Crush

Features

• Multi-Model: choose from a wide range of LLMs or add your own via OpenAI- or Anthropic-compatible APIs
• Flexible: switch LLMs mid-session while preserving context
• Session-Based: maintain multiple work sessions and contexts per project
• LSP-Enhanced: Crush uses LSPs for additional context, just like you do
• Extensible: add capabilities via MCPs (http, stdio, and sse)
• Works Everywhere: first-class support in every terminal on macOS, Linux, Windows (PowerShell and WSL), Android, FreeBSD, OpenBSD, and NetBSD
• Industrial Grade: built on the Charm ecosystem, powering 25k+ applications, from leading open source projects to business-critical infrastructure

Installation

Use a package manager:

# Homebrew
brew install charmbracelet/tap/crush

# NPM
npm install -g @charmland/crush

# Arch Linux (btw)
yay -S crush-bin

# Nix
nix run github:numtide/nix-ai-tools#crush

# FreeBSD
pkg install crush

Windows users:

# Winget
winget install charmbracelet.crush

# Scoop
scoop bucket add charm https://github.com/charmbracelet/scoop-bucket.git
scoop install crush

Crush is available via the official Charm NUR in nur.repos.charmbracelet.crush, which is the most up-to-date way to get Crush in Nix.

You can also try out Crush via the NUR with nix-shell:

# Add the NUR channel.
nix-channel --add https://github.com/nix-community/NUR/archive/main.tar.gz nur
nix-channel --update

# Get Crush in a Nix shell.
nix-shell -p '(import <nur> { pkgs = import <nixpkgs> {}; }).repos.charmbracelet.crush'

NixOS & Home Manager Module Usage via NUR

Crush provides NixOS and Home Manager modules via NUR. You can use these modules directly in your flake by importing them from NUR. Since it auto detects whether its a home manager or nixos context you can use the import the exact same way :)

{
  inputs = {
    nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
    nur.url = "github:nix-community/NUR";
  };

  outputs = { self, nixpkgs, nur, ... }: {
    nixosConfigurations.your-hostname = nixpkgs.lib.nixosSystem {
      system = "x86_64-linux";
      modules = [
        nur.modules.nixos.default
        nur.repos.charmbracelet.modules.crush
        {
          programs.crush = {
            enable = true;
            settings = {
              providers = {
                openai = {
                  id = "openai";
                  name = "OpenAI";
                  base_url = "https://api.openai.com/v1";
                  type = "openai";
                  api_key = "sk-fake123456789abcdef...";
                  models = [
                    {
                      id = "gpt-4";
                      name = "GPT-4";
                    }
                  ];
                };
              };
              lsp = {
                go = { command = "gopls"; enabled = true; };
                nix = { command = "nil"; enabled = true; };
              };
              options = {
                context_paths = [ "/etc/nixos/configuration.nix" ];
                tui = { compact_mode = true; };
                debug = false;
              };
            };
          };
        }
      ];
    };
  };
}

sudo mkdir -p /etc/apt/keyrings
curl -fsSL https://repo.charm.sh/apt/gpg.key | sudo gpg --dearmor -o /etc/apt/keyrings/charm.gpg
echo "deb [signed-by=/etc/apt/keyrings/charm.gpg] https://repo.charm.sh/apt/ * *" | sudo tee /etc/apt/sources.list.d/charm.list
sudo apt update && sudo apt install crush

echo '[charm]
name=Charm
baseurl=https://repo.charm.sh/yum/
enabled=1
gpgcheck=1
gpgkey=https://repo.charm.sh/yum/gpg.key' | sudo tee /etc/yum.repos.d/charm.repo
sudo yum install crush

Or, download it:

• Packages are available in Debian and RPM formats
• Binaries are available for Linux, macOS, Windows, FreeBSD, OpenBSD, and NetBSD

Or just install it with Go:

go install github.com/charmbracelet/crush@latest

On illumos (OpenIndiana, OmniOS), the command above works as-is. Only native OS notifications are unavailable there; terminal-based notifications (OSC) and the terminal bell still work. On Oracle Solaris, add -tags sqlite3_dotlk so the local database uses dot-file locking:

go install -tags sqlite3_dotlk github.com/charmbracelet/crush@latest

[!WARNING] Productivity may increase when using Crush and you may find yourself nerd sniped when first using the application. If the symptoms persist, join the [Slack][slack] or [Discord][discord] and nerd snipe the rest of us.

Getting Started

The quickest way to get started is to choose a Hyper model from model picker. Follow the steps to authenticate and you’ll be good to go.

Hyper, from Charm, is the official Crush provider. It’s subscription-based, with a free tier, and optimized for Crush. It’s privacy focused, with zero data retention (ZDR) is and designed to comply with GDPR. More on Hyper.

API Keys

You can also use Crush with many other providers such as Anthopic, OpenAI, Gemini, OpenRouter and so on. Press ctrl+l to open the model picker, choose the provider of your choice, and paste your API key.

That said, you can also set environment variables for preferred providers:

Environment Variable	Provider
HYPER_API_KEY	Charm Hyper
ANTHROPIC_API_KEY	Anthropic
OPENAI_API_KEY	OpenAI
VERCEL_API_KEY	Vercel AI Gateway
GEMINI_API_KEY	Google Gemini
ZAI_API_KEY	Z.ai
MINIMAX_API_KEY	MiniMax
SYNTHETIC_API_KEY	Synthetic
HF_TOKEN	Hugging Face Inference
CEREBRAS_API_KEY	Cerebras
OPENROUTER_API_KEY	OpenRouter
IONET_API_KEY	io.net
ALIBABA_SINGAPORE_API_KEY	Alibaba (Singapore)
ALIBABA_US_API_KEY	Alibaba (United States)
GROQ_API_KEY	Groq
AVIAN_API_KEY	Avian
OPENCODE_API_KEY	OpenCode Zen & Go
VERTEXAI_PROJECT	Google Cloud VertexAI (Gemini)
VERTEXAI_LOCATION	Google Cloud VertexAI (Gemini)
AWS_ACCESS_KEY_ID	Amazon Bedrock (Claude)
AWS_SECRET_ACCESS_KEY	Amazon Bedrock (Claude)
AWS_REGION	Amazon Bedrock (Claude)
AWS_PROFILE	Amazon Bedrock (Custom Profile)
AWS_BEARER_TOKEN_BEDROCK	Amazon Bedrock
AZURE_OPENAI_API_ENDPOINT	Azure OpenAI models
AZURE_OPENAI_API_KEY	Azure OpenAI models (optional when using Entra ID)
AZURE_OPENAI_API_VERSION	Azure OpenAI models
MOONSHOT_API_KEY	Moonshot

Also note that Crush can support nearly any provider, including Local Models. For more info see Custom Providers below.

By the Way

Is there a provider you’d like to see in Crush? Is there an existing model that needs an update?

Crush’s default model listing is managed in Catwalk, a community-supported, open source repository of Crush-compatible models, and you’re welcome to contribute.

Configuration

[!TIP] Crush ships with a builtin skill for configuring itself. Most of the time you can just tell what you want it to configure and it will get the job done.

Crush runs great with no configuration. That said, if you do need or want to customize Crush, you can, with a crushrc.

A crushrc is just Bash with some Crush-specific builtins. It’s a lot like a .bashrc, just for your Crush. Because Crush has a native, built-in Bash interpreter, Bash-based config works identically across all platforms, including Windows.

For example:

# Add Ollama.
provider add ollama --type ollama --base-url "http://localhost:11434/v1"

# Register a model on Ollama.
model add ollama/llama3.3 --name "Llama 3.3" --context-window 128000

# Auto-approve some tools.
permissions allow view edit

# Include some other file on a specific machine.
if [[ $HOSTNAME == "babysquid" ]]; then
    source ~/my-stuff/babysquid.sh
fi

# Add an MCP server, with a GitHub API token stored in 1password.
mcp add github \
  --type http \
  --url "https://api.githubcopilot.com/mcp/" \
  --header Authorization "Bearer $(op read 'op://my-secret-key')"

Configuration can be added either local to the project itself, or globally, with the following priority:

Priority	Unix-like	Windows
1	./.crushrc	.\.crushrc
2	./crushrc	.\crushrc
3	~/.config/crush/crushrc	%USERPROFILE%\.config\crush\crushrc

(Crush respects the XDG Base Directory Specification, so your paths may differ depending on your XDG_CONFIG_HOME value. Data directories such as ~/.local/share/crush and %LOCALAPPDATA%\crush contain JSON state only; Crush does not execute a crushrc from them.)

What about the old JSON format? It’s still supported, but it should be consdiered deprecated. See: the config docs for details.

[!TIP] You can override the user and data config locations by setting:

• CRUSH_GLOBAL_CONFIG
• CRUSH_GLOBAL_DATA

As an additional note, Crush also stores ephemeral data, such as application state, in one additional location. This is state and should not be edited by hand, nor should it be considered configuration.

# Unix
$HOME/.local/share/crush/crush.json

# Windows
%LOCALAPPDATA%\crush\crush.json

A note on security

Both crushrc and crush.json are trusted code; crushrc runs in a full shell, and any $(...) in crush.json runs at load time. Don’t launch Crush in a directory whose config you haven’t reviewed, and don’t randomly source files from the internet into your config.

Environment Variables

The top-level env field sets environment variables at startup, before providers are configured. This is useful for variables that affect provider authentication (e.g. the AWS SDK credential chain) without wrapping the crush command in a shell script or exporting them in your shell profile:

{
  "$schema": "https://charm.land/crush.json",
  "env": {
    "AWS_PROFILE": "my-sso-profile"
  }
}

Values support the same $VAR and $(command) expansion as other config fields, so you can reference existing environment variables or shell out for a value.

LSPs

Crush can use LSPs for additional context to help inform its decisions, just like you would. LSPs can be added manually like so:

# crushrc

lsp add go --command "gopls" --env "GOTOOLCHAIN go1.24.5"
lsp add typescript --command "typescript-language-server" --args --stdio
lsp add nix --command "nil"

MCPs

Crush also supports Model Context Protocol (MCP) servers through three transport types: stdio for command-line servers, http for HTTP endpoints, and sse for Server-Sent Events.

# crushrc

# Add a local MCP server that runs a Node.js script.
mcp add filesystem --command node --args /path/to/mcp-server.js \
  --timeout 10 --disabled-tools some-tool-name --env NODE_ENV production

# Add a GitHub MCP server that uses an API token.
mcp add github --type http --url "https://api.githubcopilot.com/mcp/" \
  --timeout 10 --header Authorization "Bearer $GH_PAT" \
  --disabled-tools create_issue --disabled-tools create_pull_request

# Add a streaming MCP server that uses SSE.
mcp add streaming-service --type sse --url "https://example.com/mcp/sse" \
  --timeout 10 --header API-Key "$API_KEY"

MCP OAuth

HTTP and SSE MCP servers that require OAuth can use Crush’s built-in authorization-code flow instead of a static Authorization header. Set "oauth": true to enable it:

{
  "mcp": {
    "linear": {
      "type": "http",
      "url": "https://mcp.linear.app/mcp",
      "oauth": true
    }
  }
}

Pre-registered clients

Some servers (GitHub, Slack) don’t support dynamic client registration. For those, register an OAuth app with the provider and supply the credentials directly. All values support shell expansion:

{
  "mcp": {
    "github": {
      "type": "http",
      "url": "https://api.githubcopilot.com/mcp/",
      "oauth": true,
      "oauth_client_id": "Iv1.abc123def456",
      "oauth_client_secret": "$GITHUB_MCP_SECRET",
      "oauth_callback_port": 40704
    }
  }
}

When oauth_client_id is set, Crush skips dynamic client registration and authenticates as the specified client. When omitted, Crush attempts dynamic registration automatically (works with Linear, Notion, and other servers that support RFC 7591).

Hooks

Crush has preliminary support for hooks. For details, see the hook guide.

Sharing a workspace across clients

When Crush is run against a shared backend (for example two TUIs talking to the same crush serve), clients are grouped into workspaces keyed by their resolved --cwd. Two clients with the same --cwd join the same underlying workspace, so they share the session list, message history, permission queue, LSP, and MCP state.

Joining is implicit: pointing a second client at the same working directory attaches it to the existing workspace. Each new invocation, however, starts in its own fresh session by default. To pick up the conversation another client already has open, use the session manager (the session picker) and select it. Sessions surface two signals there:

• IsBusy is set while an agent turn is in flight for that session.
• AttachedClients reports how many clients are currently viewing it.

A non-zero AttachedClients (often combined with IsBusy) is the cue that a session is “in progress” on another client and joining it will mirror that view live.

The first client to create a workspace fixes its process-wide flags. In particular, --yolo and --debug follow a first-wins rule: later clients that arrive at the same --cwd with different values for those flags do not change the running workspace. A debug log line is emitted recording the mismatch, and the workspace keeps the flags it was created with.

A workspace lives as long as at least one client has an SSE event stream open against it. When the last stream disconnects, the workspace is torn down. There is a short grace window right after POST /v1/workspaces so a client that has created the workspace but not yet opened its event stream does not get reaped before it can attach.

Global context files

Crush automatically includes two files for cross-project instructions. Think of these are personal additions to the system prompt.

• ~/.config/crush/CRUSH.md: Crush-specific rules that would confuse other agentic coding tools. If you only use Crush, this is the only one you need to edit.
• ~/.config/AGENTS.md: generic instructions that other coding tools might read. Avoid referring to Crush-specific features or workflows here. You probably only care about this if you use multiple agentic coding tools and want to share instructions between them.

You can customize these paths with option global-context-path. Repeat the command to add multiple paths:

# Load a single markdown file.
option global-context-path "~/path/to/custom/context/file.md"

# Recursively load all Markdown files in the folder.
option global-context-path "/full/path/to/folder/of/files/"

Ignoring Files

Crush respects .gitignore files by default, but you can also create a .crushignore file to specify additional files and directories that Crush should ignore. This is useful for excluding files that you want in version control but don’t want Crush to consider when providing context.

The .crushignore file uses the same syntax as .gitignore and can be placed in the root of your project or in subdirectories.

Allowing Tools

By default, Crush will ask you for permission before running tool calls. If you’d like, you can allow tools to be executed without prompting you for permissions. Use this with care.

permissions allow view ls grep edit mcp_context7_get-library-doc

Disabling Built-In Tools

You can also deny tools, hiding then from the agent entirely:

permissions deny bash sourcegraph

To disable tools from MCP servers, see the MCP config section.

You only live once

You can also skip all permission prompts completely by running Crush with the --yolo flag. Be very, very careful with this feature.

Disabling Skills

You can prevent Crush from using certain skills entirely. Disabled skills are hidden from the agent, including builtin skills and skills discovered from disk.

option disable-skill crush-config

Agent Skills

Crush supports the Agent Skills open standard for extending agent capabilities with reusable skill packages. Skills are folders containing a SKILL.md file with instructions that Crush can discover and activate on demand.

The global paths we looks for skills are:

• $CRUSH_SKILLS_DIR
• $XDG_CONFIG_HOME/agents/skills or ~/.config/agents/skills/
• $XDG_CONFIG_HOME/crush/skills or ~/.config/crush/skills/
• ~/.agents/skills/
• ~/.claude/skills/
• On Windows, we also look at
  • %LOCALAPPDATA%\agents\skills\ or %USERPROFILE%\AppData\Local\agents\skills\
  • %LOCALAPPDATA%\crush\skills\ or %USERPROFILE%\AppData\Local\crush\skills\
• Additional paths configured via options.skills_paths

On top of that, we also load skills in your project from the following relative paths:

• .agents/skills
• .crush/skills
• .claude/skills
• .cursor/skills

Or load directories of skills specifically in your config:

option skill-path "$HOME/squid-skills" "./other-skills"

You can get started with example skills from anthropics/skills:

# Unix
mkdir -p ~/.config/crush/skills
cd ~/.config/crush/skills
git clone https://github.com/anthropics/skills.git _temp
mv _temp/skills/* . && rm -rf _temp

# Windows (PowerShell)
mkdir -Force "$env:LOCALAPPDATA\crush\skills"
cd "$env:LOCALAPPDATA\crush\skills"
git clone https://github.com/anthropics/skills.git _temp
mv _temp/skills/* . ; rm -r -force _temp

User-Invocable Skills

Skills can be made invocable as commands from the commands palette (ctrl+p). Add user-invocable: true to the skill’s YAML frontmatter:

---
name: my-hot-skill
description: A skill that can be invoked as a command.
user-invocable: true
---

User-invocable skills appear in the commands palette with a user: or project: prefix:

• Skills from global directories show as user:skill-name
• Skills from project directories show as project:skill-name

When invoked, the skill’s instructions are loaded into the conversation context.

To prevent the model from auto-triggering a skill (while still allowing user invocation), add disable-model-invocation: true:

---
name: my-skill
description: Only invocable by users, not the model.
user-invocable: true
disable-model-invocation: true
---

Skills with disable-model-invocation won’t appear in the model’s available skills list but can still be invoked manually by users.

Desktop notifications

Crush sends desktop notifications when a tool call requires permission and when the agent finishes its turn. They’re only sent when the terminal window isn’t focused and your terminal supports reporting the focus state.

# Choose auto, native, osc, bell, or disabled.
option notifications disabled

auto uses native notifications locally and OSC notifications over SSH when supported.

Initialization

When you initialize a project, Crush analyzes your codebase and creates a context file that helps it work more effectively in future sessions. By default, this file is named AGENTS.md, but you can customize the name and location with the initialize-as option:

# crushrc
option initialize-as AGENTS.md

This is useful if you prefer a different naming convention or want to place the file in a specific directory (e.g., CRUSH.md or docs/LLMs.md). Crush will fill the file with project-specific context like build commands, code patterns, and conventions it discovered during initialization.