Nix and NixOS installation

Letta Code ships a flake for Nix users who want a native install path instead of a global npm install.

Try once

From a machine with flakes enabled:

nix run github:letta-ai/letta-code

To run from a local checkout:

nix run .

Install into a profile

nix profile install github:letta-ai/letta-code
letta

Home Manager

Add Letta Code as a flake input and enable the module:

{
  inputs.letta-code.url = "github:letta-ai/letta-code";

  outputs = { nixpkgs, home-manager, letta-code, ... }: {
    homeConfigurations.example = home-manager.lib.homeManagerConfiguration {
      pkgs = import nixpkgs { system = "x86_64-linux"; };
      modules = [
        letta-code.homeManagerModules.default
        {
          programs.letta-code.enable = true;
        }
      ];
    };
  };
}

NixOS service

For an always-on listener or channel host, enable the NixOS module and provide secrets through a root-readable environment file:

{
  inputs.letta-code.url = "github:letta-ai/letta-code";

  outputs = { nixpkgs, letta-code, ... }: {
    nixosConfigurations.agent-host = nixpkgs.lib.nixosSystem {
      system = "x86_64-linux";
      modules = [
        letta-code.nixosModules.default
        {
          services.letta-code = {
            enable = true;
            environmentFile = "/run/secrets/letta-code.env";
            extraArgs = [ "listen" ];
          };
        }
      ];
    };
  };
}

The environment file can contain values such as:

LETTA_API_KEY=...
ANTHROPIC_API_KEY=...
OPENAI_API_KEY=...
SLACK_BOT_TOKEN=...
SLACK_SIGNING_SECRET=...

Use your normal NixOS secret manager, such as sops-nix or agenix, to materialize that file.

What this provides

The flake exposes:

• packages.<system>.default / packages.<system>.letta-code
• apps.<system>.default / apps.<system>.letta
• homeManagerModules.default and the compatibility alias homeModules.default
• nixosModules.default

The package builds the Letta Code CLI from this repository with Bun. Dependency resolution is driven by the checked-in bun.lock; the generated bun.nix file lets the flake prefetch those Bun dependencies reproducibly for offline Nix builds. The resulting letta binary is wrapped with common runtime tools, and agent configuration and credentials stay in the normal Letta Code locations.

When bun.lock changes, regenerate the Nix dependency expression before opening the PR:

bunx bun2nix -o bun.nix

Follow-up packaging work

This in-repository flake is the fastest path for Nix users to try and deploy Letta Code. A future nixpkgs or Home Manager upstream package should reuse the same shape, but may need additional hardening around native Node dependencies such as node-pty, sharp, and optional ripgrep binaries.