# AgentResolver — OpenAPI Select (Capability Routing)

> AgentResolver — OpenAPI Select (Capability Routing) is a paid API for AI agents from agentresolver.vercel.app, paid per call via x402, $0.005/call, status unknown (last checked 2026-09-18).

Given a goal and an OpenAPI spec URL, selects the best matching operation from that spec to fulfill the agent's intent.

## Facts

- Endpoint: POST https://agentresolver.vercel.app/api/openapi-select
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-18
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentresolver-openapi-select-capability-routing-1372fe0e
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Kw3-K9437V9UNA78aAp2L

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 agentresolver-openapi-select-capability-routing-1372fe0e -d '<json body>'
```

Example prompt: I have the goal 'retrieve the current weather for a city' and an OpenAPI spec at https://api.example.com/openapi.json — which operation in that spec should I call to accomplish it?

## When to prefer this

Use this endpoint when your agent has a natural language goal and a known OpenAPI spec URL and needs to programmatically identify which specific operation to invoke — particularly useful in multi-API orchestration, dynamic tool selection, or when the agent doesn't have the spec pre-loaded. Prefer over manual spec parsing or LLM-only reasoning when you need a fast, structured selection result backed by a dedicated routing service.

## Known failure modes

- specUrl is unreachable or returns non-OpenAPI content — service cannot parse the spec
- goal is too vague or ambiguous — match quality degrades or no confident selection is returned
- OpenAPI spec has no operation semantically close to the goal — may return a low-confidence or empty result
- malformed specUrl (not a valid URL) — request validation error
- payment not included or insufficient — 402 Payment Required response

## How this service works

Verify an x402 endpoint before paying: live payTo, USDC quote, network, asset, resource binding, TLS and endpoint safety for $0.001 on Base or Solana.

## Output

Returns the best-matching OpenAPI operation (path, method, and relevant details) from the provided spec that fulfills the stated goal, enabling the agent to know exactly which endpoint to call next.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "goal": {
   "type": "string",
   "maxLength": 600,
   "minLength": 1
  },
  "specUrl": {
   "type": "string",
   "pattern": "^https://",
   "maxLength": 500
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {}
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentresolver-openapi-select-capability-routing-1372fe0e/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from agentresolver.vercel.app](https://www.zero.xyz/host/agentresolver.vercel.app/llms.txt)