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

Searches 500+ indexed MCP servers and A2A tools by capability query, returning compressed, firewall-filtered tool matches via a single meta-router endpoint.

## Facts

- Endpoint: GET https://onchain-risk.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: onchain-risk.agentdiet.dev
- Website: https://onchain-risk.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/onchain-risk-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-90631207
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_j42M4gL9OM2qOWyVDsWdR

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 onchain-risk-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-90631207
```

Example prompt: Search the MCP and A2A tool marketplace for available tools that handle SEC filings and financial intelligence — I want to see what's indexed and available to call.

## When to prefer this

Use this endpoint when an AI agent needs to dynamically discover available MCP servers or A2A tools by capability rather than hardcoding tool URLs. Ideal for swarm orchestration, dynamic tool selection, and agent bootstrapping scenarios where the full ecosystem of available tools is unknown. Prefer over manual tool registries when token efficiency and prompt-injection safety (via Prompt-Guard firewall) are required.

## Known failure modes

- Empty query string returns validation error
- No matching tools found for obscure capability queries returns empty result set
- Endpoint URL verification may return unverified status if URL is not indexed
- Rate limiting or payment failure (x402) blocks request
- Firewall (Prompt-Guard) may flag and block adversarial queries

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

## Output

Returns a compressed, firewall-filtered list of matching MCP servers or A2A tools from a 500+ entry index, including tool metadata, endpoint URLs, capability descriptions, and SLA/compliance signals. Token usage is reduced by approximately 85% versus raw tool manifests.

## 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/onchain-risk-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-90631207/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from onchain-risk.agentdiet.dev](https://www.zero.xyz/host/onchain-risk.agentdiet.dev/llms.txt)