# mcp-server

Moves tool calls into a WASM sandbox powered by QuickJS. It reduces context token usage by presenting just docs_search and execute_code to the model.

- MCP server · `type=mcp` · Claude Code, Codex, Cursor, GitHub Copilot, Windsurf (Devin Desktop), Cline, Zed, Gemini CLI · ★ 7
- Author: WasmAgent
- License: Apache-2.0 · policy=link-only · description only; the file stays with the author
- Source: https://github.com/WasmAgent/wasmagent-js/tree/HEAD/packages/mcp-server
- Updated: 2026-10-15
- HTML: https://affpapa.org/en/nevibecode/mcp/wasmagent-mcp-server

## What it does

The server packages tool collections behind a minimal two-method surface. Instead of serializing dozens of full schemas into the prompt, the host model sees only search and execution endpoints. The model then writes a small script to dispatch whichever downstream methods it needs. Under 30 downstream utilities, initial prompt token overhead drops to 13.6%.

Execution takes place inside an isolated WebAssembly QuickJS kernel. A CapabilityManifest controls access boundaries: `cpuMs` limits, `memoryLimitBytes` caps, plus strict `allowedHosts` and `allowedPaths` entries. Network requests to unapproved destinations fail immediately.

This project is in beta. Launching the zero-config binary via npx provides an empty inspection server with no tools attached. Practical deployments require a custom Node entrypoint configuring ToolRegistry.

## Requirements
- Needs: Node.js (commands run via npx)

## Install

### Claude Code (native platform)

**Platform CLI**
```bash
claude mcp add mcp-server -- npx -y @wasmagent/mcp-server
```

### Codex

**Platform CLI**
```bash
codex mcp add mcp-server -- npx -y @wasmagent/mcp-server
```

### Cursor

**Config file**
File `.cursor/mcp.json`:
```json
{
    "mcpServers": {
        "mcp-server": {
            "command": "npx",
            "args": [
                "-y",
                "@wasmagent/mcp-server"
            ]
        }
    }
}
```

### GitHub Copilot

**Config file**
File `.vscode/mcp.json`:
```json
{
    "servers": {
        "mcp-server": {
            "type": "stdio",
            "command": "npx",
            "args": [
                "-y",
                "@wasmagent/mcp-server"
            ]
        }
    }
}
```

### Gemini CLI

**Platform CLI**
```bash
gemini mcp add mcp-server npx -y @wasmagent/mcp-server
```

## When to use it
- shrink prompt token overhead for large tool registries
- isolate model-generated code in a WebAssembly sandbox
- enforce strict network and disk permissions with a manifest
- host an MCP agent across stdio or edge HTTP runtimes

## Example prompts
- Execute the data transformation inside execute_code with no network access
- Look up registered utilities using docs_search before running the script
- Run this calculation under a 5000ms CPU execution cap

## Similar
- [REA](https://affpapa.org/en/nevibecode/mcp/rea.md) — MCP server · ★ 392262
- [GitHub](https://affpapa.org/en/nevibecode/mcp/github.md) — MCP server · ★ 33989
- [Netdata](https://affpapa.org/en/nevibecode/mcp/netdata.md) — MCP server · ★ 81163
- [browser-use](https://affpapa.org/en/nevibecode/mcp/browser-use.md) — MCP server · ★ 119231
- [Codebase Memory](https://affpapa.org/en/nevibecode/mcp/codebase-memory.md) — MCP server · ★ 47577
- [mcp-server](https://affpapa.org/en/nevibecode/mcp/mcp-server.md) — MCP server · ★ 43902

## Other versions with the same name
- [mcp-server · heyputer](https://affpapa.org/en/nevibecode/mcp/mcp-server.md) — ★ 43902
- [mcp-server · mapbox](https://affpapa.org/en/nevibecode/mcp/mapbox-mcp-server.md) — ★ 363
- [mcp-server · packmindhub](https://affpapa.org/en/nevibecode/mcp/packmindhub-mcp-server.md) — ★ 319
- [mcp-server · bingowon](https://affpapa.org/en/nevibecode/mcp/bingowon-mcp-server.md) — ★ 121
- [mcp-server · ui5](https://affpapa.org/en/nevibecode/mcp/ui5-mcp-server.md) — ★ 105

---
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