# Collectors — `rl_mind.collectors`

```{eval-rst}
.. automodule:: rl_mind.collectors
   :no-members:
```

| | `TransitionCollector` | `EpisodeCollector` | `RolloutCollector` |
|---|---|---|---|
| Returns | `Transitions` — flat `[N, …]` | `list[Episode]` | `Rollout` — `[T, B, …]` |
| `collect(...)` argument | `n_steps` | `n_episodes` | `n_steps` |
| For | off-policy (DQN, DDPG, TD3, SAC) | episodic (REINFORCE) | on-policy (A2C, PPO) |
| `VecEnv` reset mode | next-step (default) | next-step (default) | requires `same_step_reset=True` |
| Environment state across calls | kept | reset at each call | kept |

```{eval-rst}
.. autoclass:: rl_mind.collectors.TransitionCollector
   :members:

.. autoclass:: rl_mind.collectors.EpisodeCollector
   :members:

.. autoclass:: rl_mind.collectors.RolloutCollector
   :members:
```