Mesa 4 migration tracking

[wang-boyu]

Summary

This issue tracks the Mesa 4 migration effort for mesa-llm in one place and helps avoid partial, inconsistent migration changes from being merged through unrelated PRs.

Mesa 4 support is not complete yet. Until this tracking issue is resolved, the project should remain pinned to Mesa 3.x.

Status

Mesa 4 support is not an active merge target right now. Mesa 4 is still in alpha (v4.0.0a0), and Mesa's current stable version is still 3.x. Mesa 4 development tracking issue is: mesa/mesa#3132. We want to avoid merging partial or inconsistent Mesa 4 migration changes before the Mesa 4 API settles further.

Important

At this stage, mesa-llm is prioritizing maintenance work over Mesa 4 migration, with the near-term goal of closing existing maintenance bug tickets on Mesa 3.x.

Mesa 4 migration changes should be kept in dedicated Mesa 4 issues and PRs linked from this tracker.

If an otherwise unrelated PR includes Mesa 4 migration changes, those migration-related parts will not be reviewed as part of that PR and should be removed or split into a separate Mesa 4 PR linked here.

Related issues

• Spatial API Unification #150
• fix: codebase incompatible with Mesa 4.x (mesa.space removed) #152
• bug: move_one_step() moves agents in wrong direction on real OrthogonalMooreGrid #197
• bug: STLTMemory uses model.steps which does not exist in Mesa 4.x #205
• bug: Reasoning.execute_tool_call() and aexecute_tool_call() use model.steps which does not exist in Mesa 4.x #216

Related PRs with Mesa 4 migration overlap

• Spatial API Unification #151
• fix: migrate codebase to Mesa 4.x API (resolves mesa.space removal) #153
• improve: add comprehensive type hints to LLMAgent and ModuleLLM; migrating to Mesa 4 API #170
• improve: add type hints to reasoning module + fix Mesa 4.x compatibility #179
• Add __repr__ methods to core classes and fix Mesa 4.x API compatibility #195
• fix: ReActReasoning.__repr__ AttributeError and STLTMemory Mesa 4.x model.steps compatibility #199
• fix: Reasoning.execute_tool_call() and aexecute_tool_call() use model.steps which does not exist in Mesa 4.x #217
• fix: replace deprecated seed= with rng= in all example models #290

If I missed any related issues or PRs, please feel free to comment below and I’ll add them here.

[ospreyboi]

hi @wang-boyu
I noticed the three example models (negotiation, sugarscape, epstein_civil_violence) still use seed= instead of rng= which causes FutureWarning in Mesa 3.5 and will break in Mesa 4.0. I would like to fix these issues.