# 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 shopify-spy.agentdiet.dev, paid per call via MPP, $0.01/call, status unknown (last checked 2026-10-21).

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

## Facts

- Endpoint: GET https://shopify-spy.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: shopify-spy.agentdiet.dev
- Website: https://shopify-spy.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/shopify-spy-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-22b667e0
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_5U-sG6_Cf9yTdM5ZDn9lA

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 shopify-spy-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-22b667e0
```

Example prompt: Search the agent tool marketplace for MCP servers and A2A tools that can do 'company enrichment and B2B lead data' — I want to find which tools are available and how to connect to them.

## When to prefer this

Choose this endpoint when an AI agent needs to dynamically discover which MCP servers or A2A tools exist for a given capability at runtime, rather than hardcoding tool lists. Especially useful for swarm orchestrators, agent-builder frameworks, or meta-agents that need to route subtasks to specialized tools on demand. Prefer over manual tool catalogs when you need token-compressed results or prompt-injection-safe tool metadata.

## Known failure modes

- Empty query string returns validation error (query is required, minLength 1)
- No matching tools found for an obscure or misspelled capability query returns empty result set
- Payment required error (HTTP 402) if x402 micropayment of $0.01 USDC not provided
- Endpoint URL verification query for a URL not in the index returns not-found result
- Index may be stale if a newly added MCP server has not yet been crawled

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

## Output

Returns a list of matching MCP server or A2A tool entries from the 500+ tool index, with endpoint metadata, capability descriptions, and token-compressed summaries. Results are filtered through the Prompt-Guard firewall to remove injected or malicious content before returning to the calling agent.

## 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/shopify-spy-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-22b667e0/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from shopify-spy.agentdiet.dev](https://www.zero.xyz/host/shopify-spy.agentdiet.dev/llms.txt)