# 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 workflows.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 tool metadata routed through a Prompt-Guard firewall.

## Facts

- Endpoint: GET https://workflows.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: workflows.agentdiet.dev
- Website: https://workflows.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/workflows-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-076196bb
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_DxPyFY0-q11whbWh9tGM9

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 workflows-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-076196bb
```

Example prompt: Search the MCP tool marketplace for servers that can handle SEC filings or company enrichment — I need a tool my agent can call, and I want results compressed to save tokens.

## When to prefer this

Choose this endpoint when an AI agent needs to dynamically discover available MCP servers or A2A tools at runtime without hardcoding tool lists — especially valuable in swarm architectures where agents must self-select capabilities, when token budget is tight (85% compression), or when safety screening of tool responses via Prompt-Guard is required before consumption.

## Known failure modes

- Empty results if query terms don't match any indexed tools
- Stale index if newly registered MCP servers haven't been crawled yet
- Payment failure (x402) if USDC balance is insufficient for the $0.01 per-call fee
- Ambiguous query returns broad unrelated results requiring query refinement
- Endpoint URL verification may return inconclusive if the target is unreachable

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

## Output

Returns a compressed list of matching MCP servers or A2A tools including their capabilities, endpoint metadata, and safety status — with up to 85% token reduction applied and Prompt-Guard firewall screening on results.

## 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/workflows-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-076196bb/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from workflows.agentdiet.dev](https://www.zero.xyz/host/workflows.agentdiet.dev/llms.txt)