macOS Development Agent

Grizzly Brain

An autonomous coding agent that thinks, plans, and builds. Powered by multi-provider AI with 64 development tools and a 2-million token context window.

Download for macOS View on GitHub
64 Tools 14 Categories 2M Token Context 5 Sub-Agents
Dual-Mode Architecture

Two Modes, One Powerful Workflow

Grizzly Brain separates planning from execution, giving you full control over when the agent observes and when it acts.

Den Mode

Read-only planning

Safely explore your codebase without making changes. Den Mode analyzes architecture, traces code paths, and designs implementation plans before a single line is written.

  • Safe codebase exploration
  • Architecture analysis
  • Implementation planning
  • Dependency mapping

Hunt Mode

Autonomous execution

Let Grizzly Brain take the wheel. Hunt Mode creates, edits, tests, and commits code autonomously across your entire project.

  • Full file operations
  • Autonomous code generation
  • Test execution & validation
  • Git operations & commits
Sub-Agent Architecture

A Team of Specialized Agents

Grizzly Brain's sub-agent architecture divides complex tasks across five specialized agents, each with deep expertise in their domain.

Research Bear

Explores codebases, finds patterns, and gathers context for informed decisions

Planner Bear

Designs implementation strategies, breaks down tasks, and coordinates agent workflows

Executor Bear

Writes, modifies, and creates code with precision and project-aware context

Reviewer Bear

Reviews changes for quality, consistency, and adherence to project patterns

Validator Bear

Runs tests, verifies builds, and ensures changes don't break existing functionality

AI Providers

Multi-Provider Intelligence

Route tasks to the best model for the job. Grizzly Brain supports four major AI providers with extended thinking and streaming responses.

Anthropic

Extended thinking, 200K context, tool-use excellence

OpenAI

Reasoning models, vision capabilities, function calling

Google

2M token context, multimodal understanding, code generation

xAI

Default provider, fast streaming, image generation via xAI Files API

Model Context Protocol

Extend Grizzly Brain's capabilities with custom MCP servers. Connect to databases, APIs, and external tools through a standardized protocol.

MCP Client Tool Discovery Custom Servers
Development Toolkit

64 Tools Across 14 Categories

Every tool an autonomous Riverbane AI agent needs to navigate, understand, modify, and ship code.

File Operations

Read, write, create, and manage files across your project. Full directory traversal, file patching, and batch operations for autonomous file management.

Code Search

Grep, glob, and semantic search across entire codebases. Find symbols, trace references, and understand code structure at any scale.

Git Integration

Commits, branches, diffs, and pull request management

Testing

Run test suites, analyze failures, and auto-fix broken tests

Jira & Confluence

Create tickets, search issues, read documentation

GitHub

PRs, issues, code review, and repository management

Built Native

Crafted for macOS

Grizzly Brain is a native macOS application built with Swift and SwiftUI, designed to feel right at home on your Mac. For a cross-platform AI assistant experience, check out Function Fable — its counterpart that runs everywhere.

Swift & SwiftUI Liquid Glass UI Native macOS MVVM-S Architecture
Riverbane AI Engine Async/Await Combine Framework Markdown Rendering Streaming Responses Extended Thinking

Ready to Let the Bear Loose?

Grizzly Brain is the autonomous coding agent that turns your development workflow into a collaborative AI partnership.

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