Review - Aster

aster review reviews a diff: the current branch, a range, a PR, or stdin.

aster review                               # current branch
aster review --range main..HEAD
git diff HEAD~1 | aster review --diff -
aster review --pr 42 [--repo owner/repo] [--token T]
aster review --pr 42 --comment [-y]        # post inline PR comments
aster review --tui                         # browse findings
aster review --json                        # data for CI
aster review --stream                      # NDJSON progress for UIs
aster review -i "src/**/*.rs" -x "**/*.lock" --min-confidence 0.6
aster review --no-index                    # faster, less evidence
aster review --effort high

How it works

Hypothesize. A model reads the diff and forms candidate findings.
Retrieve. A local symbol index pulls the code around each candidate, so the verifier sees context, not just the hunk.
Verify. A second pass tries to refute each finding. What survives is reported; what is refuted is dropped.
Shape. Findings carry file, line, severity, category, title, suggestion, and confidence.

The refutation pass is the point: a finding that cannot be refuted after an honest attempt is worth your time. --no-index skips the symbol index for speed at the cost of evidence.

Configuration

Under review: in aster.yaml:

Key	Does
`model`	The review model; `auto` picks from OpenRouter’s live rankings
`hypothesis_model`, `verify_model`	Override per stage
`base_url`	Custom endpoint
`min_confidence`	Drop findings below this (0 to 1)
`max_diff_bytes`	Refuse diffs larger than this
`analyzers`	`[semgrep, ast-grep]`, run alongside the model pass
`astgrep_rules`	Extra ast-grep rule paths
`effort`	Reasoning budget for the review
`web_search`	Let the review search the web
`focus_areas`	Steer attention, e.g. security or error handling
`include`, `exclude`	Glob filters over the diff

model: auto tiers with ASTER_ROUTER_TIER=cheap|balanced|strong; aster model router shows the current pick. Environment overrides: ASTER_VERIFY_MODEL, ASTER_HYPOTHESIS_MODEL, ASTER_VERIFY_CONCURRENCY.

In CI

--json prints findings as data; exit code reflects severity, so a plain aster review --json step fails the build on a critical finding. The --pr --comment pair posts findings inline on the PR. See Fix for consuming the JSON.