orbiter.a2a.types - Orbiter Docs

A2A protocol types — agent cards, configs, and task events. All model classes use Pydantic BaseModel with frozen=True.

python

from orbiter.a2a.types import (
    AgentCapabilities,
    AgentCard,
    AgentSkill,
    ClientConfig,
    ServingConfig,
    TaskArtifactUpdateEvent,
    TaskState,
    TaskStatus,
    TaskStatusUpdateEvent,
    TransportMode,
)

TransportMode

python

class TransportMode(StrEnum)

Supported A2A transport protocols.

Value	Description
`JSONRPC = "jsonrpc"`	JSON-RPC over HTTP
`GRPC = "grpc"`	gRPC transport
`WEBSOCKET = "websocket"`	WebSocket transport

TaskState

python

class TaskState(StrEnum)

Lifecycle states for a remote A2A task.

Value	Description
`SUBMITTED = "submitted"`	Task has been submitted
`WORKING = "working"`	Agent is processing the task
`COMPLETED = "completed"`	Task completed successfully
`FAILED = "failed"`	Task execution failed
`CANCELED = "canceled"`	Task was canceled

AgentSkill

python

class AgentSkill(BaseModel, frozen=True)

A single capability advertised by an agent.

Field	Type	Default	Description
`id`	`str`	(required)	Unique skill identifier
`name`	`str`	(required)	Human-readable name
`description`	`str`	`""`	What the skill does
`tags`	`tuple[str, ...]`	`()`	Classification tags

AgentCapabilities

python

class AgentCapabilities(BaseModel, frozen=True)

Runtime capabilities of an A2A agent.

Field	Type	Default	Description
`streaming`	`bool`	`False`	Supports streaming responses
`push_notifications`	`bool`	`False`	Supports push notifications
`state_transition_history`	`bool`	`False`	Tracks state transitions

AgentCard

python

class AgentCard(BaseModel, frozen=True)

Complete metadata descriptor for a remote A2A agent. Published at /.well-known/agent-card for discovery.

Field	Type	Default	Description
`name`	`str`	(required)	Agent identifier
`description`	`str`	`""`	Agent purpose
`version`	`str`	`"0.0.1"`	Agent version
`url`	`str`	`""`	Agent endpoint URL
`capabilities`	`AgentCapabilities`	`AgentCapabilities()`	Runtime capabilities
`skills`	`tuple[AgentSkill, ...]`	`()`	Advertised skills
`default_input_modes`	`tuple[str, ...]`	`("text",)`	Accepted input formats
`default_output_modes`	`tuple[str, ...]`	`("text",)`	Produced output formats
`supported_transports`	`tuple[TransportMode, ...]`	`(TransportMode.JSONRPC,)`	Transport protocols

Example

python

card = AgentCard(
    name="research-agent",
    description="Performs web research",
    url="http://localhost:8000",
    capabilities=AgentCapabilities(streaming=True),
    skills=(
        AgentSkill(id="search", name="Web Search", tags=("research",)),
    ),
)

ServingConfig

python

class ServingConfig(BaseModel, frozen=True)

Server-side configuration for publishing an agent via A2A.

Field	Type	Default	Description
`host`	`str`	`"localhost"`	Bind host
`port`	`int`	`0`	Bind port (0 = auto)
`endpoint`	`str`	`"/"`	Base URL path
`streaming`	`bool`	`False`	Enable streaming
`version`	`str`	`"0.0.1"`	Advertised version
`skills`	`tuple[AgentSkill, ...]`	`()`	Skills to advertise
`input_modes`	`tuple[str, ...]`	`("text",)`	Accepted input formats
`output_modes`	`tuple[str, ...]`	`("text",)`	Produced output formats
`transports`	`tuple[TransportMode, ...]`	`(TransportMode.JSONRPC,)`	Enabled transports
`extra`	`dict[str, Any]`	`{}`	Extension point for custom config

ClientConfig

python

class ClientConfig(BaseModel, frozen=True)

Client-side configuration for connecting to a remote A2A agent.

Field	Type	Default	Description
`streaming`	`bool`	`False`	Request streaming
`timeout`	`float`	`600.0`	Request timeout in seconds (must be > 0)
`transports`	`tuple[TransportMode, ...]`	`(TransportMode.JSONRPC,)`	Preferred transports
`accepted_output_modes`	`tuple[str, ...]`	`()`	Accepted output formats (empty = any)
`extra`	`dict[str, Any]`	`{}`	Extension point for custom config

TaskStatus

python

class TaskStatus(BaseModel, frozen=True)

Current status of a remote A2A task.

Field	Type	Default	Description
`state`	`TaskState`	(required)	Task lifecycle state
`reason`	`str`	`""`	Reason / error message

TaskStatusUpdateEvent

python

class TaskStatusUpdateEvent(BaseModel, frozen=True)

Emitted when a remote task changes state.

Field	Type	Default	Description
`task_id`	`str`	(required)	Task being updated
`status`	`TaskStatus`	(required)	New status

TaskArtifactUpdateEvent

python

class TaskArtifactUpdateEvent(BaseModel, frozen=True)

Emitted when a remote task produces output.

Field	Type	Default	Description
`task_id`	`str`	(required)	Task being updated
`text`	`str`	`""`	Artifact text content
`last_chunk`	`bool`	`False`	Whether this is the final chunk