> On npm 11.x? npx can crash during install with Cannot destructure property 'package' of 'node.target' (an npm/arborist bug, before GitNexus runs). Use pnpm instead — it builds the native deps explicitly:
>
>

> pnpm --allow-build=@ladybugdb/core --allow-build=gitnexus --allow-build=tree-sitter dlx gitnexus@latest analyze
>

> Fastest MCP startup: install globally (npm i -g gitnexus) before running gitnexus setup — this writes an absolute-path MCP config that bypasses npx entirely. On a cold cache, an npx-based MCP install can exceed Claude Code's MCP_TIMEOUT default (~30s).

> No C++ toolchain? Set GITNEXUS_SKIP_OPTIONAL_GRAMMARS=1 before npm install -g gitnexus to skip the vendored grammar materialize/build for tree-sitter-dart, tree-sitter-proto, tree-sitter-swift, and tree-sitter-kotlin — those four languages won't be parsed, but install completes in seconds without python3/make/g++. Strict =1 only — any other value falls through to the rebuild.

> Behind an HTTP proxy / regional firewall? onnxruntime-node's postinstall downloads optional CUDA binaries from api.nuget.org and ignores HTTP_PROXY/HTTPS_PROXY (#2370). The embedding stack is an optional dependency, so a failed download no longer breaks the install — and it self-heals: the first gitnexus analyze --embeddings (or gitnexus embeddings install) fetches the stack through your npm registry config (mirrors/proxies apply, no NuGet) into ~/.gitnexus/embedding-runtime (override with GITNEXUS_EMBEDDING_RUNTIME_DIR). The on-demand prefix needs Node with module.registerHooks (≥ 22.15 on 22.x, ≥ 23.5 on 23.x); on older Node, keep the stack in the install itself with ONNXRUNTIME_NODE_INSTALL=skip npm install -g gitnexus (works on every supported Node).

> About tree-sitter-kotlin: like Dart/Proto/Swift, Kotlin is a vendored grammar (under gitnexus/vendor/tree-sitter-kotlin). Upstream ships source only (no prebuilt binaries), so GitNexus cross-builds the platform prebuilds itself (via the build-tree-sitter-prebuilds GitHub Actions workflow) and vendors them — the same uniform pipeline used for Dart, Proto, and Swift. node-gyp-build selects the right .node at require time, so no C/C++ toolchain is needed. If no prebuild matches your platform-arch, only Kotlin (.kt/.kts) parsing is unavailable; the rest of gitnexus is unaffected.

Claude Code (full support — MCP + skills + hooks):

# macOS / Linux
claude mcp add gitnexus -- npx -y gitnexus@latest mcp

# Windows
claude mcp add gitnexus -- cmd /c npx -y gitnexus@latest mcp

Codex (full support — MCP + skills + hooks):

codex mcp add gitnexus -- npx -y gitnexus@latest mcp

Or via ~/.codex/config.toml (system scope) / .codex/config.toml (project scope):

[mcp_servers.gitnexus]
command = "npx"
args = ["-y", "gitnexus@latest", "mcp"]

Codex hooks (PreToolUse graph enrichment + PostToolUse stale-index detection in ~/.codex/hooks.json, same schema as Claude Code) need the bundled adapter script, so they are installed by gitnexus setup -c codex rather than manually.

Alternatively, install everything as a Codex plugin (MCP + skills + hooks in one step):

codex plugin marketplace add abhigyanpatwari/GitNexus
# then inside Codex: /plugins → install "GitNexus"

> Codex notes: SessionStart is intentionally not registered — Codex reads AGENTS.md natively, which already carries the GitNexus context block. Newly installed hooks need a one-time approval in Codex via /hooks before they run. Pick one install route (gitnexus setup -c codex or the plugin): plugin hooks load alongside ~/.codex/hooks.json, so installing both can fire duplicate hooks per tool call.

Cursor (~/.cursor/mcp.json — global, works for all projects):

{
  "mcpServers": {
    "gitnexus": {
      "command": "npx",
      "args": ["-y", "gitnexus@latest", "mcp"]
    }
  }
}

Antigravity (Google) — ~/.gemini/antigravity/mcp_config.json:

{
  "mcpServers": {
    "gitnexus": {
      "command": "npx",
      "args": ["-y", "gitnexus@latest", "mcp"]
    }
  }
}

> gitnexus setup also merges an AfterTool entry into ~/.gemini/settings.json (under the canonical Gemini CLI hooks schema) and installs skills to ~/.gemini/antigravity/skills/. Existing user hooks are preserved. The hook adapter's path is rewritten at install time, so run gitnexus setup rather than hand-editing.

OpenCode (~/.config/opencode/config.json):

{
  "mcp": {
    "gitnexus": {
      "type": "local",
      "command": ["gitnexus", "mcp"]
    }
  }
}

CodeBuddy (Tencent) — priority chain, edit the first non-empty file that exists: ~/.codebuddy/.mcp.json (recommended) → ~/.codebuddy/mcp.json (deprecated) → ~/.codebuddy.json (legacy). CodeBuddy reads only the first existing file, so adding servers to a higher-priority file than the one currently in use would hide the servers below it. Create ~/.codebuddy/.mcp.json only if none exist:

{
  "mcpServers": {
    "gitnexus": {
      "command": "npx",
      "args": ["-y", "gitnexus@latest", "mcp"]
    }
  }
}

Qoder (Alibaba) — ~/.qoder.json:

{
  "mcpServers": {
    "gitnexus": {
      "command": "npx",
      "args": ["-y", "gitnexus@latest", "mcp"]
    }
  }
}

Set GITNEXUS_MCP_READ_ONLY=1 before starting the MCP server to expose only the proven single-repository read surface. Raw cypher, rename and group tools, group routing, and group resources are omitted from discovery and rejected before backend dispatch. Tool descriptions and generated setup/context resources are scrubbed so they do not recommend unavailable routes.

The default is unchanged when the variable is unset or 0. Any other value fails server startup rather than silently weakening the policy.

Set GITNEXUS_MCP_ALLOWED_REPOS to a comma-separated list of canonical registry names or absolute indexed paths. Entries are trimmed, resolved against the registry, and deduplicated at startup. When exactly one repository is allowed it becomes the implicit default; when several are allowed, callers must select one unless GITNEXUS_MCP_DEFAULT_REPO is also set.

The default repository must resolve to an allowed repository. Invalid, ambiguous, blank, or mismatched configuration fails startup before stdio or HTTP begins serving. The allowlist applies to tools, aliases, discovery, resources, templates, implicit resolution, and embedded HTTP; hidden repository details are not included in selection errors. Setting only GITNEXUS_MCP_DEFAULT_REPO chooses a default without restricting explicit repository selections. An allowed repository whose name is duplicated in the registry must be configured by path, and its context resource is only served for the unique name form.

The query, context, and impact tools accept an optional positive-integer maxTokens argument. It bounds the complete formatted MCP response, including hints and error text, using a deterministic four-UTF-8-bytes-per-token estimate. When truncation is required, the response ends with … and remains valid UTF-8.

Set GITNEXUS_MCP_DEFAULT_MAX_TOKENS to apply the same guardrail when callers do not send maxTokens. An explicit tool argument takes precedence. Leaving both unset preserves the existing response byte-for-byte; this is a transport guardrail, not semantic pagination or an exact model-specific tokenizer limit.

gitnexus eval-server binds to 127.0.0.1 by default. Loopback bindings do not require authentication. Any non-loopback bind, including 0.0.0.0, a LAN address, or a hostname that resolves to a LAN IPv4 address, requires GITNEXUS_AUTH_TOKEN. Every endpoint then requires an exact Authorization: Bearer header.

GITNEXUS_AUTH_TOKEN='replace-me' gitnexus eval-server --host 0.0.0.0

The token may be set in the shell, .env.local, or .env in the working directory. Precedence is shell > .env.local > .env. Only GITNEXUS_AUTH_TOKEN is read from those files; their other values are not added to the process environment. Keep token files uncommitted.

gitnexus analyze --force         # Full rebuild: re-parse + graph rebuild + FTS rebuild
gitnexus analyze --repair-fts    # Fast path: rebuild/verify only FTS indexes on existing index data
gitnexus analyze --skills        # Generate repo-specific skill files from detected communities
gitnexus analyze --skip-embeddings  # Skip embedding generation (faster)
gitnexus analyze --embeddings [limit]  # Enable embedding generation (slower, better search)
gitnexus analyze --skip-agents-md   # Preserve custom AGENTS.md/CLAUDE.md gitnexus section edits
gitnexus analyze --skip-skills      # Skip installing standard skill files under .claude/skills/ and .agents/skills/
gitnexus analyze --skip-git         # Index folders that are not Git repositories
gitnexus analyze --default-branch develop  # Branch used in the generated regression-compare example (base_ref)
gitnexus analyze --verbose       # Log skipped files when parsers are unavailable
gitnexus analyze --worker-timeout 60  # Increase worker idle timeout for slow parses
gitnexus analyze --workers <n>   # Parse worker pool size (>=1; default: cores-1, capped at 16,
                                 # auto-sized to the repo). 0 is rejected — there is no sequential mode.
gitnexus analyze --wal-checkpoint-threshold 67108864  # LadybugDB WAL auto-checkpoint threshold in bytes
                                 # (default 67108864 = 64 MiB; -1 keeps Ladybug stock ~16 MiB)

If analyze reports a worker parse timeout on a large or unusual repository, it keeps running and falls back safely. To give slow worker jobs more time, use --worker-timeout 60 or set GITNEXUS_WORKER_SUB_BATCH_TIMEOUT_MS=60000. For very large files, GITNEXUS_WORKER_SUB_BATCH_MAX_BYTES controls the worker job byte budget.

Embeddings node limit — gitnexus analyze --embeddings generates semantic search vectors with a default 50,000-node safety cap to protect memory on large repositories:

gitnexus analyze --embeddings          # default 50,000 node safety cap
gitnexus analyze --embeddings 0        # disable the cap entirely
gitnexus analyze --embeddings 100000   # custom cap

If embeddings are skipped on a large repository, the indexed graph likely exceeds the default cap — re-run with --embeddings 0 or a higher limit.

gitnexus group create <name>                           # Create a repository group
gitnexus group add <group> <groupPath> <registryName>  # Add a repo. <groupPath> is a hierarchy path
                                                       # (e.g. hr/hiring/backend); <registryName> is the
                                                       # repo's name from the registry (see `gitnexus list`)
gitnexus group remove <group> <groupPath>              # Remove a repo by its hierarchy path
gitnexus group list [name]                             # List groups, or show one group's config
gitnexus group sync <name>                             # Extract contracts and match across repos/services
gitnexus group contracts <name>                        # Inspect extracted contracts and cross-links
gitnexus group query <name> <q>                        # Search execution flows across all repos in a group
gitnexus group status <name>                           # Check staleness of repos in a group
gitnexus group impact <name> --target <symbol> --repo <groupPath>  # Cross-repo blast radius

Commit a .gitnexusrc JSON file at the repo root to preconfigure recurring analyze options per project, instead of re-passing the same flags every run. It is read from the resolved repo root (not .gitnexus/, which is gitignored index storage). CLI flags always override .gitnexusrc.

{
  // Default branch used in the generated regression-compare example (base_ref).
  // Use this so a project on `develop`/`master` doesn't get "main" rewritten
  // over its fix on every analyze. (Alias: "branch".)
  "defaultBranch": "develop",
  "skipContextFiles": true, // alias of skipAgentsMd: keep your own AGENTS.md/CLAUDE.md
  "skipSkills": true, // don't install standard skill files under .claude/skills/ and .agents/skills/
  "embeddings": true, // generate embeddings by default
  "workerTimeout": 60,
}

A nested analyze block is also accepted (and overrides flat keys for the same option):

{ "analyze": { "defaultBranch": "develop", "skipSkills": true } }

Notes:

• The default branch is resolved as: --default-branch > .gitnexusrc defaultBranch/branch > auto-detected origin/HEAD > main.
• skipContextFiles / skipAiContext are aliases for skipAgentsMd — they skip the AGENTS.md / CLAUDE.md block only. They do not imply skipSkills. indexOnly is the stronger option that skips all file injection.
• Supported keys: defaultBranch (branch), skipAgentsMd (skipContextFiles, skipAiContext), skipSkills, indexOnly, stats/noStats, embeddings, dropEmbeddings, name, allowDuplicateName, maxFileSize, workerTimeout, walCheckpointThreshold, workers, embeddingThreads, embeddingBatchSize, embeddingSubBatchSize, embeddingDevice.
• The file is JSON only. Unknown keys and invalid values fail fast with an actionable error before analysis starts.

Most analyze knobs are also CLI flags (--workers, --worker-timeout, --max-file-size, --verbose). Use the env-var form when you'd otherwise repeat the same flag every run, or when invoking GitNexus from a long-running host (MCP server, eval-server, CI shell) that already manages its own environment. CLI flags take precedence over env vars; env vars take precedence over built-in defaults.

gitnexus uninstall reverses gitnexus setup — it removes the GitNexus MCP entries, hooks, and skill directories it added to each detected editor. Skill directories are identified by bundled gitnexus skill name (e.g. gitnexus-cli/), so if you customized files inside an installed skill directory, back them up first. It is a dry-run preview by default and prints the exact paths it would remove; pass --force to apply. Per-repo indexes (gitnexus clean --all) and the global npm package (npm uninstall -g gitnexus) are left for you to remove.

<code class="ra0-md-code">looptech-ai/understand-quickly</code> is a public registry of code-knowledge graphs that lists gitnexus@1 as a first-class format. After registering your repo once (npx @understand-quickly/cli add or the wizard), gitnexus publish fires a single repository_dispatch event so the registry resyncs your entry on demand instead of waiting for the nightly job.

It is opt-in and a no-op without UNDERSTAND_QUICKLY_TOKEN — a fine-grained GitHub PAT with Repository dispatches: write on the registry repo. Nothing else happens; no graph file is uploaded. See the protocol spec for the full contract.