Fw Context MCP vs Stack Chan

configure_llm

Configure LLM settings for the current project. Writes to ``<project>/.fw-context/local.toml`` ONLY (gitignored, per-developer). Does NOT modify the global config or the shared project ``config.toml``. After writing, tests the configuration by making a simple API call (skipped when LLM is disabled). IMPORTANT: When ``chat_api_base`` points to an external host, source code snippets in chat prompts will be sent to that endpoint. Ensure this complies with your organization's data security policies. Consider using local Ollama or an internal API proxy first. Args: project_root: Project root directory. Auto-detected if omitted. project: Project name or project_id — call list_projects to get them. Use it to ask about a project that is not the project of the current directory. It is an alternative to project_root, which takes a root path. Give one of the two, not both. chat_api_base: Chat API URL (see description for format details). chat_api_key: Bearer token for cloud/proxy APIs. chat_api_format: Override auto-detection: "auto", "ollama", "openai". model: Chat model name. embed_model: Embedding model name (Ollama only). auto_pull: Whether to auto-pull models on 404. stream: Stream chat responses via SSE. True avoids reverse-proxy idle timeouts. Returns: dict: {status ("ok"|"error"), chat_api (dict — configured, endpoint, format, model), model (str), auto_pull (bool), stream (bool), test_latency_s (float, on success), test_response (str, on success), compliance_warning (str, when chat_api_base is external), message (str)}

get_active_build

MANDATORY FIRST CALL for C/C++ projects. Return metadata about the most recently indexed build configuration — check index health before using any other fw-context tools. Read-only, and it spawns no subprocess — the startup daemon thread and the file watcher own the background reindex. Act on ``status``: * ``"ready"`` — up to date. Continue. * ``"reindexing"`` — background reindex running; queries stay accurate. Continue. ``reindex_progress`` holds its last log line. * ``"reindex_needed"`` — schema mismatch, changed compile_commands.json, or a source file that compile_commands.json does not cover. Queries still work on existing data. Read ``reindex_reasons``: a missing source file needs ``fw-context index --build``, the other two need only ``fw-context index``. * ``"no_index"`` — initialized, never indexed. Run ``fw-context index``. * ``"not_initialized"`` — run ``fw-context init``. * ``"error"`` — DB corruption or access error. Use other tools. Three conditions set ``reindex_needed``: an outdated schema, a changed compile_commands.json, and a source file that is on disk but absent from compile_commands.json. The third one needs a build, because only the build system writes that file — a plain reindex has no translation unit for the file and skips it without a word. Modified source files are something else: they are handled per-query, and never set it. ``indexed_at`` and ``first_indexed_at`` are UTC; file mtimes are local time. Never compare the two directly — in UTC+2 a correctly indexed file looks 2 hours newer than ``indexed_at``. Call with ``fast=False`` to find modified files. ``analysis`` splits the LLM-analysis coverage into project and vendor symbols: * ``model`` — the model of the analysis, or None. One model only, even when several were used. * ``analyze_vendor`` — the value at index time, not the current config. * ``project`` / ``vendor`` — ``{analyzed, skipped, total}``. ``skipped`` = tried, but not analyzable (body larger than the model context, an unparseable answer, or a body that was not readable). * ``complete`` — no work left: every project symbol is analyzed or skipped. True exactly when ``reindex_reasons`` holds no "unanalyzed symbols" entry. Vendor symbols excluded by ``analyze_vendor=False`` never block it, thus ``vendor.total`` large with ``vendor.analyzed=0`` is expected, not a defect. Args: project_root: Project root directory. Auto-detected from CWD if omitted. project: Project name or project_id — call list_projects to get them. Use it to ask about a project that is not the project of the current directory. It is an alternative to project_root, which takes a root path. Give one of the two, not both. fast: When True (default), the header check reuses the cached manifest hashes. Both modes run the per-file scan, thus ``modified_files_count`` is accurate either way — a tool that reported "ready" while the search tools warned about the same file gave the caller two readings and no way to choose. False recomputes the header hashes and costs several times more. Returns: dict: {config_hash, project_id, project_root, build_system, compile_commands, indexed_at (str — "YYYY-MM-DD HH:MM:SS" in UTC, the completion time of the last full index), symbol_count, file_count, reference_count, modified_files_count (int — files whose content no longer matches the index; counted in both modes), header_affected_tus (int — number of TUs with stale header dependencies), manifest_verification (str — "full" when manifest.json exists, "none" otherwise), analysis (dict — LLM-analysis coverage split by project/vendor: {model, analyze_vendor, project: {analyzed, skipped, total}, vendor: {analyzed, skipped, total}, complete}), description (str), first_indexed_at (str — UTC, same format as indexed_at), vendor_paths (list[str] — config index.vendor_paths), project_paths (list[str] — config index.project_paths), bg_reindex_running (bool), reindex_progress (str or None — last log line when reindex is running), schema_version (int — DB schema version), current_schema (int — code expects), status (str — "ready"|"reindexing"| "reindex_needed"|"no_index"|"not_initialized"|"error"), reindex_needed (bool — structural mismatch requiring a full reindex), reindex_reasons (list[str] — why reindex is needed, empty when False. One of them asks for `fw-context index --build` rather than a plain reindex: when the tree is on a different branch than the index, compile_commands.json belongs to the OLD branch and carries its file list and its compiler flags, so only a build regenerates it. Read the reason text — it names the command it needs), stale (bool — True when reindex_needed or header_affected_tus > 0), _warning (str, optional — when manifest verification is not "full"), vec_available (bool), vec_error (str, optional), index_message (str — human-readable summary of index state), multi (bool — True for a multi-variant project), variants (list[dict] — {name, description, board}), images (list[dict] — {name, description, dir, type}), variant_images (dict — variant name to its image names), active_variant (str or None — [build] default_variant), active_image (str or None — [build] default_image), entry_point (str — the `ENTRY()` of the linker script of the build that the other fields describe, empty when no script names one), memory (list[dict] — the `MEMORY` regions of that build: {name, attributes, origin, length, origin_value, length_value, file_path, line})} About ``memory``: ``origin`` and ``length`` hold the expression the script writes, thus they differ by platform — an mbed script writes `0xefe00` and a Zephyr script writes `((673792) - 0xe6)`. ``origin_value`` and ``length_value`` hold the number, and both are None for an expression that names a symbol, such as `ORIGIN(RAM) + LENGTH(RAM)`. The end of a region is ``origin_value + length_value``. ``memory`` and ``entry_point`` describe ONE build. For a multi-variant project they follow ``config_hash``, which is the build named by ``[build] default_variant``, and both are empty when the config names no default. Use ``list_variants`` for the map of every build. ``memory`` is empty for a build system that records no linker script. A PlatformIO project is the measured case: SCons writes no ninja file and no link command the index can read, and the map file never names the script. An empty list means "not recorded", never "no memory". ``defines`` (dict — the `-D` flags of that build) and ``defines_varying`` (int). ``defines`` holds only the names that EVERY translation unit of the build carries with the same value, so the tool never shows the defines of one file as the defines of the build. ``defines_varying`` counts the names left out, thus a name absent from ``defines`` is either not defined at all or not defined everywhere — measured on the Mbed project: 27 names in all 881 units, 59 in only some, where the three assembly files get a shorter set. This is the configuration the BUILD states, not every macro the preprocessor saw. The second is three orders of magnitude larger — 27800 distinct names on the STM32 project — and almost all of it comes from the headers and the compiler. A Zephyr build keeps its real configuration in ``autoconf.h`` (740 `CONFIG_*` names) and passes few `-D` flags, so ``defines`` says little there and a great deal on an mbed build, where it holds `APPLICATION_ADDR`, `APPLICATION_SIZE`, and `CMSIS_VECTAB_VIRTUAL`. For a project that is not initialized, the result holds only ``status``, ``project_root``, and ``index_message``. When no index exists, the result adds ``project_id``.

get_environment_status

Return the complete project environment status in one call. Read-only. Aggregates five domains into a single call so the LLM can see everything at session start without extra round-trips: - ``deps`` — dependency audit (``run_full_check``), each entry with an optional ``action`` (``message`` + shell ``command``). ``status="skipped"`` means a prerequisite is missing (e.g. ``libclang-so`` skipped because ``libclang-python`` is absent) — not a failure. - ``build_system`` — detected build system, ``None`` when unknown. - ``compile_db`` — whether compile_commands.json exists and its entry count. Reported as ``{"exists": false, ...}`` before init (no config to resolve the path from, and loading one would create empty config files). - ``index`` — the FULL ``get_active_build()`` result, unchanged (its action lives in ``index_message``). - ``llm`` — LLM backend status with an optional ``action``. When the project is not initialized (``index.status == "not_initialized"``), only the config-independent dependency subset runs (checks that do not need a project config) — Ollama/model/db/build checks are skipped. Args: project_root: Project root directory. Auto-detected from CWD if omitted. project: Project name or project_id — call list_projects to get them. Use it to ask about a project that is not the project of the current directory. It is an alternative to project_root, which takes a root path. Give one of the two, not both. Returns: dict: {init_status (str — "initialized" or "not_initialized"), deps (list[dict] — name, status, message, and an optional action), build_system (str or None), compile_db (dict — {exists (bool), path (str or None), entry_count (int or None — None before init, and when fw-context cannot read the file)}), index (dict — the full ``get_active_build`` result), llm (dict — {enabled, ollama_running, chat_model, embed_model}, plus ``ollama_enabled`` when the LLM check ran, plus an optional ``action``)}.

get_project_info

Return project metadata (name, type, root_path) for a project ID. Looks up the global project registry at ``~/.fw-context/projects.db``. Use this to identify a project from its UUID4 — find out what build system it uses, its name, and where it was last indexed. Read-only. No side effects. Args: project_id: Project ID (UUID4 hex) to look up. Returns: dict: {project_id, name, project_type, root_path, created_at, updated_at} or {"error": "..."} when the project_id is not registered. On failure the dict holds only ``error`` with the reason.

list_projects

List all indexed firmware projects with their statistics. Read-only. No side effects. Use at session start to discover available projects; use ``get_active_build`` for details on the currently active project. ``indexed_at`` and ``first_indexed_at`` are UTC, in ``"YYYY-MM-DD HH:MM:SS"`` format — the same format that ``get_active_build`` returns. ``analysis`` holds the ``project`` and ``vendor`` counts only. For the ``model``, ``analyze_vendor``, and ``complete`` fields, call ``get_active_build`` for that project. Args: project_root: Project root. Auto-detected if omitted. Pass to distinguish multiple indexed projects. project: Project name or project_id — call list_projects to get them. Use it to ask about a project that is not the project of the current directory. It is an alternative to project_root, which takes a root path. Give one of the two, not both. Returns: list of dicts, each with: project_id, name, root_path, build_system, symbol_count, file_count, indexed_at (str — UTC), description (str), first_indexed_at (str — UTC), schema_version, current_schema, reindex_needed (bool), status (str — "ready" or "reindex_needed"), db (path to SQLite database file), variant_count (int — number of build variants), image_count (int — number of sysbuild images), analysis (dict — LLM-analysis coverage {project: {analyzed, skipped, total}, vendor: {analyzed, skipped, total}}, or None when no build is indexed). When no project has an index, the result is a single dict with an ``info`` key. When fw-context cannot read a database, the result holds a dict with ``db`` and ``error`` keys for that file.

list_variants

List every indexed build with its (variant, image, board) identity. Read-only diagnostic — shows what is actually indexed, not what the config declares. Each row is one ``(variant, image)`` build with its own ``config_hash`` and symbol count. For single-project indexes this returns one row with ``variant``/``image`` empty. Use ``get_active_build`` for the mandatory first-call health check and the human-readable ``variants``/``images`` discovery; use this tool to see the per-build ``config_hash`` and symbol counts (authoritative per-build state). Args: project_root: Project root directory. Auto-detected from CWD if omitted. project: Project name or project_id — call list_projects to get them. Use it to ask about a project that is not the project of the current directory. It is an alternative to project_root, which takes a root path. Give one of the two, not both. Returns: dict: {builds (list[dict]), multi (bool — True when the config declares variants or a build has a non-empty variant name)}. Each build dict holds: variant (str — empty for a single-project index), image (str — empty for a single-project index), board (str), config_hash (str), symbol_count (int), file_count (int), manifest_verification (str — "full" or "none"), entry_point (str — the `ENTRY()` of the linker script of this build, empty when no script names one), memory (list[dict] — the `MEMORY` regions of this build: {name, attributes, origin, length, origin_value, length_value, file_path, line}). `origin` and `length` are the expression the script writes; `origin_value` and `length_value` are numbers, and they are None for an expression that names a symbol such as `ORIGIN(RAM) + LENGTH(RAM)`. Empty for a build whose system records no linker script — see the note below. THIS is where a per-build memory map lives, not in the `images` list of ``get_active_build``: that list holds one entry per image NAME, and one name can belong to two variants with different addresses. When the project is not initialized, or has no index, the result is {builds: [], multi: False, error (str)}.

reindex_file

Re-parse a single source file with libclang and update its symbols in the index. Not read-only — uses the exact compiler flags from ``compile_commands.json``. Use after editing a file to keep the index current without a full rebuild. A source file must be listed in ``compile_commands.json``. A header is not listed there, thus it is re-parsed through one unit that includes it. That answer covers a single compilation context, thus the result carries a ``warning`` — only a full ``fw-context index`` covers every unit that includes the header. Also regenerates LLM analysis and method override relationships for affected symbols when those features are enabled in config. An unchanged symbol keeps its stored analysis. Args: file_path: Path to the file to re-parse. A source file must be in compile_commands.json; a header goes through one including unit. project_root: Project root directory. Auto-detected if omitted. project: Project name or project_id — call list_projects to get them. Use it to ask about a project that is not the project of the current directory. It is an alternative to project_root, which takes a root path. Give one of the two, not both. Returns: dict: {file, translation_units, symbols_updated, elapsed_s, analysis_updated (if LLM enabled), or error}.

reindex_file_impl

Re-parse a single source file with libclang and update its symbols in the index. Not read-only — uses the exact compiler flags from ``compile_commands.json``. Use after editing a file to keep the index current without a full rebuild. A source file must be listed in ``compile_commands.json``. A header is not listed there — compile_commands.json names translation units — so it is re-parsed through one unit that includes it, taken from the manifest. That answer describes a single compilation context, thus the result carries a ``warning``: another unit can see the header under a different set of ``#define`` values and still hold stale symbols. Only a full ``fw-context index`` covers every context. One unit and not all of them is a cost decision — an application header reaches a median of 3 units but as many as 266 on a real project, at tens of seconds each. Also regenerates LLM analysis and method override relationships for affected symbols when ``with_analysis=True``. The analysis is content-addressed, thus an unchanged symbol is never re-analysed. Args: file_path: Path to the file to re-parse. A source file must be in compile_commands.json; a header goes through one including unit. project_root: Project root directory. Auto-detected if omitted. project: Project name or project_id — call list_projects to get them. Use it to ask about a project that is not the project of the current directory. It is an alternative to project_root, which takes a root path. Give one of the two, not both. with_analysis: When True (default), also regenerates LLM symbol analysis, method override relationships, PageRank, and embeddings. Set False for a fast symbol-only update (used by background auto-reindex). Returns: dict: {file, translation_units, symbols_updated, elapsed_s, analysis_updated (if LLM enabled with analysis), or error}. On failure the dict holds only ``error`` with the reason.

reset_index

Delete the entire symbol index for a project. Not read-only — permanently deletes the SQLite database and WAL files. Call with ``confirm=False`` first (dry-run) to see what would be deleted. Re-index with ``fw-context index`` afterwards. Handles corrupt databases gracefully — you can delete a corrupt index without needing to open it first. Args: project_root: Project root directory. Auto-detected if omitted. project: Project name or project_id — call list_projects to get them. Use it to ask about a project that is not the project of the current directory. It is an alternative to project_root, which takes a root path. Give one of the two, not both. confirm: Must be True to execute. Call without first as dry-run. Returns: dict: {project_root, db, project_id, action: "dry_run"|"deleted", message, symbol_count, indexed_at (dry-run)}. A ``warning`` key means that the database is corrupt — the integrity check failed, thus the counts can be incomplete. On failure the dict holds only ``error`` with the reason.

lookup_symbol

Look up a C/C++ symbol by name via libclang index — exact or prefix matching. Finds symbols text-based search can miss: build-conditional code, template instantiations, macro-expanded names. Macros are extracted via ``clang -dM -E`` during indexing so ``#ifdef``-conditional macros resolve correctly for the active build config. Prefer this over search_code when you know the exact symbol name or a prefix (``uart_`` finds all UART symbols). Use search_code for keyword/concept search. Read-only: yes. May auto-reindex stale files (non-blocking). Args: name: Symbol name (exact match) or prefix (set exact=False). E.g. 'uart_init' finds the exact function; 'uart_' finds all symbols starting with 'uart_'. project_root: Project directory. Auto-detected if omitted. project: Project name or project_id — call list_projects to get them. Use it to ask about a project that is not the project of the current directory. It is an alternative to project_root, which takes a root path. Give one of the two, not both. exact: True = exact name match, False = prefix LIKE match (default). limit: Maximum results (default 50). variant: Build variant (multi-project). Omit for the default variant, ``"*"`` for all. image: Sysbuild image in the variant. Omit for all images. Returns: list[dict]: Symbols with name, qualified_name, kind, file, line, signature, docstring, is_definition, is_template, is_virtual, is_pure_virtual fields. Enum constants include ``enum_value`` with the integer value. Macro results include ``kind="macro"``, ``value`` (raw definition), and ``expanded_value`` (preprocessor- resolved value). May also include ``template_usr``, ``parent_usr``, and ``llm_analysis`` (``{summary, inputs, outputs}``) when available. A model wrote the text in ``llm_analysis``, and the code did not — use it to find a symbol, and quote ``signature``, ``docstring``, or ``get_source`` instead. When no results found, may include ``_did_you_mean`` with suggested symbol names. When no symbol matches, the list is empty — this tool gives no ``info`` entry for an empty result. **Note:** C++ constructors share their name with the enclosing class, so ``lookup_symbol("Foo")`` may return both ``class Foo`` and ``constructor Foo::Foo()``. Use the ``kind`` field to filter when you need a specific symbol type. A symbol that comes from the relaxed prefix fallback carries ``_fallback: True`` — the name is not an exact match of *name*. A list with one dict that holds an ``error`` key means that the project has no index, or that the lookup failed. Read that key before you read the result fields.