# DeadDrop

> One-time secret sharing API. POST an encrypted secret, get a link that
> self-destructs after a single read. Zero-knowledge: the server stores only
> ciphertext; the AES-256-GCM key rides in the URL fragment and never reaches
> the server. No accounts, no API keys - machines pay per call in USDC on
> Base via the x402 protocol (HTTP 402).

Base URL: https://deaddrop.jerrywrongalot.workers.dev

## Paid endpoint ($0.01 in USDC per call, x402 "exact" scheme, network "base")

POST /secret
- Request body: {"ciphertext": "<base64url(iv || AES-256-GCM bytes)>", "ttlSeconds": 86400}
- ciphertext max 90000 chars; ttlSeconds optional (default 86400, max 604800).
- Unpaid response: HTTP 402 with an x402 challenge in the body ("accepts").
  Any x402 client (e.g. x402-fetch) handles it: sign the EIP-3009
  authorization for the challenge amount and retry with the X-PAYMENT header.
  The payer needs USDC on Base but no ETH (gasless for the payer).
- Paid response: 201 {"id", "expiresAt", "revealPath"} plus an
  X-PAYMENT-RESPONSE receipt header (base64 JSON, on-chain tx).
- Share as: https://deaddrop.jerrywrongalot.workers.dev/s/<id>#<base64url AES key> - keep the fragment
  client-side; whoever holds the full link can read the secret once.

## Free endpoints (recipients need no wallet)

- GET /s/:id - metadata (JSON) or the human reveal page (HTML). NEVER
  consumes the secret, so link previews cannot burn it.
- POST /s/:id/reveal - returns {"ciphertext"} exactly once, then the secret
  is destroyed. 404 when already read or expired.
- GET / - service description (JSON for non-HTML clients).
- GET /healthz - health check.

## Notes for agents

- Decrypt client-side: base64url-decode, first 12 bytes are the AES-GCM IV,
  the rest is ciphertext; the key is the link fragment.
- Rate limit: 30 requests per 60 s per IP on the secret routes.
- Nothing is charged unless the secret is stored (verify-before-work,
  settle-after-success).
- Security policy: https://deaddrop.jerrywrongalot.workers.dev/.well-known/security.txt