An ACME-based certificate authority, written in Go.
C-Rank Grade: S (Elite) - 72/100
External PR Merge Rate: 81%
Response Time: 5h
First Timer Success: 80%
letsencrypt/boulder has a recorded first-timer success rate of 80.0%. Repositories ranked S typically provide actionable feedback during code reviews and actively nurture new community contributors.
Maintainers in letsencrypt/boulder respond to incoming external pull requests in approximately 5.2 hours on average. Keeping PRs focused on single tasks and ensuring tests pass helps maintainers review faster.
The C-Rank™ system evaluates GitHub projects on a 0–100 scale using real data: PR merge rates, review turnaround time, active maintainer presence, and first-time contributor success. A score of 71.8 places letsencrypt/boulder in the S tier.
The external contributor pull request merge rate for letsencrypt/boulder is 81.5%, based on public PR activity from non-core contributors.
letsencrypt/boulder currently has 5 active issue(s) tagged with beginner-friendly labels like "good first issue", "beginner", or "up-for-grabs".
Balanced & professional review environment in letsencrypt/boulder. Maintains strict focus on technical quality and test standards.
Average Response Latency
Tracks hours until a maintainer leaves a review, comment, or PR response.
External Acceptance Rate
Percentage of community pull requests successfully merged into main.
First PR Conversion
Rate at which developers submitting their first repository PR succeed.
Show contributors that your repository actively reviews and merges external pull requests.
[](https://getmerged.abhishekco.de/letsencrypt/boulder?utm_source=github&utm_medium=badge)
Historical health & responsiveness evolution
External PR acceptance
First PR success rate
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90% receive response in
Maintainer review activity heatmap & prime window prediction
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Detected: UTC
Maintainers are most responsive around 22:00 UTC (22:00 UTC in your timezone). Recommended submission window is Wednesday - Friday from 20:00 to 00:00 UTC (20:00 - 00:00 UTC local).
Maintainer Strategy: Maintainer Sweet Spot: PRs under 150 lines merge in ~4 hours (96% approval). Large PRs (>500 lines) take ~25 hours (37% approval). Keep your diff compact for rapid review.
Wait for IN-12738 to be completed. Once we've successfully set this in Production we can make this field required and also remove the guard against it being empty in *WebFrontEndImpl.prepChallengeForDisplay().
This is an issue I have asked Claude to put together as a result of its audit of Boulder against the RFCs Boulder implements. Checklist of cases where Boulder emits a field the RFC defines but its meaning, status code, or population logic diverges from the spec. Distinct from the "non-standard fields to remove" and "missing fields to add" lists — every item here is a field Boulder already implements and already sends on the wire, but with the wrong semantics. unauthorized problem returns HTTP 403 instead of 401 for deactivated accounts. RFC 8555 §7.3.6: "If a server receives a POST or POST-as-GET from a deactivated account, it MUST return an error response with status code 401 (Unauthorized) and type urn:ietf:params:acme:error:unauthorized." Boulder's Unauthorized helper hardcodes http.StatusForbidden, and the JWS verification layer raises berrors.UnauthorizedError for deactivated accounts, which the web layer maps to HTTP 403. The type URN is correct; the status code is not. Dea
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When evaluating whether to contribute to letsencrypt/boulder, response velocity and maintainer engagement are crucial. GetMerged continuously tracks pull request trajectories, first-comment latency, and code review rounds to help developers avoid submitting pull requests to backlogged repositories.
Currently, maintainers of letsencrypt/boulder acknowledge new external contributions in approximately 5 hours. Out of all submitted pull requests from non-core authors in the last 180-day window, 81.5% were successfully merged into the primary branch.
letsencrypt/boulder has a recorded first-timer success rate of 80.0%. Repositories ranked Elite typically provide actionable feedback during code reviews and actively nurture new community contributors.
The initial maintainer response time averages ~5 hours. Keeping PRs scoped to single concerns and ensuring CI checks succeed will optimize review turnaround.
The C-Rank™ index scores repositories on a 0 to 100 scale using an objective formula: external PR merge rates, initial response speed, active maintainer count, and first-time contributor retention. A score of 71.8 places letsencrypt/boulder in the Elite tier.
The external pull request merge rate is 81.5%. GetMerged isolates non-core community contributions so external developers get an accurate benchmark of PR acceptance probability.
Yes, letsencrypt/boulder currently has 5 active issue(s) tagged with beginner-friendly labels. You can inspect these directly from the repository issues tab.
All metrics displayed for letsencrypt/boulder are automatically retrieved via the public GitHub API and recalculated daily. Insider pull requests submitted by repository owners or organization members are excluded from merge rate calculations to preserve objective external contributor statistics.