# Agent Tools API Lookup

> Agent Tools API Lookup is a paid API for AI agents from agent-tools.faling-bot.workers.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-31).

Looks up API documentation, authentication methods, base URLs, key endpoints, and rate limits for any named API or domain

## Facts

- Endpoint: POST https://agent-tools.faling-bot.workers.dev/api/api-lookup?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-31
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-tools-api-lookup-dbf5d46f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RvEKw8CK7jUiaSyVSbuL8

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 agent-tools-api-lookup-dbf5d46f -d '<json body>'
```

Example prompt: Look up the Stripe API for me — I need its base URL, authentication method, key endpoints, and rate limits, specifically focused on how to create a payment.

## When to prefer this

Choose this endpoint when an AI agent needs to dynamically discover how to call an unfamiliar API — especially its auth method, base URL, and key endpoints — without requiring a human to supply documentation. Ideal for zero-setup agentic workflows where the agent must self-configure integrations on the fly. Less appropriate when the target API's docs are already embedded in the agent's context or when you need live API call execution rather than documentation lookup.

## Known failure modes

- Unknown or obscure API name returns empty or partial fields
- Docs URL is outdated or the API has no public documentation
- Rate limit or auth info not publicly documented results in null fields
- Mismatched API name (e.g. ambiguous brand names) returns info for wrong API
- Payment fails or x402 protocol not supported by caller results in 402 error with no data returned

## How this service works

Pay-per-call web tools for AI agents. No signup, no API key: pay USDC on Base or Solana per request via x402.

## Output

Returns a structured object containing the API's base URL, OpenAPI spec URL, llms.txt URL, authentication details, key endpoints list, rate limit information, error documentation, and source references — giving an agent everything it needs to start calling the target API.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "api": {
   "type": "string",
   "description": "API name, domain or docs URL"
  },
  "question": {
   "type": "string",
   "description": "optional focus, e.g. 'how to create a payment'"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "api": {
   "type": "string"
  },
  "auth": {
   "type": "string"
  },
  "errors": {
   "type": "string"
  },
  "sources": {
   "type": "array"
  },
  "base_url": {
   "type": "string"
  },
  "openapi_url": {
   "type": "string"
  },
  "rate_limits": {
   "type": "string"
  },
  "llms_txt_url": {
   "type": "string"
  },
  "key_endpoints": {
   "type": "array"
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-tools-api-lookup-dbf5d46f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agent-tools.faling-bot.workers.dev](https://www.zero.xyz/host/agent-tools.faling-bot.workers.dev/llms.txt)