Receipt demo

Last updated: 2026-10-13

A signed receipt from start to finish, using only free calls: get a receipt from a free example call, check it with POST /v1/receipt/verify, see a changed receipt fail, then check it offline. Step 5 adds the free trial on a real route. No payment, wallet or account is needed. The commands use curl and jq.

1. Get a receipt

GET /v1/sample/fetch runs the real fetch code on the example page and signs the result with the example key.

curl -s https://s2h6qt73jtzlgbgnnfacln2poq.srv.us/v1/sample/fetch > sample.json
jq '{tier, page: .page.http_status, kind: .page.content_kind, sha: .page.content_sha256}' sample.json
jq -r .receipt sample.json > receipt.txt

The response has the page result and a receipt field: a compact JWS (header.payload.signature). The receipt records the URL, final URL, status, content_kind, page hashes, time of the fetch and a hash of the request.

2. Check it

jq -n --rawfile r receipt.txt '{receipt: ($r | rtrimstr("\n"))}' > body.json
curl -s -X POST https://s2h6qt73jtzlgbgnnfacln2poq.srv.us/v1/receipt/verify -H 'Content-Type: application/json' -d @body.json

The answer:

{
  "valid": true,
  "kid": "https://s2h6qt73jtzlgbgnnfacln2poq.srv.us/.well-known/jwks.json#sample",
  "tier": "sample",
  "payload": {
    "v": 1,
    "iss": "https://s2h6qt73jtzlgbgnnfacln2poq.srv.us",
    "kind": "fetch",
    "tier": "sample",
    "url": "https://s2h6qt73jtzlgbgnnfacln2poq.srv.us/v1/sample/page",
    "http_status": 200,
    "content_kind": "real",
    "content_sha256": "0e429607…",
    "payment": null,
    "…": "…"
  }
}

payload.content_sha256 matches page.content_sha256 from step 1.

3. Change one character

jq -n --rawfile r receipt.txt '{receipt: ($r | rtrimstr("\n") | .[0:-2] + (if .[-2:-1] == "A" then "B" else "A" end) + .[-1:])}' > bad.json
curl -s -X POST https://s2h6qt73jtzlgbgnnfacln2poq.srv.us/v1/receipt/verify -H 'Content-Type: application/json' -d @bad.json

The answer has "valid": false and "reason": "bad_signature".

4. Check it offline

The offline checker is one Node.js file. It checks the receipt against the published keys at /.well-known/jwks.json without calling the verify route.

curl -sO https://s2h6qt73jtzlgbgnnfacln2poq.srv.us/dl/verify-receipt.mjs
node verify-receipt.mjs "$(cat receipt.txt)" --issuer https://s2h6qt73jtzlgbgnnfacln2poq.srv.us

5. Try a real route

For a receipt about a URL of your choice, call a paid route such as fetch. There is no free trial at the moment; use the free samples instead.

A free example receipt is signed with the example key and says nothing about any page other than the example page. Paid and trial receipts cover the URL you asked for. See free example calls, Verify a receipt and Payments.