Trailmark Review Gate
Apply deterministic security gate rules to Trailmark structural diff evidence. This skill does not replace line-level review. It produces a compact structural packet reviewers can cite while they inspect the code.
When to Use
- Reviewing a branch, pull request, release diff, or fix commit
- Checking whether a change expands attack surface
- Looking for removed validation or authorization on reachable paths
- Comparing before/after taint, privilege-boundary, blast-radius, or complexity signals
- Producing graph evidence for a differential review
When NOT to Use
- Single-snapshot analysis. Use
trailmarkortrailmark-structural. - Text-diff review only. Use
differential-review. - Full vulnerability discovery. Use an audit or bug-finding workflow.
- One static finding. Use
trailmark-finding-triage. - Tooling is unavailable and the user wants manual review only.
Rationalizations to Reject
| Rationalization | Why It Is Wrong | Required Action |
|---|---|---|
| "The line diff is small, so no graph gate is needed" | Small changes can create new call paths | Compare before/after graphs |
| "Graph gate passed, so the PR is secure" | The gate only checks structural regressions | Still perform line-level review |
| "Trailmark failed, so pass the gate" | Tool failure is unknown risk, not success | Emit UNKNOWN |
| "Tests pass, so removed validation is fine" | Tests may miss affected entrypoint paths | Review the removed path manually |
| "Only new code matters" | Removed auth, validation, and callers can be higher risk than additions | Review removals and path changes |
Workflow
Review Gate Progress: - [ ] Step 1: Resolve before/after inputs - [ ] Step 2: Build graph-evolution evidence - [ ] Step 3: Normalize structural changes - [ ] Step 4: Apply gate rules - [ ] Step 5: Emit review packet and actions
Step 1: Resolve Inputs
Accept two refs, a branch name, a commit range, or before/after directories.
Do not check out branches unnecessarily. Prefer git diff, git show, and
git worktrees, following the graph-evolution snapshot workflow.
Step 2: Build Graph Evidence
Run graph-evolution or equivalent Trailmark before/after graph analysis.
Both snapshots must run engine.preanalysis() so taint, privilege-boundary,
blast-radius, complexity, and entrypoint signals are available.
Record Trailmark version and any feature probes. If graph construction fails,
emit UNKNOWN.
Step 3: Normalize Changes
Normalize evidence into:
- added, removed, and modified nodes
- added and removed edges
- entrypoint set changes
- taint membership changes
- privilege-boundary membership changes
- blast-radius changes
- complexity changes
- newly reachable sensitive sinks
- unresolved, proxy, or dynamic edge changes
Step 4: Apply Gate Rules
Apply the rules in references/gate-rules.md. Gate verdicts are:
| Verdict | Meaning |
|---|---|
FAIL | A high-risk structural regression needs review before acceptance |
WARN | A meaningful graph change needs reviewer attention |
PASS | No configured structural gate fired |
UNKNOWN | Trailmark failed or evidence is too incomplete |
Step 5: Emit Packet
Write the packet using
references/output-format.md, then hand it to
the branch reviewer. Use
references/review-integration.md when
combining this packet with differential-review or another PR review process.
Requirements
- Never mutate the user's working branch while comparing refs.
- Never report
PASSwhen Trailmark failed. - Separate graph evidence from manual security judgment.
- Include exact changed nodes or paths for every
FAILandWARN. - Include limitations when parser, proxy, unresolved-call, or dynamic-dispatch uncertainty affects the verdict.
