Start with one public page.

1. Inspect without paying

curl "https://delta-witness-api.ruphussten.workers.dev/v1/quote?product=capture"
curl "https://delta-witness-api.ruphussten.workers.dev/v1/demo"

These are read-only GET requests. The current historical example has legacy_unverifiable integrity and not_anchored attestation. It shows the output format, not a completed request of your own.

You can also inspect an unsigned challenge. An HTTP 402 response is expected here; no capture has run:

curl -i "https://delta-witness-api.ruphussten.workers.dev/v1/capture" \
  -H "content-type: application/json" \
  -d '{"url":"https://example.com/"}'

A successful challenge is not paid-client compatibility. A real buyer flow also needs wallet authorization, settlement and completed delivery.

2. Choose a public source and review the quote

Use a URL that is public without a login. Do not submit credentials, session tokens, private portal links or personal data in URL parameters. DELTA does not share your current browser session.

Per request, paid in USDC on Base mainnet. No subscription. Opening a link does not make a payment. Review the current quote and authorize payment in your own wallet.

Your x402 client must validate the selected product, exact amount, Base network, canonical USDC asset and DELTA recipient before signing. A Capture-only approval must not become a Preflight or Pilot payment.

3. Keep the delivered record beside the decision

A completed Capture returns ok: true, proof_id, public_proof_url, manifest_url, bundle_root and observed_at. Save the response with your own decision ID, source URL and rationale. Keep the settlement evidence from your payment client separately.

Count delivery only when the response is a completed result with the expected proof fields. HTTP success alone is insufficient:

• 402: payment requirements, not a completed observation
• 202 / processing: still processing, not delivered
• 502 / retryable_failure: capture failed after the paid flow; resolve payment and delivery state before another authorization
• Timeout or malformed response: outcome unknown; do not blindly make a fresh payment

Idempotent replay requires the identical payment header and matching normalized request. Retain the original request/payment context. A newly signed payment may be a different paid request.

Optional: check a literal condition

Public Preflight costs 5 USDC. This is a request-shape example, not a live supplier result. Replace the illustrative URL and text with an authorized public source and your actual condition.

POST /v1/preflight
content-type: application/json

{
  "url": "https://example.com/",
  "expected": {
    "contains": ["Example Domain"],
    "excludes": ["Final sale"]
  }
}

Text checks are case-sensitive substring matches on captured Markdown. You can also compare expected hashes or a prior DELTA proof for the same URL. Inspect safe, changed, reason and diff; safe: true means your deterministic checks matched. With no comparison criteria, the result is unknown. DELTA does not authorize or execute the downstream action.

Optional: package up to three sources

The Guarded-Action Pilot costs 10 USDC for 1–3 public HTTPS URLs and at most one optional deterministic preflight. It returns separate proof references. It does not purchase, submit, or enforce a decision.

Use the OpenAPI schema for the exact Pilot input. This guide does not claim a verified paid integration or that current SDKs expose a Pilot method.

Integration references

• JavaScript client: paid methods require your own approved x402-capable fetch
• OpenAPI 3.1 · Agent skill · Postman collection
• Authenticated partner Capture, partner Preflight and each new Watch check cost 1 USDC under their separate prepaid partner flow. They are not the public Preflight route.