# Context Management
Claude models have a finite context window (200,000 tokens). As your conversation grows, it fills up. yoyo helps you manage this.
## Checking context usage
Use `/tokens` to see how full your context window is:
```
/tokens
```
Output:
```
Active context:
messages: 24
current: 85.2k / 200.0k tokens
████████░░░░░░░░░░░░ 43%
Session totals (all API calls):
input: 120.5k tokens
output: 45.2k tokens
cache read: 30.0k tokens
cache write: 15.0k tokens
est. cost: $0.892
```
When the context window exceeds 75%, you'll see a warning:
```
⚠ Context is getting full. Consider /clear or /compact.
```
## Manual compaction
Use `/compact` to compress the conversation:
```
/compact
```
This summarizes older messages while preserving recent context. You'll see:
```
compacted: 24 → 8 messages, ~85.2k → ~32.1k tokens
```
## Auto-compaction
When the context window exceeds **80%** capacity, yoyo automatically compacts the conversation. You'll see:
```
⚡ auto-compacted: 30 → 10 messages, ~165.0k → ~62.0k tokens
```
This happens transparently after each prompt response. You don't need to do anything — yoyo handles it.
## Clearing the conversation
If you want to start completely fresh:
```
/clear
```
This removes all messages and resets the conversation. Unlike `/compact`, nothing is preserved.
## Tips
- For long sessions, use `/tokens` periodically to monitor usage
- If you notice the agent losing track of earlier context, try `/compact`
- Starting a new task? Use `/clear` to avoid confusing the agent with unrelated history
## Checkpoint-restart strategy
For automated pipelines (like CI scripts), compaction can be lossy. The `--context-strategy checkpoint` flag provides an alternative: when context usage exceeds 70%, yoyo stops the agent loop and exits with code **2**.
```bash
yoyo --context-strategy checkpoint -p "do some long task"
# Exit code 2 means "context was getting full — restart me"
```
The calling script can then restart yoyo with fresh context. This is useful for multi-phase pipelines where a structured restart produces better results than lossy compaction.
The default strategy is `compaction`, which uses auto-compaction as described above.