libraos-sdk

Python reference SDK for LibraOS — the agentic operating system that lets you build vertical AI products on a multi-model, multi-tenant runtime.

Published to PyPI as libraos-sdk. Status: v1.2.0 — stable; the public API has been frozen since v1.0.0.

• Source · Issues · Changelog · Docs

Install

pip install libraos-sdk
# Optional — for Anthropic SDK drop-in compatibility
pip install anthropic

Usage

from libraos import Client, AnthropicCompatClient, WebhookRouter

# LibraOS extended client (multi-model, employees, bundles, async jobs, ...)
async with Client(base_url="https://nova.partner.com", api_key="...") as c:
    agents = [a async for a in c.agents.list()]
    msg = await c.messages.create(
        agent_id="...",
        messages=[{"role": "user", "content": "hi"}],
    )

# Drop-in Anthropic SDK compat — partners using the Anthropic SDK
# can switch base_url and ship without any other code changes.
client = AnthropicCompatClient(base_url="https://nova.partner.com", api_key="...")
msg = client.messages.create(
    model="Qwen/Qwen3.6-35B-A3B",
    messages=[{"role": "user", "content": "hello"}],
    max_tokens=256,
)

# Mode B custom-tool webhook router (FastAPI mount shown; Flask/Lambda also supported)
router = WebhookRouter(secret="...")
@router.tool("fetch_invoice")
async def fetch_invoice(input, ctx): ...
app.include_router(router.fastapi_router(), prefix="/nova/cb")

See python/examples/ on GitHub for 20 worked examples covering every public surface, and examples/simulator/ for end-to-end synthetic-customer evaluation runs. The examples are not shipped inside the installed package — they are scripts to read and copy, not importable modules.

Synthetic-customer simulator

client.simulate() runs a synthetic customer against one of your agents and tells you whether the agent got the job done. An archetype describes the persona the simulator plays — including facts the customer will not volunteer — so you can answer questions like "can this agent handle a customer who withholds information?"

from libraos import Client

client = Client(base_url="https://nova-eval.partner.com", api_key="...")

result = client.simulate(
    target_agent_id="intake-bot",
    archetype={
        "name": "cautious-applicant",
        "description": "Applicant with a prior visa refusal they are reluctant to raise.",
        "hidden_facts": [
            "visitor visa refused in 2024 — only admits it when asked directly",
            "partner holds a Brazilian passport — only mentions it when asked about family",
        ],
        "disclosure_willingness": "cautious",
        "success_signal": "lawyer matched for immigration with common-law representation",
        "failure_signals": ["lawyer not matched after 10 turns"],
        "termination_conditions": {"max_turns": 10},
    },
)

print(result.outcome)         # "success" | "failure" | "timeout" | "error"
print(result.outcome_reason)  # e.g. "success_signal_matched", "max_turns_reached: 10"
for turn in result.transcript:
    print(f"{turn.role}: {turn.content}")

archetype= accepts a plain dict (as above), an Archetype instance, or a path to a YAML file — Archetype.from_dict(...) / Archetype.from_yaml_path(...). All three run the full validation chain and raise ArchetypeValidationError with a field path and a human-readable reason, before any call is made.

Archetype fields

What you get back

SimulationResult is a frozen dataclass: transcript (a list of Turn, each with role — "simulator" or "target" — plus content, timestamp, metadata), outcome, outcome_reason, evaluation_signals (success_signal_match, failure_signal_matches, turn_count), duration_ms, tokens_used, and error.

Streaming and async

Pass stream=True to watch a run live — an iterator of TurnEvent, one event per turn plus a final outcome event. The outcome event always fires, even on error, timeout, or cancellation; failures arrive as events rather than raised exceptions:

from libraos.simulator import TurnEvent

for event in client.simulate("intake-bot", archetype, stream=True):
    if event.kind in ("simulator_turn", "target_turn"):
        print(f"{event.role}: {event.content}")
    elif event.kind == "outcome":
        print(event.outcome.outcome, event.outcome.outcome_reason)

client.async_simulate(...) is the async variant — await it for a SimulationResult, or iterate it with async for when stream=True.

Run evaluations against a separate instance. simulate() generates real traffic; pointing it at production accumulates eval rows in the production call_log. The recommended setup is a sibling LibraOS instance with its own database and empty knowledge collections.

A full CI-ready runner — loads every archetype in a directory, streams turns, writes JSON transcripts, exits non-zero on error — is at examples/simulator/run_eval.py.

Model names — vendor prefix required for the gateway

When LibraOS routes through the MegaNova gateway (the default for cloud + most self-hosted deployments), every model name MUST carry a <vendor>/ prefix:

This applies to:

• The model= arg on c.messages.create(...) and c.jobs.create(...)
• model_config.{answer,planner,skill}.primary in agent + employee YAML
• The model: field in agent markdown frontmatter

For partners using the Anthropic SDK directly: the SDK's natural default (claude-opus-4-7 without prefix) won't resolve through the gateway. Either pin to a gateway-safe prefixed model in your config (for example, ANTHROPIC_HIGH_MODEL=Qwen/Qwen3.6-35B-A3B) or add a translation layer that prefixes bare Anthropic model names with anthropic/ when routing through LibraOS.

The agent_inference_model and ollama_embed_model settings are exempt — they route to a local Ollama and use <tag>:<version> shape (e.g. gemma4:e4b).

To list all registered models (catalog discovery):

# Direct gateway query, requires a gateway-scoped key
import httpx
r = httpx.get("https://nova.partner.com/v1/models", headers={"Authorization": f"Bearer {api_key}"})
print([m["id"] for m in r.json()["data"]])

Server-side tool observability — known v1.0.0 limitation

Anthropic-provided server-side tools (web_search_20250305, code_execution_20250522, etc.) execute on Anthropic's infrastructure and DO NOT emit discrete content_block_start / content_block_stop events on the SSE stream. Audit hooks that fire on content_block_stop for tool_use blocks won't see these invocations.

Visible: the model's text response references the search; MessageResponse.content[] (non-streaming) contains server_tool_use blocks. Not visible: discrete tool-invocation events on the streaming path. Affects observability hooks that watch the SSE stream for tool_use events.

This is a pre-existing constraint of the underlying Anthropic API; LibraOS forwards what it receives. Partner-defined custom tools (Mode B via WebhookRouter) emit custom_tool_use events normally.

Workaround for partners on v1.0.0: inspect MessageResponse.content after the stream completes for server_tool_use blocks; OR use the non-streaming messages.create path when discrete tool observability matters.

Tracking libraos/sdk#10 for v1.1 — adds gateway-side synthetic event emission so audit hooks Just Work for server-side tools.

Error handling

from libraos import (
    NovaOSError,
    NotFoundError,
    RateLimitedError,
    BillingError,
    VertexSchemaError,
)

try:
    agent = await c.agents.get("does-not-exist")
except NotFoundError:
    print("agent not found")
except RateLimitedError as e:
    print(f"rate limited — retry after {e.retry_after}s")
except BillingError as e:
    print(f"billing issue: {e.code}")
except VertexSchemaError as e:
    # Deterministic schema bug — do NOT retry, fix the tool schema
    print(f"Vertex schema error on tool={e.tool_name} param={e.parameter_path}")
    print(f"Hint: {e.fix_hint}")

Idempotency

Pass idempotency_key= to any create() call to safely retry on network failure:

agent = await c.agents.create(
    id="marketing-assistant",
    type="skill",
    idempotency_key="create-marketing-agent-v1",
)

Resources

All twelve resources are bound on the client, and their methods are async (c.messages.stream() returns an async context manager rather than a coroutine). The sync mirror currently covers agents, employees, messages and jobs only — reach the other eight through the async surface.

Knowledge search, the most commonly looked-for surface:

collections = await c.knowledge.collections()
hits = await c.knowledge.search(query="refund policy", collection=collections[0])

Sync mirror

# For scripts and notebooks — not inside async handlers
sync_agents = c.sync.agents.list()          # returns a plain list
agent = c.sync.agents.create(id="foo", type="skill")

Streaming

c.messages.stream() opens an SSE connection and returns an async context manager:

async with c.messages.stream(
    agent_id="invoice-bot",
    messages=[{"role": "user", "content": "Process invoice INV-9912"}],
) as stream:
    async for event in stream:
        if event["event"] == "text":
            print(event["data"]["content"], end="", flush=True)
        elif event["event"] == "done":
            print()  # newline at end

Mode A — custom-tool inline (intercept the LLM tool call, compute result, resume):

async with c.messages.stream(
    agent_id="invoice-bot",
    messages=[{"role": "user", "content": "Fetch invoice INV-9912"}],
    message_id="my-request-id",  # required for submit_tool_result before done
) as stream:
    async for event in stream:
        if event["event"] == "custom_tool_use":
            result = await my_invoice_lookup(event["data"]["input"]["invoice_id"])
            await stream.submit_tool_result(event["data"]["id"], result)

Webhook router (Mode B)

WebhookRouter receives LibraOS custom-tool dispatches on your HTTP endpoint, verifies the HMAC-SHA256 signature, dedupes by idempotency key, and dispatches to registered handlers:

from libraos import WebhookRouter

router = WebhookRouter(secret="your-webhook-secret")

@router.tool("fetch_invoice")
async def fetch_invoice(input: dict, ctx: dict) -> str:
    invoice = await db.get_invoice(input["invoice_id"])
    return f"Invoice {invoice.id}: ${invoice.amount}"

FastAPI mount:

from fastapi import FastAPI

app = FastAPI()
app.include_router(router.fastapi_router(), prefix="/nova/callbacks")

Flask mount:

from flask import Flask

app = Flask(__name__)
app.register_blueprint(router.flask_blueprint(), url_prefix="/nova/callbacks")

AWS Lambda mount:

handler = router.aws_lambda_handler()  # pass to Lambda runtime

Changelog

See CHANGELOG.md.

Development

cd python
pip install -e ".[dev]"
pytest tests/ -v

License

MIT.