Python agent-host SDK for the Synadia Agent Protocol for NATS. Embed AgentService in a Python agent harness (Hermes-style, claude-code, openclaw, pi, …) to register a spec-compliant agent on a NATS bus.

Calling agents (rather than hosting them)? → use the sibling synadia-ai-agents package (from synadia_ai.agents import Agents, …). This package depends on it for the shared wire primitives.

From a checkout (no published wheel yet):

uv pip install -e ../../client-sdk/python
uv pip install -e .

When both packages are on PyPI, plain pip install synadia-ai-agent-service will pull synadia-ai-agents>=0.6 automatically.

import asyncio
import nats
from synadia_ai.agents import Envelope                       # shared wire types
from synadia_ai.agent_service import AgentService, PromptStream

async def echo(envelope: Envelope, stream: PromptStream) -> None:
    await stream.send(f"echo: {envelope.prompt}")

async def main() -> None:
    nc = await nats.connect(servers="nats://127.0.0.1:4222")
    service = AgentService(
        agent="demo",            # your harness identifier (§2: lowercase + hyphens)
        owner="alice",           # operator / account (§2)
        session_name="worker-1", # 5th subject token / session this instance serves
        nc=nc,
        description="demo echo agent",
    )
    service.on_prompt(echo)
    await service.start()
    try:
        await asyncio.Event().wait()   # run until Ctrl-C
    finally:
        await service.stop()
        await nc.close()

asyncio.run(main())

A spec-compliant runnable echo agent ships at examples/_reference_agent.py — used both as the test harness for the client-side numbered demos in ../../client-sdk/python/examples/ and as the wire-compat counterparty for cross-SDK interop.

• This package — synadia_ai.agent_service: AgentService, PromptStream, PromptHandler, the heartbeat publisher loop, the status endpoint handler, and the reference agent.
• Sibling package — synadia_ai.agents (the client SDK): the shared wire primitives (Envelope, Attachment, HeartbeatPayload, AgentSubject, error classes, discovery constants, load_context_options, parse_nats_url).

• Root README — protocol overview and monorepo layout.
• synadia-ai-agents — the client surface this package depends on.
• Synadia Agent Protocol for NATS spec — wire-level source of truth.
• CHANGELOG.md — release notes.
• CLAUDE.md — project context and engineering conventions.

uv sync
uv run ruff check . && uv run ruff format --check . && uv run mypy src tests examples && uv run pytest

Integration tests spawn a real nats-server per session and record wire evidence under tests/_evidence/<test-nodeid>/. The local [tool.uv.sources] override resolves synadia-ai-agents to the sibling client-sdk checkout, so no PyPI publish is required for CI to pass.

Apache-2.0. See LICENSE.