158 lines
5.8 KiB
Markdown
158 lines
5.8 KiB
Markdown
# Letta Code (Research Preview)
|
|
|
|
A self-improving, stateful coding agent that can learn from experience and improve with use.
|
|
|
|
https://github.com/user-attachments/assets/5561a3ff-afd9-42a9-8601-55d245946394
|
|
|
|
---
|
|
|
|
## What is Letta Code?
|
|
|
|
Letta Code is a command-line harness around the stateful Letta [Agents API](https://docs.letta.com/api-reference/overview). You can use Letta Code to create and connect with any Letta agent (even non-coding agents!) - Letta Code simply gives your agents the ability to interact with your local dev environment, directly in your terminal.
|
|
|
|
> [!IMPORTANT]
|
|
> Letta Code is a **research preview** in active development, and may have bugs or unexpected issues. To learn more about the roadmap and chat with the dev team, visit our Discord at [discord.gg/letta](https:/discord.gg/letta). Contributions welcome, join the fun.
|
|
|
|
## Quickstart
|
|
|
|
> Get a Letta API key at: [https://app.letta.com](https://app.letta.com/)
|
|
|
|
Install the package via [npm](https://docs.npmjs.com/downloading-and-installing-node-js-and-npm):
|
|
```bash
|
|
npm install -g @letta-ai/letta-code
|
|
```
|
|
|
|
Make sure you have your Letta API key set in your environment:
|
|
```bash
|
|
export LETTA_API_KEY=...
|
|
```
|
|
|
|
Then run `letta` to start Letta Code (see various command-line options below):
|
|
```
|
|
letta
|
|
```
|
|
|
|
Any of the agents you create in Letta Code will be viewable (and fully interactable!) inside the [Agent Development Environment](https://app.letta.com).
|
|
|
|
## Persistence
|
|
|
|
All agents in Letta are **stateful**: they maintain context forever and can self-edit their own [memory blocks](https://www.letta.com/blog/memory-blocks). Agents can share memory blocks across projects—for example, multiple agents can share user coding preferences while maintaining project-specific memories independently.
|
|
|
|
### Memory Configuration
|
|
|
|
Letta Code uses a hierarchical memory system with both global and local blocks:
|
|
|
|
**Global** (`~/.letta/settings.json`)
|
|
- `persona` block - defines agent behavior
|
|
- `human` block - stores user coding preferences
|
|
|
|
**Local** (`./.letta/settings.json`)
|
|
- `project` block - stores project-specific context
|
|
|
|
### Starting Letta
|
|
|
|
```bash
|
|
letta # New agent (attaches to existing memory blocks or creates new)
|
|
letta --continue # Resume last agent session
|
|
letta --agent <id> # Resume specific agent session
|
|
```
|
|
|
|
When you start a new agent, it automatically connects to existing memory block IDs from your settings files. If none exist, it creates them.
|
|
|
|
Memory blocks are highly configurable — see our [docs](https://docs.letta.com/guides/agents/memory-blocks) for advanced configuration options. Join our [Discord](https://discord.gg/letta) to share feedback on persistence patterns for coding agents.
|
|
|
|
## Usage
|
|
|
|
### Interactive Mode
|
|
```bash
|
|
letta # Start new session (new agent with shared memory blocks)
|
|
letta --continue # Resume last session (last recently used agent)
|
|
letta --agent <id> # Open specific agent
|
|
```
|
|
|
|
### Headless Mode
|
|
```bash
|
|
letta -p "your prompt" # Run non-interactive
|
|
letta -p "commit changes" --continue # Continue previous session
|
|
letta -p "run tests" --allowedTools "Bash" # Control tool permissions
|
|
letta -p "run tests" --disallowedTools "Bash" # Control tool permissions
|
|
|
|
# Pipe input from stdin
|
|
echo "Explain this code" | letta -p
|
|
cat file.txt | letta -p
|
|
gh pr diff 123 | letta -p --yolo # Review PR changes
|
|
```
|
|
|
|
You can also use the `--tools` flag to control the underlying *attachment* of tools (not just the permissions).
|
|
Compared to disallowing the tool, this will additionally remove the tool schema from the agent's context window.
|
|
```bash
|
|
letta -p "run tests" --tools "Bash,Read" # Only load specific tools
|
|
letta -p "analyze code" --tools "" # No tools (analysis only)
|
|
```
|
|
|
|
### Permissions
|
|
|
|
**Tool selection** (controls which tools are loaded):
|
|
```bash
|
|
--tools "Bash,Read,Write" # Only load these tools
|
|
--tools "" # No tools (conversation only)
|
|
```
|
|
|
|
**Permission overrides** (controls tool access, applies to loaded tools):
|
|
```bash
|
|
--allowedTools "Bash,Read,Write" # Allow specific tools
|
|
--allowedTools "Bash(npm run test:*)" # Allow specific commands
|
|
--disallowedTools "Bash(curl:*)" # Block specific patterns
|
|
--permission-mode acceptEdits # Auto-allow Write/Edit tools
|
|
--permission-mode plan # Read-only mode
|
|
--permission-mode bypassPermissions # Allow all tools (use carefully!)
|
|
--yolo # Alias for --permission-mode bypassPermissions
|
|
```
|
|
|
|
Permission modes:
|
|
- `default` - Standard behavior, prompts for approval
|
|
- `acceptEdits` - Auto-allows Write/Edit/NotebookEdit
|
|
- `plan` - Read-only, allows analysis but blocks modifications
|
|
- `bypassPermissions` - Auto-allows all tools (for trusted environments)
|
|
|
|
Permissions are also configured in `.letta/settings.json`:
|
|
```json
|
|
{
|
|
"permissions": {
|
|
"allow": ["Bash(npm run lint)", "Read(src/**)"],
|
|
"deny": ["Bash(rm -rf:*)", "Read(.env)"]
|
|
}
|
|
}
|
|
```
|
|
|
|
## Installing from source
|
|
|
|
First, install Bun if you don't have it yet: [https://bun.com/docs/installation](https://bun.com/docs/installation)
|
|
|
|
### Run directly from source (dev workflow)
|
|
```bash
|
|
# install deps
|
|
bun install
|
|
|
|
# run the CLI from TypeScript sources (pick up changes immediately)
|
|
bun run dev:ui
|
|
bun run dev:ui -- -p "Hello world" # example with args
|
|
```
|
|
|
|
### Build + link the standalone binary
|
|
```bash
|
|
# build bin/letta (includes prompts + schemas)
|
|
bun run build
|
|
|
|
# expose the binary globally (adjust to your preference)
|
|
bun link --global # or: bun add --global .
|
|
|
|
# now you can run the compiled CLI
|
|
letta
|
|
```
|
|
> Whenever you change source files, rerun `bun run build` before using the linked `letta` binary so it picks up your edits.
|
|
|
|
---
|
|
|
|
Made with 💜 in San Francisco
|