Quickstart

Tern uses a lightweight local CLI to connect to your codebase. Run this in your repo:

curl -fsSL https://tern.sh/install.sh | bash
tern connect

After getting you signed in, you’ll see something like this:

onboarding

From here, you’ll:

Confirm the agent connection (the app pings your local agent).
Paste an API key for Anthropic, OpenAI, or Gemini.
Verify repo access.

(Didn’t run tern connect from a repo? Want to work with multiple repos?
Run tern repo add /path/to/repo at any time.)

That’s it! Go ahead and start planning.

Running in Docker

If you’re running Tern CLI in a Docker container, there are a few requirements:

Port forwarding: Your browser must be able to reach localhost:1457 (or whatever port you configure). Forward this port from your container:
```
docker run -p 1457:1457 ...
```
Root CA certificates: Tern CLI must be able to reach app.tern.sh. Minimal base images (like ubuntu:latest or scratch) may not include the necessary root CA certificates to establish secure connections. Language images like node:22 typically include proper CA bundles.

Here’s a minimal working Dockerfile:

FROM node:22

RUN curl -fsSL https://tern.sh/install.sh | bash
ENV PATH="/root/.tern/bin:$PATH"

EXPOSE 1457

ENTRYPOINT ["tern"]
CMD ["connect"]

Build the image:

docker build -t tern .

Run the container with persistence:

docker run --rm \
  -p 1457:1457 \
  -v ~/.tern-docker/:/root/.tern/ \
  tern

We recommend using ~/.tern-docker (not ~/.tern) to avoid conflicts between host and container binaries. Tern downloads architecture-specific tools that won’t work across macOS/Linux boundaries.