canforge-mcp
canforge-mcp is a local, read-only MCP server for inspecting DBC files anddecoding CAN capture logs.
Files stay on the machine running the server. The server exposes bounded toolsinstead of uploading captures or returning unbounded traces.
Tools
| Tool | Purpose |
|---|---|
dbc_info |
DBC version, message/signal/node counts, and node names |
list_messages |
Bounded message summaries, with optional search |
get_message |
Full message and signal detail by name or arbitration ID |
search_signals |
Bounded signal search across a DBC |
decode_frame |
Decode one hexadecimal CAN payload |
validate_dbc |
Structured DBC validation issues |
diff_dbcs |
Added, removed, and changed messages and signals |
probe_log |
Detect a log format and read header metadata |
log_stats |
Frame count, span, ID counts, and median cycle times |
read_frames |
Bounded raw-frame samples with ID and time filters |
decode_log |
Bounded decoded frames from a DBC and log |
signal_timeseries |
Downsampled timestamp/value points for one signal |
See the tool reference for arguments, return shapes, and hardcaps.
Install
Run directly with uvx:
uvx canforge-mcp
Or install with pip:
pip install canforge-mcp
canforge-mcp
Requires Python >=3.11.
Configure
Claude Code:
claude mcp add canforge -- uvx canforge-mcp
Claude Desktop (claude_desktop_config.json):
{
"mcpServers": {
"canforge": {
"command": "uvx",
"args": ["canforge-mcp"]
}
}
}
Restart the client after changing its MCP configuration.
Design
- Local-first: tools accept filesystem paths and do not send file content overthe network.
- Read-only: no tool creates, edits, encodes, or overwrites a file.
- Bounded: list and frame tools enforce hard caps and report
total,returned, andtruncated; timeseries are downsampled server-side. - Cached: parsed DBCs are cached by resolved path and nanosecond modificationtime for repeated inspection during one server session.
- Composable: capkit reads capture formats;dbckit parses and decodes DBC content.
- Stdio-only: version 0.1 exposes no network transport or hosted service.
Scope and Caveats
- Supported capture formats come from capkit 0.2: Kvaser CanKing TXT, candumptext, and Vector ASC.
- DBC support and validation behavior follow dbckit 1.x.
- Timestamps are floats exactly as recorded by capkit; they are not rebased.
- Median cycle time is the median gap between consecutive occurrences of an ID.
signal_timeseriesuses deterministic, evenly spaced index sampling when aseries exceedsmax_points; it is intended for inspection, not resampling orsignal processing.- Paths are resolved by the machine running the MCP server. A remote client'sfilesystem is not visible to a server running elsewhere.
Development
python -m venv .venv
source .venv/bin/activate
pip install -e ".[dev]"
ruff check .
mypy canforge_mcp
pytest --cov=canforge_mcp --cov-fail-under=90
python -m build
License
MIT
