# 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 mcp-compiler.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-screened tool recommendations via a single connection.

## Facts

- Endpoint: GET https://mcp-compiler.agentdiet.dev/v1/agent-tool-marketplace?utm_source=zero.xyz
- Price: $0.01/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: mcp-compiler.agentdiet.dev
- Website: https://mcp-compiler.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/mcp-compiler-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-456e30e8
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_4qA3WR7aOZ_dEQyyqTq1E

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 mcp-compiler-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-456e30e8
```

Example prompt: Search the agent tool marketplace for MCP servers or A2A tools that can do 'company enrichment' — I need the best available options with compressed descriptions so I can pick one to wire into my workflow.

## When to prefer this

Choose this endpoint when you need to dynamically discover which MCP server or A2A tool can fulfill a capability at runtime, rather than hardcoding a specific tool. It is especially valuable in swarm or meta-agent architectures where the right downstream tool is not known in advance, or when you want a single firewall-protected entry point that indexes hundreds of tools with token-compressed responses.

## Known failure modes

- Empty or missing 'query' parameter returns a validation error
- No matching tools found for obscure or overly narrow queries
- Prompt-Guard firewall may reject queries that resemble injection attempts
- Upstream MCP server index may have stale or outdated entries
- x402 payment failure if wallet balance is insufficient for the $0.01 call fee

## 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://mcp-compiler.agentdiet.dev/v1/agent-tool-marketplace)

## Output

Returns a compressed, token-efficient list of matching MCP servers and A2A tools from a 500+ item index, including capability descriptions, endpoint metadata, and safety-screened results via the integrated Prompt-Guard firewall.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "required": [
  "query"
 ],
 "properties": {
  "query": {
   "type": "string",
   "minLength": 1,
   "description": "Capability search query (e.g. 'context compression', 'github security', 'sec filings', 'company enrichment') or endpoint URL to verify"
  }
 }
}
```

## Response schema (JSON Schema)

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

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/mcp-compiler-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-456e30e8/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mcp-compiler.agentdiet.dev](https://www.zero.xyz/host/mcp-compiler.agentdiet.dev/llms.txt)