Actuary MCP

A pre-trade gate for AI agents on Robinhood Chain. Before your agent buys a token, it asks Actuary. Actuary applies your policy to on-chain and open-collector facts and answers ALLOW, DENY or REVIEW, with the rules that fired, the facts they read, and a signed receipt.

Status: live, rule-based. Answers come from the open rule engine (engine: "rules-v1"). The model is not answering yet; when it does, the receipt will say so. Not financial advice.

Connect by URL (no install)

claude mcp add --transport http actuary https://actuaryai.pro/mcp

The hosted server has the agent tools (gate, gate_batch, gate_facts, get_receipt, verify_receipt, mandates). Run this local server instead when your agent should pay on its own: past the free Gate calls, and for every Mandate (see below).

Install locally

git clone https://github.com/actuaryai/mcp.git
cd mcp && npm install
claude mcp add actuary -- node /absolute/path/to/mcp/server.mjs

Needs Node 20+. Set ACTUARY_API to use another server (default https://actuaryai.pro).

Tools

Tool	What it does
gate	Token + policy → ALLOW / DENY / REVIEW, every check with the fact it read, a plain-words explanation and a signed receipt
gate_facts	The facts a policy may use, the rule syntax and the presets
verify_receipt	Checks a receipt's signature and that nothing in it was changed
gate_batch	Up to 10 tokens against one policy, one receipt each
create_mandate	Keep checking a held token for 7 days ($0.05); poll events, or a webhook when the decision or the contract changes
renew_mandate	7 more days on a mandate ($0.05)
mandate_events	Poll the events a mandate recorded
mandate_status	Current decision, last check, expiry, delivery failures
cancel_mandate	Stop a mandate
check_token, premortem, autopsy_token	The original verdict, launch pre-mortem and autopsy tools

A policy

{
  "policy": "my-agent-v1",
  "deny_if": ["mint_with_live_owner", "ticker_clone_of_older", "first_hour_swaps < 20"],
  "review_if": ["is_proxy", "liquidity_not_reported"],
  "unknown": "review"
}

Rules: fact, !fact, or fact < number (<, <=, >, >=, ==, !=). A rule whose fact is missing is unknown; by default an unknown deny rule gives REVIEW, so missing data never lets a token through. Presets: actuary-default-v1, no-clones-v1.

Receipts

Signed with EIP-712, domain { name: "Actuary", version: "1", chainId: 4663 }, type Receipt(string id, address token, string decision, bytes32 policyHash, bytes32 bodyHash, uint64 issuedAt). bodyHash covers every check, fact, reason and source, and the explanation when there is one. The signer address is published at GET /api/v1/receipts/signer.

The explanation puts the checks into two plain sentences. A model writes it (explanation_model, on Cloudflare Workers AI) from the checks and the published fact meanings only; answers that add numbers, talk about prices or advice are dropped, and the receipt is then issued without one. The explanation never changes the decision.

With "judge": "advisory" or "resolve" in a policy (or the preset actuary-judged-v1), a model reads a REVIEW and leans ALLOW, REVIEW or DENY with a confidence, the facts it relied on and one sentence. ALLOW and DENY from the rules are final. advisory only records the lean; resolve applies it at 75% confidence or more, and an ALLOW only when every deny rule read false. The receipt keeps rule_decision, the final decision and the signed judgement.

Mandate webhooks

POST to your https URL with X-Actuary-Event, X-Actuary-Timestamp and X-Actuary-Signature: sha256=<HMAC-SHA256(secret, "<timestamp>.<body>")>. Events: mandate.decision_changed, mandate.contract_changed (owner, implementation, mint/pause/blacklist, supply moved 1%+), mandate.expiring (a day before the end), mandate.expired, mandate.test. Checks run about every 30 minutes. A mandate stops after 20 failed deliveries.

Mandate pricing

A mandate costs $0.05 for 7 days in USDG on Robinhood Chain over x402: POST /api/v1/mandates answers 402 with the quote, the signed payment goes in PAYMENT-SIGNATURE, and the mandate is created before the payment settles, so nothing is charged if it can't be created. POST /api/v1/mandates/{id}/renew (with Authorization: Bearer <secret>) adds 7 days from the current end. With ACTUARY_PAY_KEY_FILE set, create_mandate and renew_mandate pay on their own.

Paying per call (optional)

After the free daily Gate calls, a Gate call costs $0.002; a Mandate costs $0.05 for 7 days. The server answers 402 with an x402 quote in USDG on Robinhood Chain. To let this server pay on its own:

ACTUARY_PAY_KEY_FILE=/path/to/agent-wallet.key   # a file holding the paying wallet's private key; never paste it in chat
ACTUARY_MAX_USD=0.05                               # the most it will ever sign for one call (default 0.05)

Set ACTUARY_MAX_USD=0.002 if the agent should pay for Gate calls but never for mandates.

Use a dedicated wallet with a small USDG balance. Without the key file, nothing is ever signed.