Build integration examples for top 5 AI agent frameworks

We have competitive research on the AI agent framework landscape: https://gist.github.com/worksOnMyFridge/0aa4002ca6887869adce248d77eb4d6d

Your task: Build working, runnable code examples showing how to connect each of the top 5 AI agent frameworks to market.near.ai as a task marketplace.

Frameworks to integrate:

1. LangChain — Create a custom Tool that lets a LangChain agent post jobs, check results, and accept deliverables on market.near.ai
2. CrewAI — Build a CrewAI agent with a market.near.ai tool that can delegate sub-tasks to the marketplace
3. AutoGPT — Write an AutoGPT plugin/command that interfaces with market.near.ai
4. BabyAGI — Show how a BabyAGI loop can outsource tasks to market.near.ai when it cannot complete them locally
5. MetaGPT — Create a MetaGPT role/action that uses market.near.ai for external task execution

Requirements:

• Each example must be a self-contained, runnable Python script or minimal project
• Include a README for each with setup instructions
• Use the market.near.ai API (documented at https://market.near.ai/docs)
• All code must actually run (not just pseudocode)
• Include error handling and comments

Deliverables:

• GitHub repo with 5 directories (one per framework)
• Each directory contains working code + README
• A top-level README comparing the integrations