# Runtime



### Session Message Buffer [#session-message-buffer]

Acontext will track the agent task and user feedback in the session,
the following settings control how and when tracking is conducted.

<ParamField path="PROJECT_SESSION_MESSAGE_USE_PREVIOUS_MESSAGES_TURNS" type="integer" default="3">
  Number of previous message turns to include in the context when processing new incoming messages.

  Higher values provide more context for task maintaining but consume more tokens.
</ParamField>

<ParamField path="PROJECT_SESSION_MESSAGE_BUFFER_MAX_TURNS" type="integer" default="16">
  Maximum number of untracked message turns to keep in the session buffer.

  This controls the size of the messages we want to process at the same time, the larger the buffer,
  the longer context we can use for once for task maintaining,
  and the less total token costs.
</ParamField>

### Agent Iteration Limits [#agent-iteration-limits]

<ParamField path="DEFAULT_TASK_AGENT_MAX_ITERATIONS" type="integer" default="4">
  Maximum number of iterations a task agent can perform before stopping. Prevents infinite loops in task execution.
</ParamField>

## `.env` Examples [#env-examples]

<CodeGroup>
  ```bash title="Default Configuration"
  # Session Management
  PROJECT_SESSION_MESSAGE_USE_PREVIOUS_MESSAGES_TURNS=3
  PROJECT_SESSION_MESSAGE_BUFFER_MAX_TURNS=16
  PROJECT_SESSION_MESSAGE_BUFFER_MAX_OVERFLOW=16

  # Agent Limits
  DEFAULT_TASK_AGENT_MAX_ITERATIONS=4
  ```

  ```bash title="High-Context Setup"
  # Increased context for complex conversations
  PROJECT_SESSION_MESSAGE_USE_PREVIOUS_MESSAGES_TURNS=8
  PROJECT_SESSION_MESSAGE_BUFFER_MAX_TURNS=32
  PROJECT_SESSION_MESSAGE_BUFFER_MAX_OVERFLOW=24

  # More iterations for complex tasks
  DEFAULT_TASK_AGENT_MAX_ITERATIONS=8
  ```

  ```bash title="Performance Optimized"
  # Reduced context for faster processing
  PROJECT_SESSION_MESSAGE_USE_PREVIOUS_MESSAGES_TURNS=2
  PROJECT_SESSION_MESSAGE_BUFFER_MAX_TURNS=8
  PROJECT_SESSION_MESSAGE_BUFFER_MAX_OVERFLOW=8

  # Lower iteration limits for speed
  DEFAULT_TASK_AGENT_MAX_ITERATIONS=3
  ```
</CodeGroup>

<Warning>
  Setting iteration limits too high may lead to excessive API usage and longer response times. Setting them too low may prevent agents from completing complex tasks.
</Warning>

## Message Buffer Tuning [#message-buffer-tuning]

### Buffer Size Impact [#buffer-size-impact]

* **Small buffers** (8-16 turns):
  * ✅ **Lower update latency** - Tasks and skills update faster
  * ❌ **Higher token cost** - More frequent processing with less context sharing

* **Large buffers** (32+ turns):
  * ✅ **Lower token cost** - Batch processing with shared context
  * ❌ **Higher update latency** - Tasks and skills update less frequently

<Note>
  The buffer idle timeout is fixed at 8 seconds and is not configurable per project. The buffer flushes when it reaches `BUFFER_MAX_TURNS` or when no new messages arrive for 8 seconds, whichever comes first.
</Note>

<Tip>
  For **development**: Use smaller buffers (8-16) for faster feedback loops. For **production**: Use larger buffers (24-32) to optimize costs.
</Tip>