Gittellsyou
what changed.
Wetellyou why.
Codebase Time Machine reads your entire Git history with IBM Bob and turns it into a queryable brain. Onboard in hours, not weeks. Never lose tribal knowledge again.
▸ Public repos work instantly▸ ~60s to index▸ No credit card
Your codebase has a memory problem.
Git records every keystroke and forgets every reason. We turn that asymmetry into your competitive advantage.
Senior devs leave. Their context leaves with them.
Years of decisions, trade-offs, and gotchas live in heads, not files. When they walk, your codebase forgets how to explain itself.
PR descriptions just say "fix." Slack threads vanish.
Why did we choose this library? Why is this loop here? The answers are scattered across Notion pages no one updates and DMs no one searches.
New hires lose 2–4 weeks asking "why is this like this?"
Every onboarding repeats the same archaeology. Multiply by team size and you've burned a quarter of velocity on rediscovery.
Five ways to time-travel your code.
Each one reads the same shared brain: your repository's full history, embedded and indexed by IBM Bob.
Ask any question. Get a narrative answer with citations.
RAG over your full Git history — commits, diffs, PR descriptions, ADRs. Every answer cites the exact commits it learned from.
Why does middleware.ts early-return on null?
Added in a3f9c2e by @dougwilson after a prod incident where a falsy session crashed the request chain. See PR #4421.
Scrub through any file's history. See every major change explained.
Drag the timeline. Watch a file grow. See the commit that introduced this if-statement, the PR that refactored it, the author who removed it.
Architectural Decision Records, extracted from history in one click.
Bob detects decision patterns across commits, surfaces the alternatives that were considered, and writes the ADR you wish someone had written.
Sessions can be falsy after Redis expiry. Pre-fix, middleware downstream of requireAuth would crash.
Return 401 early when req.session is null.
+ Clean error semantics. − Custom flows must opt-out via header.
Chat with the synthesized expertise of contributors who left.
Their commits, comments, and decisions become a persona you can interrogate. Get the answer the departed senior dev would have given.
How would you have handled the streaming body case?
Don't buffer. Use the lazy parser introduced in body-parser@1.18. I shipped that exact pattern in c2d8a14.
Files, authors, decisions — visualized as an interactive map.
Hover any node to see who owns it, what depends on it, and which decisions shaped it. Find the load-bearing files no one wants to touch.
Three steps from URL to queryable brain.
No setup, no plugins, no manual tagging. Paste, wait a minute, ask anything.
Paste any GitHub URL
Public repos work instantly. Drop in expressjs/express, your-org/api, or a side project.
We index your history
IBM Bob analyzes commits, diffs, authors, and decisions. ~60 seconds for a 5k-commit repo.
Ask anything, travel anywhere
Chat, scrub the timeline, generate ADRs, explore the graph. The whole brain is yours.
We didn't just use AI.
We built with the smartest dev partner there is.
IBM Bob pair-programmed every layer of this product — from the pgvector schema to the Ghost Author persona engine. Every architectural call is checked in under bob_sessions/.
Free for public code.
Fair for teams.
No seat traps. No usage cliffs. Cancel anytime, export everything.
Explorer
For solo builders and OSS maintainers.
- Up to 3 public repos
- Full Why Engine + Time Travel
- Community support
- API rate-limited to 50 queries/day
Team
For teams ready to time-travel together.
billed annually
- Unlimited public + private repos
- Ghost Author + ADR export
- Team workspaces & roles
- Slack integration
- Priority support
- 10k queries/month per dev
Enterprise
For platforms with serious history.
tailored to your team
- SSO (Okta, Azure AD)
- RBAC + audit logs
- On-prem deployment option
- Custom integrations
- Dedicated success manager
- Volume pricing
Questions, answered.
Stop losing knowledge.
Start time-traveling.
Free forever for public repos. No credit card required. ~60 seconds to your first answer.
▸ Works with any public repo▸ Indexed in ~60s▸ No setup