arbor

<p align="center"> <img src="docs/assets/arbor-logo.svg" alt="Arbor logo" width="120" height="120" /> </p>

<h1 align="center">Arbor</h1>

<p align="center"> <strong>Graph-native intelligence for codebases.</strong><br> Know what breaks <em>before</em> you break it. </p>

<p align="center"> <a href="https://github.com/Anandb71/arbor/actions"><img src="https://img.shields.io/github/actions/workflow/status/Anandb71/arbor/rust.yml?style=flat-square&label=Rust%20CI" alt="Rust CI" /></a> <a href="https://crates.io/crates/arbor-graph-cli"><img src="https://img.shields.io/crates/v/arbor-graph-cli?style=flat-square&label=crates.io" alt="Crates.io" /></a> <a href="https://github.com/Anandb71/arbor/releases"><img src="https://img.shields.io/github/v/release/Anandb71/arbor?style=flat-square&label=release" alt="Latest release" /></a> <a href="https://github.com/Anandb71/arbor/pkgs/container/arbor"><img src="https://img.shields.io/badge/GHCR-container-blue?style=flat-square" alt="GHCR" /></a> <a href="https://glama.ai/mcp/servers/@Anandb71/arbor"><img src="https://img.shields.io/badge/MCP%20Directory-Glama-6f42c1?style=flat-square" alt="Glama MCP Directory" /></a> <img src="https://img.shields.io/badge/license-MIT-green?style=flat-square" alt="MIT License" /> </p>

<p align="center"> <img src="docs/assets/arbor-demo.gif" alt="Side-by-side: an agent navigating tokio with grep-and-read (47 tool calls, still searching) vs the same agent with arbor's code graph (4 graph calls + 1 read, done)" width="900" /> </p> <p align="center"> _{Simulated replay — the <code>arbor</code> commands and their output are real (tokio @ 178k LOC). Methodology: <a href="docs/BENCHMARKS.md">BENCHMARKS.md</a>} </p>

v2.6.0 — Ground Truth · The graph was wrong in ways v2.5.0 made fast. Colliding symbols were silently dropped, resolution depended on hash order, every edge claimed certainty, and every exported TypeScript symbol was indexed twice. All fixed, all tested. Edge recall +14% on TypeScript, +44% on Rust; 25% of a TS graph was phantom nodes. Reproduce it yourself: cargo run -p arbor-watcher --example graph_stats -- <dir>

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Why Arbor

Most AI coding tools treat code as text. Arbor builds a semantic dependency graph — functions, classes, and modules as nodes; calls, imports, and inheritance as edges — then answers execution-aware questions with deterministic precision:

| Question | Arbor answer | |----------|--------------| | If I change this symbol, what breaks? | Blast radius with depth, confidence, and risk level | | Who calls this — directly and transitively? | Caller/callee traversal on the call graph | | What's the shortest path between A and B? | A path through real dependencies | | Is this PR too risky to merge?* | CI gate on blast-radius thresholds |

No keyword guessing. No embedding hallucinations. One graph, every interface.

Where the graph is unsure, it says so — edges carry a confidence, and ambiguous resolutions are labelled rather than hidden. An honest unknown beats a confident wrong answer.

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What's new in v2.6.0

Correctness, not speed. Each of these was silently wrong before.

| Fix | Why it mattered | |-----|-----------------| | Colliding symbols are kept | SymbolTable used HashMap::insert, so a second handler, new, or process replaced the first. The loser had zero callers and was invisible to blast radius. | | Resolution is deterministic | Same-directory locality was decided by iterating a HashMap. Rust seeds RandomState per process, so the same binary on the same input could build different edges between runs. Now asserted across eight fresh processes. | | Edges carry confidence | A proven same-file call and a same-directory guess were identical evidence. Each edge now scores [0,1] by how it resolved. | | Exported TS symbols indexed once | export_statement recursed into its children, then the generic loop recursed again — every exported symbol became two vertices sharing one node id. 133 phantom nodes on a 149-file app, 25% of the graph. | | Method calls on untyped receivers resolve | obj.method() was dropped outright, leaving the graph nearly edgeless on TS/JS — and an empty graph reports a blast radius of zero, which reads as "safe" rather than "unknown". | | Centrality is a percentile rank | Scores were divided by the graph maximum, so the top node was 1.0 by construction and a 0.6 threshold meant nothing consistent between repos. Adding one hub rescaled every other node. | | Resolution is O(1), not O(refs × nodes × files) | Unresolvable references — stdlib and third-party calls, most call sites in real code — paid the worst case. Suffixes are now indexed. |

New capability — concept search. Substring matching cannot find get_authenticated from login; they share no substring. Identifiers are now tokenized and expanded through curated concept clusters, and docstrings, signatures, and paths are indexed alongside names. Deterministic, offline, no model. Available on the library as ArborGraph::search_ranked (arbor query remains literal-substring for now).

New capability — hunk-level impact. changed_node_ids_for_ranges keeps only symbols whose lines actually changed, instead of every symbol in a touched file.

Measured on identical node sets, after the duplicate-extraction fix:

| Codebase | Before | After | |----------|--------|-------| | TypeScript (149 files) | 172 edges | 196 (+14%) | | Rust (arbor-graph) | 116 edges | 167 (+44%) |

Graph caches from earlier versions are invalidated — centrality now means something different, so a stale cache would be read wrong.

<details> <summary><strong>v2.5.0 — The Last Excuse</strong> (PageRank 23x, parallel indexing, warm-start centrality)</summary>

| Change | Measured | |--------|----------| | PageRank rewrite — flat call-graph adjacency replaces per-iteration traversal | 149.8ms → 6.6ms on a 10k-node graph (23x), verified side-by-side vs the old implementation | | Parallel indexing — parse fans out across all cores, deterministic assembly | Arbor: 253ms → 95ms · tokio (178k LOC): 2.7s → 1.6s | | Warm-start centrality — watcher recomputes seed from previous scores | Converges in ~2 rounds after a one-file patch instead of the full 20-iteration budget | | Convergence early-exit | Iteration stops at 1e-9 max delta — the budget is a ceiling, not a sentence |

Think a number is wrong? cargo bench -p arbor-graph and prove it: BENCHMARKS.md.

</details>

<details> <summary><strong>v2.4.0 — The Agent-Native Leap</strong> (MCP <code>2026-07-28</code>, HTTP transport, Tasks, MCP Apps)</summary>

| Feature | What it does | |---------|--------------| | MCP 2026-07-28 | Stateless server/discover, response caching (ttlMs/cacheScope), dual-version fallback for 2025-03-26 clients | | Tasks extension | tasks/get · tasks/update · tasks/cancel — cold-start indexing returns task handles, not errors | | MCP Apps | Interactive blast-radius graph (ui://arbor/blast-radius) and architecture map (ui://arbor/architecture-map) inside agent hosts | | HTTP transport | arbor bridge --http --port 3333 — stateless MCP behind load balancers | | Real get_blast_radius | Git-diff-aware impact analysis via shared arbor-graph::compute_blast_radius | | Pagination | offset / limit / hasMore on search_symbols and get_map | | Benchmarks | Criterion suite + CI regression gate — see BENCHMARKS.md |

</details>

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Quickstart

# Install
cargo install arbor-graph-cli

# Index your project (one command)
cd your-project && arbor setup

# Explore before you edit
arbor map . --exclude-test          # ranked project skeleton (~1k tokens)
arbor refactor parse_file           # blast radius of changing a symbol
arbor diff                          # impact of uncommitted git changes

# Wire up your AI agent
claude mcp add --transport stdio --scope project arbor -- arbor bridge

Agent workflow: call get_map first → search_symbols / get_file_graph to locate code → Read only the target file. Full MCP guide →

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For AI agents (MCP)

Arbor ships a production MCP server via arbor bridge. Stdio is the default; HTTP is opt-in for remote/enterprise.

# Stdio (Claude, Cursor, VS Code)
arbor bridge

# HTTP (MCP 2026-07-28)
arbor bridge --http --port 3333

Cursor / VS Code

{
  "mcpServers": {
    "arbor": {
      "type": "stdio",
      "command": "arbor",
      "args": ["bridge"]
    }
  }
}

Templates: templates/mcp/ · Setup scripts: scripts/setup-mcp.sh · scripts/setup-mcp.ps1

16 MCP tools

| Tier | Tools | Use when | |------|-------|----------| | Orientation | get_map | First call — token-budgeted project skeleton ranked by PageRank | | Surgical | list_entry_points · get_callers · get_callees · search_symbols · get_file_graph · get_node_detail | Navigate to a specific symbol or file | | Broad | get_logic_path · analyze_impact · find_path · get_knowledge_path | Trace dependencies, blast radius, paths | | Agent-native | get_blast_radius · explain_symbol · audit_security · get_architecture_overview · batch_query | PR impact, onboarding, security audit, bulk lookup |

Every tool returns { ok, tool, data, meta: { suggested_next_tool, suggested_next_args } } so agents chain calls without re-prompting.

Registry: io.github.Anandb71/arbor · Official API lookup · Glama listing

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CLI reference

| Command | Description | |---------|-------------| | arbor setup | One-shot init + index | | arbor map | Ranked, token-budgeted project skeleton | | arbor query <term> | Fuzzy symbol search (supports \| OR) | | arbor callers / callees <sym> | One-hop graph traversal | | arbor entry-points | HTTP handlers, main, jobs, webhooks | | arbor file-graph <path> | Symbols + edges in one file | | arbor inspect <sym> | Full symbol detail | | arbor path <a> <b> | Shortest call-graph path | | arbor refactor <sym> | Blast radius before refactoring | | arbor diff | Git-change impact report | | arbor check | CI safety gate (--max-blast-radius N) | | arbor summary | Auto-generate PR description | | arbor agent review | Autonomous PR architecture review | | arbor agent onboard | Codebase onboarding guide | | arbor agent guard | Real-time architectural safety gate | | arbor bridge | MCP server (add --http for HTTP transport) | | arbor watch | Live re-index on file changes | | arbor gui | Native desktop UI |

All query commands support --json. map additionally supports --tokens N, --focus "pattern", --focus-changed.

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Visual tour

<p align="center"> <img src="docs/assets/visualizer-screenshot.png" alt="Arbor visualizer screenshot" width="760" /> </p>

Full recording: media/recording-2026-01-13.mp4

---

Installation

# Rust / Cargo
cargo install arbor-graph-cli

# Homebrew (macOS/Linux)
brew install Anandb71/tap/arbor

# Scoop (Windows)
scoop bucket add arbor https://github.com/Anandb71/arbor && scoop install arbor

# npm wrapper (cross-platform)
npx @anandb71/arbor-cli

# Docker
docker pull ghcr.io/anandb71/arbor:latest

No-Rust installers:

• macOS/Linux: curl -fsSL https://raw.githubusercontent.com/Anandb71/arbor/main/scripts/install.sh | bash
• Windows: irm https://raw.githubusercontent.com/Anandb71/arbor/main/scripts/install.ps1 | iex

Pinned installs: docs/INSTALL.md

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Language support

Production parsers: Rust · TypeScript / JavaScript · Python · Go · Java · C / C++ · C# · Dart

Fallback parsers: Kotlin · Swift · Ruby · PHP · Shell

Adding languages →

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CI & pull requests

arbor diff --markdown
arbor check --max-blast-radius 30 --markdown
arbor summary

GitHub Action (pre-built binary, ~5s vs ~3–5min compile):

name: Arbor Check
on: [pull_request]

jobs:
  arbor:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - uses: Anandb71/arbor@v2.4.0
        with:
          command: check . --max-blast-radius 30 --markdown
          comment-on-pr: true
          github-token: ${{ secrets.GITHUB_TOKEN }}

---

Architecture

arbor-core (Tree-sitter parsing)
    └── arbor-graph (petgraph + PageRank + impact analysis)
            ├── arbor-cli      — CLI + MCP bridge
            ├── arbor-mcp      — MCP protocol server
            ├── arbor-server   — WebSocket JSON-RPC
            ├── arbor-watcher  — incremental file watcher
            └── arbor-gui      — desktop UI

Docs: Quickstart · Architecture · Graph schema · MCP integration · Benchmarks · Roadmap · Philosophy

Release channels: GitHub Releases · crates.io · GHCR · npm · VS Code / Open VSX · Homebrew · Scoop — Releasing guide

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Philosophy

1. Consumer first — beautiful, intuitive, instantly useful
2. Accessibility second — works across ecosystems, runs anywhere
3. Affordability next — minimal overhead, from laptops to monoliths

Arbor is local-first: no mandatory data exfiltration, offline-capable, open source. Security policy →

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Contributing

cargo build --workspace
cargo test --workspace
cargo clippy --workspace --all-targets --all-features

CONTRIBUTING.md · Good first issues · Code of conduct

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Contributors

<!-- CONTRIBUTORS:START --> <p align="center"> <a href="https://github.com/Anandb71" title="Anandb71" style="text-decoration:none; margin:6px; display:inline-block;"> <img src="https://avatars.githubusercontent.com/u/169837340?v=4" alt="Anandb71" width="72" height="72" loading="lazy" style="border-radius:50%; border:2px solid #30363d; box-sizing:border-box;" /> </a> <a href="https://github.com/holg" title="holg" style="text-decoration:none; margin:6px; display:inline-block;"> <img src="https://avatars.githubusercontent.com/u/1383439?v=4" alt="holg" width="72" height="72" loading="lazy" style="border-radius:50%; border:2px solid #30363d; box-sizing:border-box;" /> </a> <a href="https://github.com/cabinlab" title="cabinlab" style="text-decoration:none; margin:6px; display:inline-block;"> <img src="https://avatars.githubusercontent.com/u/66889299?v=4" alt="cabinlab" width="72" height="72" loading="lazy" style="border-radius:50%; border:2px solid #30363d; box-sizing:border-box;" /> </a> <a href="https://github.com/Karthiksenthilkumar1" title="Karthiksenthilkumar1" style="text-decoration:none; margin:6px; display:inline-block;"> <img src="https://avatars.githubusercontent.com/u/182195883?v=4" alt="Karthiksenthilkumar1" width="72" height="72" loading="lazy" style="border-radius:50%; border:2px solid #30363d; box-sizing:border-box;" /> </a> <a href="https://github.com/zacwolfe" title="zacwolfe" style="text-decoration:none; margin:6px; display:inline-block;"> <img src="https://avatars.githubusercontent.com/u/2164736?v=4" alt="zacwolfe" width="72" height="72" loading="lazy" style="border-radius:50%; border:2px solid #30363d; box-sizing:border-box;" /> </a> <a href="https://github.com/sanjayy-j" title="sanjayy-j" style="text-decoration:none; margin:6px; display:inline-block;"> <img src="https://avatars.githubusercontent.com/u/178475117?v=4" alt="sanjayy-j" width="72" height="72" loading="lazy" style="border-radius:50%; border:2px solid #30363d; box-sizing:border-box;" /> </a> <a href="https://github.com/sathguru07" title="sathguru07" style="text-decoration:none; margin:6px; display:inline-block;"> <img src="https://avatars.githubusercontent.com/u/182798669?v=4" alt="sathguru07" width="72" height="72" loading="lazy" style="border-radius:50%; border:2px solid #30363d; box-sizing:border-box;" /> </a> </p> <p align="center">_{<strong>7 contributors</strong> | <a href="https://github.com/Anandb71/arbor/graphs/contributors">View all</a>}</p>

<!-- CONTRIBUTORS:END -->

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License

MIT — see LICENSE.