Getting started

leech ships as a GitHub Action. You add it to the repository you want your solutions synced into, give it your LeetCode cookies as secrets, and describe the output you want in a config block.

1. Get your LeetCode cookies

leech authenticates the same way your browser does — with the session cookies, not a password or API key.

1. Log in to leetcode.com (or leetcode.cn).
2. Open DevTools → Network, reload the page, and click any request to leetcode.com.
3. In the request headers, copy the cookie header value and extract:
   • LEETCODE_SESSION
   • csrftoken

On LeetCode China use site: leetcode.cn in the config. The GraphQL API, the cookie names, and the schema are the same.

Cookies expire

LEETCODE_SESSION is a session cookie. When it expires the action fails with a "session cookie is likely invalid or expired" error — repeat the steps above and update the secret. This is the single most common failure.

2. Add repository secrets

In your solutions repository (not the leech repo), go to Settings → Secrets and variables → Actions and add:

Secret	Value
LEETCODE_SESSION	the LEETCODE_SESSION cookie
LEETCODE_CSRF_TOKEN	the csrftoken cookie

3. Add a workflow

Create .github/workflows/leech.yml:

name: Sync LeetCode
on:
  workflow_dispatch:
  schedule:
    - cron: "0 8 * * 6"

permissions:
  contents: write

concurrency:
  group: leech-sync
  cancel-in-progress: false # queue instead of cancelling: only one sync runs at a time

jobs:
  sync:
    runs-on: ubuntu-latest
    steps:
      - uses: serephus/leech@v0.1.5 # release tag (the main branch won't work)
        with:
          github-token: ${{ github.token }}
          leetcode-session: ${{ secrets.LEETCODE_SESSION }}
          leetcode-csrf-token: ${{ secrets.LEETCODE_CSRF_TOKEN }}
          dry-run: "false" # optional; render and log only, create no commits
          verbose: "false" # optional; verbose logging
          # The `|` after `config:` means its value is one inline YAML string
          # (the leech configuration), not structured keys of this workflow
          # file — keep it indented under `config:`.
          # A structured YAML mapping won't work because GitHub Actions only
          # accepts flat key-value pairs as action inputs.
          config: |
            destination: "solutions"
            site: leetcode.com
            filters:
              status: accepted
              languages: [python3, typescript]
            commit:
              prefix: "leech: "
              message: "{{ question.title }} ({{ submission.lang }})"
            files:
              - filename: "{{ question.title_slug }}/README.md"
                content: |
                  ---
                  title: "{{ question.title }}"
                  slug: "{{ question.title_slug }}"
                  difficulty: {{ question.difficulty }}
                  timestamp: {{ submission.timestamp }}
                  ---

                  # {{ question.title }}

                  {{ question.content | toMarkdown({ gfm: true }) }}
              - filename: "{{ question.title_slug }}/{{ submission.lang }}.{{ submission.lang_ext }}"
                content: "{{ submission.code }}"

The tag should match the latest release — the current one is

serephus/leech@v0.1.5. If you'd rather not update the workflow, note that

@main will not work: dist/ is built and attached to release tags, not committed to the branch.

4. Run it

Trigger the workflow manually (Actions → Sync LeetCode → Run workflow) or wait for the schedule. On success you'll get one commit per newly discovered submission, each authored at the original submission time.

If it fails, see Limitations and the FAQ. The most common causes are expired cookies, a missing permissions: contents: write, and config not being a single indented YAML scalar.

Next steps

• Configuration — every option and its default.
• Templates — the variables you can use.
• Filters & conversion — markdown/Typst conversion options.
• Hooks — run prettier, generate an index, notify a bot.
• Local CLI — build the same pipeline outside Actions.