# Swarms MCP Client Proxy - Execute Tool Call

> Swarms MCP Client Proxy - Execute Tool Call is a paid API for AI agents from mcp-gateway.swarms.world, paid per call via x402, $0.01/call, status unknown (last checked 2026-09-15).

Proxies a tool call to a target MCP (Model Context Protocol) server and returns the execution result

## Facts

- Endpoint: POST https://mcp-gateway.swarms.world/mcp/request
- Price: $0.01/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-15
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/swarms-mcp-client-proxy-execute-tool-call-74d6249f
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_JUZOSVyiy9dcynvo8YM-J

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 swarms-mcp-client-proxy-execute-tool-call-74d6249f -d '<json body>'
```

Example prompt: Forward this tool call to the MCP server at https://my-mcp-server.example.com — invoke the 'get_weather' tool with arguments {"city": "San Francisco"} and give me the result.

## When to prefer this

Use this endpoint when you need to invoke a specific tool on a remote MCP server without establishing a direct connection to it, or when you want to route MCP tool calls through a managed gateway with per-call billing. Prefer this over direct MCP connections when operating in environments where outbound MCP connections are restricted or when you want centralized logging and billing via the Swarms gateway.

## Known failure modes

- Target MCP server unreachable — isError: true with connection error in content
- Invalid tool name or arguments — isError: true with validation error details
- MCP server returns an error for the tool call — isError: true with server error message
- Payment not processed — 402 Payment Required before request is fulfilled
- Malformed request body — 400 Bad Request if MCP payload structure is invalid

## How this service works

Proxy MCP (Model Context Protocol) tool calls to a target MCP server.

## Output

Returns an object with a 'content' array containing the tool execution results (each item is an object with tool-specific data) and an 'isError' boolean indicating whether the call failed. On success, isError is false and content holds the structured output from the MCP tool.

## Response schema (JSON Schema)

```json
{
 "type": "object",
 "properties": {
  "content": {
   "type": "array",
   "items": {
    "type": "object",
    "additionalProperties": true
   },
   "description": "Tool execution results"
  },
  "isError": {
   "type": "boolean",
   "description": "Whether the tool call resulted in an error"
  }
 },
 "description": "MCP tool call result",
 "additionalProperties": true
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/swarms-mcp-client-proxy-execute-tool-call-74d6249f/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from mcp-gateway.swarms.world](https://www.zero.xyz/host/mcp-gateway.swarms.world/llms.txt)