> ## Documentation Index
> Fetch the complete documentation index at: https://docs.blaxel.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# SSL certificate verification errors when cloning repositories

> Fix Git SSL certificate verification failures in Blaxel sandboxes by installing CA certificates or choosing a base image that includes them.

Cloning a repository in a Blaxel sandbox can fail with an SSL certificate verification error. Minimal base images often omit the certificate authorities required to verify HTTPS connections.

## Example error

The Git error resembles:

```text theme={null}
fatal: unable to access 'https://github.com/blaxel-ai/sdk-typescript.git': server certificate verification failed
```

## Root cause

Slim base images such as `node:22-bookworm-slim` do not always include CA certificates. Without a trusted certificate authority bundle, Git cannot verify the remote server's SSL certificate.

## Install CA certificates

Add `ca-certificates` to the packages installed by your Dockerfile:

```dockerfile theme={null}
RUN apt-get update && apt-get install -y --no-install-recommends \
    git \
    ca-certificates \
    && rm -rf /var/lib/apt/lists/*
```

## Choose another base image

Alternatively, use a base image that includes CA certificates:

* `node:22-alpine`
* `node:22-bookworm`, using the full image instead of the slim variant

The Alpine variant has been tested successfully with repository cloning. If you switch to Alpine, update your package installation commands because Alpine uses `apk` instead of `apt-get`, and package names or availability may differ.

<CardGroup cols={2}>
  <Card title="Docker sandbox tutorial" href="/Tutorials/Docker">
    Learn how to build and run Docker images in sandboxes.
  </Card>

  <Card title="Sandbox proxy and network" href="/Sandboxes/Proxy">
    Review sandbox networking configuration.
  </Card>
</CardGroup>


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