Six flows. The mechanic that enforces every commitment.

# what your project signs · class C session_creation
{
  "v": 1,
  "kind": "oc-me-event",
  "id": "oc-me-9k2x4f7p",
  "class": "C",
  "subtype": "session_creation",
  "identity": "bc1q...e3lr",         // your user's oc identity
  "site": "yourcompany.com",          // your project domain
  "session_duration_seconds": 604800, // 7 days
  "occurred_at": "2026-04-30T16:11:08Z",
  "gross_fee_sats": 64,               // funded by your project
  "platform_fee_sats": 13,            // 20% to OC (charter §07)
  "user_earned_sats": 33,             // 65% of post-platform 80%
  "site_rebate_sats": 18,             // your residual
  "sig": "ed25519:2b:9pK4...rT8x"     // signed by OC on your behalf
}

# computeFees() · the canonical formula
//  in lib/events/types.ts (CI-tested, conformance-vector-locked)

const PLATFORM = 0.20;

function computeFees(cfg, payment_amount_sats?) {
  const gross = cfg.site_pays.kind === 'fixed_sats'
    ? cfg.site_pays.sats
    : Math.round(payment_amount_sats * cfg.site_pays.pct);

  const platform = Math.round(gross * PLATFORM);
  const post     = gross - platform;
  const user     = Math.round(post * cfg.user_share_pct);
  const rebate   = post - user;

  return { gross, platform, user, rebate };
}

// example · gross 1000, user_share 0.65
//   → platform 200, user 520, rebate 280

# the federation descriptor · published per-user
{
  "v": 1,
  "identity": "bc1q...e3lr",
  "signing_method": "federation_threshold",
  "guardian_set_id": "fed11qgqrgvnhwd...",
  "threshold": "5-of-7",
  "graduation_path": [
    "stay-federation",
    "graduate-to-fedimint",
    "graduate-to-self-custody"
  ]
}

# after /me/graduate · same identity, new method
{
  "v": 1,
  "identity": "bc1q...e3lr",        // unchanged
  "signing_method": "bip322",
  "graduated_at": "2026-05-15T09:21:00Z",
  "previous_method": "federation_threshold"
}

# oc_session JWT · what every consumer subdomain reads
{
  "alg": "EdDSA",
  "kid": "oc-auth-1",
  "sub": "did:btc:bc1q...e3lr",
  "addr": "bc1q...e3lr",
  "npub": "npub1...8q9w",
  "iat": 1714512000,
  "exp": 1715116800,
  "scope": ["identity", "payment"],
  "session_policy": {
    "duration_seconds": 604800,
    "refresh": "sliding"
  }
}

# JWKS published at ochk.io/.well-known/jwks.json
# verified locally · no ochk.io round-trip per request

# subtype → class mapping · in lib/events/types.ts
//  CI-tested · ratified · changeable only via spec PR

export const SUBTYPE_CLASS: Record<EventSubtype, EventClass> = {
  // Class A — state transitions
  account_creation:           'A',
  account_recovery:           'A',
  attest_bond_increased:      'A',
  payment_method_connected:   'A',
  agent_delegation_issued:    'A',
  recovery_method_updated:    'A',

  // Class B — action-bound
  payment_authorization:      'B',
  scoped_action_authorization:'B',
  attest_verification_at_gate:'B',
  stamp_signing:              'B',
  pledge_resolution:          'B',

  // Class C — sessions
  session_creation:           'C',
};

# verify any envelope offline · ~30 lines of node
import { ed25519 } from '@noble/curves/ed25519';
import { sha256 } from '@noble/hashes/sha256';
import { canonicalize } from '@orangecheck/me-client';

const envelope = await fetch('https://me.ochk.io/api/envelope/' + id).then(r => r.json());
const canonical = canonicalize(envelope);
const hash = sha256(new TextEncoder().encode(canonical));

// 1. OC signature · the load-bearing one
const ocJwks = await fetch('https://me.ochk.io/.well-known/oc-envelope-jwks.json').then(r => r.json());
const ocKey = ocJwks.keys.find(k => k.kid === envelope.kid);
const ocOk = ed25519.verify(parseSig(envelope.sig), hash, parseJwk(ocKey));

// 2. project co-signature · optional, OC-hosted (integrator hosts nothing)
const projectJwks = await fetch(`https://me.ochk.io/api/integrator/${envelope.project_key}/jwks.json`).then(r => r.json());
const projectOk = projectJwks.keys.length === 0
  ? null // project uses its HMAC secret · no co-sig to verify
  : ed25519.verify(parseSig(envelope.project_sig), hash, parseJwk(projectJwks.keys[0]));

// 3. ots proof → bitcoin
// $ ots verify envelope.ots
//   Success! Bitcoin block 879543 attests existence as of 2026-04-30 16:11:08 UTC

console.log({ projectOk, ocOk });