miller

Miller

Miller is a local code-intelligence server for coding agents. It keeps a current SQLite-backed view of a workspace, then answers structural questions through MCP and a matching CLI: find symbols, inspect files, build focused context, trace relationships, assess change impact, and check workspace freshness without asking an agent to grep and reread the repo by hand.

Miller is the free local core in the Miller/Eros product split. It stays deterministic, lexical/structural, daemon-light, and local-first, with optional local semantic retrieval that is off-switchable and leaves lexical-only results byte-identical. Eros sits above it for fleet-level semantics: cross-workspace ranking, higher-level guidance, confidence/evidence views, and commercial orchestration.

The practical difference from a one-time graph dump is that Miller is built for active agent work:

• workspace state, freshness, refresh, and selectors are first-class;
• CLI and MCP calls share the same read cores, so examples can be dogfooded in a shell and used by agents;
• the registry, telemetry, and dashboard show what Miller knows right now;
• telemetry-derived onboarding can summarize how agents have used this indexed repo without storing raw queries;
• stale or corrupt search sidecars fail visibly instead of silently lying; refresh the workspace or explicitly opt out with MILLER_SEARCH_SIDECAR=0 when debugging the in-memory fallback;
• cross-language bridge evidence stays structural and provider-scoped, not embedding-driven.

Current release: v1.13.0. Miller ships as agent plugins, self-contained per-platform release archives, and a source-checkout workflow. Plugin and release-archive installs include the pinned julie-extract binary; users do not install it separately.

Website: anortham.github.io/miller · Release: v1.13.0

Quickstart

Most Claude Code and Codex users should start with the agent plugin. The plugin launcher downloads the matching Miller release archive, verifies its .sha256 sidecar, caches it under ~/.miller/plugin-cache/, and starts miller serve as an MCP server. That archive includes Miller's pinned .tools/julie-extract binary, so plugin users do not install julie-extract or the .NET SDK separately.

Plugin installs require Node.js on PATH — the launcher is a Node script. If Node.js is missing (common with Claude Code's native installer, which does not need Node itself), the plugin fails to connect with the opaque MCP error -32000 and writes no Miller log. Install Node.js LTS and restart your agent. The manual install paths below run the miller binary directly and do not need Node.js.

Claude Code:

/plugin marketplace add anortham/miller
/plugin install miller@miller

Codex:

codex plugin marketplace add anortham/miller
codex
# then open /plugins and install Miller from the miller marketplace

Cursor: install Miller from the Cursor plugin marketplace, or add a user-global ~/.cursor/mcp.json entry with an absolute path to miller serve. Miller binds its workspace from MCP client roots on the first tool call, so one global install works per editor window without ${workspaceFolder} placeholders.

The Claude Code plugin also injects a ~2.4KB Miller routing block at session start through a SessionStart hook, so the tool-routing guidance stays in context even though clients truncate MCP server instructions. The Codex plugin ships the same hook: Codex runs it once you review and trust the plugin's hooks, and current Codex builds load hooks from ~/.codex/hooks.json rather than from plugin roots (openai/codex#16430). Set MILLER_SESSION_HOOKS=0 to opt out.

After extracting a release archive (see Manual Binary Install), add to ~/.cursor/mcp.json:

{
  "mcpServers": {
    "miller": {
      "type": "stdio",
      "command": "/absolute/path/to/miller-1.13.0-aarch64-apple-darwin/miller",
      "args": ["serve"]
    }
  }
}

On Windows, use the full path to miller.exe as command. Optional override for clients without MCP roots: set "env": { "MILLER_WORKSPACE_ROOT": "/absolute/path/to/project" } on the server entry.

For Miller development in this checkout, run scripts/install-cursor-local-dev.sh (or .ps1) to write ~/.cursor/mcp.json with your Release build path and retire legacy plugin-cache installs.

Reload Cursor after adding the entry, then ask your agent to search, inspect, build context, trace, or check impact with Miller. Miller writes its local index under that workspace's .miller/ directory.

Common Agent Workflow

Use Miller's structural tools before broad file reads: