Context window management

Lifecycle

Phase	Action
Bootstrap	Load spec, constraints, key paths only—not whole repo
During task	Append deltas; replace full file reads with summaries after use
Before compaction	Write Session state block (objective, done, open, paths)
Session end	Drop tool noise; keep decisions and verification evidence

Strategy order

1. Do not load — use search/read targeted files only.
2. Reference — pointers (paths, line ranges) instead of full paste.
3. Summarize — compress completed work; keep decisions and open items.
4. Drop — remove obsolete tool output and duplicated content.

What to keep in active context

• Current objective and acceptance criteria
• Constraints (env, versions, "do not touch")
• Recent errors and fixes
• Open questions

What to offload

• Full file contents already summarized
• Long command outputs (keep exit code + last N lines)
• Exploratory branches that did not ship

Compaction pattern

## Session state (compacted)
Objective: ...
Done: ...
Open: ...
Key paths: ...
Do not repeat: [list already-established facts]

Multi-file work

• Load one module at a time when possible.
• Prefer ripgrep/semantic search over dumping trees.
• For RAG: retrieve only top-k relevant chunks.

Anti-patterns

• Pasting entire repos or logs into chat.
• Re-explaining architecture every turn without delta.
• Keeping failed attempts at full length after resolution.

Session setup (context engineering)

Before long tasks, establish a minimal working set:

1. Objective block — one paragraph: goal, non-goals, done-when
2. Constraint block — versions, env, files off-limits
3. Reference map — paths to spec, ADR, or ticket; load on demand
4. Tool policy — which tools/skills apply; avoid loading unused skill bodies

Refresh the objective block after major pivots; do not re-paste full history.

Pairing

Use with rag-systems for external knowledge; clarify-underspecified when scope grows mid-session; interview-me before loading large specs.