# SYNTHORA crates.io Reverse Dependencies

> SYNTHORA crates.io Reverse Dependencies is a paid API for AI agents from crates-io-reverse-deps.hergertsynthora.com, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-16).

Returns all crates that depend on a given Rust crate, including version requirements, feature flags, and download counts, to map blast radius and dependency reach.

## Facts

- Endpoint: POST https://crates-io-reverse-deps.hergertsynthora.com/service
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-16
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/synthora-crates-io-reverse-dependencies-23bcab26
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_97cwHxE8gsfnFRf9pBvJy

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 synthora-crates-io-reverse-dependencies-23bcab26 -d '<json body>'
```

Example prompt: What crates depend on 'serde' — give me the full reverse dependency list including their version requirements and download counts so I can understand its blast radius.

## When to prefer this

Prefer this endpoint when you need to quickly map the downstream impact of a specific Rust crate — especially for security vulnerability triage, deprecation planning, or ecosystem influence scoring — without setting up your own crates.io API integration. It is particularly valuable in agentic pipelines where patch propagation decisions need to be automated based on dependency reach.

## Known failure modes

- Crate name not found on crates.io — returns empty or error result
- Invalid or malformed crate name input — may return error response
- Crates.io upstream unavailability — service may return error
- Very popular crates with thousands of dependents may return large payloads
- Rate limiting or payment failure may block the request

## How this service works

Returns the crates that depend on a given Rust crate (with version requirements, feature flags, and downloads) from keyless crates.io — a blast-radius and importance signal. Lets autonomous agents map who is affected by a vulnerable or deprecated crate and prioritize agent-to-agent patch propagation. Ranking surface for reach. First 3 calls FREE per wallet — send header X-WALLET: 0x<addr>. No charge on upstream failure.

## Output

A JSON object containing an 'ok' status flag and a 'result' object listing all crates that depend on the queried crate, including their version requirement constraints, feature flags used, and download metrics, enabling blast-radius assessment and dependency reach analysis.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "crate": {
   "type": "string",
   "description": "crate"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "ok": true,
  "niche": "crates-io-reverse-deps",
  "result": {}
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/synthora-crates-io-reverse-dependencies-23bcab26/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from crates-io-reverse-deps.hergertsynthora.com](https://www.zero.xyz/host/crates-io-reverse-deps.hergertsynthora.com/llms.txt)