feat: nemo gym integration

[cmunley1]

Description

Integrates NVIDIA NeMo Gym with a few example environments. Entire multiturn rollout is offloaded to nemo gym through the rollout collection helper in nemo gym, which includes agent, model, and resources servers.
Example usage

vf-eval nemo-gym-workplace-assistant -m local -d -n 1 -r 1
vf-eval nemo-gym-structured-outputs -m local -d -n 1 -r 1    
vf-eval nemo-gym-code-gen -m local -d -n 1 -r 1    
vf-eval nemo-gym-reasoning-gym -m local -d -n 1 -r 1    
vf-eval nemo-gym-reasoning-gym-reflection -m local -d -n 1 -r 1    

Type of Change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• Documentation update
• Test improvement

Testing

• All existing tests pass when running uv run pytest locally.
• New tests have been added to cover the changes

Checklist

• My code follows the style guidelines of this project as outlined in AGENTS.md
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published

Additional Notes

---

Note

Medium Risk
Introduces a new async/threaded integration that starts and manages external NeMo Gym servers and maps their rollouts into Verifiers state, plus expands local install path resolution; these changes touch execution lifecycle and environment installation behavior.

Overview
Adds NVIDIA NeMo Gym integration via a new NemoGymEnv that delegates rollouts to NeMo Gym’s rollout collection helper, manages head/policy server configuration and lifecycle, and converts NeMo Gym results into Verifiers trajectory/completion plus a reward sourced from NeMo Gym.

Adds multiple example NeMo Gym environment packages under environments/nemo_gym/* (each exposing load_environment() and pyproject.toml metadata) and updates docs/README and tests to reference the new integration and skip the parent nemo_gym directory.

Improves tooling compatibility by letting install_from_local() discover environments one directory deeper (nested under environments/*/<env_name>) and treating raw messages with role developer as system in message normalization.

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[cursor]

Tool call arguments may produce invalid JSON

Medium Severity

_nemo_item_to_assistant_message uses str() to convert the arguments field of a function call item, but ToolCall.arguments is expected to be a valid JSON string throughout the codebase. If NeMo Gym returns arguments as a dict, str() produces Python repr (e.g., "{'key': 'value'}") instead of valid JSON ('{"key": "value"}'). Multiple consumers in the codebase call json.loads(tool_call.arguments) (in tool_env.py, stateful_tool_env.py, etc.), which would fail on Python repr format. The existing _normalize_raw_tool_calls in message_utils.py handles this correctly by checking isinstance(arguments, str) first and falling back to json.dumps().

 

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[cursor]

Cursor Bugbot has reviewed your changes and found 1 potential issue.

There are 2 total unresolved issues (including 1 from previous review).

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[cursor]

NemoGymEnv install instructions missing from docs

Low Severity

NemoGymEnv is added to the integrations list but the follow-up install paragraph at line 794 only mentions extras for TextArena, BrowserEnv, and OpenEnvEnv. Since NemoGymEnv requires a different install flow (editable local clone, no pip extra defined in pyproject.toml), users reading "These require additional dependencies installed via extras" will be confused about how to install the NeMo Gym dependency.

 

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