# Show HN: Arbor – code graph MCP server so agents stop grep-reading your codebase

> Source: <https://github.com/Anandb71/arbor/releases/tag/v2.4.0>
> Published: 2026-07-08 17:15:02+00:00

# Arbor v2.4.0 — The Agent-Native Leap

**Release date:** July 2026

First code-graph MCP server built for MCP `2026-07-28`

.

## What's New

### MCP 2026-07-28 Protocol

- Protocol version
`2026-07-28`

with dual-version fallback for`2025-03-26`

clients - Stateless
`server/discover`

endpoint - Response caching metadata (
`ttlMs`

,`cacheScope`

) on list/read operations - Extensions capability map for Tasks and MCP Apps

### Tasks Extension

`tasks/get`

,`tasks/update`

,`tasks/cancel`

for long-running operations- Background indexing returns task handles instead of errors during cold start
- Agents poll task progress while the graph builds

### MCP Apps (SEP-1865)

- Interactive blast-radius graph UI (
`ui://arbor/blast-radius`

) - Interactive architecture map UI (
`ui://arbor/architecture-map`

) `analyze_impact`

and`get_architecture_overview`

declare`_meta.ui`

resource URIs

### Streamable HTTP Transport

```
arbor bridge --http --port 3333
```

- Stateless HTTP alongside stdio
`Mcp-Method`

/`Mcp-Name`

header routing- Deploy behind load balancers for remote/enterprise use

### Tool Quality

— real git-diff blast radius analysis (replaces stub)`get_blast_radius`

**Pagination** on`search_symbols`

and`get_map`

(`offset`

,`limit`

,`hasMore`

)- Async tokio stdio (replaces blocking stdin loop)

### Benchmarks

- Criterion suite:
`cargo bench -p arbor-graph`

- CI regression gate via
`.github/workflows/benchmarks.yml`

- Updated
`docs/BENCHMARKS.md`

with token-savings methodology

## Upgrade Guide

**MCP clients (Claude / Cursor)** — no changes required for stdio:

```
claude mcp add --transport stdio --scope project arbor -- arbor bridge
```

**HTTP clients (new):**

```
arbor bridge --http --port 3333
# POST http://127.0.0.1:3333/mcp
# Headers: Mcp-Method: tools/call, Mcp-Name: analyze_impact
```

Clients on `2025-03-26`

keep working. Clients on `2026-07-28`

get Tasks, Apps, caching, and pagination.

## Full Changelog

### Added

- MCP 2026-07-28 protocol:
`server/discover`

,`_meta`

parsing, response caching, dual-version fallback - Tasks extension:
`tasks/get`

,`tasks/update`

,`tasks/cancel`

- MCP Apps: blast-radius graph + architecture map HTML templates
- Streamable HTTP:
`arbor bridge --http [--port 3333]`

- Real
`get_blast_radius`

via shared`arbor-graph::compute_blast_radius`

- Pagination on
`search_symbols`

and`get_map`

- Criterion benchmarks + CI workflow

### Changed

- Async MCP stdio (tokio replaces blocking stdin loop)
- MCP tool annotations:
`_meta.ui`

on`analyze_impact`

and`get_architecture_overview`

- Workspace version bumped to
**2.4.0**

## Deferred to v2.5.0

- Parallel (rayon) indexing
- Incremental PageRank
- Unified parser pipelines
- Process-level graph daemon

**Install:** `cargo install arbor-graph-cli`

· [GitHub](https://github.com/Anandb71/arbor) · [MCP Registry](https://github.com/modelcontextprotocol/servers)

## 🤖 Arbor MCP Quick Install

Use Arbor as a local MCP server in your AI client:

### Claude Code (project-scoped)

```
claude mcp add --transport stdio --scope project arbor -- arbor bridge
claude mcp list
```

In Claude Code, run:

```
/mcp
```

### Cursor MCP config (`.cursor/mcp.json`

)

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

### VS Code MCP config (`.vscode/mcp.json`

)

```
{
  "servers": {
    "arbor": {
      "type": "stdio",
      "command": "arbor",
      "args": ["bridge"]
    }
  },
  "inputs": []
}
```

### MCP Directories

- Glama:
[https://glama.ai/mcp/servers/@Anandb71/arbor](https://glama.ai/mcp/servers/@Anandb71/arbor) - Skills Playground:
[https://skillsplayground.com/mcps/nandb71-arbor/](https://skillsplayground.com/mcps/nandb71-arbor/)

## Arbor v2.4.0

### Installation

```
# Cargo
cargo install arbor-graph-cli --version 2.4.0

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

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

# npm
npx @anandb71/arbor-cli

# Docker
docker pull ghcr.io/anandb71/arbor:v2.4.0
```

### Assets

| Platform | Architecture | File |
|---|---|---|
| Linux | x86_64 | `arbor-linux-x86_64.tar.gz` |
| Linux | aarch64 | `arbor-linux-aarch64.tar.gz` |
| macOS | x86_64 | `arbor-macos-x86_64.tar.gz` |
| macOS | Apple Silicon | `arbor-macos-aarch64.tar.gz` |
| Windows | x86_64 | `arbor-windows-x86_64.zip` |

## What's Changed

**Full Changelog**: `v2.3.0...v2.4.0`