> ## Documentation Index > Fetch the complete documentation index at: https://checkfu.mintlify.site/llms.txt > Use this file to discover all available pages before exploring further. # Invoke or observe an installed Agent through A2A v1 > A2A v1 JSON-RPC bound to one exact installed placement. SendMessage creates or reuses the canonical ConversationBinding and Session; task reads, cancellation, listing, and SSE subscription are projections of and mutations through that same Session authority. The bearer must be a person Principal credential issued for audience `a2a`; every operation re-checks the active placement and live PermissionAssignments. Checkfu support posture: preview; hosted. Required evidence journey: a2a-serve. Deployment-specific readiness and the latest proven release are available from GET /v1/support/capabilities. ## OpenAPI ````yaml /openapi.json post /a2a/v1/workspaces/{workspace}/agent-installations/{installation}/surface-scopes/{surface} openapi: 3.1.0 info: title: Checkfu API version: '2026-08-27' description: >- Authentication is declared per operation: API-key, runtime, or connector bearer; Automation signature; or credential-free pairing redemption. Every general Checkfu REST request requires the dated `Checkfu-Version` header (one of: 2026-08-27); the three MCP JSON-RPC transports use `MCP-Protocol-Version`, A2A uses `A2A-Version`, and the provider OAuth callback carries neither Checkfu header. API keys resolve one Workspace without a request selector; authenticated responses identify it with `Checkfu-Workspace-Id`. servers: - url: https://api.checkfu.com security: - bearerAuth: [] tags: - name: organizations - name: sourceRepositories - name: tenants - name: workspaces - name: principals - name: principalGroups - name: principalAccessCredentials - name: apiKeys - name: agents - name: harnesses - name: harnessRuntime - name: sandboxProfiles - name: computerProfiles - name: permissionAssignments - name: actionPolicies - name: files - name: memoryStores - name: dreams - name: modelCredentials - name: modelRoutingProfiles - name: blueprintInstallations - name: toolSources - name: skills - name: skillSources - name: agentSources - name: skillProposals - name: instructionProposals - name: catalog - name: concepts - name: support - name: connections - name: connectionVaults - name: connectionAssignments - name: connectedRuntimes - name: projects - name: collaboration - name: automationGraphs - name: automations - name: actionApprovals - name: standingApprovals - name: usage - name: models - name: outcomes - name: budgets - name: billing - name: sessions - name: audit - name: sessionExports - name: runs - name: runnerPools - name: transcripts - name: sessionWatches - name: webhookEndpoints - name: integrationGateway - name: agentDeployments - name: workEnvironments - name: computers - name: computerScreens - name: computerBrowserObservations - name: computerBrowserActions - name: environments - name: vaults - name: apiMcp - name: a2a paths: /a2a/v1/workspaces/{workspace}/agent-installations/{installation}/surface-scopes/{surface}: post: tags: - a2a summary: Invoke or observe an installed Agent through A2A v1 description: >- A2A v1 JSON-RPC bound to one exact installed placement. SendMessage creates or reuses the canonical ConversationBinding and Session; task reads, cancellation, listing, and SSE subscription are projections of and mutations through that same Session authority. The bearer must be a person Principal credential issued for audience `a2a`; every operation re-checks the active placement and live PermissionAssignments. Checkfu support posture: preview; hosted. Required evidence journey: a2a-serve. Deployment-specific readiness and the latest proven release are available from GET /v1/support/capabilities. operationId: a2a.rpc parameters: - name: workspace in: path required: true schema: type: string pattern: ^wrkspc_[0-9a-f]{32}$ - name: installation in: path required: true schema: type: string pattern: ^aini_[0-9a-f]{32}$ - name: surface in: path required: true schema: type: string pattern: ^surf_[0-9a-f]{32}$ - name: a2a-version in: header required: false description: >- A2A service version. Omission selects the protocol-defined legacy 0.3 default, which this v1 endpoint rejects with JSON-RPC VERSION_NOT_SUPPORTED. schema: type: string enum: - '1.0' requestBody: required: true content: application/json: schema: anyOf: - type: object properties: jsonrpc: type: string enum: - '2.0' id: $ref: '#/components/schemas/Inline5_Union_' method: type: string enum: - SendMessage params: $ref: '#/components/schemas/Inline5_Objects_' required: - jsonrpc - id - method - params additionalProperties: false - type: object properties: jsonrpc: type: string enum: - '2.0' id: $ref: '#/components/schemas/Inline5_Union_' method: type: string enum: - SendStreamingMessage params: $ref: '#/components/schemas/Inline5_Objects_' required: - jsonrpc - id - method - params additionalProperties: false - type: object properties: jsonrpc: type: string enum: - '2.0' id: $ref: '#/components/schemas/Inline5_Union_' method: type: string enum: - GetTask params: type: object properties: tenant: $ref: '#/components/schemas/Inline5_Union_1' id: type: string allOf: - minLength: 1 - maxLength: 512 historyLength: $ref: '#/components/schemas/Inline5_Union_5' required: - id additionalProperties: false required: - jsonrpc - id - method - params additionalProperties: false - type: object properties: jsonrpc: type: string enum: - '2.0' id: $ref: '#/components/schemas/Inline5_Union_' method: type: string enum: - ListTasks params: type: object properties: tenant: $ref: '#/components/schemas/Inline5_Union_1' contextId: $ref: '#/components/schemas/Inline5_Union_1' status: 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 pageSize: type: integer allOf: - minimum: 1 maximum: 100 pageToken: type: string allOf: - maxLength: 1024 historyLength: $ref: '#/components/schemas/Inline5_Union_5' statusTimestampAfter: $ref: '#/components/schemas/A2aTimestamp' includeArtifacts: type: boolean additionalProperties: false required: - jsonrpc - id - method - params additionalProperties: false - type: object properties: jsonrpc: type: string enum: - '2.0' id: $ref: '#/components/schemas/Inline5_Union_' method: type: string enum: - CancelTask params: type: object properties: tenant: $ref: '#/components/schemas/Inline5_Union_1' id: type: string allOf: - minLength: 1 - maxLength: 512 metadata: $ref: '#/components/schemas/Inline5_Union_2' required: - id additionalProperties: false required: - jsonrpc - id - method - params additionalProperties: false - type: object properties: jsonrpc: type: string enum: - '2.0' id: $ref: '#/components/schemas/Inline5_Union_' method: type: string enum: - SubscribeToTask params: type: object properties: tenant: $ref: '#/components/schemas/Inline5_Union_1' id: type: string allOf: - minLength: 1 - maxLength: 512 required: - id additionalProperties: false required: - jsonrpc - id - method - params additionalProperties: false - type: object properties: jsonrpc: type: string enum: - '2.0' id: $ref: '#/components/schemas/Inline5_Union_' method: type: string enum: - CreateTaskPushNotificationConfig params: $ref: >- #/components/schemas/A2aCreateTaskPushNotificationConfigRequest required: - jsonrpc - id - method - params additionalProperties: false - type: object properties: jsonrpc: type: string enum: - '2.0' id: $ref: '#/components/schemas/Inline5_Union_' method: type: string enum: - GetTaskPushNotificationConfig params: type: object properties: tenant: $ref: '#/components/schemas/Inline5_Union_1' taskId: type: string allOf: - minLength: 1 - maxLength: 512 id: type: string allOf: - minLength: 1 - maxLength: 512 required: - taskId - id additionalProperties: false required: - jsonrpc - id - method - params additionalProperties: false - type: object properties: jsonrpc: type: string enum: - '2.0' id: $ref: '#/components/schemas/Inline5_Union_' method: type: string enum: - ListTaskPushNotificationConfigs params: type: object properties: tenant: $ref: '#/components/schemas/Inline5_Union_1' taskId: type: string allOf: - minLength: 1 - maxLength: 512 pageSize: type: integer allOf: - minimum: 1 maximum: 100 pageToken: type: string allOf: - maxLength: 1024 required: - taskId additionalProperties: false required: - jsonrpc - id - method - params additionalProperties: false - type: object properties: jsonrpc: type: string enum: - '2.0' id: $ref: '#/components/schemas/Inline5_Union_' method: type: string enum: - DeleteTaskPushNotificationConfig params: type: object properties: tenant: $ref: '#/components/schemas/Inline5_Union_1' taskId: type: string allOf: - minLength: 1 - maxLength: 512 id: type: string allOf: - minLength: 1 - maxLength: 512 required: - taskId - id additionalProperties: false required: - jsonrpc - id - method - params additionalProperties: false responses: '200': description: A2A JSON-RPC response or replay-then-live SSE envelopes headers: a2a-version: schema: type: string enum: - '1.0' content: application/json: schema: anyOf: - type: object properties: jsonrpc: type: string enum: - '2.0' id: anyOf: - anyOf: - type: string allOf: - maxLength: 1024 - type: integer allOf: - minimum: -9007199254740991 maximum: 9007199254740991 - type: 'null' result: anyOf: - $ref: '#/components/schemas/A2aSendMessageResponse' - $ref: '#/components/schemas/A2aTaskArtifacts' - type: object properties: tasks: type: array items: $ref: '#/components/schemas/A2aTaskArtifacts' allOf: - maxItems: 100 nextPageToken: type: string allOf: - maxLength: 1024 pageSize: type: integer allOf: - minimum: 0 maximum: 100 totalSize: type: integer allOf: - minimum: 0 maximum: 2147483647 additionalProperties: false - $ref: '#/components/schemas/A2aStreamResponse' - $ref: >- #/components/schemas/Inline6_A2aTaskPushNotificationConfig - type: object properties: configs: type: array items: $ref: >- #/components/schemas/Inline6_A2aTaskPushNotificationConfig allOf: - maxItems: 100 nextPageToken: type: string allOf: - maxLength: 1024 additionalProperties: false required: - jsonrpc - id - result additionalProperties: false - type: object properties: jsonrpc: type: string enum: - '2.0' id: anyOf: - anyOf: - type: string allOf: - maxLength: 1024 - type: integer allOf: - minimum: -9007199254740991 maximum: 9007199254740991 - type: 'null' error: type: object properties: code: type: integer message: type: string allOf: - maxLength: 1024 - minLength: 1 data: anyOf: - $ref: '#/components/schemas/Inline6_Objects_2' - type: array items: $ref: '#/components/schemas/Inline6_Objects_2' allOf: - maxItems: 64 required: - code - message additionalProperties: false required: - jsonrpc - id - error additionalProperties: false text/event-stream: schema: anyOf: - type: object properties: jsonrpc: type: string enum: - '2.0' id: anyOf: - anyOf: - type: string allOf: - maxLength: 1024 - type: integer allOf: - minimum: -9007199254740991 maximum: 9007199254740991 - type: 'null' result: $ref: '#/components/schemas/Inline7_A2aStreamResponse' required: - jsonrpc - id - result additionalProperties: false - type: object properties: jsonrpc: type: string enum: - '2.0' id: anyOf: - anyOf: - type: string allOf: - maxLength: 1024 - type: integer allOf: - minimum: -9007199254740991 maximum: 9007199254740991 - type: 'null' error: type: object properties: code: type: integer message: type: string allOf: - maxLength: 1024 - minLength: 1 data: anyOf: - $ref: '#/components/schemas/Inline7_Objects_2' - type: array items: $ref: '#/components/schemas/Inline7_Objects_2' allOf: - maxItems: 64 required: - code - message additionalProperties: false required: - jsonrpc - id - error additionalProperties: false '401': description: Missing, invalid, or wrong-audience Principal credential '403': description: >- The current placement or live PermissionAssignments deny the operation '404': description: The installed placement or task is unavailable '413': description: The JSON-RPC body exceeded the bounded request size '415': description: The request was not application/json '500': description: The operation could not be completed security: - a2aPrincipalAuth: [] components: schemas: Inline5_Union_: anyOf: - anyOf: - type: string allOf: - maxLength: 1024 - type: integer allOf: - minimum: -9007199254740991 maximum: 9007199254740991 - type: 'null' Inline5_Objects_: type: object properties: tenant: $ref: '#/components/schemas/Inline5_Union_1' message: type: object properties: messageId: type: string allOf: - minLength: 1 - maxLength: 512 contextId: $ref: '#/components/schemas/Inline5_Union_1' taskId: $ref: '#/components/schemas/Inline5_Union_1' role: type: string enum: - ROLE_USER - ROLE_AGENT parts: type: array prefixItems: - $ref: '#/components/schemas/A2aPart' minItems: 1 items: $ref: '#/components/schemas/A2aPart' allOf: - maxItems: 256 metadata: $ref: '#/components/schemas/Inline5_Union_2' extensions: type: array items: $ref: '#/components/schemas/A2aUri' allOf: - maxItems: 256 referenceTaskIds: type: array items: type: string allOf: - minLength: 1 - maxLength: 512 allOf: - maxItems: 256 required: - messageId - role - parts additionalProperties: false configuration: type: object properties: acceptedOutputModes: type: array items: type: string allOf: - minLength: 1 - maxLength: 256 - pattern: ^[^\s/]+\/[^\s/]+(?:\s*;.*)?$ allOf: - maxItems: 64 taskPushNotificationConfig: $ref: '#/components/schemas/A2aTaskPushNotificationConfig' historyLength: $ref: '#/components/schemas/Inline5_Union_5' returnImmediately: type: boolean additionalProperties: false metadata: $ref: '#/components/schemas/Inline5_Union_2' required: - message additionalProperties: false Inline5_Union_1: anyOf: - type: string allOf: - minLength: 1 - maxLength: 512 - type: 'null' Inline5_Union_5: anyOf: - type: integer allOf: - minimum: 0 maximum: 2147483647 - type: 'null' A2aTimestamp: type: string allOf: - maxLength: 64 Inline5_Union_2: anyOf: - type: object additionalProperties: $ref: '#/components/schemas/A2aJsonValue' allOf: - maxProperties: 256 - x-checkfu-json-budget: maximumBytes: 1048576 maximumDepth: 64 maximumNodes: 100000 maximumInspectionWork: 100000 - type: 'null' A2aCreateTaskPushNotificationConfigRequest: type: object properties: tenant: $ref: '#/components/schemas/Inline5_Union_1' id: $ref: '#/components/schemas/Inline5_Union_1' taskId: $ref: '#/components/schemas/Inline5_Union_1' url: $ref: '#/components/schemas/A2aHttpsEndpointUrl' token: $ref: '#/components/schemas/Inline5_Union_3' authentication: $ref: '#/components/schemas/Inline5_Union_4' required: - url additionalProperties: false A2aSendMessageResponse: type: object properties: task: $ref: '#/components/schemas/Inline6_Union_' message: $ref: '#/components/schemas/Inline6_Union_2' additionalProperties: false A2aTaskArtifacts: type: object properties: id: type: string allOf: - minLength: 1 - maxLength: 512 contextId: $ref: '#/components/schemas/Inline6_Union_1' status: $ref: '#/components/schemas/Inline6_Objects_' artifacts: type: array items: $ref: '#/components/schemas/Inline6_Objects_3' allOf: - maxItems: 256 history: type: array items: $ref: '#/components/schemas/Inline6_Objects_1' allOf: - maxItems: 1000 metadata: $ref: '#/components/schemas/Inline6_Union_3' required: - id - status additionalProperties: false A2aStreamResponse: type: object properties: task: $ref: '#/components/schemas/Inline6_Union_' message: $ref: '#/components/schemas/Inline6_Union_2' statusUpdate: type: object properties: taskId: type: string allOf: - minLength: 1 - maxLength: 512 contextId: type: string allOf: - minLength: 1 - maxLength: 512 status: $ref: '#/components/schemas/Inline6_Objects_' metadata: $ref: '#/components/schemas/Inline6_Union_3' required: - taskId - contextId - status additionalProperties: false artifactUpdate: type: object properties: taskId: type: string allOf: - minLength: 1 - maxLength: 512 contextId: type: string allOf: - minLength: 1 - maxLength: 512 artifact: $ref: '#/components/schemas/Inline6_Objects_3' append: type: boolean lastChunk: type: boolean metadata: $ref: '#/components/schemas/Inline6_Union_3' required: - taskId - contextId - artifact additionalProperties: false additionalProperties: false Inline6_A2aTaskPushNotificationConfig: type: object properties: tenant: $ref: '#/components/schemas/Inline6_Union_1' id: $ref: '#/components/schemas/Inline6_Union_1' taskId: $ref: '#/components/schemas/Inline6_Union_1' url: $ref: '#/components/schemas/A2aHttpsEndpointUrl' token: $ref: '#/components/schemas/Inline6_Union_4' authentication: type: object properties: scheme: type: string allOf: - minLength: 1 - maxLength: 256 - pattern: ^[!#$%&'*+.^_\x60|~0-9A-Za-z-]+$ credentials: type: string allOf: - maxLength: 16384 required: - scheme - credentials additionalProperties: false required: - url additionalProperties: false Inline6_Objects_2: type: object additionalProperties: $ref: '#/components/schemas/A2aJsonValue' allOf: - maxProperties: 256 - x-checkfu-json-budget: maximumBytes: 1048576 maximumDepth: 64 maximumNodes: 100000 maximumInspectionWork: 100000 Inline7_A2aStreamResponse: type: object properties: task: $ref: '#/components/schemas/Inline7_A2aTaskArtifacts' message: $ref: '#/components/schemas/Inline7_Union_1' statusUpdate: type: object properties: taskId: type: string allOf: - minLength: 1 - maxLength: 512 contextId: type: string allOf: - minLength: 1 - maxLength: 512 status: $ref: '#/components/schemas/Inline7_Objects_' metadata: $ref: '#/components/schemas/Inline7_Union_2' required: - taskId - contextId - status additionalProperties: false artifactUpdate: type: object properties: taskId: type: string allOf: - minLength: 1 - maxLength: 512 contextId: type: string allOf: - minLength: 1 - maxLength: 512 artifact: $ref: '#/components/schemas/Inline7_Objects_3' append: type: boolean lastChunk: type: boolean metadata: $ref: '#/components/schemas/Inline7_Union_2' required: - taskId - contextId - artifact additionalProperties: false additionalProperties: false Inline7_Objects_2: type: object additionalProperties: $ref: '#/components/schemas/A2aJsonValue' allOf: - maxProperties: 256 - x-checkfu-json-budget: maximumBytes: 1048576 maximumDepth: 64 maximumNodes: 100000 maximumInspectionWork: 100000 A2aPart: type: object properties: text: type: string allOf: - maxLength: 16384 raw: type: string allOf: - maxLength: 16777216 - pattern: ^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$ url: $ref: '#/components/schemas/A2aUri' data: $ref: '#/components/schemas/A2aJsonValue' metadata: $ref: '#/components/schemas/Inline5_Union_2' filename: $ref: '#/components/schemas/Inline5_Union_3' mediaType: type: string allOf: - minLength: 1 - maxLength: 256 - pattern: ^[^\s/]+\/[^\s/]+(?:\s*;.*)?$ additionalProperties: false A2aUri: type: string allOf: - minLength: 1 - maxLength: 2048 A2aTaskPushNotificationConfig: type: object properties: tenant: $ref: '#/components/schemas/Inline5_Union_1' id: $ref: '#/components/schemas/Inline5_Union_1' taskId: $ref: '#/components/schemas/Inline5_Union_1' url: $ref: '#/components/schemas/A2aHttpsEndpointUrl' token: $ref: '#/components/schemas/Inline5_Union_3' authentication: $ref: '#/components/schemas/Inline5_Union_4' required: - url additionalProperties: false A2aJsonValue: x-checkfu-json-budget: maximumBytes: 1048576 maximumDepth: 64 maximumNodes: 100000 maximumInspectionWork: 100000 description: >- A JSON value bounded to 1 MiB, depth 64, 100,000 nodes, and 100,000 inspected own keys. A2aHttpsEndpointUrl: type: string allOf: - maxLength: 2048 Inline5_Union_3: anyOf: - type: string allOf: - maxLength: 1024 - minLength: 1 - type: 'null' Inline5_Union_4: anyOf: - type: object properties: scheme: type: string allOf: - minLength: 1 - maxLength: 256 - pattern: ^[!#$%&'*+.^_\x60|~0-9A-Za-z-]+$ credentials: type: string allOf: - maxLength: 16384 required: - scheme - credentials additionalProperties: false - type: 'null' Inline6_Union_: anyOf: - $ref: '#/components/schemas/A2aTaskArtifacts' - type: 'null' Inline6_Union_2: anyOf: - $ref: '#/components/schemas/Inline6_Objects_1' - type: 'null' Inline6_Union_1: anyOf: - type: string allOf: - minLength: 1 - maxLength: 512 - type: 'null' Inline6_Objects_: type: object properties: state: 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 message: $ref: '#/components/schemas/Inline6_Union_2' timestamp: $ref: '#/components/schemas/A2aTimestamp' required: - state additionalProperties: false Inline6_Objects_3: type: object properties: artifactId: type: string allOf: - minLength: 1 - maxLength: 512 name: $ref: '#/components/schemas/Inline6_Union_4' description: type: string allOf: - maxLength: 16384 parts: type: array prefixItems: - $ref: '#/components/schemas/Inline6_A2aPart' minItems: 1 items: $ref: '#/components/schemas/Inline6_A2aPart' allOf: - maxItems: 256 metadata: $ref: '#/components/schemas/Inline6_Union_3' extensions: $ref: '#/components/schemas/Inline6_Union_5' required: - artifactId - parts additionalProperties: false Inline6_Objects_1: type: object properties: messageId: type: string allOf: - minLength: 1 - maxLength: 512 contextId: $ref: '#/components/schemas/Inline6_Union_1' taskId: $ref: '#/components/schemas/Inline6_Union_1' role: type: string enum: - ROLE_USER - ROLE_AGENT parts: type: array prefixItems: - $ref: '#/components/schemas/Inline6_A2aPart' minItems: 1 items: $ref: '#/components/schemas/Inline6_A2aPart' allOf: - maxItems: 256 metadata: $ref: '#/components/schemas/Inline6_Union_3' extensions: $ref: '#/components/schemas/Inline6_Union_5' referenceTaskIds: type: array items: type: string allOf: - minLength: 1 - maxLength: 512 allOf: - maxItems: 256 required: - messageId - role - parts additionalProperties: false Inline6_Union_3: anyOf: - $ref: '#/components/schemas/Inline6_Objects_2' - type: 'null' Inline6_Union_4: anyOf: - type: string allOf: - maxLength: 1024 - minLength: 1 - type: 'null' Inline7_A2aTaskArtifacts: type: object properties: id: type: string allOf: - minLength: 1 - maxLength: 512 contextId: $ref: '#/components/schemas/Inline7_Union_' status: $ref: '#/components/schemas/Inline7_Objects_' artifacts: type: array items: $ref: '#/components/schemas/Inline7_Objects_3' allOf: - maxItems: 256 history: type: array items: $ref: '#/components/schemas/Inline7_Objects_1' allOf: - maxItems: 1000 metadata: $ref: '#/components/schemas/Inline7_Union_2' required: - id - status additionalProperties: false Inline7_Union_1: anyOf: - $ref: '#/components/schemas/Inline7_Objects_1' - type: 'null' Inline7_Objects_: type: object properties: state: 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 message: $ref: '#/components/schemas/Inline7_Union_1' timestamp: $ref: '#/components/schemas/A2aTimestamp' required: - state additionalProperties: false Inline7_Union_2: anyOf: - $ref: '#/components/schemas/Inline7_Objects_2' - type: 'null' Inline7_Objects_3: type: object properties: artifactId: type: string allOf: - minLength: 1 - maxLength: 512 name: type: string allOf: - maxLength: 1024 - minLength: 1 description: type: string allOf: - maxLength: 16384 parts: type: array prefixItems: - $ref: '#/components/schemas/Inline7_A2aPart' minItems: 1 items: $ref: '#/components/schemas/Inline7_A2aPart' allOf: - maxItems: 256 metadata: $ref: '#/components/schemas/Inline7_Union_2' extensions: $ref: '#/components/schemas/Inline7_Union_3' required: - artifactId - parts additionalProperties: false Inline6_A2aPart: type: object properties: text: type: string allOf: - maxLength: 16384 raw: type: string allOf: - maxLength: 16777216 - pattern: ^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$ url: $ref: '#/components/schemas/A2aUri' data: $ref: '#/components/schemas/A2aJsonValue' metadata: $ref: '#/components/schemas/Inline6_Union_3' filename: $ref: '#/components/schemas/Inline6_Union_4' mediaType: type: string allOf: - minLength: 1 - maxLength: 256 - pattern: ^[^\s/]+\/[^\s/]+(?:\s*;.*)?$ additionalProperties: false Inline6_Union_5: anyOf: - type: array items: $ref: '#/components/schemas/A2aUri' allOf: - maxItems: 256 - type: 'null' Inline7_Union_: anyOf: - type: string allOf: - minLength: 1 - maxLength: 512 - type: 'null' Inline7_Objects_1: type: object properties: messageId: type: string allOf: - minLength: 1 - maxLength: 512 contextId: $ref: '#/components/schemas/Inline7_Union_' taskId: $ref: '#/components/schemas/Inline7_Union_' role: type: string enum: - ROLE_USER - ROLE_AGENT parts: type: array prefixItems: - $ref: '#/components/schemas/Inline7_A2aPart' minItems: 1 items: $ref: '#/components/schemas/Inline7_A2aPart' allOf: - maxItems: 256 metadata: $ref: '#/components/schemas/Inline7_Union_2' extensions: $ref: '#/components/schemas/Inline7_Union_3' referenceTaskIds: type: array items: type: string allOf: - minLength: 1 - maxLength: 512 allOf: - maxItems: 256 required: - messageId - role - parts additionalProperties: false Inline7_A2aPart: type: object properties: text: type: string allOf: - maxLength: 16384 raw: type: string allOf: - maxLength: 16777216 - pattern: ^(?:[A-Za-z0-9+/]{4})*(?:[A-Za-z0-9+/]{2}==|[A-Za-z0-9+/]{3}=)?$ url: $ref: '#/components/schemas/A2aUri' data: $ref: '#/components/schemas/A2aJsonValue' metadata: $ref: '#/components/schemas/Inline7_Union_2' filename: type: string allOf: - maxLength: 1024 - minLength: 1 mediaType: type: string allOf: - minLength: 1 - maxLength: 256 - pattern: ^[^\s/]+\/[^\s/]+(?:\s*;.*)?$ additionalProperties: false Inline7_Union_3: anyOf: - type: array items: $ref: '#/components/schemas/A2aUri' allOf: - maxItems: 256 - type: 'null' securitySchemes: bearerAuth: type: http scheme: bearer a2aPrincipalAuth: type: http scheme: bearer description: >- A Checkfu Principal credential issued with audience `a2a`; ordinary API-MCP credentials are rejected. ````