LLMLingua was the original ML text compressor (BERT-based). Kompress
(ModernBERT, trained on 330K structured tool outputs) replaced it with
better compression quality and simpler architecture.
Removed across 35 files:
- Deleted headroom/transforms/llmlingua_compressor.py
- Deleted tests/test_transforms/test_llmlingua_compressor.py
- Deleted tests/test_proxy_llmlingua.py
- Removed all enable_llmlingua config, _get_llmlingua methods,
LLMLingua fallback paths, LLMLINGUA strategy enum values
- Removed CLI flags, model configs, compression handler references
- Simplified ContentRouter: Kompress is primary and only text compressor
CodeAwareCompressor now analyzes intra-file symbol relationships before
compression, using tree-sitter AST walks to count references, map call
graphs, and detect public/private visibility. This replaces uniform
"keep first N body lines" compression with budget-based allocation driven
by the existing target_compression_rate config.
Key design decisions:
- Distribution-based scoring (min-max normalized within each file) so it
adapts to any file structure: utility libs, test files, orchestrators
- Budget allocation: target_compression_rate determines total body line
budget, distributed proportionally to importance × body size
- max_body_lines respected as a hard cap over budget allocation
- Context-aware: the existing `context` parameter now boosts symbols
matching the user's task (word-boundary matching, not substring)
- Qualified names (ClassName.method) internally to avoid collisions
between identically-named methods in different classes
- Omitted comments include call graph info from AST analysis
- Zero new dependencies — uses tree-sitter already in headroom[code]
- semantic_analysis=True by default, fully backward-compatible when False
CodeAwareCompressor:
- Tree-sitter based AST parsing for Python, JS, TS, Go, Rust, Java, C, C++
- Preserves imports, signatures, type annotations, error handlers
- Guarantees syntactically valid output
- Uses tree-sitter-language-pack for broad language support
ContentRouter:
- Intelligent compression orchestrator
- Auto-routes content to optimal compressor based on type detection
- Source hint support for high-confidence routing
Custom Model Configuration:
- HEADROOM_MODEL_LIMITS env var and ~/.headroom/models.json support
- Pattern-based inference for unknown models (opus/sonnet/haiku tiers)
- Support for Claude 4.5, Claude 4, o3, o3-mini
- Graceful fallback - never crashes on unknown models
