occ-crewai

OCC cryptographic proof signing for CrewAI.

Every tool call produces an Ed25519-signed proof entry in proof.jsonl, creating a tamper-evident audit log of agent actions.

Install

pip install occ-crewai

Quick Start

Decorator

from crewai.tools import tool
from occ_crewai import occ_tool

@occ_tool
@tool("Search")
def search(query: str) -> str:
    """Search the web."""
    return do_search(query)

Wrap All Tools

from occ_crewai import wrap_tools

safe_tools = wrap_tools([search_tool, calc_tool])
agent = Agent(role="researcher", tools=safe_tools)

Step Callback

from occ_crewai import occ_step_callback

crew = Crew(
    agents=[researcher, writer],
    tasks=[research_task, write_task],
    step_callback=occ_step_callback(),
)

Custom Signer

from occ_crewai import OCCSigner, occ_tool

signer = OCCSigner(state_dir="/tmp/.occ", proof_file="audit.jsonl")

@occ_tool(signer=signer)
@tool("Search")
def search(query: str) -> str:
    """Search the web."""
    return do_search(query)

Proof Format

Each line in proof.jsonl is a JSON object:

{
  "version": "occ/proof/1",
  "timestamp": "2026-03-20T12:00:00.000Z",
  "signer": "<base64url-ed25519-public-key>",
  "payload": {
    "type": "tool-call",
    "tool": "search",
    "inputHash": "<sha256-hex>",
    "outputHash": "<sha256-hex>"
  },
  "signature": "<base64url-ed25519-signature>",
  "prev": "<sha256-hex-of-previous-proof>"
}

Proofs are chained: each proof's prev field contains the SHA-256 hash of the previous proof's canonical JSON.

Configuration

• State directory: Keypair stored in .occ/signer-state.json (defaults to CWD)
• Proof file: Defaults to proof.jsonl in CWD
• Both configurable via OCCSigner(state_dir=..., proof_file=...)

License

Apache-2.0