Context Preservation Skill

Generate structured context summaries when compaction is imminent or requested, ensuring session continuity without information loss.

Output Format (STRICT - NO DEVIATIONS)

### 1. Current Objective & Status
- **Goal**: [Robust, multi-sentence description of what we are building. Include critical details, context, and the "Definition of Done". Do not summarize into a single vague line.]
- **Status**: [Completed | In Progress | Blocked]
- **Immediate Next Step**: [The very next command or code edit required. Be specific.]

### 2. Active Context
- **Active Files**:
  - `[Absolute Path]`
  - `[Absolute Path]`
- **Recent Changes**: [Specific descriptions of what *just* changed in the code, referencing specific functions or logic.]
- **Variables/State**: [Key variable names, data structures, or temporary states currently in focus.]

### 3. Constraints & Decisions (CRITICAL)
- **Preferences**: [User preferences stated in this session, e.g., "no external deps", "use snake_case"]
- **Discarded Approaches**: [What did we try that failed? Do not repeat these mistakes.]
- **Architectural Rules**: [Patterns we agreed on, e.g., "Service Layer pattern", "DTOs required"]

### 4. Continuity Handoff
- "When resuming, the first thing to do is..."

Content Extraction

Section 1: Current Objective & Status

• Extract goal from user's initial request, explicit goal statements, Definition of Done indicators
• Status: Completed (all objectives achieved), In Progress (work ongoing), Blocked (explicit blocker)
• Next step: last in-progress item, last "next I will..." statement, or first pending objective

Section 2: Active Context

• Files touched via Read/Write/Edit operations, prioritized by recency
• ALWAYS use absolute paths (e.g., /Users/turla/Code/project/src/auth.ts)
• Summarize function additions, modifications, deletions with specific names and line refs
• Key variables, data structures, environment variables in focus

Section 3: Constraints & Decisions

• Preferences: "don't use...", "prefer...", "always...", "never..."
• Discarded approaches: failed attempts with reasons
• Architectural rules: pattern agreements, structure decisions, dependency choices

Section 4: Continuity Handoff

• Always begin with "When resuming, the first thing to do is..."
• Must be specific enough for a fresh Claude instance to immediately continue

Anti-Patterns (NEVER DO)

Goal Description

WRONG:

• "Building a feature"
• "Working on authentication"

RIGHT:

• "Building a user authentication system with OAuth2 PKCE flow for the mobile app. The system must support Google and Apple SSO, store refresh tokens securely in the device keychain. Definition of Done: user can complete full login flow, tokens persist across app restarts, logout clears all tokens."

Active Files

WRONG:

• file.ts
• ./src/auth.ts

RIGHT:

• /Users/turla/Code/myproject/src/auth/oauth-handler.ts

Recent Changes

WRONG:

• "Updated the file"
• "Fixed some issues"

RIGHT:

• "Added validateTokenExpiry() function to /Users/turla/Code/myproject/src/auth/token-storage.ts (lines 42-67) that checks JWT expiration. Modified refreshToken() to call this before attempting refresh."

Immediate Next Step

WRONG:

• "Continue working"
• "Finish the implementation"

RIGHT:

• "Run npm test -- --testPathPattern=oauth-handler to verify the new validateTokenExpiry() function works with expired tokens"

Validation Checklist

Section 1

• Goal is 2+ sentences with Definition of Done
• Status is exactly: Completed, In Progress, or Blocked
• Next step is a specific command or edit

Section 2

• All file paths are absolute (start with /)
• Recent changes reference specific function/method names

Section 3

• Discarded approaches explain WHY they were discarded
• No empty sections (use "None stated this session" if applicable)

Section 4

• Starts with "When resuming, the first thing to do is..."
• Contains a specific, actionable instruction