GitHub Actions Runtime Regression Audit

Use this skill to detect runtime regressions between historical baseline runs and current runs.

What this skill does

• Reads baseline and current GitHub Actions run JSON exports (gh run view --json ...)
• Calculates average and p95 runtime per repository + workflow + job
• Compares current metrics against baseline and ranks largest regressions
• Flags warn/critical regressions by absolute seconds and percent delta
• Emits text summary for humans or JSON for automation

Inputs

Required:

• BASELINE_GLOB (glob for baseline run JSON files)
• CURRENT_GLOB (glob for current run JSON files)

Optional:

• TOP_N (default: 20)
• OUTPUT_FORMAT (text or json, default: text)
• WARN_DELTA_SECONDS (default: 30)
• CRITICAL_DELTA_SECONDS (default: 90)
• WARN_DELTA_PERCENT (default: 15)
• CRITICAL_DELTA_PERCENT (default: 35)
• FAIL_ON_CRITICAL (0 or 1, default: 0)
• WORKFLOW_MATCH (regex, optional)
• WORKFLOW_EXCLUDE (regex, optional)
• JOB_MATCH (regex, optional)
• JOB_EXCLUDE (regex, optional)
• REPO_MATCH (regex, optional)
• REPO_EXCLUDE (regex, optional)

Collect run JSON

gh run view <run-id> --json databaseId,workflowName,headBranch,headSha,url,repository,jobs \
  > artifacts/github-actions/run-<run-id>.json

Capture a stable baseline window (for example previous 2 weeks), then current runs from latest commits.

Run

Text report:

BASELINE_GLOB='artifacts/github-actions/baseline/*.json' \
CURRENT_GLOB='artifacts/github-actions/current/*.json' \
TOP_N=15 \
WARN_DELTA_SECONDS=45 \
CRITICAL_DELTA_SECONDS=120 \
bash skills/github-actions-runtime-regression-audit/scripts/runtime-regression-audit.sh

JSON output with CI gate:

BASELINE_GLOB='artifacts/github-actions/baseline/*.json' \
CURRENT_GLOB='artifacts/github-actions/current/*.json' \
OUTPUT_FORMAT=json \
FAIL_ON_CRITICAL=1 \
bash skills/github-actions-runtime-regression-audit/scripts/runtime-regression-audit.sh

Run with bundled fixtures:

BASELINE_GLOB='skills/github-actions-runtime-regression-audit/fixtures/baseline-*.json' \
CURRENT_GLOB='skills/github-actions-runtime-regression-audit/fixtures/current-*.json' \
bash skills/github-actions-runtime-regression-audit/scripts/runtime-regression-audit.sh

Output contract

• Exit 0 in reporting mode (default)
• Exit 1 when FAIL_ON_CRITICAL=1 and at least one job crosses critical regression thresholds
• text mode prints summary + top regressions + new jobs without baseline
• json mode outputs summary, ranked regressions, and newly observed jobs