Welcome OSS contributors with AI review
For open-source projects: LGTM's review on every incoming PR catches bugs early, gives first-time contributors fast feedback, and frees maintainers from style/triage work.
OSS maintainers can't review every PR within an hour. Drive-by contributors lose interest by the time human feedback arrives. LGTM responds immediately so the contributor stays engaged.
The OSS maintainer's PR problem
Volunteer maintainer with a day job. Gets 5-15 PRs/week. Review time available: maybe 2-3 hours on weekends. Result: PRs sit for days, drive-by contributors lose interest, the project's velocity drops, the maintainer burns out.
AI code review fills the gap. Within 60 seconds of PR open, contributor gets feedback: bugs flagged, style improvements suggested, security smells caught. Conversation starts immediately, before contributor context-switches away.
Maintainer's role shifts: instead of doing the entire review, they sanity-check AI findings + provide architectural judgment + decide on merge. Time-per-PR drops from 30-60 minutes to 5-10 minutes.
Security-first stance for OSS
Open-source repos face supply-chain attack vectors that closed repos don't: forks can open PRs that exploit workflow misconfigurations (pull_request_target combined with checking out fork code → secret exfiltration).
LGTM Security's CI/CD detector set catches these patterns at PR review time. Self-hosted runner abuse, mutable action references, dangerous trigger combinations — all flagged as blocker-severity, blocking merge until resolved.
Specifically tuned for the OSS threat model: the runtime watchdog runs as a GitHub Action installed on default branch and triggers on every push (including direct commits if a maintainer goes rogue). Defense in depth for the most-attacked OSS pathway.
Setup for an OSS repo
Free plan covers most OSS use cases: 20 reviews/month, all 6 agents, all 16 security detectors, BYOK. Sufficient for a typical OSS project with moderate PR volume.
Higher-volume OSS: Pro at ₹399/mo or USD equivalent. Or: ask for OSS sponsorship — established OSS projects with public health metrics (GitHub Sponsors, OpenCollective, etc.) can email tarinagarwal@gmail.com for free Pro access.
BYOK approach: keys you bring are yours — but if you want LGTM-provided keys for an OSS project (so contributors don't need accounts), the sponsorship path covers this.
Tone — flagging without scaring contributors
First-time contributor PR feedback is delicate. Aggressive nitpicking drives people away. LGTM's tone is configurable: Settings → Repos → {repo} → Tone → 'OSS Welcome'.
OSS Welcome tone changes: findings are framed as suggestions, not commands. Cosmetic findings get rolled into the summary rather than inline (less visual noise). Security findings still surface as blocker-severity (those matter).
Comparison: 'OSS Welcome' vs default 'Standard' tone. Standard says 'This is wrong — fix X'. OSS Welcome says 'Consider X — this would improve Y' for non-critical findings. For critical findings (security, blocker bugs), both tones are direct because correctness matters more than feelings.
Recognition + contributor experience
LGTM's review comment includes a friendly opener for first-time contributors to the repo (detected via GitHub's `author_association` field on the PR). 'Welcome to {repo}! Here's some automated feedback before a maintainer reviews...'
Findings include 'why' context, not just 'what'. 'This null check is redundant because X is already validated above on line N' — teaches the contributor, doesn't just dictate.
Contributor's response to AI findings (resolved / ignored / disputed) is captured in the audit log. Useful data for maintainers to see which agents are most/least useful for their project.
How LGTM serves OSS maintainers
Free tier · OSS Welcome tone · supply-chain attack detection
Go to the product pageFAQs
Will LGTM be too aggressive for a friendly OSS project?
Configure 'OSS Welcome' tone — cosmetic findings soften, security findings stay direct. Most OSS maintainers find this strikes the right balance.
Can I require LGTM's check to pass before merging an OSS PR?
Yes — add to branch protection like any other check. Most OSS projects don't gate hard on AI review (maintainer judgment wins) but DO require LGTM Security findings to be resolved (security gating is appropriate even for OSS).
Does LGTM see private OSS contributor data?
Only what's in the public PR — diff, commit metadata, GitHub username. Anything else (email, IP) isn't visible to us. PRs from forked repos work the same as own-repo PRs from a permissions perspective.
Cost for OSS — token economics?
20 free reviews/month on Free plan, no token usage from your side (LGTM-provided keys at low volume). If you exceed 20/month and want continuity, either upgrade to Pro (₹399/mo) or apply for OSS sponsorship (free Pro for verified OSS projects).
Do contributors need LGTM accounts to see AI reviews on their PRs?
No. Reviews post as GitHub PR comments visible to anyone with PR access (which for OSS = everyone). Contributors don't need to sign up to read the review.
Related across LGTM
pull_request_target attack
The #1 attack vector OSS maintainers face — what LGTM Security flags.
Self-hosted runner abuse
Why public repos with self-hosted runners get attacked + mitigations.
Supply-chain attack
OSS is the most-attacked supply-chain layer — defense patterns.
LGTM for OSS maintainers
Persona positioning page — sponsorship + Welcome tone + free tier.
Related use cases
Use LGTM as a CI gate
Configure LGTM's review verdict as a required Check Run in branch protection. A failed review blocks the merge until findings are resolved — automated quality gate, no human bottleneck.
Pre-push local review
Review your working diff locally with the lgtm CLI before pushing — catch issues before the PR opens, save round-trips with reviewers, faster iteration.
Roll out LGTM across many repos
Install LGTM org-wide once, then enroll specific repos progressively. Per-repo config inherits from org defaults. Multi-repo rollout in days, not months.