evaluate_step
Ask the AgenticRail gate to ALLOW or DENY a single step of an agent sequence BEFORE it runs. A denied step must not be executed. You walk away holding a signed, hash-chained record of the run that you can hand to anyone, and they can verify it offline - no callback to us and no account with us. The gate is deterministic (same state+request -> same verdict) and enforces step order, replay protection, timestamp freshness and sealing. START HERE - send this, changing only CHANGE-ME to any unique string of your own, and it will be ALLOWED: {"sequence_id":"CHANGE-ME","step":"intake","action_type":"CHECK_STATE","step_order":["intake","settle"]}. Then send the same call with step 'settle' to close and seal it. Use the demo key by sending no Authorization header, or send Authorization: Bearer . NOTE: an anonymous call has its sequence_id rewritten to 'demo-mcp-'. This is intended, not a leak: it scopes the run to the public demo lane and is how anonymous MCP traffic is identified. Always reuse the sequence_id RETURNED in the response for later steps and for verify_receipt -- the id you sent will not resolve. Typical use is gating the order of a regulated workflow the caller already runs: customer and third-party due diligence, verification of identity before a payment or business relationship, company registry, beneficial-ownership and sanctions screening, supplier and contractor onboarding. This tool performs none of those checks and holds no registry or watchlist data. It decides only whether the step you are about to run is allowed at this point in the order you declared.
Input Schema
| Name | Required | Description | Default |
|---|---|---|---|
| step | Yes | The step being attempted, e.g. 'intake' or 'review_and_sign'. This is a NAME, not a description. It must be spelled identically on every call, must appear in step_order (for custom sequences), and must equal `function`. The gate compares it byte for byte, so a sentence that changes with the subject can never match and is denied UNKNOWN_STEP. Put the human-readable sentence in `action` instead. | |
| nonce | No | Optional unique-per-step UUID for replay protection. Generated automatically if omitted. | |
| action | No | Optional human-readable label for the action. | |
| inputs | No | Optional free-form inputs recorded with the decision. | |
| function | No | Defaults to `step`. The rule step === function always holds. | |
| step_order | No | The full ordered list of step names for a CUSTOM sequence. Send it on every call, IDENTICAL each time. Omit only if using AgenticRail's built-in MSMD spine. It is LOCKED on the sequence's first call: a different list later is DENIED with STEP_ORDER_MISMATCH, and that denial returns locked_step_order - the list this sequence is held to. Do NOT try to clear the lock by omitting this field; that selects the MSMD spine and your steps will come back UNKNOWN_STEP. To change the plan, start a new sequence_id. One step is a valid sequence. An UNKNOWN_STEP denial returns expected_step_order (the list your step had to be in) and step_order_source ('caller' or 'msmd_spine'); msmd_spine means you sent no step_order at all and got the built-in spine. | |
| action_type | Yes | The action class for this step. The whole vocabulary is exactly these eight and nothing else is accepted: CHECK_STATE, CLARIFY_NEXT_STEP, SELECT_NEXT_STEP, RECORD_RESULT, WAIT_FOR_SIGNAL, VALIDATE_INPUT, PAUSE_CYCLE, REDUCE_STIMULUS. These are ENFORCEMENT CLASSES, NOT a description of what your step does. READ, QUERY, LOOKUP, SEARCH, EXECUTE, ANALYZE and TOOL_CALL are the most common wrong guesses and every one of them is denied: a step that searches, drafts, queries or analyses is still CHECK_STATE if it reads state, or RECORD_RESULT if it writes an outcome. EACH STEP THEN ACCEPTS ONLY A SUBSET of the eight - e.g. intake takes VALIDATE_INPUT, CHECK_STATE or CLARIFY_NEXT_STEP and nothing else. A wrong one is DENIED with ACTION_NOT_ALLOWED before your step runs, and that denial returns allowed_action_types listing exactly what the step would have accepted - read it and retry rather than guessing. A denial does not spoil the sequence and runs nothing. | |
| sequence_id | Yes | Stable identifier for this run of the sequence. Reuse it across every step of the same sequence. An anonymous call is rewritten to 'demo-mcp-<your id>' and an authenticated demo call to 'demo-<your id>'; take the id back from the response and use that one from then on. Give every RUN a fresh id - a run, not an attempt: sealing is permanent, and on the shared demo lane a fixed id is shared with everyone else. A DENIED step does not spoil a sequence and does not run anything, so a denial is not a reason to start a new one: fix the call instead. |