A2A Types

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Core Types

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JSONRPCRequest

from a2a.types import JSONRPCRequest

• id - Unique identifier for the request
• method - The RPC method to call (e.g., “message/send”, “message/stream”)
• params - Parameters for the method
• jsonrpc - Protocol version (“2.0”)

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JSONRPCResponse

from a2a.types import JSONRPCResponse

• id - Request identifier this response corresponds to
• result - The result data (if successful)
• error - Error information (if failed)
• jsonrpc - Protocol version (“2.0”)

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JSONRPCError

from a2a.types import JSONRPCError

• code - Numeric error code
• message - Human-readable error message
• data - Additional error details (optional)

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AgentCard

from a2a.types import AgentCard

• name - Agent name
• description - Agent description
• url - Agent base URL
• version - Agent version
• skills - List of agent skills
• capabilities - Supported capabilities
• additionalInterfaces - Additional communication interfaces
• securitySchemes - Authentication schemes
• security - Security requirements
• defaultInputModes - Default input content types
• defaultOutputModes - Default output content types
• supportsAuthenticatedExtendedCard - Whether extended card is supported
• signatures - Cryptographic signatures

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AgentSkill

from a2a.types import AgentSkill

• name - Skill identifier
• description - Skill description
• tags - Categorization tags (optional)
• examples - Usage examples (optional)

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AgentCapabilities

from a2a.types import AgentCapabilities

• streaming - Whether the agent supports streaming responses
• statefulness - Whether the agent maintains conversation state
• asyncProcessing - Whether the agent supports asynchronous task processing

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SendStreamingMessageRequest

from a2a.types import SendStreamingMessageRequest

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Task

from a2a.types import Task

• id - Task identifier
• status - Current task status
• state - Task state information
• created - Creation timestamp
• updated - Last update timestamp

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TaskState

from a2a.types import TaskState

• pending - Task is queued
• working - Task is in progress
• completed - Task finished successfully
• failed - Task encountered an error
• cancelled - Task was cancelled

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TaskStatus

from a2a.types import TaskStatus

• state - Current task state (TaskState)
• progress - Progress percentage (0-100, optional)
• message - Status message (optional)

from a2a.types import TaskState, TaskStatus

in_progress = TaskStatus(state=TaskState.working)
done = TaskStatus(state=TaskState.completed)

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Usage Example

from a2a.types import (
    AgentCard,
    AgentCapabilities,
    AgentSkill,
    JSONRPCRequest,
    JSONRPCResponse,
    JSONRPCError,
)

# Create an agent card
card = AgentCard(
    name="My Agent",
    description="A helpful assistant",
    url="http://localhost:8000",
    version="1.0.0",
    skills=[
        AgentSkill(
            name="search",
            description="Search the web for information"
        )
    ],
    capabilities=AgentCapabilities(
        streaming=True,
        statefulness=True,
        asyncProcessing=True
    ),
)

# Handle a JSON-RPC request
request = JSONRPCRequest(
    id="123",
    method="message/send",
    params={"message": "Hello"},
    jsonrpc="2.0"
)

# Create a response
response = JSONRPCResponse(
    id=request.id,
    result={"message": "Hello! How can I help?"},
    jsonrpc="2.0"
)

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Import Path

from a2a.types import (
    AgentCapabilities,
    AgentCard,
    AgentSkill,
    JSONRPCError,
    JSONRPCRequest,
    JSONRPCResponse,
    SendStreamingMessageRequest,
    Task,
    TaskState,
    TaskStatus,
)