moltrust-crewai

Add trust verification to CrewAI in one line.

moltrust-crewai checks the calling agent's MolTrust trust score before every tool call in a CrewAI crew. Agents below your minimum score are blocked (or warned/logged). It hooks into CrewAI's native hook system — no changes to your agents or tasks.

Install

pip install moltrust-crewai

Usage (one line)

from moltrust_crewai import MolTrustGuardrail

# register the guardrail globally, then run your crew as usual
MolTrustGuardrail(min_score=60).install()

from crewai import Crew
crew = Crew(agents=[...], tasks=[...])
crew.kickoff()

That's it — the guardrail fires automatically on every tool call via crewai.hooks. No API key required to get started (see tiers below).

Usage Tiers

Tier 1 — No account required

pip install moltrust-crewai

guard = MolTrustGuardrail(min_score=60)
guard.install()
# Reads trust scores without an API key. Rate-limited.

Tier 2 — Free account

guard = MolTrustGuardrail(min_score=60, api_key="mt_...")
# Higher rate limits + interaction feedback (score improvement over time)

The API key (arg or MOLTRUST_API_KEY env) is sent as the X-API-Key header only when present.

Note on the API: CrewAI 1.x wires middleware through its hook system (crewai.hooks), not a Crew(callbacks=[...]) argument. install() registers the before_tool_call / before_llm_call hooks for you. Call guard.uninstall() (or use it as a context manager) to remove them.

Options

MolTrustGuardrail(
    min_score=60,          # min trust score, 0-100 scale (see below)
    action="block",        # "block" | "warn" | "log" | "raise"
    agent_did_map={         # map a CrewAI agent role → its MolTrust DID
        "Researcher": "did:moltrust:0123456789abcdef",
    },
    did_key="did",         # or read the DID from tool_input["did"]
    pass_without_did=True,  # allow calls with no resolvable DID
)

What it does

Before every tool call, MolTrustGuardrail resolves the calling agent's MolTrust DID (via agent_did_map or a did in the tool input) and reads its trust score from GET /skill/trust-score/{did}. min_score is on the MolTrust trust score scale (0–100, behavioral trust) — not the 0–5 reputation/rating scale. The CrewAI hook contract is simple: the hook returns False to block the tool call, or None/True to allow it.

Trust scores are recomputable — you never have to take MolTrust's word for a number. Verify the on-chain solvency component of any agent independently:

https://api.moltrust.ch/credits/solvency/{did}

Difference from Microsoft AGT

Microsoft's Agent Governance Toolkit enforces policies — what an agent may do (scope, sandboxing, zero-trust identity). MolTrust verifies behavioral trust — is this agent trustworthy, based on verifiable history. They are complementary, not competing: use AGT to bound authority, use MolTrust to decide who has earned it.

Honest limitations (0.1.0)

• CrewAI agents have no MolTrust DID by default — you map them explicitly via agent_did_map, or carry a did in the tool input. There is no magic auto-binding yet.
• min_score is on the 0–100 MolTrust trust score (trust_score from /skill/trust-score/{did}), the phase-2 behavioral score — not the 0–5 reputation/rating average.
• A withheld score (registered agent with too few endorsements → API returns trust_score: null, withheld: true) is treated like an unregistered agent: fail-closed in block, fail-open in warn/log.
• On a registry/transport error the guardrail fails open (allows the call, logs a warning) so a MolTrust hiccup never breaks your crew.
• before_llm_call is a no-op placeholder (a hook point for injecting trust context into prompts); extend it as needed.

License

MIT © CryptoKRI GmbH — see LICENSE.