# Verified Catalog Lookup > Verified Catalog Lookup is a paid API for AI agents from verified-catalog-lookup.withgrokbot.workers.dev, paid per call via x402, $0.02/call, status unknown (last checked 2026-10-10). Looks up x402 API endpoints for a given task at or under a price cap, returning reliability data from real paid receipts and known-answer pass/fail results. ## Facts - Endpoint: GET https://verified-catalog-lookup.withgrokbot.workers.dev/v1/lookup/paid?utm_source=zero.xyz - Price: $0.02/call - Payment: x402 - Status: unknown - Last checked: 2026-10-10 - Activations on Zero: 0 - Tags: x402 - Canonical page: https://www.zero.xyz/c/verified-catalog-lookup-22d70fd0 - Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_oJxxnXE66L3yqeFv5Q-KN Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently. ## How to call it through Zero Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`): ```sh zero fetch --capability verified-catalog-lookup-22d70fd0 ``` Example prompt: Find me up to 10 verified x402 endpoints for the 'web-search' task priced at $0.01 or less, showing 5 paid receipts each, so I can pick the most reliable one. ## When to prefer this Use this endpoint when an AI agent needs to discover and rank x402-compatible API services for a specific task with objective reliability evidence — real paid receipts and known-answer pass/fail — rather than relying on unverified listings. Prefer it over general API directories when budget constraints (max_price) matter and when agent decision-making depends on proven uptime and quality, not just advertised specs. ## Known failure modes - Missing required 'task' or 'endpoint' parameter returns an error — at least one must be provided - max_price out of range or malformed causes a validation error - n or limit outside 1-20 bounds returns an error - Payment not completed or insufficient USDC balance blocks access - No matching services found returns matched:0 with empty results array - Stale data flagged via stale:true on individual results if receipts are outdated ## How this service works Is an x402 endpoint reliable for task X at price <= Y? Facts from our own paid calls: receipts with settlement tx, delivered yes/no and a known-answer pass/fail. Pricing: 5 free lookups per client per UTC day, then HTTP 402 with an x402 payment requirement of $0.02 USDC on Base per lookup. Payment buys query access only. It never changes results, sort order, listings, check results or known-answer outcomes: free, paid and exempt lookups run the same code on the same data and get identical results. Not investment advice; we hold no customer funds. ## Output Returns a JSON object with the query parameters echoed, payment access metadata (tx hash, tier, charged USD), total matched count, and a results array where each entry includes service ID, endpoint URL, staleness flag, a list of paid receipt objects (tx, timestamp, quality pass/fail, delivered, charged USD), aggregate pass rate, and listed price. Also includes a 'facts_only' array and a payment policy statement confirming results are not influenced by payment status. ## Request schema (JSON Schema) ```json { "type": "object", "$schema": "https://json-schema.org/draft/2020-12/schema", "required": [ "input" ], "properties": { "input": { "type": "object", "required": [ "type", "method" ], "properties": { "type": { "type": "string", "const": "http" }, "method": { "enum": [ "GET" ], "type": "string" }, "headers": { "type": "object", "additionalProperties": { "type": "string" } }, "queryParams": { "type": "object", "properties": { "n": { "type": "string", "description": "paid receipts per service, 1-20 (default 5)" }, "ref": { "type": "string", "description": "where you found this lookup (optional, attribution only)" }, "task": { "type": "string", "description": "task name, e.g. web-search (see /v1/tasks); task or endpoint is required" }, "limit": { "type": "string", "description": "services returned, 1-20 (default 10)" }, "payer": { "type": "string", "description": "your 0x wallet (optional)" }, "client": { "type": "string", "description": "your agent or app name (optional)" }, "endpoint": { "type": "string", "description": "a service id or endpoint URL instead of a task" }, "max_price": { "type": "string", "description": "maximum listed price per call, USD, e.g. 0.01" } } } }, "additionalProperties": false }, "output": { "type": "object", "required": [ "type" ], "properties": { "type": { "type": "string" }, "example": { "type": "object" } } } } } ``` ## Response schema (JSON Schema) ```json { "type": "json", "example": { "query": { "n": 5, "task": "web-search", "limit": 10, "endpoint": null, "max_price_usd": 0.01 }, "access": { "tx": "0x...", "tier": "paid", "charged_usd": "0.02" }, "matched": 1, "results": [ { "id": "example-search", "stale": false, "endpoint": "https://example.com/search", "receipts": [ { "tx": "0x...", "time": "2026-10-02T18:48:42Z", "quality": "pass", "delivered": true, "charged_usd": "0.01" } ], "pass_rate": 1, "price_usd": "0.01" } ], "facts_only": [], "payment_policy": "Payment buys query access only. It never changes results, sort order, listings, check results or known-answer outcomes: free, paid and exempt lookups run the same code on the same data and get identical results." } } ``` ## More - Live health (JSON, refreshed every minute): https://www.zero.xyz/c/verified-catalog-lookup-22d70fd0/health.json - [Zero catalog index](https://www.zero.xyz/llms.txt) - [Other services from verified-catalog-lookup.withgrokbot.workers.dev](https://www.zero.xyz/host/verified-catalog-lookup.withgrokbot.workers.dev/llms.txt)