# 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 defi-yield.agentdiet.dev, paid per call via MPP, $0.01/call, status unknown (last checked 2026-10-23).

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

## Facts

- Endpoint: POST https://defi-yield.agentdiet.dev/v1/broker/catalog?utm_source=zero.xyz
- Price: $0.01/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-23
- Activations on Zero: 0
- Provider: defi-yield.agentdiet.dev
- Website: https://defi-yield.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/defi-yield-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-4e562466
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_q0AQ4Tt--QTUfXSci3J9-

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 defi-yield-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-4e562466 -d '<json body>'
```

Example prompt: Search the MCP and A2A tool catalog for servers that can handle SEC filings and company enrichment — I need to find the right tool to connect my agent to.

## When to prefer this

Choose this endpoint when an agent needs to dynamically discover which MCP server or A2A tool to invoke for a given capability, rather than hard-coding tool endpoints. Especially useful for swarm orchestration scenarios where the right downstream tool is not known in advance, or when you want a single compressed, firewall-screened catalog instead of querying hundreds of individual registries.

## Known failure modes

- Empty query string returns validation error
- Query matches no indexed tools, returning empty result set
- Downstream MCP server unavailable causing partial catalog results
- Rate limiting or payment failure via x402 returning 402 status
- Malformed idempotency key header causing request rejection

## 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://defi-yield.agentdiet.dev/v1/broker/catalog)

## Output

Returns a catalog of matching MCP servers and A2A tools relevant to the query, with 85% token-compressed metadata describing each tool's capabilities, endpoint URLs, and safety status as filtered by the 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/defi-yield-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-4e562466/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from defi-yield.agentdiet.dev](https://www.zero.xyz/host/defi-yield.agentdiet.dev/llms.txt)