---
title: "treeship-sdk (Python)"
description: Python SDK for Treeship. Wraps the CLI binary for signing, verification, session reporting, and hub operations.
---

import { Callout } from 'fumadocs-ui/components/callout';

## Install

```bash
pip install treeship-sdk
```

<Callout type="info">
The Python SDK shells out to the `treeship` CLI binary. The CLI must be installed and initialized (`treeship init`) before using the SDK.
</Callout>

## Quick start

```python
from treeship_sdk import Treeship

ts = Treeship()

# Attest an action
result = ts.attest_action(
    actor="agent://my-agent",
    action="tool.call",
)
print(result.artifact_id)

# Verify it
verified = ts.verify(result.artifact_id)
print(verified.outcome)  # "pass"

# Upload a closed session's receipt and get the permanent public URL
report = ts.session_report()
print(report.receipt_url)
```

## Treeship class

Wraps the `treeship` CLI. All methods raise `TreeshipError` on CLI failure.

### `attest_action(actor, action, ...)`

Create a signed action receipt.

```python
result = ts.attest_action(
    actor="agent://coder",
    action="tool.call",
    parent_id="art_abc123",
    meta={"tool": "read_file", "path": "src/main.rs"},
)
```

| Parameter | Type | Description |
|-----------|------|------|
| `actor` | `str` | Actor URI |
| `action` | `str` | Label for the action |
| `parent_id` | `Optional[str]` | Parent artifact id for chain linking |
| `approval_nonce` | `Optional[str]` | Nonce from an existing approval |
| `meta` | `Optional[Dict[str, Any]]` | Arbitrary metadata |

Returns `ActionResult(artifact_id)`.

### `attest_approval(approver, description, expires_in=None)`

Create a signed approval receipt with a binding nonce. (Replay posture is package-local in v0.9.6; cross-package enforcement lands in v0.10 via the local Approval Use Journal.)

Returns `ApprovalResult(artifact_id, nonce)`.

### `attest_handoff(from_actor, to_actor, artifacts, approvals=None)`

Create a signed handoff receipt between agents.

Returns `ActionResult(artifact_id)`.

### `attest_decision(actor, model=None, tokens_in=None, ...)`

Create a signed decision receipt capturing LLM reasoning context.

Returns `ActionResult(artifact_id)`.

### `verify(artifact_id)`

Verify an artifact and walk its chain.

```python
result = ts.verify("art_abc123")
if result.outcome == "pass":
    print(f"Chain length: {result.chain}")
```

Returns `VerifyResult(outcome, chain, target)`.

### `hub_push(artifact_id)`

Push an artifact to the configured hub.

Returns `PushResult(hub_url, rekor_index)`.

### `wrap(command, actor=None)`

Wrap a shell command with a signed receipt.

```python
result = ts.wrap("npm test", actor="agent://ci")
```

Returns `ActionResult(artifact_id)`.

### `session_report(session_id=None)`

Upload a closed session's [Session Receipt](/docs/concepts/session-receipts) to the configured hub and return the permanent public URL.

```python
# Upload the most recently closed session
result = ts.session_report()
print(result.receipt_url)
# https://treeship.dev/receipt/ssn_42e740bd9eb238f6

# Upload a specific session by id
result = ts.session_report(session_id="ssn_42e740bd9eb238f6")
```

| Parameter | Type | Description |
|-----------|------|------|
| `session_id` | `Optional[str]` | Session id to upload. Defaults to the most recently closed session's package under `.treeship/sessions/`. |

Returns `SessionReportResult(session_id, receipt_url, agents, events)`.

This method shells out to [`treeship session report`](/docs/cli/session#treeship-session-report), which reads the `.treeship` package from disk, DPoP-signs a PUT to the hub, and prints the receipt URL. The Python wrapper parses the text output and returns the structured result.

<Callout type="info">
The returned `receipt_url` is permanent and public. Share it freely; no token, no expiry, no auth required to fetch it. See the [receipt API docs](/docs/api/receipt-get) for the endpoint reference.
</Callout>

## Result types

All results are simple dataclasses exported from `treeship_sdk`.

### `ActionResult`

```python
@dataclass
class ActionResult:
    artifact_id: str
```

### `ApprovalResult`

```python
@dataclass
class ApprovalResult:
    artifact_id: str
    nonce: str
```

### `VerifyResult`

```python
@dataclass
class VerifyResult:
    outcome: str  # "pass", "fail", "error"
    chain: int
    target: str
```

### `PushResult`

```python
@dataclass
class PushResult:
    hub_url: str
    rekor_index: Optional[int] = None
```

### `SessionReportResult`

```python
@dataclass
class SessionReportResult:
    session_id: str
    receipt_url: str
    agents: int = 0
    events: int = 0
```

## Error handling

The SDK raises `TreeshipError` when the CLI exits non-zero, when the CLI is missing from PATH, or when the CLI output cannot be parsed.

```python
from treeship_sdk import Treeship, TreeshipError

ts = Treeship()

try:
    result = ts.session_report()
except TreeshipError as e:
    print(f"session report failed: {e}")
    print(f"CLI args used: {e.args_used}")
```
