Agent on Demand Python SDK Skill

The aod-sdk Python package (import name aod) wraps every endpoint in docs/openapi.yaml with typed pydantic models, sync + async clients, and a typed SSE event stream. Package source lives at clients/python/ in this repo.

When This Skill Applies

Use this skill when:

• Writing Python that calls the AoD API via from aod import Client / AsyncClient
• Extending clients/python/ itself (new resources, new models, new stream helpers)
• Debugging a traceback from aod.errors.AodHTTPError or its subclasses

For HTTP-level questions (route table, state machine, 409/422/429 semantics), defer to the agent-on-demand-api skill. For TypeScript, use aod-sdk-typescript.

Install & Configure

pip install aod-sdk
# or, in-tree development:
cd clients/python && uv pip install -e ".[dev]"

Client / AsyncClient read these in order of precedence:

1. Constructor kwargs: base_url=..., token=...
2. Env vars: AOD_API_URL, AOD_API_TOKEN
3. base_url default: http://localhost:8777. token is required — missing raises ValueError, not a 401.

Both clients are context managers. Use them as such — they own an httpx.Client/AsyncClient.

from aod import Client, AsyncClient

with Client(token="aod_...") as client:
    ...

async with AsyncClient() as client:  # reads AOD_API_TOKEN from env
    ...

Resources Shape

Every client exposes three resource namespaces with identical method names on both sync and async variants:

Namespace	Methods
client.agents	list(), create(...), get(id), update(id, version=..., **fields), archive(id), versions(id)
client.environments	list(), create(...), get(id), update(id, version=..., **fields), archive(id), delete(id), versions(id)
client.sessions	list(), create(agent_id=..., prompt=..., [environment_id=], [timeout=], [resources=]), get(id), prompt(id, prompt=...), turns(id), terminate(id), delete(id), stream(id, since=None)

• Every method accepts str | UUID for IDs; they're stringified on the wire.
• Return types are pydantic models from aod.models (Agent, Environment, Session, SessionAck, SessionTurn, AgentVersion, EnvironmentVersion). Unknown fields are ignored (extra="ignore"), so new server fields don't blow up old clients.
• sessions.create and sessions.prompt and sessions.terminate return SessionAck — a trimmed payload, not a full Session. Only id + status are guaranteed; stream_url/environment_id/resources/current_turn are populated when the server provides them. Fetch client.sessions.get(id) for the full record.

Streaming

client.sessions.stream(session_id, since=None) is a context manager that yields a StreamEvent iterator. The nesting matters — it owns an HTTP connection:

with client.sessions.stream(session_id) as events:
    for event in events:
        if event.type == "output":
            print(event.extra["data"], end="")
        elif event.type in ("exit", "error", "terminated", "stale"):
            break

Async:

async with client.sessions.stream(session_id) as events:
    async for event in events:
        ...

StreamEvent shape: type: StreamEventType + id: int | None + extra: dict[str, Any]. Every server-side field except type and id lands in extra. This is deliberate — the event schema is still evolving, and keeping the raw payload accessible avoids breakage.

Event types: start, turn_start, output, stage, exit, error, terminated, stale. Terminal types are exit/error/terminated/stale — break the loop when you see one.

To resume after a disconnect, pass since=<last event id>. since=None / omitted = full replay.

Errors

All non-2xx responses raise a typed subclass of AodError:

Status	Exception	Common trigger
401/3	AuthError	Missing/invalid token
404	NotFoundError	Resource missing or not owned by the token's user
409	ConflictError	Archive-already, terminal session, stale version, failed-resume
422	ValidationError	Pydantic validation on the server — detail is a list
429	RateLimitError	Concurrent-session quota. Has .limit and .active attrs
5xx	ServerError	Sprites upstream error or unhandled exception

All share .status_code, .detail, .method, .url. detail is whatever the server sent — a string for most codes, a list of error dicts for 422 (Pydantic). Match with isinstance rather than on status_code.

from aod import ConflictError, RateLimitError

try:
    client.agents.update(agent.id, version=agent.version, name="renamed")
except ConflictError as e:
    # stale version — refetch and retry
    latest = client.agents.get(agent.id)
    client.agents.update(latest.id, version=latest.version, name="renamed")
except RateLimitError as e:
    print(f"quota: {e.active}/{e.limit}")

Optimistic Concurrency Idiom

Agents and environments require version=<current> on every update. Stale → ConflictError. Standard pattern is read-then-write:

agent = client.agents.get(agent_id)
client.agents.update(agent.id, version=agent.version, system="...")

Merge/replace semantics match the HTTP API (covered in agent-on-demand-api):

• metadata is merged per-key; empty string deletes the key.
• env_vars is fully replaced — re-send every key you want to keep.

Runtime-Scoped Pretty Printing

aod.pretty holds optional formatters that turn raw agent stdout into display lines. These are runtime-specific (runtime output formats are not part of the AoD API contract), so they live under a separate namespace and don't ship as part of the core Client.

from aod.pretty.claude import ClaudeFormatter

fmt = ClaudeFormatter()
with client.sessions.stream(session_id) as events:
    for event in events:
        for line in fmt.consume(event):  # filters to output+stdout internally
            print(line)
    for line in fmt.flush():              # drain any half-buffered line
        print(line)

Currently shipped: ClaudeFormatter (consumes the Claude CLI stream-json output format). Other runtimes have no formatter yet — iterate event.extra["data"] yourself for output events.

Common Gotchas

1. Missing token is a ValueError at construction, not an AuthError. You won't hit the network to discover the config is broken.
2. Session response has no prompt. prompt lives on SessionTurn — fetch it via client.sessions.turns(session_id).
3. SessionAck.environment_id is None on prompt / terminate acks. It's only set on create because that's the only ack where the server knows it needs to echo it.
4. The stream context manager must be exited for the connection to close. Breaking out of the inner for is fine; don't hold the events iterator past the with block.
5. extra["data"] on output events is a string. stream/turn also live in extra. Don't assume a fixed schema — consult agent-on-demand-api for the per-event payload shape.
6. Sync vs async symmetry is strict. Every Client method has an AsyncClient counterpart with the same name and signature — except close() → aclose() and context manager forms.

End-to-End Example

from aod import Client

with Client(token="aod_...") as client:
    env = client.environments.create(
        name="demo",
        packages={"pip": ["requests"]},
        env_vars={"DEMO": "1"},
        networking={"type": "limited", "allowed_hosts": ["pypi.org"]},
    )
    agent = client.agents.create(
        name="demo",
        model="anthropic/claude-sonnet-4-6",
        runtime="claude",
        system="You are terse.",
        environment_id=env.id,
    )
    ack = client.sessions.create(
        agent_id=agent.id,
        prompt="summarize README.md",
        resources=[{"type": "github_repository", "url": "https://github.com/me/repo"}],
    )
    with client.sessions.stream(ack.id) as events:
        for event in events:
            if event.type == "output":
                print(event.extra["data"], end="")
            elif event.type in ("exit", "error", "terminated", "stale"):
                break
    final = client.sessions.get(ack.id)
    print(f"status={final.status} exit_code={final.exit_code}")

Related Files

• clients/python/src/aod/client.py — Client / AsyncClient; config resolution
• clients/python/src/aod/resources/ — agents.py, environments.py, sessions.py
• clients/python/src/aod/models.py — pydantic models (Agent, Session, StreamEvent, etc.)
• clients/python/src/aod/errors.py — exception hierarchy + raise_for_status
• clients/python/src/aod/stream.py — sync/async SSE iterators
• clients/python/src/aod/pretty/ — runtime-scoped formatters (claude.py)
• clients/python/README.md — user-facing docs
• Sibling skill agent-on-demand-api — HTTP semantics, status codes, state machine