Filter 11: compact

[leseb]

Purpose

Token counting and context window management. Summarize conversation history when threshold is exceeded.

Behavior

• Check context_management parameter for compaction config
• Count tokens via provider usage (from previous_usage) or tiktoken estimate
• If token count > threshold:
  • Build summarization prompt from conversation messages
  • Prepend instructions to summarization prompt
  • Call inference API with configured compaction_model
  • Extract summary text
  • Apply summary_prefix if configured
  • Create OpenAIResponseCompaction item with summary as encrypted_content
  • Replace conversation history with compaction item + preserved user messages
  • Store compaction response in response store (hidden, usable as previous_response_id)
  • Hide compaction items from input_items API response
• Update responses.messages with compacted messages
• Also handles explicit POST /v1/responses/compact requests

Config

filter: compact
default_model: gpt-4o-mini  # model for summarization
tiktoken_encoding: cl100k_base

Praxis trait methods

• on_request — check token count, compact if needed

Dependencies

• Inference backend (for summarization)
• Response store

Reference

• Proposal: Responses API Filters — Filter 11
• Part of Epic: Responses API and Agentic Loop Orchestration #93