Foodblock MCP

FoodBlock

The smallest language strangers in food need to agree on, with no boss. Everything else is data.

A block is three fields, signed by its author on their own device:

{

"type": "promise", "state": { "terms": { "price": { "minor": 450, "currency": "GBP" }, "quantity": { "value": "30", "unit": "{egg}" } }, "at": "2026-10-15T09:00:00.000Z", "audience": "public", "seq": 4 }, "refs": { "author": "a1b2…", "prev": "c3d4…", "from": "a1b2…", "what": "e5f6…" } }

This is an offer: it is signed by its from side. Its id is the hash of its canonical form (one exact way of writing it as text: RFC 8785). The author signs the same bytes with Ed25519 (the suite std; p256 and sm are two more). Nobody's clock decides who has authority. The other side can check that authority. Without the author's key no one can make a block that counts as theirs, or change one without changing its id, and a key that signs two versions of its history leaves the proof. What the protocol cannot do (keep a lost key safe, stop a custodian who holds your key, see inside a sealed block it was not sent) is in the threat model (a draft).

• The spec: spec/protocol.md, FoodBlock 1.7 (2026-10-27; it adds to 1.6, except the few deletions the CHANGELOG lists). It is normative: where anything else here disagrees, it governs. Beside it: protocol.json (every list, for code to load), the canonical form, transport (email is the envelope, FoodBlock the letter) and the conformance vectors. There is no earlier version in the protocol: 1.6 is year zero. Old data enters once, through a converter that is not part of the protocol. NECESSITY.md shows, for every field, term, verb, closed type, reference key and invariant, which vectors fail without it; EXPERIMENTS.md records the compressions tried.
• The paper: the FoodBlock whitepaper v1.6 (PDF) (DOI 10.5281/zenodo.23457910): why the protocol exists. Where it and the spec differ, the spec is current.

The language

Seven types, in three moods:

Seven verbs, the refs that link blocks: updates, answers (the only way to consent), confirms, defeats, for, derives_from, same_as. prev and after say what came before.

Strict. Only four types carry authority and are closed (actor, promise, transfer, grant); any other word is an open type that a node stores and passes on. A node writes and reads only the current version's shapes: no nulls, no floats (money is { minor, currency }, an amount { value, unit } with a decimal string), exact UTC times, sets written sorted, every block in its key's chain (state.seq, refs.prev). It never repairs a block: it refuses it, and the author signs a new one.

Three sizes of peer

Every peer speaks the protocol itself: a phone, a robot kitchen, a van, a sensor. Machines are peers like people. There are three sizes (protocol.json peers, and spec/protocol.md): micro (a device that measures and signs), edge (the local operator, works offline) and node (the lasting level, serves pull and push to anyone). Only people and machines hold nodes. A business, a household or a community is a circle of them, never a node of its own.

What is here

Each SDK's README says which profile it covers.

For autonomous systems

FoodBlock is built for people, autonomous systems and machines to use together. An autonomous system can read and write it directly:

• MCP server: mcp/, for Claude, Cursor, Windsurf, Gemini CLI and any MCP-compatible autonomous system
• The spec in one file: spec/protocol.md, with every list machine-readable in spec/protocol.json
• LLM quick reference: https://foodx.network/llms.txt
• About FoodX: https://foodx.network

Quick start

const fb = require('@foodxdev/foodblock') // in this repository: require('./sdk/javascript/src/index.cjs')

const keys = fb.generateKeypair() // one key is the whole ceremony const me = fb.identity.genesis(keys, { kind: 'person', at: '2026-10-15T09:00:00.000Z', audience: 'public' }) // who you are: its hash is your id; kind, at and audience are yours to state const eggs = fb.write('thing', { kind: 'eggs', name: 'Free-range eggs' }, {}, { author: me.hash, key: keys, held: [me], at: '2026-10-15T09:01:00.000Z', audience: 'public' }) fb.valid(eggs, [me]) // [] : sound, signed by a key of its author, in its chain

From a terminal:

cd cli && npm install

node bin/fb.js init me.json --kind person --audience public --reach P30D node bin/fb.js create thing eggs --state '{"name":"Free-range eggs"}' --identity me.json

Between nodes

Anyone can leave a node with everything they signed. Peers swap blocks with two messages, pull and push, and every answer is signed by a key of the node's holder (spec/modules/nodes.md). .well-known/foodblock says who the node is, what it holds and its admission rule.

Run one with docker compose -f server/docker-compose.yml up, or cd server && npm install && npm start with a Postgres at DATABASE_URL and a key file from fb key at NODE_KEY.

Tests

Licence

Public domain (CC0 1.0; decided 2026-10-29, replacing MIT). FOODX WORLD LIMITED (England and Wales, company 16406719), which wrote it and runs this repository, waived its copyright: the protocol needs no one's permission to implement, copy or change.

How a change is proposed and how versions work: GOVERNANCE.md. How we treat each other, and what content is not allowed: CODE_OF_CONDUCT.md. Reporting a weakness: SECURITY.md.

To cite FoodBlock, see CITATION.cff.