# FastX402 Crate Versions Lookup

> FastX402 Crate Versions Lookup is a paid API for AI agents from fastx402.tools, paid per call via x402, $0.003/call, status unknown (last checked 2026-10-27).

Returns all published versions of a Rust crate from crates.io, including version numbers, release dates, and yanked status.

## Facts

- Endpoint: GET https://fastx402.tools/crate-versions?utm_source=zero.xyz
- Price: $0.003/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-27
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/fastx402-crate-versions-lookup-381a7b90
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_gasQhTBwMFXxCXKzhdfEF

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 fastx402-crate-versions-lookup-381a7b90
```

Example prompt: What versions of the tokio crate are available on crates.io, and which ones have been yanked?

## When to prefer this

Use this endpoint when you need programmatic, pay-per-call access to Rust crate version history without setting up a crates.io API key or account. Ideal for AI agents that need to resolve dependency versions, audit yanked releases, or check release timelines on demand.

## Known failure modes

- Crate name not found on crates.io — returns empty or error response
- Invalid or misspelled crate name — no versions returned
- Payment failure via x402 — 402 response before data is served
- Rate limiting or upstream crates.io unavailability

## How this service works

200 pay-per-call tools for AI agents, from $0.001 per request in USDC on Base or Solana with x402. No account, no API key.

## Output

A JSON object containing the crate name and an array of version objects, each with a version number string (e.g. '1.0.210'), a boolean indicating whether it was yanked, and an ISO 8601 timestamp of when it was released.

## 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"
    },
    "queryParams": {
     "type": "object",
     "required": [
      "crate"
     ],
     "properties": {
      "crate": {
       "type": "string",
       "description": "Crate name"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object",
     "properties": {
      "crate": {
       "type": "string"
      },
      "versions": {
       "type": "array",
       "items": {
        "type": "object",
        "properties": {
         "num": {
          "type": "string"
         },
         "yanked": {
          "type": "boolean"
         },
         "released": {
          "type": "string"
         }
        }
       }
      }
     }
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "crate": "serde",
  "versions": [
   {
    "num": "1.0.210",
    "yanked": false,
    "released": "2024-09-19T18:45:32.123456+00:00"
   },
   {
    "num": "1.0.209",
    "yanked": false,
    "released": "2024-09-13T05:12:08.654321+00:00"
   },
   {
    "num": "1.0.208",
    "yanked": false,
    "released": "2024-08-29T19:34:51.111222+00:00"
   }
  ]
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/fastx402-crate-versions-lookup-381a7b90/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from fastx402.tools](https://www.zero.xyz/host/fastx402.tools/llms.txt)