The Council of Many: Multi-Agent Orchestration Patterns

# .github/workflows/orchestrator-fan-out.yml
name: Multi-Agent Orchestrator (Fan-Out)

on:
  issues:
    types: [labeled]

jobs:
  orchestrate:
    if: contains(github.event.label.name, 'multi-agent-task')
    runs-on: ubuntu-latest
    outputs:
      subtasks: ${{ steps.plan.outputs.subtasks }}
    steps:
      - uses: actions/checkout@v4

      - name: Plan and partition task
        id: plan
        run: |
          # Orchestrator determines how to split the task
          python3 work/gh-600/scripts/partition_task.py \
            --issue "${{ github.event.issue.number }}" \
            --max-subtasks 4 \
            --output partition.json
          
          SUBTASKS=$(cat partition.json | jq -c '.subtasks')
          echo "subtasks=$SUBTASKS" >> "$GITHUB_OUTPUT"

  sub-agents:
    needs: orchestrate
    if: needs.orchestrate.outputs.subtasks != '[]'
    runs-on: ubuntu-latest
    strategy:
      matrix:
        subtask: ${{ fromJSON(needs.orchestrate.outputs.subtasks) }}
      max-parallel: 4
    steps:
      - uses: actions/checkout@v4

      - name: Execute sub-task
        run: |
          echo "=== Sub-Agent executing: ${{ matrix.subtask.id }} ==="
          echo "Task: ${{ matrix.subtask.description }}"
          
          python3 work/gh-600/scripts/run_subtask.py \
            --subtask-id "${{ matrix.subtask.id }}" \
            --description "${{ matrix.subtask.description }}" \
            --output "subtask-${{ matrix.subtask.id }}-result.json"

      - name: Upload sub-task result
        uses: actions/upload-artifact@v4
        with:
          name: subtask-result-${{ matrix.subtask.id }}
          path: "subtask-${{ matrix.subtask.id }}-result.json"

  aggregate:
    needs: sub-agents
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4

      - name: Download all sub-task results
        uses: actions/download-artifact@v4
        with:
          pattern: subtask-result-*
          path: ./subtask-results/

      - name: Aggregate results
        id: aggregate
        run: |
          python3 work/gh-600/scripts/aggregate_results.py \
            --results-dir ./subtask-results/ \
            --issue "${{ github.event.issue.number }}" \
            --output final-report.json

      - name: Post aggregated report
        uses: actions/github-script@v7
        with:
          script: |
            const report = require('./final-report.json');
            await github.rest.issues.createComment({
              owner: context.repo.owner,
              repo: context.repo.repo,
              issue_number: context.issue.number,
              body: `## Multi-Agent Task Complete\n\n${report.summary}\n\n${report.details}`
            });

# .github/workflows/orchestrator-chain.yml
name: Multi-Agent Chain (Research → Plan → Implement)

on:
  workflow_dispatch:
    inputs:
      task_description:
        description: "Task for the agent chain"
        required: true

jobs:
  research-agent:
    runs-on: ubuntu-latest
    outputs:
      findings: $
    steps:
      - uses: actions/checkout@v4
      - name: Research phase
        id: research
        run: |
          echo "Research agent: gathering context for task"
          # Agent reads existing code, docs, issues
          # Produces structured findings
          FINDINGS=$(echo '{"files_to_modify": ["src/api.js"], "patterns": ["REST"]}')
          echo "findings=$FINDINGS" >> "$GITHUB_OUTPUT"

  planning-agent:
    needs: research-agent
    runs-on: ubuntu-latest
    outputs:
      plan: $
    steps:
      - uses: actions/checkout@v4
      - name: Planning phase
        id: plan
        run: |
          # Plan agent uses research findings to create implementation plan
          FINDINGS='$'
          echo "Planning agent working from research: $FINDINGS"
          PLAN=$(echo '{"steps": [{"action": "modify", "file": "src/api.js"}]}')
          echo "plan=$PLAN" >> "$GITHUB_OUTPUT"

  implementation-agent:
    needs: planning-agent
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - name: Implementation phase
        run: |
          PLAN='$'
          echo "Implementation agent executing plan: $PLAN"
          # Agent modifies the specified files