code-kb-core 2.0.0

Core library for code-kb AST fact querying, slicing, and progressive disclosure
Documentation

code-kb

Interactive Showcase & Benchmarks: https://anortham.github.io/code-kb/

code-kb is a fast, lightweight code-intelligence engine and Model Context Protocol (MCP) server designed specifically for AI coding agents.

Backed by the rich AST fact tables produced by julie-extractors, code-kb provides progressive disclosure, semantic symbol navigation, and surgical context slicing—enabling agents to navigate and understand codebases with 80–90% fewer tokens without burning context on full file reads or noisy text grep. Agents edit with their native filesystem tools; code-kb automatically refreshes indexed files after filesystem changes.

Why code-kb?

Traditional AI coding agents burn massive amounts of context loading entire source files into their prompt windows just to inspect a single type signature or implementation detail.

code-kb solves this with a progressive disclosure architecture:

  1. Repository Orientation (codebase_outline): Understand directory structures and key exports in ~200 tokens.
  2. File Skeletons (file_skeleton): Inspect function signatures, types, traits, and docstrings with implementation bodies stripped.
  3. Symbol Lookup & Discovery (lookup_symbol / search_symbols): Instant exact/prefix identifier lookups and conceptual search over names, signatures, and docstrings; substrings inside identifiers are found (sha256 finds parseSha256Sidecar).
  4. Surgical Symbol Context (get_symbol_context): In a single turn, fetch a target function's body along with its callee signatures, parameter types, and associated unit tests.
  5. Fresh Indexes: Filesystem edits automatically refresh indexed files, and target body and skeleton reads refresh their file before answering.

Key Principles

  • Small Retained Memory: Written in Rust, zero heavy runtimes (no web dashboard, no GPU models), retained process memory is about 25 MB. The plugin launcher is a small Node script that replaces itself with the native binary via process.execve on supported POSIX Node 22+ runtimes (or waits via spawn on Windows/older Node).
  • Sub-5ms Query Latency: Direct SQLite queries in WAL mode with zero in-memory heap bloat.
  • Zero Workspace Parameters: Pure semantic tool calling (lookup_symbol(query="...")). The agent is never burdened with workspace_id, repo_path, or path confusion.
  • CLI-First Parity: Every MCP tool has an exact 1:1 CLI command for instantaneous terminal verification and dogfooding.
  • Continuous 3-Tier Sync: Tool-driven updates, JIT staleness guards before reads, and a debounced background watcher with a Git storm circuit breaker.

Install

Install the plugin for your agent. The plugin ships a small Node.js launcher. On the first run it downloads the matching code-kb release archive for your platform, verifies its SHA-256, and unpacks code-kb and julie-extract into ~/.code-kb/dist/<version>/. Later runs start instantly. Nothing else to download or put on PATH.

Requirements:

  • Node.js 18 or newer on PATH (the launcher is a Node script; the server itself is a native binary).
  • Windows 10 build 17063 or newer (the launcher unpacks with the built-in tar.exe).

Claude Code

/plugin marketplace add anortham/code-kb

/plugin install code-kb@code-kb

(Send as two separate prompts.) The plugin registers the MCP server, the progressive disclosure skill, a /code-kb:telemetry command for usage and token-savings reports, and SessionStart and SubagentStart hooks that inject routing instructions.

Codex

codex plugin marketplace add anortham/code-kb
codex plugin add code-kb@code-kb

Run codex, open /hooks, and trust the two code-kb hooks.

To update, refresh the marketplace snapshot first. codex plugin remove followed by codex plugin add reinstalls the version already in the snapshot:

codex plugin marketplace upgrade
codex plugin remove code-kb@code-kb
codex plugin add code-kb@code-kb

Antigravity CLI (AGY)

agy plugin install https://github.com/anortham/code-kb

The plugin registers the MCP server and a PreInvocation hook. Antigravity has no SessionStart hook, so routing directives arrive per turn through injectSteps.

Grok CLI

grok plugin install anortham/code-kb --trust

First Run & Automatic Indexing

You do not need to run code-kb scan by hand. The first code-kb tool call or CLI command in a repository creates <workspace>/.code-kb/artifact.db and runs the initial scan. A git worktree copies its parent repository's index instead of scanning again. Files that changed while no session ran, for example after a branch switch, are reconciled before the first answer. Pre-index a large repository before a session with:

code-kb scan

Launcher environment variables:

Variable Effect
CODE_KB_HOME Directory that holds dist/ (default ~/.code-kb).
CODE_KB_VERSION Release version to fetch instead of the plugin's own version.
CODE_KB_BIN Run this binary and skip the download entirely (local builds).

Two overrides need no environment variable, which matters in harnesses that do not pass the environment to MCP servers (Codex):

  • A binary or symlink at ~/.code-kb/bin/code-kb (code-kb.exe on Windows) runs instead of any download, in every harness. For development: ln -s /path/to/code-kb/target/release/code-kb ~/.code-kb/bin/code-kb.
  • A plugin installed from a source checkout runs that checkout's target/release/code-kb when it exists.

With either in place, cargo build --release plus a session restart is the whole development loop.

Uninstall

Harness Command / Action
Claude Code /plugin remove code-kb
Codex codex plugin remove code-kb@code-kb
Antigravity (AGY) agy plugin uninstall code-kb
Grok CLI grok plugin uninstall code-kb

Delete ~/.code-kb/dist to remove the downloaded binaries. Each workspace keeps its index in <workspace>/.code-kb/; delete that directory to remove the index.

Manual Configuration

Use this path for harnesses without a plugin manager, or when you would rather manage the binary yourself.

Step 1: Get the Binaries

  • GitHub Releases: download the archive for your platform from GitHub Releases:

    • Linux x86_64 and ARM64 (.tar.gz)
    • macOS Apple Silicon and Intel (.tar.gz)
    • Windows x86_64 and ARM64 (.zip)

    Unpack it and put both binaries on your PATH (for example ~/.local/bin, /usr/local/bin, or C:\tools). code-kb and julie-extract are packaged side by side, and code-kb finds julie-extract next to its own executable.

  • Cargo:

    cargo binstall code-kb-cli
# or
cargo install code-kb-cli

    Cargo installs code-kb only. Download the pinned julie-extract from the julie-extractors releases (version in scripts/julie-pins.json) and put it on your PATH or set JULIE_EXTRACT_BIN.

  • Verify:

    code-kb --version

Step 2: Register the MCP Server

Every harness runs the same command: code-kb serve. Hooks run code-kb hook <Event>.

How code-kb Finds Your Workspace

Tools never take a workspace parameter. The server binds a workspace in three steps, and each later step replaces the earlier one:

  1. At start: --root <path> on the serve command, or, without it, the directory the process starts in, searched upward for .git or a project marker.
  2. At handshake: the roots the host sends in the MCP initialize request, if any.
  3. At each tool call: an absolute path inside a repository in any file_path or path argument.

Terminal harnesses (Claude Code, Codex, AGY, Grok CLI, Copilot CLI, Pi, Swival, Zed) start the server in the project directory, so code-kb serve alone is enough.

GUI apps (Cursor, Windsurf, the Antigravity IDE, Visual Studio, VS Code, Claude Desktop) start the server from their own install directory, not from your project. For these apps, put the MCP config inside the project and pass --root with the absolute path of the project:

"args": ["serve", "--root", "/absolute/path/to/project"]

Without --root, the first tool call in a GUI app fails with Database artifact not found ... configure code-kb with '--root <repo-path>'. That error is the signal to add the flag. A tool call with an absolute path inside a repository also binds the server, so a session can recover, but --root removes the guesswork.

Claude Code (without the plugin)

claude mcp add --scope user code-kb -- code-kb serve

Codex (without the plugin)

In ~/.codex/config.toml:

[mcp_servers.code-kb]
command = "code-kb"
args = ["serve"]

Antigravity CLI (without the plugin)

agy mcp add code-kb code-kb serve

Global config (~/.gemini/config/mcp_config.json) with "eager": true. The AGY CLI starts the server in the project directory. The Antigravity IDE starts it from its own install directory, so add --root when you use the IDE:

{
  "mcpServers": {
    "code-kb": {
      "command": "code-kb",
      "args": ["serve", "--root", "/absolute/path/to/project"],
      "disabled": false,
      "eager": true,
      "force_all_tools_eager": true
    }
  }
}

Lifecycle hook configuration (~/.gemini/config/hooks.json):

{
  "code-kb": {
    "PreInvocation": [
      {
        "command": "code-kb hook PreInvocation",
        "timeout": 10,
        "type": "command"
      }
    ]
  }
}

Progressive disclosure skill linking:

ln -sf /path/to/code-kb/skills/code-kb ~/.gemini/config/skills/code-kb

Grok CLI (without the plugin)

Project-level .mcp.json:

{
  "mcpServers": {
    "code-kb": {
      "command": "code-kb",
      "args": ["serve"]
    }
  }
}

Cursor

In .cursor/mcp.json at the repository root. Cursor is a GUI app, so pass --root:

{
  "mcpServers": {
    "code-kb": {
      "command": "code-kb",
      "args": ["serve", "--root", "/absolute/path/to/project"]
    }
  }
}

OpenCode

Add to opencode.json in the project:

{
  "mcpServers": {
    "code-kb": {
      "command": "code-kb",
      "args": ["serve", "--root", "/absolute/path/to/project"]
    }
  }
}

Claude Desktop

Claude Desktop has one global config and no project directory, so --root pins one project. Add to claude_desktop_config.json (%APPDATA%\Claude\claude_desktop_config.json on Windows, ~/Library/Application Support/Claude/claude_desktop_config.json on macOS):

{
  "mcpServers": {
    "code-kb": {
      "command": "code-kb",
      "args": ["serve", "--root", "/absolute/path/to/project"]
    }
  }
}

Other GUI Apps (Windsurf, Visual Studio, VS Code)

Use the app's project-level MCP config file and the same arguments: ["serve", "--root", "/absolute/path/to/project"]. On Windows write the path with forward slashes, for example C:/source/project.

GitHub Copilot CLI & Terminal Agents

Terminal harnesses (Copilot CLI, Pi, Swival, Zed) start the server in the project directory: configure the MCP server to run code-kb serve with no --root.

To remove a manual configuration, delete the code-kb entry from the harness config (claude mcp remove code-kb, agy mcp remove code-kb, or edit the file) and delete the binaries from your PATH.

Qt and QML

For a Qt developer, code-kb answers the everyday questions about a QML code base. file_skeleton prints the component as its object tree: declared properties, signals, functions, inline components, and every nested object under its owner. find_references crosses component files: it lists the components that extend a base type as extends rows, the plain and qualified instantiations (Kirigami.Page as well as Page), the files that read a singleton, and the signal handlers, each labelled handler when the receiver names the owner and handler (candidate) when it does not. qmldir module files and .qmltypes type descriptors are indexed. Qt JavaScript files parse, including the .pragma library and .import directives. KDE test files under autotests/ and files named tst_*.qml are hidden from search by default; --include-tests shows them.

Current source builds use julie-extract 3.3.1. QML references retain inline component ownership, respect shadowed id names, and resolve parent and this from their enclosing object. QML import directives appear as structural facts. Qt JavaScript .import symbols preserve their exact spans, so body reads exclude trailing comments. code-kb facts pragma --path src lists .pragma facts from both QML and Qt JavaScript.

A Qt C++ header indexes the same way. file_skeleton prints one Q_PROPERTY(...) row per declared property under its class, keeping the READ, WRITE, NOTIFY, and MEMBER accessors the macro names. A method declared in a Q_SIGNALS: section is an event row, and the skeleton marks it // event before its line range because its C++ signature reads like a method. A method in a Q_SLOTS: section carries qt_slot, and a Q_INVOKABLE method carries qt_invokable. A class records the QML element name it declares with QML_ELEMENT or QML_NAMED_ELEMENT. A forward declaration such as class ColumnView; emits no row, so lookup_symbol of a class name returns one row, at its definition. find_structural_facts takes a property alias that covers the QML property declarations and the Qt C++ Q_PROPERTY facts together, each fact naming its class. Property facts expose their available Qt metadata, including property_type, accessors, and the optional designable, scriptable, stored, user, and revision attributes. Until upstream header updates preserve C++ language detection, one batch of changed .h files triggers a content-aware workspace scan that only re-extracts changed files.

First-class Qt support: QML, qmldir, .qmltypes, Qt JavaScript, and Qt C++ headers, validated on pinned corpus revisions; static reference results have documented limits; .ui and CMake files are not indexed.

Historical 1.6.0 / Julie 3.3.0 measurements

Corpus Pinned commit QML files C++ files
Omarchy shell (Quickshell) 49306774 106 0
KDE Kirigami ca7d636 225 102
KDE plasma-workspace a45871a 222 1051
Quickshell examples c6d1236 14 0

These corpus revisions and examples were measured with code-kb 1.6.0 and julie-extract 3.3.0. They are historical measurements, not 3.3.1 results.

# Omarchy
code-kb skeleton shell/Ui/Button.qml
# 71 lines for a 209-line file; the object tree nests, so ToolTip, Row, MouseArea,
# and HoverHandler hold their own children.

code-kb refs BarWidget --file shell/Ui/BarWidget.qml --limit 200
# 15 rows: 12 `extends` rows, one per component that extends BarWidget.
# The other 3 rows are signal handlers, grouped one row per file.

code-kb refs Color --file shell/Commons/Color.qml --limit 200
# 53 rows, one per file that reads the Color singleton.

code-kb refs clicked --file shell/Ui/Button.qml
# 20 rows: 4 emit sites, 1 `handler` row, and 15 `handler (candidate)` rows.

code-kb lookup SpeedDial
# 1 row: class SpeedDial [shell/Ui/SpeedTestOverlay.qml:206-411],
# signature `component SpeedDial: Item`, an inline component.

# Kirigami
code-kb refs Page --file src/controls/Page.qml --limit 200
# 60 rows, of which 7 are `extends` rows (four of them inline components).

# Kirigami, Qt C++
code-kb skeleton src/layouts/columnview.h
# 231 lines for a 785-line file, 38 `Q_PROPERTY(...)` rows, no parse-error banner.

code-kb lookup ColumnView
# 1 class row: `class ColumnView [src/layouts/columnview.h:276-783]`.
# The forward declaration in the same file adds no second row.

code-kb facts property --path src/layouts/columnview.h --limit 5
# 5 of the file's 38 `cpp.qt_property.v1` facts, each naming the class that owns it
# (`ScrollIntentionEvent`, `ColumnViewAttached`).

Known limits

  • A project macro that the extractor does not know is not blanked before the parse, so it can still cause a parse diagnostic. Diagnostics remain on both C++ corpora: 31 on Kirigami and 298 on plasma-workspace, down 97% and 94% from julie-extract 3.2.0. None of them is macro-shaped; a file-local #define used as a statement accounts for 12 of Kirigami's 31.
  • Q_DECLARE_FLAGS(Modes, Mode) and a Q_OBJECT_BINDABLE_PROPERTY(...) member are blanked as whole statements, so the typedef and the member emit no row.
  • A macro used inside a line, such as Q_ARG(bool, true) in a QMetaObject::invokeMethod call, is left alone by design, because rewriting it would delete real arguments.
  • .ui designer files and CMake files are not indexed.
  • A QML module imported through an alias resolves to a workspace file only when the alias is not a Qt module. QtQuick.* and QtQml.* aliases never name a workspace symbol.
  • A reference list caps at 200 rows. For a heavily used singleton, refs groups the member accesses per file, one row per file with a count.

MCP Tool Catalog

Tool Purpose Key Parameters Aliases
codebase_outline High-level architectural orientation of directory layout & symbols. path (opt), depth (opt, default 2) dir, subpath
file_skeleton File outline with function & method bodies stripped (80–90% token savings); a directory returns its outline. file_path (req) file, path
lookup_symbol Fast identifier lookup (exact name or prefix) across repo or scoped path. Test functions, test containers, and rows from test files are hidden unless is_test is true, except a row whose name equals the query. query (req), path (opt), kind (opt), is_test (opt), limit (opt) name, q
search_symbols Conceptual search over symbol names, signatures & docstrings; substrings inside identifiers are found (sha256 finds parseSha256Sidecar). Results are reranked by crediting each query term once from its strongest field (name, signature, docstring), weighted by the term's rarity across the index, plus kind and path priors; score is that rerank score. Test functions, test containers, and rows from test files are hidden unless is_test is true. query (req), path (opt), kind (opt), is_test (opt), limit (opt) name, q
get_symbol_body Slices the exact implementation body of a symbol from disk. Exactly one symbol_name or current-index symbol_id; file_path (opt) symbol, name, path
get_symbol_context Surgical bundle: target body + callee signatures + parameter types + tests. Exactly one symbol_name or current-index symbol_id; file_path (opt), include_external (opt, def: false) symbol, name, path
find_references Callers or callees of a symbol, matched by name from AST call sites and ranked by same file, same directory, then receiver type; callers also include type usages and member accesses (filters external stdlib noise; qualify overloaded names). Exactly one symbol_name or current-index symbol_id; file_path (opt), direction ("callers" | "callees", def: callers), include_external (opt, def: false) symbol, name, file, path
blast_radius Multi-hop reverse reachability (CTEs) & targeted test prediction. symbol or current-index symbol_id (opt), file (opt guard for an ID), depth (opt, def: 2), limit (opt) name, path, impact
find_structural_facts Queries framework facts (routes, SQL queries, config keys, tables). Lists all categories when omitted. category (opt), path (opt), limit (opt) cat, kind, type, file, file_path
telemetry_summary Token savings with their coverage, call counts, and error rates from ~/.code-kb/telemetry.db, across all workspaces or scoped to the current one. time_window (opt, def: all), workspace_only (opt, def: false), json (opt) since, window

CLI Commands (Direct Terminal Usage)

Every MCP capability can be executed directly from your terminal with 1:1 parity:

# Architectural outline of current repo (depth 2)
code-kb outline

# Skeleton of a specific file (implementation bodies stripped)
code-kb skeleton src/main.rs

# Lookup symbols by exact name or prefix (alias: code-kb symbol)
code-kb lookup Workspace --kind struct --path crates/code-kb-core

# Conceptual search over names, signatures, and docstrings (sha256 finds parseSha256Sidecar)
code-kb search "syntax validation concurrency"

# Same search with the rerank breakdown under each result (JSON: an `explain` object per result)
code-kb search "sha256 sidecar" --explain

# Retrieve exact implementation body of a symbol
code-kb body Workspace

# Get surgical context bundle: body + callees + types + tests (alias: code-kb slice)
code-kb context ensure_fresh_file

# Find callers or callees of a function (language-agnostically filters stdlib noise)
code-kb refs open_read_only --direction callers

# View callees including external standard library tokens
code-kb refs open_read_only --direction callees --include-external

# Predict blast radius and targeted tests to run for a symbol or file
code-kb blast-radius compute_blast_radius

# Zero-argument blast radius: auto-discovers uncommitted git working-tree changes
code-kb blast-radius
# (alias: code-kb impact)

# Query framework structural facts (or omit category to list all detected categories)
code-kb facts
code-kb facts config --path Cargo.toml
code-kb facts route --limit 10

# View active log file and recent diagnostic messages
code-kb logs

# Token savings, call counts, and error rates (alias: code-kb telemetry)
code-kb stats --since month
code-kb stats --workspace

# Self-contained diagnostic bundle (versions, index facts, recent errors, log tail) with a
# pre-filled GitHub issue link; the /report-issue skill files it through `gh issue create`
code-kb bug-report --title "lookup returns nothing" --description "what went wrong"

# Output agent lifecycle hook payload (SessionStart / SubagentStart / PreInvocation)
code-kb hook SessionStart
code-kb hook SubagentStart
code-kb hook PreInvocation

Telemetry and What "Saved" Means

code-kb records every tool call in ~/.code-kb/telemetry.db. telemetry_summary and code-kb stats report the calls, the latency, the error rate, the tokens served, and the tokens saved.

Saved is the size, in estimated tokens, of the files the answer points into, minus the tokens served. A skeleton, body, or context read is measured against its own file. A lookup, search, references, blast-radius, or facts answer is measured against the distinct files its rows name, at most 20 files. A call with no file to point at, such as an outline or a telemetry summary, records no baseline and is not counted as saved.

The report states that coverage beside the number, so you can see how much of the window it covers:

Est. Tokens Saved: ~<saved> (baseline known for <K> of <M> calls)

Each tool row carries the same pair as ~N (K/M). Rows written before this measurement existed carry no baseline and are never rewritten.

Development

For contributors building code-kb from source:

Prerequisites

  • Rust (1.95+ / Edition 2024)
  • Extractor binary: Run ./scripts/restore-julie-extract.sh to download the pinned julie-extract binary

Build and Install Locally

# Restore pinned julie-extract binary
./scripts/restore-julie-extract.sh

# Install code-kb binary from local checkout
cargo install --path crates/code-kb-cli --force

Running Tests & Verification

# Run test suite
cargo test --workspace

# Run the plugin launcher and manifest tests
node --test tests/plugin/*.test.cjs

# Run release pre-flight verification
./scripts/release-preflight.sh

To run the Claude Code plugin from this checkout, build and load it. The launcher runs target/release/code-kb when it exists, so no download happens:

cargo build --release
claude --plugin-dir .

Architecture & Engineering Plans

code-kb was designed based on extensive benchmarking and retrospectives from earlier code intelligence engines:

License

Dual-licensed under MIT or Apache-2.0.