datumline-agent-guard

An independent verifier for AI agent work. An agent says a job is COMPLETED; agent-guard checks the artifacts it claims to have produced and returns a verdict. A completion claim with a missing artifact is reported as FALSE_DONE, not as a pass.

Standard library only, no dependencies. It imports nothing from the runtime it audits, so it can contradict that runtime.

Install

pip install datumline-agent-guard

CLI

agent-guard manifest.json          # human-readable receipt
agent-guard manifest.json --json   # machine-readable receipt

Exit code is 0 only on VERIFIED; every other verdict exits 1 (bad input exits 2), so it can gate CI or an agent loop.

Manifest

{
  "job": "WO-123",
  "claimed_status": "COMPLETED",
  "artifacts": [
    {"type": "file", "path": "out/report.md", "min_bytes": 200, "must_contain": ["## Findings"]},
    {"type": "json", "path": "out/feed.json", "required_keys": ["last_marked", "entries"]},
    {"type": "url",  "url": "https://example.com/feed.json", "status": 200, "must_contain": ["last_marked"]},
    {"type": "file", "path": "out/data.parquet", "sha256": "<hex>"}
  ]
}

Relative paths resolve against the current working directory.

Verdicts

Library

from datumline_agent_guard import verify, verify_file

receipt = verify({"claimed_status": "COMPLETED", "artifacts": [{"type": "file", "path": "out/report.md"}]})
if receipt["verdict"] != "VERIFIED":
    raise SystemExit(receipt["verdict"])

LangChain

pip install "datumline-agent-guard[langchain]"

from datumline_agent_guard.langchain_tool import AgentGuardTool

tool = AgentGuardTool()  # name: agent_guard_verify
tool.invoke({"manifest": {"claimed_status": "COMPLETED", "artifacts": [{"type": "file", "path": "out/report.md"}]}})
# -> JSON receipt; anything other than "verdict": "VERIFIED" means not done

Give it to an agent as a tool, or call it yourself before accepting the agent's "done". It also takes manifest_path instead of manifest. It passes LangChain's standard tool tests (langchain-tests). Requires Python 3.10+; the core package needs only 3.9 and has no dependencies.

Related

The same verifier ships inside the free, MIT-licensed Receipted Operator Claude Code plugin, which adds a receipt ledger, truthful statuses and a hook that refuses unreceipted "done". Datumline also publishes paid method kits at datumlinehq.gumroad.com.

License

MIT