open-case

name	open-case
description	This skill should be used when the user asks to "open a case", "start an investigation", "investigate this problem", "begin detective mode", or wants to apply structured investigation methodology to solve an unknown-target problem. Initializes a CaseBoard and begins the case-opening phase.

Open Case — Initialize a Detective Investigation

Start a new investigation by creating a CaseBoard and establishing the case foundation with the user.

Process

1. Understand the Problem

Before creating the case, conduct a brief exchange with the user to understand:

• What triggered this investigation (the "crime scene")
• What the desired outcome looks like (can be vague — "find the cause" is valid)
• Any initial clues or suspicions they already have
• Resource constraints (time budget, action limits)

If the user provided a clear problem description as an argument, skip directly to case creation.

2. Create the CaseBoard

Initialize the case using the board script:

python $PLUGIN_ROOT/scripts/board.py init .detective/cases/<case-id>.json "<title>" "<description>"

Use a slug derived from the title as <case-id> (e.g., "perf-regression-2026-05").

3. Seed Initial Fragments

Add the founding fragments to the board:

Crime Scene (always required):

{"content": "<initial context>", "role": "observation", "maturity": "evidence", "source": "user_authority"}

Case Goal (always required):

{"content": "<what we're trying to determine>", "role": "observation", "maturity": "anchor", "source": "user_authority", "metadata": {"is_goal": true}}

Initial Clues (if user provided any):

{"content": "<clue>", "role": "observation", "maturity": "clue", "source": "user_input"}

Initial Hypotheses (if user has suspicions):

{"content": "<hypothesis>", "role": "hypothesis", "maturity": "clue", "confidence": 0.5, "source": "user_input"}

4. Configure Investigation Parameters

Set case-specific configuration by updating the board JSON:

• checkpoint_interval: How many actions between user check-ins (default: 5)
• max_actions: Budget limit (default: 50)
• confidence_threshold_confirm: When to confirm a hypothesis (default: 0.85)
• confidence_threshold_eliminate: When to auto-eliminate (default: 0.15)

Adjust based on problem complexity — simple problems: lower max_actions, higher checkpoint frequency.

5. Present the Board

After initialization, display a summary:

• Case title and ID
• Crime scene summary
• Goal statement
• Initial fragments count
• Suggested first investigation direction
• How to proceed (/detective:investigate to start the loop)

Output Format

Present the initialized case to the user in this structure:

## Case Opened: <title>
ID: <case-id>
Phase: Opening

**Crime Scene**: <one-line summary>
**Goal**: <what we're solving>
**Initial Clues**: <count> fragments on board
**Budget**: <max_actions> actions, checkpoint every <interval>

**Suggested First Move**: <what to investigate first>

Run `/detective:investigate` to begin the investigation loop.

State File Location

All case files stored at: .detective/cases/<case-id>.json (project-local)

Create the .detective/cases/ directory if it doesn't exist.

Additional Resources

Scripts

• scripts/board.py — CaseBoard CRUD operations (init, add-fragment, add-thread, status)