QNX MCP Server

A read-only MCP server for diagnosing a QNX 8.0 target from a Linux development host. The local demo reproduces a real synchronous IPC deadlock in two original C programs and shows the wait cycle from structured QNX evidence.

Why QNX

On QNX, a thread that sends a message can wait for a receiver (SEND) or for a reply after the receiver accepted the message (REPLY). A thread in RECEIVE can simply be an idle server. A generic process list cannot tell you which IPC peer or channel is involved. This server reports those details from pidin and leaves unknown fields empty, so an assistant can distinguish an idle receiver from a real dependency cycle. QNX message passing

MCP client ── stdio ── Linux / WSL2 qnx-mcp ── verified SSH/SFTP ── QNX 8.0

The supported MVP target is QEMU x86_64. The tested host uses Ubuntu 24.04 WSL2, Python 3.12, and the Linux QNX SDP 8.0 series with 8.0.5 components. The guest reports QNX 8.0.0 x86pc through uname. The original demo uses qcc -Vgcc_ntox86_64. The MCP process itself needs no SDK, compiler, AWS credentials, or application-side LLM key.

Related MCP server: Linux MCP Server

Install and connect

1. Obtain your own QNX Everywhere SDK and license. Build and boot a private guest using the QEMU setup.

2. Inside Linux, install project dependencies with uv:

   uv sync --locked

   Alternatively, use python3 -m venv .venv and .venv/bin/python -m pip install -e . if your Linux Python provides pip.

3. Copy targets/qemu.yaml to a private file outside the repo. Set its SSH key, verified known_hosts and narrow read_roots. Relative host file paths are resolved against the profile's directory.

4. Configure your client using Claude Desktop / VS Code instructions. The launcher command for Linux is:

   /bin/sh /absolute/repo/scripts/launch-mcp.sh --profile /absolute/private/qemu.local.yaml

The server waits for MCP on stdin. It does not listen on a network port. With no --profile, it uses the loopback QEMU defaults shown in the sample YAML. An owner-selected YAML can point at another QNX 8.0 guest without code changes; only the local x86_64 setup has been validated for this release.

Tools

Every successful response includes a target ID, observation time, status, warnings and a truncation flag. partial means some evidence is unavailable or clipped; a QNX query can return exit code zero and still have permission denials. The parser uses the real-target-verified %80B width and does not invent a peer TID when pidin gives only a PID. Cross-UID visibility is restricted, and the process list is not an atomic or system-wide snapshot. QNX pidin reference

Reproduce the diagnosis

Follow the deadlock demo to build and stage the two programs manually. Read-only MCP calls show A REPLY → B and B SEND → A, plus a normal RECEIVE thread on an unrelated channel. The assistant can connect those observations to the callback-before-reply line in the source. The developer reruns in --fixed mode to demonstrate that reply-before-callback completes the request.

Manual verification describes the tested QEMU path and the separate SDK-free checks. Demo storyboard is a recording script; no demo video is bundled.

Safety

The server binds one trusted profile at startup. It accepts no arbitrary host, shell command, target write, execution, delete or cloud action. It verifies SSH host keys, uses a non-root account, bounds reads, checks path components and writes a private audit log. Configure the client to ask before every call: Claude Desktop needs Manual permission mode and VS Code needs the workspace policy in client setup. Annotations describe intent and do not enforce consent. Target text can contain prompt injection and must be treated as data. See SECURITY.md for the trust boundary, path race limitation and planned hardening.

Development

uv sync --locked
uv run --frozen ruff check .
uv run --frozen ruff format --check .
uv run --frozen pytest
uv build --wheel --no-sources

Public CI uses Linux and hand-written synthetic fixtures with a fake SSH/SFTP backend. It does not use QNX, credentials or target captures. Real target validation is a separate opt-in check. PLAN.md tracks the later cloud scenario; it is outside this release.

Original code is MIT licensed. QNX software, images, SDK files, vendor samples and target captures are not distributed. Obtain vendor components under their own terms. The demo presents functional behavior.