ACS evaluates code contributors based on publicly observable behavioral signals on GitHub. Each signal provides evidence about a contributor's trustworthiness in the context of code contributions to open source projects.
- Account age
- Follower/following count
- Public profile completeness (bio, company, blog)
- Contribution history length and consistency
- Total PRs submitted across all repos
- PR submission rate (PRs per day/week)
- Sudden velocity changes (dormant account reactivated)
- Time between account creation and first PR
- Cross-repo targeting patterns (same contributor on multiple related projects)
- Scope escalation (docs first, then types, then source code)
- PR description vs actual diff mismatch
- Which file paths are modified (security-sensitive vs non-sensitive)
- Do the changes strengthen or weaken security posture?
- Are dependencies added, removed, or version-bumped?
- Are CI/CD pipelines modified?
- Are authentication, encryption, or credential-handling paths touched?
- Has this contributor been reviewed/merged by trusted maintainers before?
- Do other trusted contributors vouch for this work?
- Is the target repo actively maintained or abandoned?
For every scored contributor:
- The score (0-100) and letter grade
- Key signals that influenced the score
- Evidence data (account age, PR counts, repos, timestamps)
- A SHA-256 hash of the evidence for independent verification
- Summary in plain language
The specific algorithm that weights signals into the final score. This is proprietary for two reasons:
- Publishing the weights would allow bad actors to game the score
- The weighting evolves as new behavioral patterns emerge
The evidence is always public. The interpretation is transparent (we explain why a score is what it is). The exact math is private.
Anyone can independently verify an ACS score by:
- Reading the published evidence data
- Checking the evidence against the GitHub API (all data is public)
- Verifying the evidence hash matches the published data
- Drawing their own conclusions from the signals
ACS provides a synthesized assessment. The raw data is always available for anyone who wants to assess it differently.