# AgentDiet MCP Injection Firewall — MCP/x402/A2A Gateway

> AgentDiet MCP Injection Firewall — MCP/x402/A2A Gateway is a paid API for AI agents from mcp-gateway.agentdiet.dev, paid per call via x402, $0.005/call, status unknown (last checked 2026-10-22).

Routes and executes agent-to-agent, MCP, and x402 API requests through a deterministic broker gateway, settling payments in USDC on Base.

## Facts

- Endpoint: GET https://mcp-gateway.agentdiet.dev/v1/mcp-injection-firewall?utm_source=zero.xyz
- Price: $0.005/call
- Payment: x402
- Status: unknown
- Last checked: 2026-10-22
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/agentdiet-mcp-injection-firewall-mcp-x402-a2a-gateway-f011e294
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_7fIbD_3ij9J8ibbtXyha2

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 agentdiet-mcp-injection-firewall-mcp-x402-a2a-gateway-f011e294
```

Example prompt: Route my GET request with the query text 'summarize today's crypto news' through the AgentDiet MCP gateway broker, picking the best matching MCP server from the 31,000+ available, and settle the $0.005 USDC fee on Base.

## When to prefer this

Choose this endpoint when you need a single unified broker to discover and execute calls across 31,000+ MCP servers, x402 APIs, or A2A agents without managing individual integrations, and when you want automatic USDC micropayment settlement on Base. Prefer this over direct MCP or x402 connections when you don't know which downstream provider to target, or when you want deterministic execution with an ROI proof returned.

## Known failure modes

- Insufficient USDC balance or payment failure on Base — payment-related 402 or rejection error
- Invalid or unsupported HTTP method provided (only GET/POST accepted)
- No matching downstream MCP server or x402 API found for the given text query — empty or error data response
- Malformed input object missing required 'type' or 'method' fields — schema validation error
- Gateway node unavailable or upstream MCP server timeout — status error or no response

## How this service works

Deterministic B2A/A2A/MCP/x402/MPP/L402 execution and intelligence node at https://mcp-gateway.agentdiet.dev settling in USDC on Base.

## Output

Returns a JSON object with a 'data' field containing the downstream execution result, a 'status' field ('ok' on success), and an 'roi_proof' object including a compression_ratio_pct metric (e.g. 91.4%) indicating efficiency of the brokered call.

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET",
      "POST"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "properties": {
      "text": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  },
  "output": {
   "type": "object",
   "required": [
    "type"
   ],
   "properties": {
    "type": {
     "type": "string"
    },
    "example": {
     "type": "object"
    }
   }
  }
 }
}
```

## Response schema (JSON Schema)

```json
{
 "type": "json",
 "example": {
  "data": {},
  "status": "ok",
  "roi_proof": {
   "compression_ratio_pct": 91.4
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/agentdiet-mcp-injection-firewall-mcp-x402-a2a-gateway-f011e294/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mcp-gateway.agentdiet.dev](https://www.zero.xyz/host/mcp-gateway.agentdiet.dev/llms.txt)