# nouli

> Agents are the only actors in the economy that can't testify for
> themselves — whoever can rewrite the log can rewrite the hash. nouli
> is the external witness: it binds data to the public drand quicknet
> beacon — a time-source no one, including the agent, can forge
> retroactively — and returns signed, hash-chained receipts that anyone
> can verify with zero trust in nouli. **Proof of Existence is the
> product**; the receipt contains the proof information on every call.

nouli binds records to the public drand quicknet beacon — a
time-source no one, including the agent, can forge retroactively —
signs every output with Ed25519, and chains every receipt. No
accounts, no API keys: calls are free under per-IP caps, then paid
per call over x402 (USDC; the current deployment settles on
Base mainnet, eip155:8453 — the 402 response names the live network,
asset, and amount). Every response is a **receipt** — the auditable
deliverable: sources, time, payment, and how to verify, all inside.
Optional prepaid lane (when the operator opened it): deposit USDC
once, claim a bearer key (noul_…), and draw from your balance at
bulk rates ($0.001–0.002 per call; min deposit $25.00 per claim) — no
per-call settlement; x402 per call stays the default.

## Proof of Existence (anchor) — "this existed, at or before this point"

- [POST /v1/anchor](https://nouli.dev/v1/anchor): the headline product —
  bind up to 1,024 of your own bytes to the public beacon and get back
  instant, verifiable proof that the data existed and entered the mix at
  the cited round. For agents journaling milestones, decisions, and
  state; content provenance; commit-before-dispute in multi-agent
  coordination; compliance logging — and instant, verifiable proof of
  fairness for raffles, sweepstakes, tournaments, audits. $0.05,
  paid-only; your bytes are cited digest-only (hash larger data
  client-side first). Honest limits: the mix and the cited round verify
  with zero trust in nouli; when the box saw your data is attested by
  the box, made tamper-evident by the public chain below — a receipt
  proves what was recorded, not that everything was; the chain makes
  gaps visible, not impossible.

## Impartial tie-breaking (flip) — a fair bit that comes with proof

- [GET /v1/flip](https://nouli.dev/v1/flip): one fair bit of the
  standard output — a decision no stakeholder can accuse you of
  rigging, and the receipt IS the proof of fairness that comes with
  it, not a courtesy artifact. $0.02, paid-only. For a fully
  verifiable tie-break: anchor the candidate list first, then flip
  the next round — commit, then reveal.

## Verifiable randomness (receipt) — the free utility facet

- [GET /v1/receipt](https://nouli.dev/v1/receipt): one 256-bit
  verifiable randomness receipt — free under cap (30 receipts/min
  burst, 300 receipts/day per IP), $0.02 over cap on the same route.
  Raw verifiable entropy, and the receipt shape every offering
  delivers.

## The public chain surface — check tamper-evidence yourself

- [GET /v1/chain/head](https://nouli.dev/v1/chain/head): the chain
  head — one digest that commits to the whole chain; it moves with
  every append, so watching it over time makes retroactive rewriting
  detectable by anyone
- [GET /v1/receipt/{id}](https://nouli.dev/v1/receipt/01M4BZDMJ621FSG32AG31G0EWY):
  any receipt by its ULID id, served exactly as issued — a stranger
  verifies without prior custody of adjacent records

## MCP mirror

- [POST /mcp](https://nouli.dev/mcp): the same rail over the Model
  Context Protocol (streamable HTTP, stateless) — tools `nouli_receipt`
  (free-first, $0.02 over cap), `nouli_anchor` ($0.05), `nouli_flip`
  ($0.02); x402 payment rides the x402 MCP transport, and the caps are
  shared with HTTP.

## Docs

- [AGENTS.md](https://nouli.dev/AGENTS.md): the canonical agent doc —
  quickstart, the x402 payment flow end to end, caps and pricing, what
  degraded means, verification, and a worked Proof of Existence example
- [llms-full.txt](https://nouli.dev/llms-full.txt): the full text —
  AGENTS.md plus the endpoint reference, generated from openapi.json
- [openapi.json](https://nouli.dev/openapi.json): OpenAPI 3.1 — every
  endpoint (including the public chain surface) with its 402/429/503
  responses and receipt schemas
- [agent-card.json](https://nouli.dev/.well-known/agent-card.json):
  A2A discovery — the anchor listed as its own skill
- [docs](https://nouli.dev/docs): the human page — error meanings,
  paying, prohibited-use note
- [verify](https://nouli.dev/verify): verify any receipt in a browser,
  zero setup, nothing uploaded

## Optional

- Prepaid lane (opt-in, per box): deposit USDC once (address published
  live at [GET /v1/prepaid/deposit](https://nouli.dev/v1/prepaid/deposit);
  a closed box answers 404), claim a bearer API key via
  [POST /v1/prepaid/claim](https://nouli.dev/v1/prepaid/claim), then draw
  from your balance on the paid routes — same rail,
  no per-call settlement;
  [GET /v1/prepaid/balance](https://nouli.dev/v1/prepaid/balance) reports
  the account's standing
- [nouli-keys.json](https://nouli.dev/.well-known/nouli-keys.json): the
  append-only Ed25519 signing keys verifiers check against
- [gumball.store](https://gumball.store): nouli is a gumball.store
  Solution — instantly-settled solutions agents buy without accounts