eulerian 0.1.0

Standalone real-time code index — live local directories and registered git repos

eulerian

Real-time code navigation for AI agents and editors. eulerian keeps a live symbol index — files, classes, functions, methods, constants, with line ranges — so an agent can jump straight to a definition instead of grepping or reading whole files.

Two ways to point it at code:

• Local mode — watch a real working directory. A filesystem watcher re-parses files the moment they're saved; the index never goes stale and there's no explicit re-index step.
• Repo mode — register a git remote, check out a (user, repo, ref) worktree, and browse it without touching your actual working tree. Freshness is checked against the remote on each call instead of pushed live, since nothing is editing the worktree directly.

Both modes share one in-memory symbol index and the same tree-sitter parser. Python only for now (multi-language grammars are straightforward to add — see parser.py).

Install

uv tool install eulerian
# or
pip install eulerian

No other runtime dependencies beyond tree-sitter, tree-sitter-python, rapidfuzz, watchfiles, fastmcp, and typer — all pulled in automatically.

CLI

# Local mode: one-shot queries against a directory, no persistent watcher
eulerian status [PATH]
eulerian outline QUERY [PATH] [-k N]
eulerian find SYMBOL [PATH]

# Local mode: live watch + MCP server (stdio by default, for an MCP client)
eulerian watch [PATH] [--http --host HOST --port PORT]

# Repo mode: register, checkout, browse
eulerian repo add URL
eulerian repo list
eulerian repo fetch REPO
eulerian repo checkout REPO REF [--user NAME]
eulerian repo outline REPO REF QUERY [--user NAME] [-k N]

MCP server

eulerian watch [PATH] starts a FastMCP server (stdio or --http) exposing:

Local mode — watch(path), unwatch(path), outline(query, paths, root, k, format), find(symbol, root), read(path, start, end, root), status(root).

Repo mode — repo_add(url), repo_fetch(repo), repo_list(), repo_pubkey(), checkout(repo, ref, user), checkout_close(repo, ref, user), git_log(repo, ref, user, n), repo_outline(repo, ref, query, paths, user, k, format, reset_head), repo_read(repo, ref, path, user, start, end, segments, reset_head).

Point any MCP-capable client (Claude Code, etc.) at eulerian watch <path> to get instant, line-precise code navigation without burning tool calls on grep/read round-trips.

Repo-mode configuration

Bare clones and worktrees live under ~/.eulerian/ by default:

Env var	Default	Purpose
EULERIAN_GIT_REPOS_PATH	~/.eulerian/repos/	Bare clone + worktree storage
EULERIAN_GIT_SSH_KEY	~/.eulerian/ssh/id_ed25519	Deploy key for private remotes
EULERIAN_GIT_WORKTREE_MAX_IDLE_SEC	3600	Idle worktree eviction threshold

Architecture

parser.py        tree-sitter Python parser -> Symbol / CallEdge / ImportEdge
index.py         in-memory Index, keyed by an opaque handle, rapidfuzz search
sources/local.py watchfiles watcher  -> handle = resolved root Path
sources/repo.py  bare clone + worktree lifecycle -> handle = (user, repo, ref)
mcp/             FastMCP server exposing both modes as tools
cli.py           typer CLI

Index doesn't care what a handle is — local mode and repo mode just pick different shapes for it. Both feed the same outline/find query surface.