Module compaction 

Semantic context compaction: token estimation, compaction markers, and oldest-first message removal that preserves the system prompt and a recent token window.

Structs

CompactionConfig

Configuration for compact_messages.

CompactionResult

Result of a compact_messages call.

Enums

CompactionMarker

Semantic markers attached to compacted content. Each variant carries a Severity that guides what the compactor tries to preserve.

Severity

Severity of a CompactionMarker: critical markers must survive compaction, important markers should survive when possible, and informational markers may be dropped freely.

Constants

IMAGE_TOKEN_COST

Fixed token cost attributed to a single image attachment.

Functions

apply_compaction

Apply compaction in-place: keep system prefix, insert a summary system note, and retain the recent tail window. No-op when under the trigger threshold.

compact_messages

Compact a message slice by removing the oldest messages first, preserving the leading system prompt and a trailing window of keep_recent tokens.

estimate_image_tokens

estimate_messages

Estimate the token cost of a message slice using zero-allocation JSON byte counting where possible.

estimate_tokens

Heuristic token estimate: ~3 characters per token.