Specialist API · portfolio item 03

Check an online product listing before you publish it

Automated listing preflight service. An agent or client submits a draft listing; the service returns a structured score out of 100, PASS / WARNING / FAIL checks, missing information and prioritised recommendations. Marketplace rules are currently prototype logic and are not official marketplace guidance. Paid API calls use x402.

Open preflight demo →Service dashboard

Endpoints

GET · JSON · free and x402-metered

GET/api/public/preflight

Run a full preflight assessment against the general profile (or pass ?platform=).

query / path params

platform, title, description, price, currency, category, keywords, features, imageCount, shipping, returns

example

/api/public/preflight?platform=general&title=Pour%20Over%20Kettle%201L&price=34.99

GET/api/public/preflight/{platform}

Platform-scoped preflight. Adds simulated marketplace-specific checks on top of the core checks.

query / path params

platform path segment: general | amazon | etsy | shopify | tiktok

example

/api/public/preflight/amazon?imageCount=6&keywords=gooseneck%20kettle,coffee%20kettle

GET/api/public/preflight-price/{platform}

Free price check. Returns the indicative price and payment details without creating a quote.

query / path params

same listing fields · strict=1 refuses missing fields

example

/api/public/preflight-price/shopify?strict=1&title=...

GET/api/public/paid-preflight/{platform}

x402-metered preflight. Returns 402 with an x402 payment challenge; retry with X-PAYMENT. The active payment network and asset are published at /api/public/pricing (Base Sepolia test-USDC rail proven end to end; live mainnet payment configuration is enabled).

query / path params

listing fields · strict=1 · headers: X-PAYMENT, Idempotency-Key

example

/api/public/paid-preflight/shopify?strict=1&title=...

GET/api/public/pricing

Machine-readable price, network, asset, limits, retry steps and discovery links.

query / path params

none

example

/api/public/pricing

GET/.well-known/x402 · /openapi.json · /llms.txt

Agent discovery: x402 manifest, OpenAPI description and a plain-language agent guide. Error codes at /errors.

query / path params

none

example

/.well-known/x402

Platform profiles

simulated marketplace rule sets

Generalgeneral
Baseline marketplace-agnostic checks only.
Amazonamazon
Demo rules approximating Amazon-style title length, bullet count and image expectations.
Etsyetsy
Demo rules approximating Etsy-style tag counts, handmade/materials detail and photo depth.
Shopifyshopify
Demo rules approximating own-store SEO needs: meta-length title, rich copy, policy clarity.
TikTok Shoptiktok
Demo rules approximating TikTok Shop short-form title, price point and media expectations.

Response shape

abridged

200 application/json

{
  "api": "product-listing-preflight",
  "version": "0.3.0-poc",
  "mode": "live",
  "platform": "amazon",
  "score": 82,
  "verdict": "NEEDS_WORK",
  "counts": { "pass": 9, "warning": 3, "fail": 0 },
  "checks": [
    {
      "id": "title.present",
      "label": "Title present",
      "scope": "core",
      "status": "PASS",
      "weight": 12,
      "detail": "Title is 63 characters."
    }
  ],
  "missingInformation": [],
  "recommendations": ["Images supplied: Demo threshold: 4+ images..."],
  "keywordObservations": { "count": 5, "unique": 5, "inTitle": ["coffee kettle"] },
  "summary": "Preflight scored 82/100 ..."
}

Scope & roadmap

· Rule data lives in an isolated engine module, so real UK and marketplace policy rules can replace the demo thresholds without changing the API contract.
· Checks are weighted; the score is the weighted proportion of passes (warnings count as half).
· Metered pay-per-call access via x402: the Base Sepolia test-USDC rail was proven end to end with three on-chain settlements, and live Base mainnet payment configuration is enabled. Marketplace checks remain prototype logic, not official marketplace guidance.
· Live Base mainnet payment configuration is enabled, and terms, refunds and contact information are published.
· Planned, not built: API keys, rule versioning, bulk submission.

All figures, thresholds and marketplace behaviours shown anywhere in this console are simulated for demonstration and are not official guidance.