Perception RE MCP Server

MCP server that bridges Claude Code to Perception.cx reverse engineering tools via AngelScript WebSocket.

Claude Code (stdio) → MCP Server (Node.js) ← WebSocket :9001 → re_server.as (Perception IDE)

Multiple Claude Code instances can share the same Perception connection simultaneously through a hub/relay architecture.

Prerequisites

• Node.js (v18+)

• Perception.cx with AngelScript IDE

• Claude Code CLI

Related MCP server: IDAssistMCP

Installation

git clone https://github.com/verifizieren/perception-mcp.git
cd perception-mcp
npm install
npm run build

dist/ is gitignored - you must run npm run build after cloning or dist/index.js won't exist.

Configuration

Global (all Claude Code sessions)

Create or edit ~/.mcp.json:

{
  "mcpServers": {
    "perception-re": {
      "command": "node",
      "args": ["<full-path-to>/perception-mcp/dist/index.js"]
    }
  }
}

Replace <full-path-to> with the absolute path to where you cloned the repo. Use forward slashes even on Windows.

Per-project

Add the same config to your project's .mcp.json in the project root.

Usage

1. Load the AngelScript server in Perception

Open re_server.as in the Perception IDE script editor and run it. The script runs in background mode - it automatically keeps trying to connect to the MCP server and reconnects if disconnected. You can load it on Perception startup.

Waiting:

[RE Server] Waiting for MCP server... (attempt 1)

Connected:

[RE Server] Connected to MCP server.

2. Start Claude Code

Open Claude Code in any project. The MCP server starts automatically via ~/.mcp.json.

3. Multiple instances

First instance = hub (WebSocket server on port 9001). Additional instances auto-connect as relays through the hub, sharing the one Perception connection. No extra setup.

Tools

All functionality is exposed through 9 dispatchers. Each takes an op selector plus the args for that op. This keeps the schema footprint small while covering every operation.

Value types: u8 u16 u32 u64 i8 i16 i32 i64 f32 f64 (plus string wstring ptr where noted).

Notes on defaults

• re_vm vad returns compact {start,size} by default - pass compact:false for protection/heap_likely metadata. Always filter (min_size, heap_only, addr_*) to avoid oversized responses.

• re_read ptr_chain returns final_address/final_value only; pass verbose:true for the per-step trace. u64/i64 final values come back as hex strings (JSON numbers can't hold 64 bits).

• re_read values/struct return u64/i64 as hex strings too; smaller ints as numbers.

• re_read bytes caps at 64KB unless you pass raw:true (hard max 1MB) — hex payloads balloon fast.

• re_write values accepts hex strings ("0x1122334455667788") for exact 64-bit writes; plain numbers still work for small types.

• re_diff diff returns changed offsets only; pass values:true for per-byte a/b. Flags truncated:true at 1000 diffs.

• re_cs2 schema — filter is required (substring on field name) unless you pass all:true; default limit 100, max 2000. Returns name:offset strings.

• re_scan value/ptr_to default page_limit is 100; count reflects the true total, has_more flags more pages. Heavy scans have a caller-side 120s timeout — the MCP request rejects on timeout, but Perception's scan loop is not cancelled and keeps running until it finishes.

Example

You: attach to cs2.exe and show me the first 10 instructions at its entry point

Claude: [re_proc op:attach name:"cs2.exe"] [re_module op:module name:"client.dll"] [re_disasm op:disasm ...]

Project Structure

perception-mcp/
├── src/
│   └── index.ts          # MCP server + WebSocket hub/relay bridge + 9 dispatchers
├── re_server.as          # AngelScript server for Perception IDE
├── package.json
├── tsconfig.json
└── dist/                 # Built output (gitignored)
    └── index.js

API Reference

Perception AngelScript API: https://docs.perception.cx/perception-angel-script-api/