Skip to main content

agent-custody (Python)

Signed, verifiable receipts for AI agent tool calls, from Python. The key, the Cedar policy, and the Merkle log live in the agent-custody sidecar, a local process from the npm package; this client talks to it over HTTP with the standard library only.

npm install -g @agent-custody/receipts && agent-custody keygen --dir keys --name app
agent-custody serve --config sdk.json          # loopback, port 8788
pip install agent-custody
from agent_custody import Client, PolicyDeniedError

client = Client()                                # http://127.0.0.1:8788/
refund = client.wrap("stripe.refund", lambda args: stripe.refund(**args))
refund({"amount": 5000})                         # decide, run, record; raises PolicyDeniedError on deny

Adapters, each tested against the real package: agent_custody.langchain.ReceiptCallbackHandler (record-only), agent_custody.crewai.wrap_tools (enforce: each CrewAI tool becomes a CustodyTool with the same name, description, and schema whose run is decided, executed, and recorded; a denial is returned as the tool result), agent_custody.openai_agents.wrap_tools (enforce and record), agent_custody.claude_agent_sdk.claude_hook (PreToolUse deny, PostToolUse record), agent_custody.hermes (a Hermes Agent plugin: pre_tool_call block, post_tool_call record; the drop-in plugin directory is hermes-plugin), agent_custody.adk.adk_callbacks (Google ADK: before_tool_callback skips a denied tool and hands the model the receipt, after_tool_callback records; LlmAgent(..., **adk_callbacks(client)); extra adk, which installs google-adk[a2a]). Receipts are verified by the TypeScript verifier; the tests do exactly that. An ADK agent's delegations to other agents over A2A are not tool calls and pass no callback; the gateway's A2A front, agent-custody gateway --a2a, covers them, and tests/test_adk_a2a.py runs ADK's own RemoteA2aAgent through it.

The memory tools. agent_custody.memory.MemoryClient (extra memory) talks to the shared memory server from @agent-custody/state over MCP: write, read, retract, history. Writes from here are claimed, quarantined until a gateway confirms them, and reads leave quarantined facts out unless asked; that is the honest position of an agent that did not go through the gateway.

async with MemoryClient("http://127.0.0.1:8790/mcp", token=os.environ["MEMORY_DIRECT_TOKEN"]) as memory:
    await memory.write("acct:42", "plan", "pro", space="team:support", actor="py-agent")
    await memory.read(subject="acct:42", include_claimed=True)

Everything recorded is claimed: the sidecar trusts what this process reports, the same as the in-process TypeScript SDK. For enforcement the agent cannot skip, put the gateway in front of the tools instead; it is an MCP server and needs nothing from this package.

uv run --extra test pytest        # from packages/python; starts a sidecar with node from ../receipts

Metadata

Release files for agent-custody 0.7.0

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for agent-custody 0.7.0
File Size Uploaded Provenance
agent_custody-0.7.0.tar.gz 391.3 kB Without provenance Details

Built distribution (wheel)

Table of built distributions (wheels) for agent-custody 0.7.0
File Interpreter ABI Platform
agent_custody-0.7.0-py3-none-any.whl Python 3 none any Details

Total release size: 405.4 kB

Release files / agent_custody-0.7.0.tar.gz

Download URL agent_custody-0.7.0.tar.gz
Size 391.3 kB
Tags Source
SHA-256 checksum
How to use checksums
432745172ce505cdf403821849f110fc2e08fd6830bb68a61c6449862a5ae906
BLAKE2b-256 checksum
How to use checksums
b578cfcdc0c0263a8e100b6c40c2d30d9dcd8cab1a2c3fbb464b7e0359a4f708
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via uv/0.9.24 {"installer":{"name":"uv","version":"0.9.24","subcommand":["publish"]},"python":null,"implementation":{"name":null,"version":null},"distro":{"name":"macOS","version":null,"id":null,"libc":null},"system":{"name":null,"release":null},"cpu":null,"openssl_version":null,"setuptools_version":null,"rustc_version":null,"ci":null}

Release files / agent_custody-0.7.0-py3-none-any.whl

Download URL agent_custody-0.7.0-py3-none-any.whl
Size 14.1 kB
Tags Python 3
SHA-256 checksum
How to use checksums
151d0323adf2fcafc765f118165de5d9b58e8fe739fce29a63c13ff9e7b7b68f
BLAKE2b-256 checksum
How to use checksums
ec9761651156fe9ff12b677ec91bd6dabdefc32a06e910e46af6cd0df66b8178
Upload date
Uploaded using Trusted Publishing?
What is trusted publishing?
No
Uploaded via uv/0.9.24 {"installer":{"name":"uv","version":"0.9.24","subcommand":["publish"]},"python":null,"implementation":{"name":null,"version":null},"distro":{"name":"macOS","version":null,"id":null,"libc":null},"system":{"name":null,"release":null},"cpu":null,"openssl_version":null,"setuptools_version":null,"rustc_version":null,"ci":null}

Security for agent-custody 0.7.0

Provenance

Provenance describes where a file came from. On PyPI, provenance is shared via attestations, which provide a verifiable record of the build or publishing details. View details, limitations and caveats.

No provenance found

None of the files in this release were uploaded with provenance metadata.

A note on package security

PyPI is a repository for distributing packages, not a service for auditing them. While third-party security researchers and our staff do their best to detect and remove malicious packages, PyPI cannot guarantee the quality, security or suitability of any given package.

To learn more about protecting yourself from malicious actors, visit our package security documentation.

Release history Release notifications | RSS feed

This release

0.7.0 This release

2 release files No provenance

Anthropic, PBC Visionary sponsor Bloomberg Visionary sponsor Hudson River Trading Visionary sponsor Meta Visionary sponsor NVIDIA Visionary sponsor Microsoft Sustainability sponsor Depot Continuous Integration AWS Cloud computing and Security Sponsor Datadog Monitoring Fastly CDN Google Download Analytics Sentry Error logging StatusPage Status page