# 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 and routes across 500+ indexed MCP servers and A2A tools via a single connection, with token compression and prompt-injection firewall protection.

## Facts

- Endpoint: GET https://workflows.agentdiet.dev/v1/b2a-router?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-af2bcfa6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_QnlnYOHkjrrDmm-wO55h9

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-af2bcfa6
```

Example prompt: Search the MCP and A2A tool index for servers that handle 'context compression' — I need to find available tools I can route my agent through for that capability.

## When to prefer this

Choose this endpoint when an AI agent needs to dynamically discover which MCP server or A2A tool supports a given capability at runtime, rather than hardcoding tool URLs. Especially useful when building swarm routers, orchestrators, or meta-agents that must select from a broad catalog of 500+ tools with minimal token overhead.

## Known failure modes

- Empty query string returns a validation error (query is required, minLength 1)
- Query matches no indexed tools — empty result set returned
- Upstream MCP server index temporarily unavailable — may return 503 or degraded results
- x402 payment not fulfilled — returns HTTP 402 requiring $0.01 USDC payment
- Prompt-Guard firewall blocks query containing suspected injection payload

## 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/b2a-router)

## Output

Returns a list of matching MCP servers and A2A tools relevant to the query, with token-compressed metadata and Prompt-Guard safety filtering applied, enabling the calling agent to discover and route to the appropriate downstream capability.

## 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-af2bcfa6/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)