> ## Documentation Index
> Fetch the complete documentation index at: https://docs.vane.build/llms.txt
> Use this file to discover all available pages before exploring further.

# CrewAI

> vane-crewai — attest every agent step and task completion in your crew.

## Installation

```bash theme={null}
pip install vane-crewai
```

No external dependencies. Uses only the Python standard library (`urllib`, `threading`, `json`).

Requires Python 3.9+.

## Three-line setup

```python theme={null}
from counsel_crewai import VaneObserver

observer = VaneObserver(
    base_url="https://vane.build",
    api_key="counsel_a1b2c3d4...",
    agent_id="contract-reviewer",
)
crew = observer.wrap(crew)
```

## `VaneObserver`

### Constructor

```python theme={null}
VaneObserver(
    base_url: str,
    api_key: str,
    agent_id: str,
    company_id: str = "",
)
```

| Parameter    | Type  | Required | Description                                                                           |
| ------------ | ----- | -------- | ------------------------------------------------------------------------------------- |
| `base_url`   | `str` | Yes      | Base URL of your Vane instance. Trailing slash is stripped.                           |
| `api_key`    | `str` | Yes      | Company-scoped API key.                                                               |
| `agent_id`   | `str` | Yes      | Agent identifier that appears on every record.                                        |
| `company_id` | `str` | No       | Company ID embedded in attestation payloads. If empty, the API key's company is used. |

### `wrap(crew)`

Attaches attestation callbacks to the crew and returns it. Preserves any existing `step_callback` and `task_callback` — both the original callbacks and the attestation callbacks will be called.

```python theme={null}
crew = observer.wrap(crew)
# crew.step_callback and crew.task_callback are now wrapped
```

### What gets attested

| Event                         | `actionType`      | Payload fields                     |
| ----------------------------- | ----------------- | ---------------------------------- |
| Tool invocation (AgentAction) | `"tool-call"`     | `tool`, `toolInput`, `observation` |
| Agent finished (AgentFinish)  | `"agent-finish"`  | `output` (the return\_values dict) |
| Any other step output         | `"agent-step"`    | `raw` (string representation)      |
| Task completed                | `"task-complete"` | `description`, `agent`, `output`   |

### Error handling

All HTTP calls happen in **daemon threads**. If the Vane server is unavailable, the error is printed to stdout and the crew execution continues uninterrupted. Attestation failures never block or crash your crew.

## Full example

```python theme={null}
from crewai import Agent, Task, Crew
from crewai_tools import SerperDevTool
from counsel_crewai import VaneObserver

# Set up the observer
observer = VaneObserver(
    base_url="https://vane.build",
    api_key="counsel_a1b2c3d4...",
    agent_id="legal-researcher",
    company_id="acme",
)

# Create your crew normally
researcher = Agent(
    role="Legal Researcher",
    goal="Find relevant legal precedents",
    backstory="Expert in EU AI regulation",
    tools=[SerperDevTool()],
    verbose=True,
)

task = Task(
    description="Research EU AI Act compliance requirements for financial services",
    agent=researcher,
    expected_output="A structured summary of compliance requirements",
)

crew = Crew(agents=[researcher], tasks=[task])

# Wrap the crew — three lines total
crew = observer.wrap(crew)

result = crew.kickoff()
print(result)
```

Every tool call and task completion in this crew will produce a signed record in Vane.

## Using with existing callbacks

If your crew already has step or task callbacks, they are preserved:

```python theme={null}
def my_existing_step_callback(step_output):
    print(f"Step: {step_output}")

crew = Crew(
    agents=[...],
    tasks=[...],
    step_callback=my_existing_step_callback,
)

# Both my_existing_step_callback AND counsel attestation will run
crew = observer.wrap(crew)
```