# UST Protocol — the MCP server ``` ▄▀▀▀▀▀▀▀▀▀▀▀▀█▄ █ ▄▄ ▄▄ █ UST Protocol ▄▄▀ ▀▀ ▄▄▄ ▀▀ █ RSS for State ▄█▀▀ ▀█▄▀▄▄▀ ▀█▀ █ █▀▄ ▄▄ ▀█ █▄ █▄ ██▀ █ █ ▀▄▄ █ ▄█ █ ▀▀ █▀ █▄ ▄ █▀ ███▄ █ █ ▄█▀ ▄▀▀ ██▄▄▄█ ▀▄▄▄▄█▀▀ ▀▀▀▀▀▀▀ ▀▀▀▀▀▀▀▀ ``` **Browser: node-only.** This package does **not** run in a browser, and that is a decision rather than an omission. See `ust:browser.why` in its `package.json` for the reason, and UST-Protocol#148 for what a browser can and cannot reach without it. UST (Universal State Transcript) is trust infrastructure for data: a signed, canonical, tamper-evident record of *state* — some data about the world at a moment — that verifies the same however it reached you. TLS secures the pipe; **UST secures the payload**, so the guarantee travels with the data instead of with the connection. > **Two rules this protocol does not trade away.** > **A minor only ADDS.** Anything that changes the meaning of what an earlier minor already defines is a MAJOR — there is no third option, because an older verifier evaluating under older rules must still be RIGHT about what it evaluated. > **A verifier never expires.** An older verifier keeps producing correct verdicts about everything it understands; newer material it does not implement is reported as NOT EVALUATED — never as invalid, never silently passed. Whether that reach is enough is the CONSUMER's policy, not the protocol's coercion. > *Both hold today: a newer minor answers `INDETERMINATE(unsupported_minor)` and a different major `INDETERMINATE(unsupported_major)` — never `INVALID`, which means only "I applied MY rules and they were violated".* **An MCP server that lets an agent verify, create, and combine UST records — using only this server and its own key.** `@ust-protocol/mcp` exposes [`ust-protocol`](https://www.npmjs.com/package/ust-protocol) as [Model Context Protocol](https://modelcontextprotocol.io) tools, so any MCP-capable agent can check that a piece of state is what it claims — who published it, when, unchanged — without trusting whoever served the bytes. > **Release candidate.** The wire format `ust:"1.0"` is stable across all rc's; this package pins its own rc on npm — pin exact versions. Extensively > red-teamed; multiple external AI reviews folded in structurally; an independent human cryptographic audit is > pending. Suitable for evaluation. Pin exact versions. ## Install ```bash npm i @ust-protocol/mcp ``` ## Run ``` npx -y @ust-protocol/mcp@rc ``` ## Add to Claude Code ``` claude mcp add ust -- npx -y @ust-protocol/mcp@rc ``` Or in any MCP client config: ```json { "mcpServers": { "ust": { "command": "npx", "args": ["-y", "@ust-protocol/mcp@rc"] } } } ``` ## Tools | Tool | Does | |------|------| | `ust_verify` | Verify a document — ONE call, resolution included: auto-fetches the publisher's discovery + witness surfaces, cross-checks witness anchors against their substrate (Rekor/Bitcoin), and reaches `VALID:HIGH` automatically when the no-fork evidence confirms (`resolution.noFork`: witness-confirmed / caller-asserted / unconfirmed). `offline:true` forbids the network (supply `genesis`+`keylog` yourself); `proof` adds anchored time | | `ust_build_observation` | Build (unsigned) an observation; returns `state` + `content_hash` + `signing_input` | | `ust_combine_derivation` | Build a derivation chained to other records by content-hash (auto seed) | | `ust_combine_attestation` | Build an attestation over N constituents (auto Merkle root) | | `ust_build_genesis` | CEREMONY (build, unsigned): the name-binding GENESIS — the self-signed root that weds a domain to a key. The MCP holds no key: it returns the unsigned state + `signing_input`, and the operator signs | | `ust_build_key_log` | CEREMONY (build, unsigned): a key-log entry that ADDs or REVOKEs a key. There is deliberately no `rotate` op — a self-authorized succession would let a compromised key name its own successor | | `ust_build_cadence` | CEREMONY (build, unsigned): declare the stream grid in seconds from `effective_from` onward, prev-chained from the genesis for the first entry | | `ust_resolve_cadence` | What grid does this publisher declare at a given moment? Resolves the cadence in force at `at` from the genesis plus the signed cadence log, verifying every entry | | `ust_fork_choice` | Fork-choice for ONE `ust_id` when you hold two or more documents claiming it with different content — a dual-writer race, or an adversary. The anchor decides, never the candidates | | `ust_resolve` | Resolve name authority → `authoritative` / `self-asserted` | | `ust_anchor_verify` | Verify a time-anchor's Merkle inclusion proof | | `ust_verify_stream` | Verify a RANGE (e.g. ust(001)…ust(007) fetched from an archive) as one authority's complete, prev-chained stream → `proven`/`provisional` (retrieval is the product's job, not the protocol's) | | `ust_key_id` | Derive a `key_id` from a public key | | `ust_canon` | Canonicalize a value (the exact bytes UST hashes/signs) | ## The agent flow — build → sign → verify, entirely through the MCP 1. `ust_build_observation` → returns the unsigned `state` and the exact `signing_input` bytes. 2. **You** sign `signing_input` with your own Ed25519 key. 3. `ust_verify` → `VALID`. The server **never holds your key**. An agent needs only this MCP and its own key. ## What it proves — and what it doesn't UST proves **fixation, not truth**: *this publisher committed to this data, at this time, unchanged* — not that the data is *correct*. You learn **whom to hold accountable** and **that nothing was tampered**. The final Bitcoin time-anchor confirmation is a substrate step delegated to the operator (it needs Bitcoin access), so it is deliberately not a stateless protocol tool — `ust_anchor_verify` proves *inclusion*, you (or the operator) confirm the root on-chain. ## Two surfaces This is the **protocol MCP** — universal, publisher-agnostic. A separate **product MCP** (pricing, receipts, archive depth) is operated by publishers such as noosphere; the two are never mixed. Depends on [`ust-protocol`](https://www.npmjs.com/package/ust-protocol). Spec: **https://github.com/thelabmd/UST-Protocol/blob/main/spec/UST-1.0.md** ## License Apache-2.0 · © 2026 THE LAB