init

.opencode/skills/context-engineering/references/context-optimization.md

@@ -0,0 +1,82 @@
+# Context Optimization
+
+Extend effective context capacity through strategic techniques.
+
+## Four Core Strategies
+
+| Strategy | Target | Reduction | When to Use |
+|----------|--------|-----------|-------------|
+| **Compaction** | Full context | 50-70% | Approaching limits |
+| **Observation Masking** | Tool outputs | 60-80% | Verbose outputs >80% |
+| **KV-Cache Optimization** | Repeated prefixes | 70%+ hit | Stable prompts |
+| **Context Partitioning** | Work distribution | N/A | Parallelizable tasks |
+
+## Compaction
+
+Summarize context when approaching limits.
+
+**Priority**: Tool outputs → Old turns → Retrieved docs → Never: System prompt
+
+```python
+if context_tokens / context_limit > 0.8:
+    context = compact_context(context)
+```
+
+**Preserve**: Key findings, decisions, commitments (remove supporting details)
+
+## Observation Masking
+
+Replace verbose tool outputs with compact references.
+
+```python
+if len(observation) > max_length:
+    ref_id = store_observation(observation)
+    return f"[Obs:{ref_id}. Key: {extract_key(observation)}]"
+```
+
+**Never mask**: Current task critical, most recent turn, active reasoning
+**Always mask**: Repeated outputs, boilerplate, already summarized
+
+## KV-Cache Optimization
+
+Reuse cached Key/Value tensors for identical prefixes.
+
+```python
+# Cache-friendly ordering (stable first)
+context = [system_prompt, tool_definitions]  # Cacheable
+context += [unique_content]                   # Variable last
+```
+
+**Tips**: Avoid timestamps in stable sections, consistent formatting, stable structure
+
+## Context Partitioning
+
+Split work across sub-agents with isolated contexts.
+
+```python
+result = await sub_agent.process(subtask, clean_context=True)
+coordinator.receive(result.summary)  # Only essentials
+```
+
+## Decision Framework
+
+| Dominant Component | Apply |
+|-------------------|-------|
+| Tool outputs | Observation masking |
+| Retrieved docs | Summarization or partitioning |
+| Message history | Compaction + summarization |
+| Multiple | Combine strategies |
+
+## Guidelines
+
+1. Measure before optimizing
+2. Apply compaction before masking
+3. Design for cache stability
+4. Partition before context problematic
+5. Monitor effectiveness over time
+6. Balance savings vs quality
+
+## Related
+
+- [Context Compression](./context-compression.md)
+- [Memory Systems](./memory-systems.md)