# 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 2026-10-23).

Searches and routes to 500+ MCP servers and A2A agent tools via a single connection, with token compression and prompt-injection firewall.

## Facts

- Endpoint: POST https://serp-extract.agentdiet.dev/v1/agent-tool-marketplace?utm_source=zero.xyz
- Price: $0.01/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-23
- 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-71992137
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_GxVuIfgppfLx_BHzCqdnW

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-71992137 -d '<json body>'
```

Example prompt: Search the agent tool marketplace for MCP servers that handle context compression — I want to find the best available tools for shrinking token usage in my agent pipeline.

## When to prefer this

Choose this endpoint when an AI agent needs to dynamically discover new tools or MCP servers at runtime rather than hardcoding integrations. Ideal for swarm orchestrators that need to find the best available tool for a given capability, or when you want a single connection point that abstracts away routing to 500+ servers with built-in prompt-injection protection and token compression.

## Known failure modes

- Empty or vague query returns no matches or low-relevance results
- Queried capability not indexed among the 500+ servers returns empty set
- Prompt-Guard firewall may block queries containing injection-like patterns
- Payment required (HTTP 402) if x402 credits are exhausted
- Malformed query (minLength not met) returns validation error
- Timeout if upstream MCP server probing is slow

## 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/agent-tool-marketplace)

## Output

Returns a list of matching MCP servers or A2A tools relevant to the query, with token-compressed descriptions, relevance scores, and routing metadata. The response includes tool capabilities, connection details, and safety/firewall status for each matched tool.

## 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/serp-extract-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-71992137/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)