> ## Documentation Index
> Fetch the complete documentation index at: https://docs.getsly.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Agent-targeted JSON-RPC

> Send a JSON-RPC message to a specific agent. The most common entrypoint for cross-agent communication.



## OpenAPI

````yaml /api-reference/openapi.json post /a2a/{agentId}
openapi: 3.1.0
info:
  title: Sly API
  description: >-
    The Agentic Economy Platform — stablecoin payments, agent wallets,
    multi-protocol commerce, and AI agent orchestration.
  version: 1.0.0
  contact:
    name: Sly
    url: https://getsly.ai
    email: support@getsly.ai
servers:
  - url: https://api.getsly.ai/v1
    description: Production
  - url: https://sandbox.getsly.ai/v1
    description: Sandbox
security:
  - bearerAuth: []
paths:
  /a2a/{agentId}:
    post:
      tags:
        - A2A (public)
      summary: Agent-targeted JSON-RPC
      description: >-
        Send a JSON-RPC message to a specific agent. The most common entrypoint
        for cross-agent communication.
      parameters:
        - schema:
            type: string
            format: uuid
          required: true
          name: agentId
          in: path
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/A2AJsonRpcRequest'
      responses:
        '200':
          description: JSON-RPC response
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/A2AJsonRpcResponse'
components:
  schemas:
    A2AJsonRpcRequest:
      type: object
      properties:
        jsonrpc:
          type: string
          enum:
            - '2.0'
        method:
          type: string
          enum:
            - message/send
            - message/stream
            - agent/discover
        params:
          type: object
          additionalProperties: {}
        id:
          anyOf:
            - type: string
            - type: number
      required:
        - jsonrpc
        - method
        - params
        - id
    A2AJsonRpcResponse:
      type: object
      properties:
        jsonrpc:
          type: string
          enum:
            - '2.0'
        result: {}
        error:
          type: object
          properties:
            code:
              type: integer
            message:
              type: string
            data: {}
          required:
            - code
            - message
        id:
          anyOf:
            - type: string
            - type: number
      required:
        - jsonrpc
        - id
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      description: >-
        API key (pk_test_* or pk_live_*), JWT session, agent token (agent_*),
        Ed25519 session (sess_*), or portal token (portal_*).

````