Convert ai_news_generator to use CrewAI flows for agentic workflow

[xpander-ai-coding-agent]

Summary

This PR solves issue #168 by converting the ai_news_generator project from a simple CrewAI crew to use CrewAI Flows, creating a proper agentic workflow.

Key Changes

• Replaced simple Crew with CrewAI Flow architecture

• Implemented NewsGeneratorFlow class extending Flow
• Added proper phase separation with decorators

• Phase 1: Research Phase (@start)

• Senior Research Analyst agent
• Comprehensive topic research using SerperDev tool
• Structured research brief output with citations

• Phase 2: Writing Phase (@listen)

• Content Writer agent
• Transforms research into engaging blog post
• Listens for research phase completion before starting

• Updated Documentation

• Added architecture section explaining the two-phase workflow
• Updated dependencies and installation instructions
• Improved README formatting and title capitalization

Technical Implementation

• Used @start() decorator to mark the initial research phase
• Used @listen(research_phase) for proper task sequencing
• Maintained existing LLM model (Cohere Command-R) and tools
• Preserved all original functionality while improving workflow structure

Benefits

• ✅ Proper task sequencing: Writing phase only starts after research completes
• ✅ Better state management: Flow handles data passing between phases
• ✅ Improved maintainability: Clear separation of concerns
• ✅ Event-driven architecture: More robust workflow execution

Test Plan

• Import test passes without syntax errors
• CrewAI Flow decorators work correctly
• All dependencies install successfully
• Application structure maintains backward compatibility

Closes #168

🤖 Generated with Claude Code

Summary by CodeRabbit

• Documentation

  • Updated the README with a clearer project description, installation instructions, and a new architecture section explaining the two-phase agentic workflow.

• Refactor

  • Streamlined content generation into a structured two-phase workflow, improving modularity and clarity without changing the user interface.

[coderabbitai]

Walkthrough

The changes refactor the AI news generator application to use CrewAI Flows, transitioning from a simple sequential agent setup to a structured, two-phase agentic workflow. The README is updated to reflect these architectural changes, and the application logic is encapsulated within a new flow class, enhancing modularity and clarity.

Changes

Cohort / File(s)	Change Summary
README Update ai_news_generator/README.md	Capitalized title, expanded project description, updated dependencies, and added a detailed architecture section describing the two-phase agentic workflow.
CrewAI Flow Refactor ai_news_generator/app.py	Refactored content generation into a NewsGeneratorFlow class with @start() and @listen() phases for research and writing, replacing the previous single-function approach. Streamlit UI remains unchanged but now calls the new flow-based logic.

Sequence Diagram(s)

sequenceDiagram
    participant User
    participant Streamlit UI
    participant NewsGeneratorFlow
    participant Senior Research Analyst
    participant Content Writer

    User->>Streamlit UI: Enter topic & submit
    Streamlit UI->>NewsGeneratorFlow: generate_content(topic)
    NewsGeneratorFlow->>Senior Research Analyst: research_phase(topic)
    Senior Research Analyst-->>NewsGeneratorFlow: research_output
    NewsGeneratorFlow->>Content Writer: writing_phase(research_output)
    Content Writer-->>NewsGeneratorFlow: final_blog_post
    NewsGeneratorFlow-->>Streamlit UI: Return final_blog_post
    Streamlit UI-->>User: Display blog post

Loading

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~15 minutes

Assessment against linked issues

Objective	Addressed	Explanation
Refactor to use CrewAI Flows for agentic workflow (#168)	✅
Create a two-phase flow: research then writing (#168)	✅
Update documentation to describe CrewAI Flows and new workflow (#168)	✅

Assessment against linked issues: Out-of-scope changes

No out-of-scope changes found.

Possibly related PRs

• AI News generator app #10: Introduced the initial app implementation with the standalone generate_content function and agent/task setup, which is directly refactored in this PR.

Poem

In the warren where code and ideas flow,
A rabbit refactored, making workflows grow.
Agents now dance in CrewAI’s embrace,
Research, then writing, each in their place.
With phases so clear and docs shining bright,
This agentic leap is a coder’s delight!
🐇✨

Note

⚡️ Unit Test Generation is now available in beta!

Learn more here, or try it out under "Finishing Touches" below.

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📜 Recent review details

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Review profile: CHILL
Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 67aa2f3 and fe048c0.

⛔ Files ignored due to path filters (1)

• ai_news_generator/__pycache__/app.cpython-311.pyc is excluded by !**/*.pyc

📒 Files selected for processing (2)

• ai_news_generator/README.md (2 hunks)
• ai_news_generator/app.py (2 hunks)

🔇 Additional comments (9)

ai_news_generator/README.md (3)

2-4: Documentation updates align well with the implementation

The title capitalization and description update accurately reflect the new CrewAI Flows architecture.

---

16-16: Dependencies list is complete

All required packages for the CrewAI Flows implementation are properly included.

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19-36: Architecture documentation is clear and comprehensive

The two-phase workflow description effectively explains the sequential nature of the research and writing phases with proper decorator annotations.

ai_news_generator/app.py (6)

5-5: Correct imports for CrewAI Flows

The Flow class and decorators are properly imported.

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49-58: Well-structured Flow class initialization

The NewsGeneratorFlow class properly extends Flow and initializes all necessary components including the LLM and search tool.

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59-112: Research phase implementation is comprehensive

The @start() decorator correctly marks this as the initial phase. The Senior Research Analyst agent configuration and task definition are thorough and well-structured.

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114-168: Writing phase correctly implements event-driven pattern

The @listen(research_phase) decorator properly establishes the dependency between phases, and the research output is effectively integrated into the writing task.

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170-173: Clean wrapper function maintains backward compatibility

The generate_content function effectively wraps the new Flow implementation, preserving the existing interface for the Streamlit UI.

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186-186: Verify Flow.kickoff() returns a .raw attribute

Please confirm that NewsGeneratorFlow.kickoff() returns an object exposing a raw property before passing result.raw into st.download_button. If the kickoff result doesn’t include .raw, adjust the flow or unwrap its return value accordingly.

• ai_news_generator/app.py: lines 172–186 (in generate_content and the download button)

✨ Finishing Touches

• 📝 Generate Docstrings

🧪 Generate unit tests

• Create PR with unit tests
• Post copyable unit tests in a comment

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