Auth

NIP-98

Kind 27235 in Authorization: Nostr <base64>.

Verified cheap-first: shape → kind → signature → ±60s → method → u → optional payload sha256.

{
  "kind": 27235,
  "created_at": 1764630000,
  "content": "",
  "tags": [
    ["u", "https://merchant.lacrypta.ar/api/coupons/mint"],
    ["method", "POST"],
    ["payload", "<sha256 hex of body>"],
    ["nonce", "k3f9xq2"]   // make the event unique — avoid replay
  ]
}

Without a unique tag, two identical requests in the same second hash to the same id. Second call → reason: "replay".

Bearer

Sign NIP-98 once → POST /api/auth/session → Authorization: Bearer <jwt> for 12 hours.

It is not more secure — it is fewer signatures. On a NIP-46 bunker, every NIP-98 is a round trip to the merchant's phone.

• Re-mint on any 401
• No logout — drop the token
• Rotate SESSION_JWT_SECRET to invalidate everything

Error reason values

expired · replay · url-mismatch · session-expired · session-invalid · malformed · missing · too-large