[!IMPORTANT] Claude Subconscious is demo app built using the Letta Code SDK, and is not intended to be used in production.
If you want to use a coding agent that runs background subconscious agents, use Letta Code, which is also fully open source.
Install the Letta Code CLI with
npm install -g @letta-ai/letta-code, then uselettato launch.
Claude Subconscious
A background agent that whispers to Claude Code. A subconcious agent that watches your sessions, reads your files, builds up memory over time, and whispers guidance back.
What Is This?
Claude Code forgets everything between sessions. Claude Subconscious is a second agent running underneath — watching, learning, and whispering back:
- Watches every Claude Code session transcript
- Reads your codebase — explores files with Read, Grep, and Glob while processing transcripts
- Remembers across sessions, projects, and time
- Whispers guidance — surfaces context, patterns, and reminders before each prompt
- Never blocks — runs in the background via the Letta Code SDK
Not just a memory layer — a background agent with real tool access that gets smarter the more you use it.
Using Letta's Conversations feature, a single agent can serve multiple Claude Code sessions in parallel with shared memory across all of them.
How It Works
After each response, the transcript is sent to a Letta agent via the Letta Code SDK. The agent reads files, searches the web, updates its memory — then whispers back before the next prompt. Nothing is written to CLAUDE.md.
┌─────────────┐ ┌──────────────────────────┐
│ Claude Code │◄────────►│ Letta Agent (background) │
└─────────────┘ │ │
│ │ Tools: Read, Grep, Glob │
│ │ Memory: persistent │
│ │ Web: search, fetch │
│ └──────────────────────────┘
│ │
│ Session Start │
├───────────────────────►│ New session notification
│ │
│ Before each prompt │
│◄───────────────────────┤ Whispers guidance → stdout
│ │
│ Before each tool use │
│◄───────────────────────┤ Mid-workflow updates → stdout
│ │
│ After each response │
├───────────────────────►│ Transcript → SDK session (async)
│ │ ↳ Reads files, updates memory
Installation
Install from GitHub:
/plugin marketplace add letta-ai/claude-subconscious
/plugin install claude-subconscious@claude-subconscious
Updating
/plugin marketplace update
/plugin update claude-subconscious@claude-subconscious
Install from Source
Clone the repository:
git clone https://github.com/letta-ai/claude-subconscious.git
cd claude-subconscious
npm install
Enable the plugin (from inside the cloned directory):
/plugin enable .
Or enable globally for all projects:
/plugin enable --global .
If running from a different directory, use the full path to the cloned repo.
Linux: tmpfs Workaround
If plugin installation fails with EXDEV: cross-device link not permitted, your /tmp is likely on a different filesystem (common on Ubuntu, Fedora, Arch). Set TMPDIR to work around this Claude Code bug:
mkdir -p ~/.claude/tmp
export TMPDIR="$HOME/.claude/tmp"
Add to your shell profile (~/.bashrc or ~/.zshrc) to make permanent.
Configuration
Required
export LETTA_API_KEY="your-api-key"
Get your API key from app.letta.com.
Optional
export LETTA_MODE="whisper" # Default. Or "full" for blocks + messages, "off" to disable
export LETTA_AGENT_ID="agent-xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx"
export LETTA_BASE_URL="http://localhost:8283" # For self-hosted Letta
export LETTA_MODEL="anthropic/claude-sonnet-4-5" # Model override
export LETTA_CONTEXT_WINDOW="1048576" # Context window size (e.g. 1M tokens)
export LETTA_HOME="$HOME" # Consolidate .letta state to ~/.letta/
export LETTA_SDK_TOOLS="read-only" # Or "full", "off"