Conduit

Conduit is an MCP debugger. One server connects Cursor, Claude, Cline, and any other MCP client to radare2, x64dbg, cdb, and Frida for disassembly, control-flow graphs, cross-references, strings, and live debugging.

The bars are engine support, not a success-rate benchmark. 100% means every engine that job applies to implements it: static jobs on radare2, and live memory on x64dbg, cdb, and Frida. 67% means x64dbg and cdb only. Frida does not step, pause, or take full breakpoints and thread control; its registers and call stack are the last hardware-breakpoint hit, not a live read. Assembly reading has an explain tool, and its accuracy was not measured. The gray “before” percents are an estimate of what a shell can do with no debugger tool, not a measured baseline.

Static analysis and live debugging share one tool surface. session_open picks the engine. Nothing is stubbed: a tool the engine does not implement returns capability_unsupported.

Install

Node.js 20 or newer and npm must already be on PATH. Then:

npm install -g github:Alyhnte/conduit

That puts the conduit command on PATH. The npm package name is conduit-debugger because conduit is already taken on the npm registry. Python is not required.

A pip build of the same project is also published as pip install conduit-debugger. The hub entry uses the npm command above.

Related MCP server: re-mcp

Prerequisites

Clean-machine install, in order:

1. Node.js ≥ 20 — node --version

2. radare2 — a prebuilt release, no compilation. Any 6.x works (goldens were captured with 6.2.2; the comparator tolerates formatting drift between r2 versions). Must be on PATH as radare2 or r2: r2 -v. Override the path with DBG_BRIDGE_R2.

3. Graphviz — dot on PATH (dot -V). Required to render a control-flow graph from get_cfg. x64dbg does not draw that graph itself.

4. Python 3.10+ — required for an x64dbg session. The loader embeds Python and the bridge needs iced_x86 (python -m pip install iced_x86). 64-bit Python must be on PATH, or set PYTHON_HOME_X64. 32-bit Python is only for x86 targets (PYTHON_HOME_X86 or %USERPROFILE%\Tools\python-x86). Regenerating the example fixture also uses Python 3. Details: plugin/x64dbg/README.md.

prerequisites reports these programs plus x64dbg, cdb, Frida, and ScyllaHide. A missing program includes indir (a URL) and nereye (where to put it). Conduit does not download it. The same hint is appended to engine_unavailable when a session tries to start a missing engine.

explain reads an assembly window: what the region does, where it jumps, and which calls are notifications (MessageBox, printf, and the like). Pass instructions already read, or a session_id. Reading a live debug session still needs confirm:true.

Run

node dist/server.js                                     # stdio (default)
node dist/server.js --transport http --port 3847        # Streamable HTTP

HTTP prints conduit streamable-http 2026-07-28 http://127.0.0.1:3847/mcp and serves POST /mcp plus GET /health. --host, --port, and --transport flags exist; DBG_BRIDGE_HOST, DBG_BRIDGE_PORT, and DBG_BRIDGE_TRANSPORT do the same.

Optional token: set DBG_BRIDGE_TOKEN and every HTTP route (including /health) requires Authorization: Bearer <token> (anything else gets 401 {error:"unauthorized"}). When unset, localhost stays open. The token is env-only (a flag would leak via the process list) and is compared in constant time. stdio needs no token: spawning the process locally is the authentication there.

Connect a client

Ready-made configs live in configs/ (stdio and HTTP variants for Cursor, Claude Desktop, Cline, and OpenCode). Replace <DBG_BRIDGE_DIR> with the absolute path of this folder and follow configs/README.md, then restart the client.

Quick check inside the client: call health. Expect status: ok and name: conduit.

Client compatibility: the server speaks 2026-07-28 and also accepts 2025-era clients (for example opencode 1.x negotiating 2025-11-25) through the SDK's legacy fallback. Verified end-to-end with real opencode and cursor-agent runs (health → session_open → open_target → disassemble).

End-to-end check

Fixture: examples/target/mini_branch.elf — a hand-packed 64-bit ELF (1536 bytes, no compiler needed) whose entry 0x400200 runs a branching function (lea + cmp/je if/else). .rodata holds HELLO-FIXTURE and mini-branch. Sources: mini_branch.c, mini_branch.asm, gen_mini_branch.py.

1. session_open {"engine": "radare2"} → session_id

2. open_target {"session_id", "path": "<abs path>/mini_branch.elf", "mode": "static"}

3. disassemble {"session_id"} → 10 ops at entry0

4. get_cfg {"session_id", "format": "both"} → 4-block CFG, JSON + DOT

5. strings {"session_id"} → HELLO-FIXTURE @ 0x400300, mini-branch @ 0x40030e

6. dump {"session_id", "address": "0x400200", "length": 34, "format": "json"}

7. xrefs {"session_id", "address": "0x400300"} → DATA xref from 0x400200

8. events_pull {"session_id"} → contains target.opened

9. close_target {"session_id"} / session_close {"session_id"}

Raw-protocol note (only if you drive the server without an MCP client): every request on protocol 2026-07-28 carries the envelope _meta: {"io.modelcontextprotocol/protocolVersion": "2026-07-28", "io.modelcontextprotocol/clientCapabilities": {}}, starting with server/discover. Over HTTP, POST /mcp also requires the Mcp-Method header (and Mcp-Name for tools/call). The golden runner (tests/run_golden.mjs) shows the exact wire format. The stdio transport pins its dialect on the first request, so a bare request or a legacy initialize locks that process into legacy mode and later server/discover calls fail with Method not found.

Debug engines

The same debug_* tool names work on every engine. Config files under configs/ do not name an engine. session_open does.

Debug fixtures live at plugin/x64dbg/test/mini_pe_x64.exe and mini_pe_x86.exe.

Test

npm test                  # node tests/run_golden.mjs
npm run test:debug        # x64dbg launch + attach (Windows)
npm run test:cdb          # cdb launch + attach (Windows)
npm run test:frida        # Frida hardware-breakpoint loop (Windows)
npm run test:dynamic      # confirm gate, live memory/code/thread/checkpoint
npm run test:explain      # assembly reading + download hints
npm run test:concurrency  # multi-client isolation over HTTP
npm run test:auth         # optional DBG_BRIDGE_TOKEN gate over HTTP

Expected: 38 passed, 0 failed. The suite checks prerequisites, fixture determinism, golden output, Graphviz rendering, and full MCP sessions over stdio and HTTP.

To re-capture goldens after an intentional behavior change:

node tests/run_golden.mjs --update

Troubleshooting

Layout

conduit/
├── src/                 engines and MCP tools
├── dist/                build output (git-ignored)
├── examples/target/     mini_branch.elf fixture
├── plugin/x64dbg/       x64dbg bridge and debug fixtures
├── tests/               golden runner and engine acceptance
├── configs/             Cursor, Claude Desktop, Cline, OpenCode
└── README.md

License

MIT. See LICENSE. The x64dbg plugin sources are vendored from ouonet/x64dbg-mcp; see plugin/x64dbg/THIRD_PARTY_NOTICES.md.