# Context Compaction Samples

This folder demonstrates context compaction patterns introduced by ADR-0019.

## Files

- `basics.py` — builds a local message list and applies each built-in strategy one at a time.
- `summarization.py` — runs `SummarizationStrategy` directly with a real summarizing chat client.
- `advanced.py` — composes multiple strategies with `TokenBudgetComposedStrategy`, including a real summarizer and tool-call groups.
- `agent_client_overrides.py` — shows client defaults, agent-level overrides, and per-run compaction overrides.
- `custom.py` — defines a custom strategy implementing the `CompactionStrategy` protocol.
- `tiktoken_tokenizer.py` — shows a `TokenizerProtocol` implementation backed by `tiktoken`.
- `compaction_provider.py` — uses `CompactionProvider` with an agent and `InMemoryHistoryProvider`.

Run samples with:

```bash
uv run samples/02-agents/compaction/basics.py
uv run samples/02-agents/compaction/summarization.py  # requires OPENAI_API_KEY
uv run samples/02-agents/compaction/advanced.py  # requires OPENAI_API_KEY
uv run samples/02-agents/compaction/agent_client_overrides.py
uv run samples/02-agents/compaction/custom.py
uv run samples/02-agents/compaction/tiktoken_tokenizer.py
uv run samples/02-agents/compaction/compaction_provider.py  # requires OPENAI_API_KEY
```

## Security Considerations

Most compaction strategies in this folder (`TruncationStrategy`, `SlidingWindowStrategy`,
`SelectiveToolCallCompactionStrategy`, `ToolResultCompactionStrategy`) only remove or reorder
existing messages and carry no additional risk. `SummarizationStrategy` is the exception: it
calls out to an LLM to produce replacement summary content that permanently becomes part of
chat history. A compromised or malicious summarization service could return a summary
containing unsafe instructions, creating a persistent indirect-prompt-injection vector. Using
`SummarizationStrategy` is optional and requires explicit configuration — only point its
chat client at a summarization service you trust as much as the primary model.