CAIN-42 · Stop risky actions

TrustLedger

Keeps a trust score per agent and checks it before every action.

Last reviewed 2026-10-01

Live   MCPGate gates · MCPGate

What it is

Deterministic per-agent trust-score ledger and pre-action gate.

Where it fits

Part of Stop risky actions: Make AI agents ask before they delete, pay, email or run anything dangerous. 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://trustledger.mcpgate.online
• Documentation https://trustledger.mcpgate.online/docs
• MCP endpoint https://trustledger.mcpgate.online/mcp

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.

• Identity, authority & delegation: 964 tested invariants — Who an agent is, what it may do, and who allowed it.
• Policy, law & governance: 966 tested invariants — The rules agents must follow, and how they are enforced.
• Attacks, threats & containment: 418 tested invariants — What happens when someone attacks: it is caught and contained.

Related

• Approvals — Risky actions wait here for a human yes or no.
• CAIN Agent Security — Catches made-up facts, unverified actions and agent-to-agent tricks before they cause damage.
• CAIN Budget — Spending limits for agents, so a runaway loop cannot burn your money.
• CAIN Control — The rulebook: decides allow, hold for approval, or block for every action an agent proposes.
• CAIN Governance — Write the rules your agents must follow, in plain terms, and enforce them everywhere.
• CAIN Impact — Predicts what an action could break before it is allowed to run.
• Kill switch — One click stops every agent at once.
• Prompt-injection inspection — Screens what an agent reads for hidden instructions planted by an attacker.
• Tools & rules — Your own rules: always block this, always ask about that, always allow the rest.