel.",
"type": "string"
},
"metadata": {
"$ref": "google.protobuf.Struct.jsonschema.json",
"description": "A flexible key-value map for passing additional context or parameters."
},
"tenant": {
"default": "",
"description": "Optional. Tenant ID, provided as a path parameter.",
"type": "string"
}
},
"title": "Cancel Task Request",
"type": "object"
},
"Client CredentialsO Auth Flow": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Defines configuration details for the OAuth 2.0 Client Credentials flow.",
"patternProperties": {
"^(refresh_url)$": {
"default": "",
"description": "The URL to be used for obtaining refresh tokens.",
"type": "string"
},
"^(token_url)$": {
"default": "",
"description": "The token URL to be used for this flow.",
"type": "string"
}
},
"properties": {
"refreshUrl": {
"default": "",
"description": "The URL to be used for obtaining refresh tokens.",
"type": "string"
},
"scopes": {
"additionalProperties": {
"type": "string"
},
"description": "The available scopes for the OAuth2 security scheme.",
"propertyNames": {
"type": "string"
},
"type": "object"
},
"tokenUrl": {
"default": "",
"description": "The token URL to be used for this flow.",
"type": "string"
}
},
"title": "Client CredentialsO Auth Flow",
"type": "object"
},
"Create Task Push Notification Config Request": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Represents a request for the `CreateTaskPushNotificationConfig` method.",
"patternProperties": {
"^(task_id)$": {
"default": "",
"description": "The parent task resource ID.",
"type": "string"
}
},
"properties": {
"config": {
"$ref": "lf.a2a.v1.PushNotificationConfig.jsonschema.json",
"description": "The configuration to create."
},
"taskId": {
"default": "",
"description": "The parent task resource ID.",
"type": "string"
},
"tenant": {
"default": "",
"description": "Optional. Tenant ID, provided as a path parameter.",
"type": "string"
}
},
"title": "Create Task Push Notification Config Request",
"type": "object"
},
"Delete Task Push Notification Config Request": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Represents a request for the `DeleteTaskPushNotificationConfig` method.",
"patternProperties": {
"^(task_id)$": {
"default": "",
"description": "The parent task resource ID.",
"type": "string"
}
},
"properties": {
"id": {
"default": "",
"description": "The resource ID of the configuration to delete.",
"type": "string"
},
"taskId": {
"default": "",
"description": "The parent task resource ID.",
"type": "string"
},
"tenant": {
"default": "",
"description": "Optional. Tenant ID, provided as a path parameter.",
"type": "string"
}
},
"title": "Delete Task Push Notification Config Request",
"type": "object"
},
"Device CodeO Auth Flow": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Defines configuration details for the OAuth 2.0 Device Code flow (RFC 8628).\n This flow is designed for input-constrained devices such as IoT devices,\n and CLI tools where the user authenticates on a separate device.",
"patternProperties": {
"^(device_authorization_url)$": {
"default": "",
"description": "The device authorization endpoint URL.",
"type": "string"
},
"^(refresh_url)$": {
"default": "",
"description": "The URL to be used for obtaining refresh tokens.",
"type": "string"
},
"^(token_url)$": {
"default": "",
"description": "The token URL to be used for this flow.",
"type": "string"
}
},
"properties": {
"deviceAuthorizationUrl": {
"default": "",
"description": "The device authorization endpoint URL.",
"type": "string"
},
"refreshUrl": {
"default": "",
"description": "The URL to be used for obtaining refresh tokens.",
"type": "string"
},
"scopes": {
"additionalProperties": {
"type": "string"
},
"description": "The available scopes for the OAuth2 security scheme.",
"propertyNames": {
"type": "string"
},
"type": "object"
},
"tokenUrl": {
"default": "",
"description": "The token URL to be used for this flow.",
"type": "string"
}
},
"title": "Device CodeO Auth Flow",
"type": "object"
},
"Get Extended Agent Card Request": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Represents a request for the `GetExtendedAgentCard` method.",
"properties": {
"tenant": {
"default": "",
"description": "Optional. Tenant ID, provided as a path parameter.",
"type": "string"
}
},
"title": "Get Extended Agent Card Request",
"type": "object"
},
"Get Task Push Notification Config Request": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Represents a request for the `GetTaskPushNotificationConfig` method.",
"patternProperties": {
"^(task_id)$": {
"default": "",
"description": "The parent task resource ID.",
"type": "string"
}
},
"properties": {
"id": {
"default": "",
"description": "The resource ID of the configuration to retrieve.",
"type": "string"
},
"taskId": {
"default": "",
"description": "The parent task resource ID.",
"type": "string"
},
"tenant": {
"default": "",
"description": "Optional. Tenant ID, provided as a path parameter.",
"type": "string"
}
},
"title": "Get Task Push Notification Config Request",
"type": "object"
},
"Get Task Request": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Represents a request for the `GetTask` method.",
"patternProperties": {
"^(history_length)$": {
"anyOf": [
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
},
{
"pattern": "^-?[0-9]+$",
"type": "string"
}
],
"description": "The maximum number of most recent messages from the task's history to retrieve. An\n unset value means the client does not impose any limit. A value of zero is\n a request to not include any messages. The server MUST NOT return more\n messages than the provided value, but MAY apply a lower limit."
}
},
"properties": {
"historyLength": {
"anyOf": [
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
},
{
"pattern": "^-?[0-9]+$",
"type": "string"
}
],
"description": "The maximum number of most recent messages from the task's history to retrieve. An\n unset value means the client does not impose any limit. A value of zero is\n a request to not include any messages. The server MUST NOT return more\n messages than the provided value, but MAY apply a lower limit."
},
"id": {
"default": "",
"description": "The resource ID of the task to retrieve.",
"type": "string"
},
"tenant": {
"default": "",
"description": "Optional. Tenant ID, provided as a path parameter.",
"type": "string"
}
},
"title": "Get Task Request",
"type": "object"
},
"HTTP Auth Security Scheme": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Defines a security scheme using HTTP authentication.",
"patternProperties": {
"^(bearer_format)$": {
"default": "",
"description": "A hint to the client to identify how the bearer token is formatted (e.g., \"JWT\").\n Primarily for documentation purposes.",
"type": "string"
}
},
"properties": {
"bearerFormat": {
"default": "",
"description": "A hint to the client to identify how the bearer token is formatted (e.g., \"JWT\").\n Primarily for documentation purposes.",
"type": "string"
},
"description": {
"default": "",
"description": "An optional description for the security scheme.",
"type": "string"
},
"scheme": {
"default": "",
"description": "The name of the HTTP Authentication scheme to be used in the Authorization header,\n as defined in RFC7235 (e.g., \"Bearer\").\n This value should be registered in the IANA Authentication Scheme registry.",
"type": "string"
}
},
"title": "HTTP Auth Security Scheme",
"type": "object"
},
"ImplicitO Auth Flow": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Deprecated: Use Authorization Code + PKCE instead.",
"patternProperties": {
"^(authorization_url)$": {
"default": "",
"description": "The authorization URL to be used for this flow. This MUST be in the\n form of a URL. The OAuth2 standard requires the use of TLS",
"type": "string"
},
"^(refresh_url)$": {
"default": "",
"description": "The URL to be used for obtaining refresh tokens. This MUST be in the\n form of a URL. The OAuth2 standard requires the use of TLS.",
"type": "string"
}
},
"properties": {
"authorizationUrl": {
"default": "",
"description": "The authorization URL to be used for this flow. This MUST be in the\n form of a URL. The OAuth2 standard requires the use of TLS",
"type": "string"
},
"refreshUrl": {
"default": "",
"description": "The URL to be used for obtaining refresh tokens. This MUST be in the\n form of a URL. The OAuth2 standard requires the use of TLS.",
"type": "string"
},
"scopes": {
"additionalProperties": {
"type": "string"
},
"description": "The available scopes for the OAuth2 security scheme. A map between the\n scope name and a short description for it. The map MAY be empty.",
"propertyNames": {
"type": "string"
},
"type": "object"
}
},
"title": "ImplicitO Auth Flow",
"type": "object"
},
"List Task Push Notification Configs Request": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Represents a request for the `ListTaskPushNotificationConfigs` method.",
"patternProperties": {
"^(page_size)$": {
"anyOf": [
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
},
{
"pattern": "^-?[0-9]+$",
"type": "string"
}
],
"default": 0,
"description": "The maximum number of configurations to return."
},
"^(page_token)$": {
"default": "",
"description": "A page token received from a previous `ListTaskPushNotificationConfigsRequest` call.",
"type": "string"
},
"^(task_id)$": {
"default": "",
"description": "The parent task resource ID.",
"type": "string"
}
},
"properties": {
"pageSize": {
"anyOf": [
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
},
{
"pattern": "^-?[0-9]+$",
"type": "string"
}
],
"default": 0,
"description": "The maximum number of configurations to return."
},
"pageToken": {
"default": "",
"description": "A page token received from a previous `ListTaskPushNotificationConfigsRequest` call.",
"type": "string"
},
"taskId": {
"default": "",
"description": "The parent task resource ID.",
"type": "string"
},
"tenant": {
"default": "",
"description": "Optional. Tenant ID, provided as a path parameter.",
"type": "string"
}
},
"title": "List Task Push Notification Configs Request",
"type": "object"
},
"List Task Push Notification Configs Response": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Represents a successful response for the `ListTaskPushNotificationConfigs`\n method.",
"patternProperties": {
"^(next_page_token)$": {
"default": "",
"description": "A token to retrieve the next page of results, or empty if there are no more results in the list.",
"type": "string"
}
},
"properties": {
"configs": {
"description": "The list of push notification configurations.",
"items": {
"$ref": "lf.a2a.v1.TaskPushNotificationConfig.jsonschema.json"
},
"type": "array"
},
"nextPageToken": {
"default": "",
"description": "A token to retrieve the next page of results, or empty if there are no more results in the list.",
"type": "string"
}
},
"title": "List Task Push Notification Configs Response",
"type": "object"
},
"List Tasks Request": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Parameters for listing tasks with optional filtering criteria.",
"patternProperties": {
"^(context_id)$": {
"default": "",
"description": "Filter tasks by context ID to get tasks from a specific conversation or session.",
"type": "string"
},
"^(history_length)$": {
"anyOf": [
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
},
{
"pattern": "^-?[0-9]+$",
"type": "string"
}
],
"description": "The maximum number of messages to include in each task's history."
},
"^(include_artifacts)$": {
"description": "Whether to include artifacts in the returned tasks.\n Defaults to false to reduce payload size.",
"type": "boolean"
},
"^(page_size)$": {
"anyOf": [
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
},
{
"pattern": "^-?[0-9]+$",
"type": "string"
}
],
"description": "The maximum number of tasks to return. The service may return fewer than this value.\n If unspecified, at most 50 tasks will be returned.\n The minimum value is 1.\n The maximum value is 100."
},
"^(page_token)$": {
"default": "",
"description": "A page token, received from a previous `ListTasks` call.\n `ListTasksResponse.next_page_token`.\n Provide this to retrieve the subsequent page.",
"type": "string"
},
"^(status_timestamp_after)$": {
"$ref": "google.protobuf.Timestamp.jsonschema.json",
"description": "Filter tasks which have a status updated after the provided timestamp in ISO 8601 format (e.g., \"2023-10-27T10:00:00Z\").\n Only tasks with a status timestamp time greater than or equal to this value will be returned."
}
},
"properties": {
"contextId": {
"default": "",
"description": "Filter tasks by context ID to get tasks from a specific conversation or session.",
"type": "string"
},
"historyLength": {
"anyOf": [
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
},
{
"pattern": "^-?[0-9]+$",
"type": "string"
}
],
"description": "The maximum number of messages to include in each task's history."
},
"includeArtifacts": {
"description": "Whether to include artifacts in the returned tasks.\n Defaults to false to reduce payload size.",
"type": "boolean"
},
"pageSize": {
"anyOf": [
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
},
{
"pattern": "^-?[0-9]+$",
"type": "string"
}
],
"description": "The maximum number of tasks to return. The service may return fewer than this value.\n If unspecified, at most 50 tasks will be returned.\n The minimum value is 1.\n The maximum value is 100."
},
"pageToken": {
"default": "",
"description": "A page token, received from a previous `ListTasks` call.\n `ListTasksResponse.next_page_token`.\n Provide this to retrieve the subsequent page.",
"type": "string"
},
"status": {
"anyOf": [
{
"pattern": "^TASK_STATE_UNSPECIFIED$",
"type": "string"
},
{
"enum": [
"TASK_STATE_SUBMITTED",
"TASK_STATE_WORKING",
"TASK_STATE_COMPLETED",
"TASK_STATE_FAILED",
"TASK_STATE_CANCELED",
"TASK_STATE_INPUT_REQUIRED",
"TASK_STATE_REJECTED",
"TASK_STATE_AUTH_REQUIRED"
],
"type": "string"
},
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
}
],
"default": 0,
"description": "Filter tasks by their current status state.",
"title": "Task State"
},
"statusTimestampAfter": {
"$ref": "google.protobuf.Timestamp.jsonschema.json",
"description": "Filter tasks which have a status updated after the provided timestamp in ISO 8601 format (e.g., \"2023-10-27T10:00:00Z\").\n Only tasks with a status timestamp time greater than or equal to this value will be returned."
},
"tenant": {
"default": "",
"description": "Tenant ID, provided as a path parameter.",
"type": "string"
}
},
"title": "List Tasks Request",
"type": "object"
},
"List Tasks Response": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Result object for `ListTasks` method containing an array of tasks and pagination information.",
"patternProperties": {
"^(next_page_token)$": {
"default": "",
"description": "A token to retrieve the next page of results, or empty if there are no more results in the list.",
"type": "string"
},
"^(page_size)$": {
"anyOf": [
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
},
{
"pattern": "^-?[0-9]+$",
"type": "string"
}
],
"default": 0,
"description": "The page size used for this response."
},
"^(total_size)$": {
"anyOf": [
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
},
{
"pattern": "^-?[0-9]+$",
"type": "string"
}
],
"default": 0,
"description": "Total number of tasks available (before pagination)."
}
},
"properties": {
"nextPageToken": {
"default": "",
"description": "A token to retrieve the next page of results, or empty if there are no more results in the list.",
"type": "string"
},
"pageSize": {
"anyOf": [
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
},
{
"pattern": "^-?[0-9]+$",
"type": "string"
}
],
"default": 0,
"description": "The page size used for this response."
},
"tasks": {
"description": "Array of tasks matching the specified criteria.",
"items": {
"$ref": "lf.a2a.v1.Task.jsonschema.json"
},
"type": "array"
},
"totalSize": {
"anyOf": [
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
},
{
"pattern": "^-?[0-9]+$",
"type": "string"
}
],
"default": 0,
"description": "Total number of tasks available (before pagination)."
}
},
"title": "List Tasks Response",
"type": "object"
},
"Message": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "`Message` is one unit of communication between client and server. It can be\n associated with a context and/or a task. For server messages, `context_id` must\n be provided, and `task_id` only if a task was created. For client messages, both\n fields are optional, with the caveat that if both are provided, they have to\n match (the `context_id` has to be the one that is set on the task). If only\n `task_id` is provided, the server will infer `context_id` from it.",
"patternProperties": {
"^(context_id)$": {
"default": "",
"description": "Optional. The context id of the message. If set, the message will be associated with the given context.",
"type": "string"
},
"^(message_id)$": {
"default": "",
"description": "The unique identifier (e.g. UUID) of the message. This is created by the message creator.",
"type": "string"
},
"^(reference_task_ids)$": {
"description": "A list of task IDs that this message references for additional context.",
"items": {
"type": "string"
},
"type": "array"
},
"^(task_id)$": {
"default": "",
"description": "Optional. The task id of the message. If set, the message will be associated with the given task.",
"type": "string"
}
},
"properties": {
"contextId": {
"default": "",
"description": "Optional. The context id of the message. If set, the message will be associated with the given context.",
"type": "string"
},
"extensions": {
"description": "The URIs of extensions that are present or contributed to this Message.",
"items": {
"type": "string"
},
"type": "array"
},
"messageId": {
"default": "",
"description": "The unique identifier (e.g. UUID) of the message. This is created by the message creator.",
"type": "string"
},
"metadata": {
"$ref": "google.protobuf.Struct.jsonschema.json",
"description": "Optional. Any metadata to provide along with the message."
},
"parts": {
"description": "Parts is the container of the message content.",
"items": {
"$ref": "lf.a2a.v1.Part.jsonschema.json"
},
"type": "array"
},
"referenceTaskIds": {
"description": "A list of task IDs that this message references for additional context.",
"items": {
"type": "string"
},
"type": "array"
},
"role": {
"anyOf": [
{
"pattern": "^ROLE_UNSPECIFIED$",
"type": "string"
},
{
"enum": [
"ROLE_USER",
"ROLE_AGENT"
],
"type": "string"
},
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
}
],
"default": 0,
"description": "Identifies the sender of the message.",
"title": "Role"
},
"taskId": {
"default": "",
"description": "Optional. The task id of the message. If set, the message will be associated with the given task.",
"type": "string"
}
},
"title": "Message",
"type": "object"
},
"Mutual Tls Security Scheme": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Defines a security scheme using mTLS authentication.",
"properties": {
"description": {
"default": "",
"description": "An optional description for the security scheme.",
"type": "string"
}
},
"title": "Mutual Tls Security Scheme",
"type": "object"
},
"O Auth2 Security Scheme": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Defines a security scheme using OAuth 2.0.",
"patternProperties": {
"^(oauth2_metadata_url)$": {
"default": "",
"description": "URL to the OAuth2 authorization server metadata [RFC 8414](https://datatracker.ietf.org/doc/html/rfc8414).\n TLS is required.",
"type": "string"
}
},
"properties": {
"description": {
"default": "",
"description": "An optional description for the security scheme.",
"type": "string"
},
"flows": {
"$ref": "lf.a2a.v1.OAuthFlows.jsonschema.json",
"description": "An object containing configuration information for the supported OAuth 2.0 flows."
},
"oauth2MetadataUrl": {
"default": "",
"description": "URL to the OAuth2 authorization server metadata [RFC 8414](https://datatracker.ietf.org/doc/html/rfc8414).\n TLS is required.",
"type": "string"
}
},
"title": "O Auth2 Security Scheme",
"type": "object"
},
"O Auth Flows": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Defines the configuration for the supported OAuth 2.0 flows.",
"patternProperties": {
"^(authorization_code)$": {
"$ref": "lf.a2a.v1.AuthorizationCodeOAuthFlow.jsonschema.json",
"description": "Configuration for the OAuth Authorization Code flow."
},
"^(client_credentials)$": {
"$ref": "lf.a2a.v1.ClientCredentialsOAuthFlow.jsonschema.json",
"description": "Configuration for the OAuth Client Credentials flow."
},
"^(device_code)$": {
"$ref": "lf.a2a.v1.DeviceCodeOAuthFlow.jsonschema.json",
"description": "Configuration for the OAuth Device Code flow."
}
},
"properties": {
"authorizationCode": {
"$ref": "lf.a2a.v1.AuthorizationCodeOAuthFlow.jsonschema.json",
"description": "Configuration for the OAuth Authorization Code flow."
},
"clientCredentials": {
"$ref": "lf.a2a.v1.ClientCredentialsOAuthFlow.jsonschema.json",
"description": "Configuration for the OAuth Client Credentials flow."
},
"deviceCode": {
"$ref": "lf.a2a.v1.DeviceCodeOAuthFlow.jsonschema.json",
"description": "Configuration for the OAuth Device Code flow."
},
"implicit": {
"$ref": "lf.a2a.v1.ImplicitOAuthFlow.jsonschema.json",
"description": "Deprecated: Use Authorization Code + PKCE instead."
},
"password": {
"$ref": "lf.a2a.v1.PasswordOAuthFlow.jsonschema.json",
"description": "Deprecated: Use Authorization Code + PKCE or Device Code."
}
},
"title": "O Auth Flows",
"type": "object"
},
"Open Id Connect Security Scheme": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Defines a security scheme using OpenID Connect.",
"patternProperties": {
"^(open_id_connect_url)$": {
"default": "",
"description": "The [OpenID Connect Discovery URL](https://openid.net/specs/openid-connect-discovery-1_0.html) for the OIDC provider's metadata.",
"type": "string"
}
},
"properties": {
"description": {
"default": "",
"description": "An optional description for the security scheme.",
"type": "string"
},
"openIdConnectUrl": {
"default": "",
"description": "The [OpenID Connect Discovery URL](https://openid.net/specs/openid-connect-discovery-1_0.html) for the OIDC provider's metadata.",
"type": "string"
}
},
"title": "Open Id Connect Security Scheme",
"type": "object"
},
"Part": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "`Part` represents a container for a section of communication content.\n Parts can be purely textual, some sort of file (image, video, etc) or\n a structured data blob (i.e. JSON).",
"patternProperties": {
"^(media_type)$": {
"default": "",
"description": "The `media_type` (MIME type) of the part content (e.g., \"text/plain\", \"application/json\", \"image/png\").\n This field is available for all part types.",
"type": "string"
}
},
"properties": {
"data": {
"$ref": "google.protobuf.Value.jsonschema.json",
"description": "Arbitrary structured `data` as a JSON value (object, array, string, number, boolean, or null)."
},
"filename": {
"default": "",
"description": "An optional `filename` for the file (e.g., \"document.pdf\").",
"type": "string"
},
"mediaType": {
"default": "",
"description": "The `media_type` (MIME type) of the part content (e.g., \"text/plain\", \"application/json\", \"image/png\").\n This field is available for all part types.",
"type": "string"
},
"metadata": {
"$ref": "google.protobuf.Struct.jsonschema.json",
"description": "Optional. metadata associated with this part."
},
"raw": {
"description": "The `raw` byte content of a file. In JSON serialization, this is encoded as a base64 string.",
"pattern": "^[A-Za-z0-9+/]*={0,2}$",
"type": "string"
},
"text": {
"description": "The string content of the `text` part.",
"type": "string"
},
"url": {
"description": "A `url` pointing to the file's content.",
"type": "string"
}
},
"title": "Part",
"type": "object"
},
"PasswordO Auth Flow": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Deprecated: Use Authorization Code + PKCE or Device Code.",
"patternProperties": {
"^(refresh_url)$": {
"default": "",
"description": "The URL to be used for obtaining refresh tokens. This MUST be in the\n form of a URL. The OAuth2 standard requires the use of TLS.",
"type": "string"
},
"^(token_url)$": {
"default": "",
"description": "The token URL to be used for this flow. This MUST be in the form of a URL.\n The OAuth2 standard requires the use of TLS.",
"type": "string"
}
},
"properties": {
"refreshUrl": {
"default": "",
"description": "The URL to be used for obtaining refresh tokens. This MUST be in the\n form of a URL. The OAuth2 standard requires the use of TLS.",
"type": "string"
},
"scopes": {
"additionalProperties": {
"type": "string"
},
"description": "The available scopes for the OAuth2 security scheme. A map between the\n scope name and a short description for it. The map MAY be empty.",
"propertyNames": {
"type": "string"
},
"type": "object"
},
"tokenUrl": {
"default": "",
"description": "The token URL to be used for this flow. This MUST be in the form of a URL.\n The OAuth2 standard requires the use of TLS.",
"type": "string"
}
},
"title": "PasswordO Auth Flow",
"type": "object"
},
"Push Notification Config": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Configuration for setting up push notifications for task updates.",
"properties": {
"authentication": {
"$ref": "lf.a2a.v1.AuthenticationInfo.jsonschema.json",
"description": "Authentication information required to send the notification."
},
"id": {
"default": "",
"description": "A unique identifier (e.g. UUID) for this push notification configuration.",
"type": "string"
},
"token": {
"default": "",
"description": "A token unique for this task or session.",
"type": "string"
},
"url": {
"default": "",
"description": "The URL where the notification should be sent.",
"type": "string"
}
},
"title": "Push Notification Config",
"type": "object"
},
"Security Requirement": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Defines the security requirements for an agent.",
"properties": {
"schemes": {
"additionalProperties": {
"$ref": "lf.a2a.v1.StringList.jsonschema.json"
},
"description": "A map of security schemes to the required scopes.",
"propertyNames": {
"type": "string"
},
"type": "object"
}
},
"title": "Security Requirement",
"type": "object"
},
"Security Scheme": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Defines a security scheme that can be used to secure an agent's endpoints.\n This is a discriminated union type based on the OpenAPI 3.2 Security Scheme Object.\n See: https://spec.openapis.org/oas/v3.2.0.html#security-scheme-object",
"patternProperties": {
"^(api_key_security_scheme)$": {
"$ref": "lf.a2a.v1.APIKeySecurityScheme.jsonschema.json",
"description": "API key-based authentication."
},
"^(http_auth_security_scheme)$": {
"$ref": "lf.a2a.v1.HTTPAuthSecurityScheme.jsonschema.json",
"description": "HTTP authentication (Basic, Bearer, etc.)."
},
"^(mtls_security_scheme)$": {
"$ref": "lf.a2a.v1.MutualTlsSecurityScheme.jsonschema.json",
"description": "Mutual TLS authentication."
},
"^(oauth2_security_scheme)$": {
"$ref": "lf.a2a.v1.OAuth2SecurityScheme.jsonschema.json",
"description": "OAuth 2.0 authentication."
},
"^(open_id_connect_security_scheme)$": {
"$ref": "lf.a2a.v1.OpenIdConnectSecurityScheme.jsonschema.json",
"description": "OpenID Connect authentication."
}
},
"properties": {
"apiKeySecurityScheme": {
"$ref": "lf.a2a.v1.APIKeySecurityScheme.jsonschema.json",
"description": "API key-based authentication."
},
"httpAuthSecurityScheme": {
"$ref": "lf.a2a.v1.HTTPAuthSecurityScheme.jsonschema.json",
"description": "HTTP authentication (Basic, Bearer, etc.)."
},
"mtlsSecurityScheme": {
"$ref": "lf.a2a.v1.MutualTlsSecurityScheme.jsonschema.json",
"description": "Mutual TLS authentication."
},
"oauth2SecurityScheme": {
"$ref": "lf.a2a.v1.OAuth2SecurityScheme.jsonschema.json",
"description": "OAuth 2.0 authentication."
},
"openIdConnectSecurityScheme": {
"$ref": "lf.a2a.v1.OpenIdConnectSecurityScheme.jsonschema.json",
"description": "OpenID Connect authentication."
}
},
"title": "Security Scheme",
"type": "object"
},
"Send Message Configuration": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Configuration of a send message request.",
"patternProperties": {
"^(accepted_output_modes)$": {
"description": "A list of media types the client is prepared to accept for response parts.\n Agents SHOULD use this to tailor their output.",
"items": {
"type": "string"
},
"type": "array"
},
"^(history_length)$": {
"anyOf": [
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
},
{
"pattern": "^-?[0-9]+$",
"type": "string"
}
],
"description": "The maximum number of most recent messages from the task's history to retrieve in\n the response. An unset value means the client does not impose any limit. A\n value of zero is a request to not include any messages. The server MUST NOT\n return more messages than the provided value, but MAY apply a lower limit."
},
"^(push_notification_config)$": {
"$ref": "lf.a2a.v1.PushNotificationConfig.jsonschema.json",
"description": "Configuration for the agent to send push notifications for task updates."
}
},
"properties": {
"acceptedOutputModes": {
"description": "A list of media types the client is prepared to accept for response parts.\n Agents SHOULD use this to tailor their output.",
"items": {
"type": "string"
},
"type": "array"
},
"blocking": {
"default": false,
"description": "If `true`, the operation MUST wait until the task reaches a terminal state\n (`COMPLETED`, `FAILED`, `CANCELED`, `REJECTED`) or an interrupted state\n (`INPUT_REQUIRED`, `AUTH_REQUIRED`) before returning. Default is `false`.",
"type": "boolean"
},
"historyLength": {
"anyOf": [
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
},
{
"pattern": "^-?[0-9]+$",
"type": "string"
}
],
"description": "The maximum number of most recent messages from the task's history to retrieve in\n the response. An unset value means the client does not impose any limit. A\n value of zero is a request to not include any messages. The server MUST NOT\n return more messages than the provided value, but MAY apply a lower limit."
},
"pushNotificationConfig": {
"$ref": "lf.a2a.v1.PushNotificationConfig.jsonschema.json",
"description": "Configuration for the agent to send push notifications for task updates."
}
},
"title": "Send Message Configuration",
"type": "object"
},
"Send Message Request": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Represents a request for the `SendMessage` method.",
"properties": {
"configuration": {
"$ref": "lf.a2a.v1.SendMessageConfiguration.jsonschema.json",
"description": "Configuration for the send request."
},
"message": {
"$ref": "lf.a2a.v1.Message.jsonschema.json",
"description": "The message to send to the agent."
},
"metadata": {
"$ref": "google.protobuf.Struct.jsonschema.json",
"description": "A flexible key-value map for passing additional context or parameters."
},
"tenant": {
"default": "",
"description": "Optional. Tenant ID, provided as a path parameter.",
"type": "string"
}
},
"title": "Send Message Request",
"type": "object"
},
"Send Message Response": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Represents the response for the `SendMessage` method.",
"properties": {
"message": {
"$ref": "lf.a2a.v1.Message.jsonschema.json",
"description": "A message from the agent."
},
"task": {
"$ref": "lf.a2a.v1.Task.jsonschema.json",
"description": "The task created or updated by the message."
}
},
"title": "Send Message Response",
"type": "object"
},
"Stream Response": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "A wrapper object used in streaming operations to encapsulate different types of response data.",
"patternProperties": {
"^(artifact_update)$": {
"$ref": "lf.a2a.v1.TaskArtifactUpdateEvent.jsonschema.json",
"description": "An event indicating a task artifact update."
},
"^(status_update)$": {
"$ref": "lf.a2a.v1.TaskStatusUpdateEvent.jsonschema.json",
"description": "An event indicating a task status update."
}
},
"properties": {
"artifactUpdate": {
"$ref": "lf.a2a.v1.TaskArtifactUpdateEvent.jsonschema.json",
"description": "An event indicating a task artifact update."
},
"message": {
"$ref": "lf.a2a.v1.Message.jsonschema.json",
"description": "A Message object containing a message from the agent."
},
"statusUpdate": {
"$ref": "lf.a2a.v1.TaskStatusUpdateEvent.jsonschema.json",
"description": "An event indicating a task status update."
},
"task": {
"$ref": "lf.a2a.v1.Task.jsonschema.json",
"description": "A Task object containing the current state of the task."
}
},
"title": "Stream Response",
"type": "object"
},
"String List": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "A list of strings.",
"properties": {
"list": {
"description": "The individual string values.",
"items": {
"type": "string"
},
"type": "array"
}
},
"title": "String List",
"type": "object"
},
"Subscribe To Task Request": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "Represents a request for the `SubscribeToTask` method.",
"properties": {
"id": {
"default": "",
"description": "The resource ID of the task to subscribe to.",
"type": "string"
},
"tenant": {
"default": "",
"description": "Optional. Tenant ID, provided as a path parameter.",
"type": "string"
}
},
"title": "Subscribe To Task Request",
"type": "object"
},
"Task": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "`Task` is the core unit of action for A2A. It has a current status\n and when results are created for the task they are stored in the\n artifact. If there are multiple turns for a task, these are stored in\n history.",
"patternProperties": {
"^(context_id)$": {
"default": "",
"description": "Unique identifier (e.g. UUID) for the contextual collection of interactions\n (tasks and messages). Created by the A2A server.",
"type": "string"
}
},
"properties": {
"artifacts": {
"description": "A set of output artifacts for a `Task`.",
"items": {
"$ref": "lf.a2a.v1.Artifact.jsonschema.json"
},
"type": "array"
},
"contextId": {
"default": "",
"description": "Unique identifier (e.g. UUID) for the contextual collection of interactions\n (tasks and messages). Created by the A2A server.",
"type": "string"
},
"history": {
"description": "The history of interactions from a `Task`.",
"items": {
"$ref": "lf.a2a.v1.Message.jsonschema.json"
},
"type": "array"
},
"id": {
"default": "",
"description": "Unique identifier (e.g. UUID) for the task, generated by the server for a\n new task.",
"type": "string"
},
"metadata": {
"$ref": "google.protobuf.Struct.jsonschema.json",
"description": "A key/value object to store custom metadata about a task."
},
"status": {
"$ref": "lf.a2a.v1.TaskStatus.jsonschema.json",
"description": "The current status of a `Task`, including `state` and a `message`."
}
},
"title": "Task",
"type": "object"
},
"Task Artifact Update Event": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "A task delta where an artifact has been generated.",
"patternProperties": {
"^(context_id)$": {
"default": "",
"description": "The ID of the context that this task belongs to.",
"type": "string"
},
"^(last_chunk)$": {
"default": false,
"description": "If true, this is the final chunk of the artifact.",
"type": "boolean"
},
"^(task_id)$": {
"default": "",
"description": "The ID of the task for this artifact.",
"type": "string"
}
},
"properties": {
"append": {
"default": false,
"description": "If true, the content of this artifact should be appended to a previously\n sent artifact with the same ID.",
"type": "boolean"
},
"artifact": {
"$ref": "lf.a2a.v1.Artifact.jsonschema.json",
"description": "The artifact that was generated or updated."
},
"contextId": {
"default": "",
"description": "The ID of the context that this task belongs to.",
"type": "string"
},
"lastChunk": {
"default": false,
"description": "If true, this is the final chunk of the artifact.",
"type": "boolean"
},
"metadata": {
"$ref": "google.protobuf.Struct.jsonschema.json",
"description": "Optional. Metadata associated with the artifact update."
},
"taskId": {
"default": "",
"description": "The ID of the task for this artifact.",
"type": "string"
}
},
"title": "Task Artifact Update Event",
"type": "object"
},
"Task Push Notification Config": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "A container associating a push notification configuration with a specific task.",
"patternProperties": {
"^(push_notification_config)$": {
"$ref": "lf.a2a.v1.PushNotificationConfig.jsonschema.json",
"description": "The push notification configuration details."
},
"^(task_id)$": {
"default": "",
"description": "The ID of the task this configuration is associated with.",
"type": "string"
}
},
"properties": {
"pushNotificationConfig": {
"$ref": "lf.a2a.v1.PushNotificationConfig.jsonschema.json",
"description": "The push notification configuration details."
},
"taskId": {
"default": "",
"description": "The ID of the task this configuration is associated with.",
"type": "string"
},
"tenant": {
"default": "",
"description": "Optional. Tenant ID.",
"type": "string"
}
},
"title": "Task Push Notification Config",
"type": "object"
},
"Task Status": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "A container for the status of a task",
"properties": {
"message": {
"$ref": "lf.a2a.v1.Message.jsonschema.json",
"description": "A message associated with the status."
},
"state": {
"anyOf": [
{
"pattern": "^TASK_STATE_UNSPECIFIED$",
"type": "string"
},
{
"enum": [
"TASK_STATE_SUBMITTED",
"TASK_STATE_WORKING",
"TASK_STATE_COMPLETED",
"TASK_STATE_FAILED",
"TASK_STATE_CANCELED",
"TASK_STATE_INPUT_REQUIRED",
"TASK_STATE_REJECTED",
"TASK_STATE_AUTH_REQUIRED"
],
"type": "string"
},
{
"maximum": 2147483647,
"minimum": -2147483648,
"type": "integer"
}
],
"default": 0,
"description": "The current state of this task.",
"title": "Task State"
},
"timestamp": {
"$ref": "google.protobuf.Timestamp.jsonschema.json",
"description": "ISO 8601 Timestamp when the status was recorded.\n Example: \"2023-10-27T10:00:00Z\""
}
},
"title": "Task Status",
"type": "object"
},
"Task Status Update Event": {
"$schema": "https://json-schema.org/draft/2020-12/schema",
"additionalProperties": false,
"description": "An event sent by the agent to notify the client of a change in a task's status.",
"patternProperties": {
"^(context_id)$": {
"default": "",
"description": "The ID of the context that the task belongs to.",
"type": "string"
},
"^(task_id)$": {
"default": "",
"description": "The ID of the task that has changed.",
"type": "string"
}
},
"properties": {
"contextId": {
"default": "",
"description": "The ID of the context that the task belongs to.",
"type": "string"
},
"metadata": {
"$ref": "google.protobuf.Struct.jsonschema.json",
"description": "Optional. Metadata associated with the task update."
},
"status": {
"$ref": "lf.a2a.v1.TaskStatus.jsonschema.json",
"description": "The new status of the task."
},
"taskId": {
"default": "",
"description": "The ID of the task that has changed.",
"type": "string"
}
},
"title": "Task Status Update Event",
"type": "object"
}
}
}