ListSmith
Grades and repairs x402 discovery metadata. /v1/grade scores one route's Bazaar extension (both SDK validators, schema quality, description traps); /v1/fix returns a complete repaired extension package that passes both validators. Use when a listing is hollow, invalid, or not converting.
1 of 2 routes settlement-verified · $0.1–$0.5 USDC/request · 2 endpoints · Verification · base network · x402 protocol
Verified routes
POST /v1/grade· $0.1 · 2026-10-26 · receipt
Other routes are unverified.
Networks: Base (settlement-verified)
Discovery is free. Agents search the catalogue here. Payment happens on the listing 402, not on PayAPI.
url https://payapi.market/mcpListing facts
- Provider
- Verdict Row
- Hosted at
list-smith-production.up.railway.app- Category
- Verification
- Price
- $0.1 to $0.5 USDC per request
- Endpoints
- 2
- Payment networks
- Base
- Settlement-verified
- 1 route, last checked 2026-10-26
- Listed on PayAPI Market
- 2026-10-25
Try ListSmith
Call a verified route without paying first. The server should answer HTTP 402 Payment Required with the price, the USDC asset, the network and the wallet to pay. An x402 client pays that amount on Base and retries with the payment header.
curl -i -X POST "https://list-smith-production.up.railway.app/v1/grade"About this API
ListSmith is listed in the Verification category with pricing at $0.1–$0.5 USDC/request. One route has been settlement-verified by PayAPI Market on 2026-10-26. View receipt on Basescan.
Payments settle on base in USDC via the x402 protocol. AI agents discover this API through the PayAPI Market MCP server and pay per request without API keys or accounts.
This API exposes 2 endpoints. Only the verified route has been tested by PayAPI Market. Other routes are unverified.
Questions about this API
What does ListSmith do?
Grades and repairs x402 discovery metadata. /v1/grade scores one route's Bazaar extension (both SDK validators, schema quality, description traps); /v1/fix returns a complete repaired extension package that passes both validators. Use when a listing is hollow, invalid, or not converting. It is provided by Verdict Row.
How much does ListSmith cost?
ListSmith is priced at $0.1 to $0.5 USDC per request, paid per call with no subscription. PayAPI Market paid 0.1 USDC for one call to /v1/grade when it verified the listing. The exact amount for each call is in the HTTP 402 response before any money moves.
Do I need an API key or account to use ListSmith?
No. ListSmith uses the x402 protocol, so an agent pays per request in USDC on Base and gets the response, with no API key, account or signup.
Has ListSmith been verified?
Yes, 1 route of its 2 endpoints. PayAPI Market paid for a real call from its own wallet, received real data back and recorded the USDC settlement on-chain, most recently on 2026-10-26. Routes that were not paid for are unverified.
How does an AI agent find ListSmith?
Through the free PayAPI Market MCP server at https://payapi.market/mcp, using search_apis or get_api, or over plain HTTP at https://payapi.market/agent/search. Discovery is free; the agent pays the provider directly on the listing's own 402.
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