# Agent Tool Router + Trust Layer

> Agent Tool Router + Trust Layer is a paid API for AI agents from mcp.dropenginehq.com, paid per call via x402, $0.002/call, status unknown (last checked 2026-10-02).

Finds, ranks, and recommends machine-payable services for a given agent capability query, applying price, latency, and quality constraints.

## Facts

- Endpoint: POST https://mcp.dropenginehq.com/api/route-tool?utm_source=zero.xyz
- Price: $0.002/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-02
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agent-tool-router-trust-layer-ee5eac45
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_dvjX2ZHoBuYbJZZtjDgA2

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-tool-router-trust-layer-ee5eac45 -d '<json body>'
```

Example prompt: Find me the best machine-payable service for crypto price lookups — optimize for speed, keep it under $0.005 per call, and make sure it has at least a 95% success rate.

## When to prefer this

Use this endpoint when an AI agent needs to dynamically discover and select the best machine-payable API for a given capability at runtime, especially when multiple competing services exist and you want constraint-based filtering (price, latency, reliability) plus optimization preferences. Prefer this over hardcoding service URLs when building adaptive agentic workflows that should route to the cheapest, fastest, or highest-quality provider automatically.

## Known failure modes

- No matching service found for the requested capability (match_found: false, recommended: null)
- All candidates filtered out by constraints (candidates_after_filters: 0)
- Registry sources unavailable, returning degraded response
- Invalid capability name format (must match ^[a-zA-Z][a-zA-Z0-9_.-]*$)
- Query string exceeds 300 character limit
- Price or latency constraints out of valid range

## How this service works

Finds and ranks machine-payable services for an agent capability.

## Output

Returns a JSON object indicating whether a matching service was found, the recommended service endpoint with its details, a list of alternative candidates, routing reasons explaining the recommendation, the number of candidates found and filtered, registry sources queried, and whether the result is cached or degraded.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "query": {
   "type": "string",
   "maxLength": 300
  },
  "capability": {
   "type": "string",
   "pattern": "^[a-zA-Z][a-zA-Z0-9_.-]*$",
   "maxLength": 80,
   "minLength": 2
  },
  "constraints": {
   "type": "object",
   "properties": {
    "max_price_usd": {
     "type": "number",
     "maximum": 1000000,
     "minimum": 0
    },
    "max_latency_ms": {
     "type": "integer",
     "maximum": 600000,
     "minimum": 1
    },
    "min_success_rate": {
     "type": "number",
     "maximum": 1,
     "minimum": 0
    }
   },
   "additionalProperties": false
  },
  "preferences": {
   "type": "object",
   "properties": {
    "optimize_for": {
     "enum": [
      "cheapest",
      "fastest",
      "quality",
      "reliability",
      "balanced"
     ],
     "type": "string"
    }
   },
   "additionalProperties": false
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "cached": false,
  "success": true,
  "degraded": true,
  "capability": "crypto_price",
  "checked_at": "2026-01-01T00:00:00.000Z",
  "match_found": false,
  "recommended": null,
  "alternatives": [],
  "routing_reason": [],
  "candidates_found": 0,
  "registry_sources": [
   "local_registry"
  ],
  "candidates_after_filters": 0
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agent-tool-router-trust-layer-ee5eac45/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mcp.dropenginehq.com](https://www.zero.xyz/host/mcp.dropenginehq.com/llms.txt)