# Universal A2A & MCP Tool Discovery, Safe-Proxy & Swarm Router (RAG Context Sanitizer)

> Universal A2A & MCP Tool Discovery, Safe-Proxy & Swarm Router (RAG Context Sanitizer) is a paid API for AI agents from preflight.agentdiet.dev, paid per call via MPP, $0.01/call, status unknown (last checked 2026-10-21).

Searches and discovers MCP servers and A2A agent tools by capability query, returning token-compressed, firewall-filtered results across 500+ indexed endpoints.

## Facts

- Endpoint: GET https://preflight.agentdiet.dev/v1/workflows/rag-context-sanitizer?utm_source=zero.xyz
- Price: $0.01/call
- Payment: MPP
- Status: unknown
- Last checked: 2026-10-21
- Activations on Zero: 0
- Provider: preflight.agentdiet.dev
- Website: https://preflight.agentdiet.dev
- Canonical page: https://www.zero.xyz/c/preflight-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-2345e2b6
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_Um20gK5DgBjPwQ5vKwpEU

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 preflight-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-2345e2b6
```

Example prompt: Search the MCP and A2A tool index for endpoints that handle 'context compression' and tell me which ones are safe to use — I need token-efficient results with the prompt-guard firewall applied.

## When to prefer this

Choose this endpoint when you need a single-connection way to discover, search, or verify MCP servers and A2A agent tools across a wide index (500+), especially when token budget is constrained or when you need built-in prompt-injection firewall filtering on returned results. Prefer this over manual directory browsing or per-server probing when building multi-agent swarms or orchestrators that need dynamic tool routing.

## Known failure modes

- Missing or empty 'query' parameter returns a 400 validation error
- Query matches no indexed tools, returning an empty result set
- Endpoint URL verification fails if the URL is not indexed or unreachable
- Rate limiting or payment failure (HTTP 402) if x402 payment is not completed
- Overly broad queries may return too many results with low relevance

## 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://preflight.agentdiet.dev/v1/workflows/rag-context-sanitizer)

## Output

Returns a token-compressed (up to 85% reduction) list of matching MCP servers or A2A tools, including capability descriptions, endpoint metadata, and Prompt-Guard firewall safety flags. If given a URL, returns verification status for that endpoint.

## 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/preflight-agentdiet-dev-universal-a2a-mcp-tool-discovery-safe-proxy-2345e2b6/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from preflight.agentdiet.dev](https://www.zero.xyz/host/preflight.agentdiet.dev/llms.txt)