cli(config): Add GOOSE_CONTEXT_STRATEGY setting (#2666)

Co-authored-by: Michael Neale <michael.neale@gmail.com>

documentation/docs/guides/environment-variables.md

@@ -62,6 +62,24 @@ export GOOSE_PLANNER_PROVIDER="openai"
 export GOOSE_PLANNER_MODEL="gpt-4"
 ```
 
+## Session Management
+
+These variables control how Goose manages conversation sessions and context.
+
+| Variable | Purpose | Values | Default |
+|----------|---------|---------|---------|
+| `GOOSE_CONTEXT_STRATEGY` | Controls how Goose handles context limit exceeded situations | "summarize", "truncate", "clear", "prompt" | "prompt" (interactive), "summarize" (headless) |
+
+**Examples**
+
+```bash
+# Automatically summarize when context limit is reached
+export GOOSE_CONTEXT_STRATEGY=summarize
+
+# Always prompt user to choose (default for interactive mode)
+export GOOSE_CONTEXT_STRATEGY=prompt
+```
+
 ## Tool Configuration
 
 These variables control how Goose handles [tool permissions](/docs/guides/tool-permissions) and their execution.

documentation/docs/guides/smart-context-management.md

@@ -58,10 +58,33 @@ You can proactively summarize your conversation before reaching context limits:
 
 The CLI offers three context management options: summarize, truncate, or clear your session.
 
+### Default Context Strategy
+
+You can configure Goose to automatically handle context limits without prompting by setting the `GOOSE_CONTEXT_STRATEGY` environment variable:
+
+```bash
+# Set default strategy (choose one)
+export GOOSE_CONTEXT_STRATEGY=summarize  # Automatically summarize (recommended)
+export GOOSE_CONTEXT_STRATEGY=truncate   # Automatically remove oldest messages
+export GOOSE_CONTEXT_STRATEGY=clear      # Automatically clear session
+export GOOSE_CONTEXT_STRATEGY=prompt     # Always prompt user (default)
+```
+
+Or configure it permanently:
+```bash
+goose configure set GOOSE_CONTEXT_STRATEGY summarize
+```
+
+**Default behavior:**
+- **Interactive mode**: Prompts user to choose (equivalent to `prompt`)
+- **Headless mode** (`goose run`): Automatically summarizes (equivalent to `summarize`)
+
 <Tabs>
   <TabItem value="automatic" label="Automatic" default>
 
-When you hit the context limit, you'll see this prompt to choose a management option, allowing you to continue your session:
+When you hit the context limit, the behavior depends on your configuration:
+
+**With default settings (no `GOOSE_CONTEXT_STRATEGY` set)**, you'll see this prompt to choose a management option:
 
 ```sh
 ◇  The model's context length is maxed out. You will need to reduce the # msgs. Do you want to?
@@ -76,6 +99,24 @@ final_summary: [A summary of your conversation will appear here]
 Context maxed out
 --------------------------------------------------
 Goose summarized messages for you.
+```
+
+**With `GOOSE_CONTEXT_STRATEGY` configured**, Goose will automatically apply your chosen strategy:
+
+```sh
+# Example with GOOSE_CONTEXT_STRATEGY=summarize
+Context maxed out - automatically summarized messages.
+--------------------------------------------------
+Goose automatically summarized messages for you.
+
+# Example with GOOSE_CONTEXT_STRATEGY=truncate
+Context maxed out - automatically truncated messages.
+--------------------------------------------------
+Goose tried its best to truncate messages for you.
+
+# Example with GOOSE_CONTEXT_STRATEGY=clear
+Context maxed out - automatically cleared session.
+--------------------------------------------------
 ```
 
   </TabItem>
@@ -118,4 +159,4 @@ Key information has been preserved while reducing context length.
         This functionality is not available in the Goose CLI. 
 
     </TabItem>
-</Tabs>
+</Tabs>