hive-mcp-imprimatur

Imprimatur: the pre-attestation gate. A signed clearance bound to an inference before it runs. Four compliance pre-conditions are checked and Ed25519-signed at execution time, and an inference that cannot present a valid, unexpired clearance is refused.

A flight recorder proves what crashed. A clearance stops the takeoff.

Every other Hive primitive signs a receipt after the model runs. Imprimatur signs a clearance before it runs. It is the control, not the record.

Discipline: Imprimatur asserts pre_clearance_conditions_met. It never asserts legality. The enterprise defines policy; Hive enforces it and signs that the enforcement ran and passed.

This MCP server is a thin, read-only public shim over the live Imprimatur surface. Issuance (/clear) is ops-gated and intentionally not exposed here.

Tools

Tool	What it does
`imprimatur_info`	Describe the gate: issuer key, four pre-conditions, assertion discipline, two modes.
`gate`	Enforce. ALLOW a call presenting a valid clearance; REFUSE one that cannot. Public, no secret.
`verify_clearance`	Ask the live gate to evaluate a presented clearance. Not an offline check, see limitation below.
`get_pubkey`	The Ed25519 issuer public key (verifies transport signatures offline, not ALLOW decisions).

Verification limitation (read before you rely on this)

An Imprimatur ALLOW decision is produced live, server-side, by the upstream issuer at the moment of the call. It depends on state a caller cannot see or reconstruct independently: the current precondition status, revocation state, and the expiry clock. That means:

gate and verify_clearance both make a live network call to the same upstream /v1/imprimatur/gate endpoint. Neither tool performs a local, offline cryptographic check that could stand on its own.
There is no public algorithm a third party can run against a clearance object alone and get a trustworthy ALLOW/REFUSE without asking the live issuer.
What IS independently, offline verifiable is the Ed25519 transport signature Hive Passport attaches to every HTTP response (X-Hive-Prov-Sig over /v1/prov/pubkey). That only proves the response bytes weren't altered in transit. It does not make the ALLOW decision itself externally provable.
This is different from SiGR, where the signed envelope is self-certifying and verifiable offline with no callback. Imprimatur's ALLOW is not self-certifying in that sense, and this README and the tool descriptions say so explicitly rather than implying otherwise.

Endpoints

Endpoint	Purpose
`POST /mcp`	JSON-RPC 2.0, MCP 2024-11-05, Streamable-HTTP
`GET /health`	Liveness
`GET /.well-known/mcp.json`	MCP discovery
`GET /.well-known/agent.json`	Agent discovery

Upstream: https://hive-passport.onrender.com/v1/imprimatur/*

Connect

Streamable-HTTP MCP server. Point your client at the deployed /mcp endpoint:

{
  "mcpServers": {
    "imprimatur": { "url": "https://hive-mcp-imprimatur.onrender.com/mcp" }
  }
}

Run locally:

npm install
node server.js
# POST http://localhost:3000/mcp

The four pre-conditions

model_approved: the model is on the approved list (composable with MiR).
inputs_eligible: the inputs are eligible for this context (composable with RCP).
context_permitted: the context/purpose is permitted.
boundary_authorized: the jurisdiction / data boundary is authorized.

All four must pass for a clearance to issue. The gate refuses anything that cannot present one.

Patent Pending. Hive Civilization. Settlement in USDC on Base. MIT licensed.