# Universal A2A & MCP Tool Discovery, Safe-Proxy & Swarm Router

> Universal A2A & MCP Tool Discovery, Safe-Proxy & Swarm Router is a paid API for AI agents from serp-extract.agentdiet.dev, paid per call via MPP, $0.01/call, status unknown (last checked 2026-10-21).

Searches a meta-index of 500+ MCP servers and A2A tools by capability query, returning matching endpoints with token-compressed results and prompt-injection firewall protection.

## Facts

- Endpoint: GET https://serp-extract.agentdiet.dev/v1/tool-broker?utm_source=zero.xyz
- Price: $0.01/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: serp-extract.agentdiet.dev
- Website: https://serp-extract.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/serp-extract-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-d9bc9ba7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_VoK7oLubG0budslQvZVOQ

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 serp-extract-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-d9bc9ba7
```

Example prompt: Search the MCP tool index for servers that handle 'SEC filings' and return the best matching endpoints I can route to.

## When to prefer this

Choose this endpoint when an AI agent or orchestration system needs to dynamically discover which MCP servers or A2A tools are available for a given capability, rather than hardcoding tool URLs. Especially useful when building swarm architectures, when you need firewall-protected proxying of unknown external tools, or when token budget is constrained and you need compressed tool manifests. Prefer this over manual tool registries or static MCP configs when the tool landscape is evolving.

## Known failure modes

- Empty query string returns 400 validation error
- No matching tools found for obscure or misspelled capability queries
- Endpoint URL verification may fail if target is offline or non-compliant
- Payment required (HTTP 402) if x402 micropayment header is missing or insufficient
- Rate limiting if too many queries are issued in rapid succession

## How this service works

Single-connection meta-router indexing 500+ MCP servers & A2A tools with 85% token compression and Prompt-Guard firewall. (Live x402 v2, IETF MPP & MCP endpoint at https://serp-extract.agentdiet.dev/v1/tool-broker)

## Output

A token-compressed list of matching MCP servers or A2A tools relevant to the query, including endpoint metadata, capability descriptions, compliance flags from the Prompt-Guard firewall, and routing recommendations — all compressed to reduce token overhead by up to 85%.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "query"
 ],
 "properties": {
  "limit": {
   "type": "integer",
   "default": 20,
   "maximum": 100,
   "minimum": 1,
   "description": "Maximum number of items to return per page (1-100)"
  },
  "query": {
   "type": "string",
   "minLength": 1,
   "description": "Capability search query (e.g. 'context compression', 'github security', 'sec filings', 'company enrichment') or endpoint URL to verify"
  },
  "cursor": {
   "type": "string",
   "description": "Opaque pagination cursor for fetching the next page"
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "object"
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/serp-extract-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-d9bc9ba7/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from serp-extract.agentdiet.dev](https://www.zero.xyz/host/serp-extract.agentdiet.dev/llms.txt)