# 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 across 500+ indexed MCP servers and A2A tools to discover, validate, and proxy agent-compatible capabilities with built-in prompt injection firewall

## Facts

- Endpoint: POST https://defi-yield.agentdiet.dev/v1/security-audit-dag?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-4efdb433
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_m-Pb4DRomtgdD4rXqIoWf

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-4efdb433 -d '<json body>'
```

Example prompt: Search the MCP and A2A tool index for any available capabilities related to 'context compression' and return the best matching endpoints with their metadata.

## 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, rather than hard-coding specific tool URLs. It is especially valuable when building swarm agents that need to route tasks to specialized tools, when you want a single connection point to 500+ tools, or when you need token-efficient capability discovery with built-in prompt injection protection. Prefer over manual MCP registry browsing or custom tool routing logic.

## Known failure modes

- Empty or vague query returns low-relevance or no results
- Query matches no indexed tools — empty result set returned
- Rate limiting or payment failure (HTTP 402) if x402 micropayment not completed
- Prompt-Guard firewall may suppress results it classifies as injection-risk
- Indexed tool may be offline or unreachable despite being listed
- Malformed query (minLength:1 not met) returns validation error

## 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/security-audit-dag)

## Output

A token-compressed (up to 85% reduction) list of matching MCP servers or A2A tools from the 500+ indexed registry, including capability metadata, endpoint URLs, and security-filtered responses passed through the Prompt-Guard firewall. Results indicate which tools match the query and relevant routing details.

## 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-4efdb433/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)