investigate
Evidence-based investigation of issues, bugs, API calls, integrations, and other aspects of software development that need a deep dive to find the root cause and solutions. Use when you need to debug, troubleshoot, diagnose, or figure out why something is broken. Does not review code for quality or style — use code-review for auditing changes or post-code-review-to-pr for posting review feedback to GitHub. Does not assess architectural health or structural risk — use architectural-analysis for architectural concerns. Does not research open-ended options, prior art, or how something works when
npx skills add testdouble/han --skill investigate --agent claude-code
Same command for any agent — swap --agent for codex, cursor, copilot.
Weekly change comes from our own snapshots, not the repository page — it measures attention, not adoption.
## Project Context - CLAUDE.md: !`find . -maxdepth 1 -name "CLAUDE.md" -type f` - project-discovery.md: !`find . -maxdepth 3 -name "project-discovery.md" -type f` - personal config directory: !`echo "${CLAUDE_CONFIG_DIR:-$HOME/.claude}"` - project .han/config.md: !`cat .han/config.md 2>/dev/null || echo ""` As your first action, use the Read tool on `.han/config.md` inside the `personal config directory` path above. A read that returns no file is no personal configuration: continue silently. When that file or the `project .han/config.md` probe supplies content, apply it per [config-rule.md](../../references/config-rule.md), which governs precedence between the two files, relative-path resolution, and what to do with a file that reads but cannot be used. ## Investigation Approach - Trace backward from symptoms — don't guess, follow the code. - Launch parallel `han-core:evidence-based-investigator` agents for different angles simultaneously — one for the error path, one for the data flow, one for recent changes. - Add one or more specialist analysts **in parallel with** the investigators when the bug type calls for it (concurrency, data flow across boundaries, database or query behav
- Project Context
- Investigation Approach
- Step 1: Research and Investigation
- Always dispatch
- Conditional specialist dispatch
- Step 2: Document Root Cause
- Step 3: Plan the Fix
- Step 4: Validation (CRITICAL)
- Step 5: Summary and User Review
What does the investigate skill do?
Evidence-based investigation of issues, bugs, API calls, integrations, and other aspects of software development that need a deep dive to find the root cause and solutions. Use when you need to debug, troubleshoot, diagnose, or figure out why something is broken. Does not review code for quality or style — use code-review for auditing changes or post-code-review-to-pr for posting review feedback to GitHub. Does not assess architectural health or structural risk — use architectural-analysis for architectural concerns. Does not research open-ended options, prior art, or how something works when
How do I install it?
Run `npx skills add testdouble/han --skill investigate --agent claude-code` — it drops the skill into your project so the agent can pick it up. Swap the --agent value for codex, cursor or copilot if you use one of those.
Where does this skill come from?
From testdouble/han, a repository with 154 stars. We read it straight from the repository tree rather than a submitted listing, so what you see here is what is actually published.
Is a popular skill a good skill?
Not necessarily. Stars measure attention, not adoption — a repository can trend for a week and be abandoned. That is why we show the weekly change from our own snapshots next to the total, instead of a single flattering number.