How the role-based workflow actually works
You give MetaGPT a one-line requirement: 'Build a task management app with due dates and priority levels.' The product manager agent writes a PRD with user stories, acceptance criteria, and UI mockups (ASCII art). The architect agent reads the PRD and designs the system: data models, API routes, file structure. The engineer agent implements the code in a real repo. The QA agent writes and runs tests. Output: a working Next.js app with a SQLite database, deployed in 4 minutes. For simple CRUD apps, the output is genuinely production-ready.
What broke on complex projects
I gave it 'build a review pipeline that fetches AI tool data from 3 APIs, merges results, applies deduplication, generates HTML, and deploys to Vercel.' The PM agent wrote a spec that missed the deduplication requirement entirely. The architect designed a single-file script instead of the modular pipeline I needed. The engineer produced code that worked for the happy path but crashed on API timeouts. The QA tests only covered 40% of the edge cases. The output was a working prototype that would fail in production. MetaGPT is good for prototyping, not production.
MetaGPT vs CrewAI vs AutoGPT
MetaGPT has preset roles (PM, Architect, Engineer, QA) that follow a structured flow: Plan → Design → Code → Test. This is more opinionated than CrewAI where you define custom roles and workflows. The opinionated structure means MetaGPT works better out of the box for software projects. CrewAI is better for custom workflows like customer support pipelines. AutoGPT is better for single-agent autonomous tasks. Use MetaGPT for prototyping software, CrewAI for business workflows, AutoGPT for research tasks.
The cost per project
A simple CRUD app (ToDo list): 15 API calls, $0.80 total. A medium app (blog with auth): 45 API calls, $2.50 total. The saas.pet pipeline attempt: 120 API calls, burned $6.50 before I stopped it. The API cost is OpenAI GPT-4 or Claude. You can switch to cheaper models (DeepSeek, GPT-4o-mini) by changing the config. With DeepSeek, the costs drop 90% but the code quality drops too: more syntax errors, more hallucinated APIs.
When to use it and when to run away
Use MetaGPT when: you have a clear, well-scoped requirement, the output is a standard web app (CRUD + simple business logic), you want a working prototype in under 10 minutes. Run away when: requirements are ambiguous, the project touches external APIs with complex error handling, you need production-grade reliability, or the project has compliance/security requirements. MetaGPT generates code, not guarantees.