# 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 capability query, routing requests through a compressed, prompt-injection-protected proxy

## Facts

- Endpoint: POST https://defi-yield.agentdiet.dev/v1/b2a-router?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-0570eb1b
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_1FPuFd-t5zxYZSiOFnIFB

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-0570eb1b -d '<json body>'
```

Example prompt: Search the MCP and A2A tool index for anything that can do company lead enrichment — I want to find available tools and route my request through a safe, compressed proxy.

## When to prefer this

Choose this endpoint when an agent needs to dynamically discover which MCP server or A2A tool can handle a specific capability without pre-wiring integrations, especially when token budget is constrained (85% compression) or when untrusted upstream content must be sandboxed through a prompt-injection firewall. Ideal for multi-agent orchestration, swarm routing, and exploratory tool discovery across a broad ecosystem of 500+ servers.

## Known failure modes

- No matching tools found for the given capability query — returns empty results or low-confidence matches
- Query too vague or too short — minLength:1 is enforced but ambiguous queries may return irrelevant tools
- Payment not accepted (HTTP 402) — x402 micropayment of $0.01 USDC required per call
- Upstream MCP server unavailable — proxy may time out or return partial results
- Prompt injection detected by Prompt-Guard firewall — response may be sanitized or blocked

## 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/b2a-router)

## Output

Returns a structured response identifying matching MCP servers or A2A tools for the queried capability, with compressed tool manifests (up to 85% token reduction) and prompt-injection firewall applied to all proxied responses.

## 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-0570eb1b/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)