# 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 an index of 500+ MCP servers and A2A tools by capability query, returning compressed, firewall-filtered results via a single meta-router connection.

## Facts

- Endpoint: GET https://serp-extract.agentdiet.dev/v1/a2a-router?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-2134e43c
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_i6LlVuBJEtFDWO4JdqzjR

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-2134e43c
```

Example prompt: Search the MCP and A2A tool index for servers that handle SEC filings or company enrichment, and give me the best matching tools with their compressed manifests.

## When to prefer this

Use this endpoint when an agent needs to dynamically discover which MCP server or A2A tool to call for a given capability, rather than hardcoding a tool. Ideal for agent orchestration layers, swarm routers, and meta-agents that need to find and safely proxy the right downstream tool at runtime. Prefer over manual tool catalogs when dealing with 500+ tool ecosystems where token budget and prompt injection safety matter.

## Known failure modes

- Empty or vague query returns no meaningful matches
- Queried endpoint URL is unreachable or non-compliant, returning an error status
- Index may not yet include newly registered MCP servers
- Token compression may omit edge-case capability details
- x402 payment failure results in 402 response before results are returned

## 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/a2a-router)

## Output

Returns a list of matching MCP servers or A2A tools ranked by relevance to the query, with 85% token-compressed capability manifests and Prompt-Guard firewall applied. If an endpoint URL is provided, returns verification and compliance status for that specific endpoint.

## 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-2134e43c/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)