# 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 2026-10-21).

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

## Facts

- Endpoint: GET https://defi-yield.agentdiet.dev/v1/a2a-mesh?utm_source=zero.xyz
- Price: $0.01/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- 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-de06dba7
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_l0Ggt33HE4BO8oOoioGDW

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-de06dba7
```

Example prompt: Search the A2A mesh index for MCP tools that handle SEC filings retrieval and return me the best matching endpoints I can connect to.

## When to prefer this

Use this endpoint when an AI agent needs to dynamically discover and connect to MCP servers or A2A tools without maintaining individual integrations, especially when token efficiency matters (85% compression) or when routing untrusted queries that require prompt-injection protection. Prefer this over direct MCP connections when the specific tool endpoint is unknown and needs to be searched.

## Known failure modes

- Empty or vague query returns no matching tools
- Queried capability not yet indexed returns empty result set
- Downstream MCP server unreachable causes proxy failure
- Prompt-Guard firewall blocks query flagged as injection attempt
- HTTP 402 payment required if x402 micropayment not provided

## 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/a2a-mesh)

## Output

Returns a list of matching MCP servers or A2A tools from the 500+ indexed catalog, including tool metadata, connection details, and token-compressed descriptions, filtered through the Prompt-Guard firewall to prevent prompt injection.

## 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-de06dba7/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)