CAIN-42 · Prove it to anyone

Offline verifiers

Small standalone programs that check CAIN's evidence on your own machine, without trusting our sites.

Last reviewed 2026-10-01

Live Developer tools · Offline verifier

What it is

CAIN-42 buyer pre-flight: one command that re-checks the evidence hygiene

Where it fits

Part of Prove it to anyone: Signed records your auditor, regulator or customer can check without trusting us. Every CAIN-42 product runs behind the same rule: an AI agent's action is checked before it runs (identity, authority, policy, risk), decided as allow, hold for a human, or block, and recorded as signed evidence. Unknown or error never becomes allow.

Use it

Open it https://cainstudio.online/proof/bundle/cain42-orchestration-fabric/cain_37_independent_verifier.py

Included

Name	What it checks	Get it
buyer_preflight.py	CAIN-42 buyer pre-flight: one command that re-checks the evidence hygiene	in a proof bundle
cain_37_independent_verifier.py	CAIN 37.0 Phase 4/10 -- Independent Evidence Chain Verifier (zero-import).	download
cain_epoch6_cleanroom_verifier.py	CAIN-42 Epoch 6: Independent Clean-Room Verifier	in a proof bundle
cain_proof_verify.py	cain-proof-verify: one-command clean-room verification of a CAIN42-PROOF-PACKAGE.	in a proof bundle
cain_verify_offline.py	CAIN Offline Evidence Verifier	in a proof bundle
cleanroom_verify_epoch6.py	CLEAN-ROOM verifier for Epoch 6 evidence (causal graph commits, journal hash chain, crash-state semantics). Stdlib only; imports nothing from CAIN.	in a proof bundle
verify_claims.py	Verify CAIN42_FINAL_PUBLIC_CLAIMS.json without trusting any CAIN-42 website.	download
verify_decision_arguments.py	Check WHICH tool arguments a signed CAIN decision record covered.	in a proof bundle
verify_decision_record.py	Check that a stored CAIN hosted decision record is exactly what the gateway signed.	download
verify_hosted_decision.py	Verify that a hosted CAIN-42 decision was really ordered by a PBFT quorum.	download
verify_pbft_qc_bundle.py	Standalone verifier for a CAIN-42 PBFT quorum-certificate evidence bundle.	download
verify_soak.py	Verify the CAIN-42 72-hour soak evidence, checkpoint by checkpoint, without trusting any site.	download

Live now

Checked from your browser when this page opened, not from a cached list.

Fire a real decision

Send an action through the live CAIN-42 pipeline from this page, with no account, and watch every stage decide. This is the same pipeline every product here sits behind; it runs for a throwaway demo tenant and is rate limited.

For AI engineers

Every product sits behind one decision path: your agent proposes an action with the exact arguments, CAIN runs it through identity, authority, policy, risk, trust and quorum consensus, and answers ALLOW, REQUIRE_APPROVAL or DENY with an Ed25519-signed record. A timeout, outage or unknown verdict never becomes ALLOW. A brand-new agent has no trust history, so its first actions usually come back REQUIRE_APPROVAL.

Python (zero dependencies)

pip install https://cainstudio.online/cainstudio-0.3.0-py3-none-any.whl
export CAIN_API_KEY=...   # free key: https://cainstudio.online/signup

import cainstudio

@cainstudio.guard()
def transfer(amount_usd: float, to: str) -> str:
    ...  # runs only if CAIN allows this call, with these arguments

try:
    transfer(5000, "acme")
except cainstudio.ApprovalRequired as e:
    print("held for a human:", e.approval_id)
except cainstudio.ActionBlocked as e:
    print("refused:", e.decision.reasons)
except cainstudio.CainUnavailable:
    print("CAIN unreachable: not run")   # fail-closed

See a real decision with no account

cainstudio try          # live pipeline, stage by stage
cainstudio try --list   # the other attack scenarios

MCP clients (Claude Code, Cursor)

claude mcp add --transport http cain https://cainstudio.online/mcp

More: Python SDK · TypeScript SDK · framework integrations · AI quickstart · decision signing key

Tested guarantees in this area

Every rule in these niches has its own page with its recorded result.

Evidence, receipts & proofs: 928 tested invariants — Signed records that prove what happened, checkable by anyone.
Consensus & distributed systems: 64 tested invariants — Many machines agreeing on one answer, even when some fail or lie.

CAIN Compliance — Keeps a running check of your agents against the EU AI Act, NIST AI RMF and ISO 42001.
CAIN Proof — Turns every decision into a signed receipt anyone can check.
Decision signing key — The public key that lets anyone check a CAIN decision was really signed by CAIN.
Enterprise Trust Center — Security, privacy and policy answers for your procurement team.
EU AI Act Pre-Conformity Portal — Work through EU AI Act readiness for your AI system, step by step.
QuorumSeal — A signed, versioned audit trail of group decisions and votes.
Verification Lab — Hands-on labs for checking CAIN evidence yourself.
Verify CAIN-42 — Check CAIN-42's own claims yourself, in your browser.

Try CAIN-42 on your own agents

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