This post goes over how to run Ollama large language models (LLM) on GitHub Actions for free.

Ollama

Ollama is a CLI that runs LLMs.

To run it on Linux, copy the install command and follow the example:

# .github/workflows/ollama.yml
name: ollama
on: push

jobs:
  ollama:
    runs-on: ubuntu-latest

    steps:
      - name: Install ollama
        run: curl -fsSL https://ollama.com/install.sh | bash

      - name: Run LLM
        run: ollama run llama3.2 'What is a large language model?'

ollama-action

To run Ollama on macOS or Windows, use ollama-action:

# .github/workflows/ollama.yml
name: ollama
on: push

jobs:
  ollama:
    runs-on: macos-latest

    steps:
      - name: Run LLM
        uses: ai-action/ollama-action@v1
        id: llm
        with:
          model: llama3.2
          prompt: What is a large language model?

      - name: Print response
        env:
          response: ${{ steps.llm.outputs.response }}
        run: echo "$response"

setup-ollama

To use the Ollama CLI on macOS or Windows, use setup-ollama:

# .github/workflows/ollama.yml
name: ollama
on: push

jobs:
  ollama:
    runs-on: windows-latest

    steps:
      - name: Setup ollama
        uses: ai-action/setup-ollama@v1

      - name: Print response
        run: ollama run llama3.2 'What is a large language model?'

Code Review Example

Here’s an example of using Ollama to add a code review comment to a pull request:

# .github/workflows/code-review.yml
name: Code Review
on: pull_request

permissions:
  contents: read
  pull-requests: write

jobs:
  code-review:
    runs-on: ubuntu-latest
    steps:
      - name: Setup ollama
        uses: ai-action/setup-ollama@v1

      - name: Checkout repository
        uses: actions/checkout@v4

      - name: Code review comment
        run: |
          PROMPT='Code review the changes below:'
          RESPONSE=$(ollama run codellama "$PROMPT\n$(gh pr diff $PR_NUMBER)")
          gh pr comment $PR_NUMBER --body "$RESPONSE"
        env:
          GITHUB_TOKEN: ${{ github.token }}
          PR_NUMBER: ${{ github.event.pull_request.number }}

See the example for more details.