3x-ui/REVIEW.md

Review instructions

3x-ui is a Go (Gin + GORM) web panel that generates configuration, share links and subscriptions for other programs — Xray-core, mihomo, sing-box, mtg-multi — and is deployed by operators who upgrade in place. Judge findings by what breaks for those consumers and operators, not by style.

Severity

Mark every finding with exactly one of these, at the start of the finding:

Severity	Use it for
CRITICAL	Security, data loss, corruption, or a severe production failure.
HIGH	A significant functional or production issue. Everything under "What HIGH means here" is at least this.
MEDIUM	A real bug, or a meaningful reliability or performance problem.
LOW	A minor but legitimate issue, including an ordinary CLAUDE.md violation the change introduces — a source comment block over two lines, a fix larger than the bug it removes, a test CLAUDE.md rejects outright. Never formatting or personal style.

A CRITICAL or HIGH finding this pull request introduced or made worse is blocking: worth fixing before it merges. Not every CLAUDE.md rule is LOW. The three listed below — the dispatch rule, the migration rule, the endpoint chain — are HIGH, because each one passes every local test and breaks a real deployment.

Severity rates the defect; a second word says whose it is. A real bug you hit while reading that this pull request neither introduced nor made worse is marked pre-existing after its severity — MEDIUM pre-existing — and is never blocking. One the change worsens is rated for the regression it added, not for the whole defect.

Checking what this panel emits means reading far more code than the diff changes, so pre-existing bugs surface on every review. One already on the base branch stays pre-existing however bad it is: this pull request did not cause it, so it cannot be a reason to hold this pull request. Say in one clause that it predates the change. The exception is a live security hole on an exposed surface — still pre-existing, but open the summary with it.

What HIGH means here

• Security on the exposed surfaces: internal/web/controller/, session and middleware code, the PUBLIC internal/sub/ subscription server, and Xray config generation in internal/xray/.
• A state-changing inbound or client operation that bypasses runtime.Runtime (internal/web/runtime/) and calls internal/xray/api.go directly, or dispatches from a controller or cron job. It passes every local test and silently breaks every multi-node deployment.
• A schema or model change without a matching hand-written migration in internal/database/db.go, one that behaves differently on SQLite and PostgreSQL, or one that loses or overwrites operator data on upgrade or rollback. There are no migration files and no down-migrations.
• A change to what the panel emits on the wire — Xray config JSON, share links, subscription/Clash YAML, mtg-multi TOML, AmneziaWG obfuscation parameters — that a downstream client would reject or read differently, or that makes two independent implementations of the same output diverge: the three link implementations (Go internal/util/link/ + internal/sub/, TS frontend/src/lib/xray/, TS docs/lib/xray/), and the AmneziaWG 3.1 generator in Go (internal/amneziawg/params.go) versus TS (frontend/src/lib/xray/amneziawg-obfuscation.ts).
• Any edit to .github/workflows/: this repository runs workflows with secrets against a public fork stream. Untrusted expression interpolation into run: blocks, broadened permissions, weakened guards, or a job that executes pull-request code.

Always check

• A new g.POST/g.GET in internal/web/controller/ needs the whole chain: an entry in frontend/src/pages/api-docs/endpoints.ts, regenerated artefacts (make gen), any new API-boundary struct added to StructAllow in tools/openapigen/main.go, and frontend/public/openapi.json copied to docs/public/openapi.json with the docs MDX regenerated (cd docs && pnpm gen:api). CI checks the first three; the docs copy is checked by nothing — a missed copy is HIGH, not LOW.
• A bug fix carries a test that would fail without the fix. A test that cannot tell the broken behaviour from the fixed one passes before and after, so it certifies nothing and is itself the finding — asserting only err != nil or len(x) > 0, or going green by regenerating golden fixtures or Vitest snapshots.
• No second way to do a thing already decided: Go tests are stdlib testing (never testify), the panel is Ant Design (never Tailwind or shadcn). Neither golangci-lint nor oxlint forbids the import, so it passes CI clean.
• No second copy of logic the repository already has. A parse, guard, formatter or type the change writes afresh usually exists in internal/util/, in the service it sits in, or in frontend/src/lib/ — grep for the behaviour, not the name. Two copies drift apart; the three link implementations are what that costs. Rate it by what the drift would break.

Try to break it

The question behind every finding is how this change fails in production, so read the changed code under the conditions this panel actually meets rather than the happy path the author had in mind:

• An upgrade over an operator's existing database. Rows written before this change: a column added with its zero value, a field the old writer never set, a settings blob in the older shape. And the way back, because there are no down-migrations — an operator who rolls the binary back reads the same rows.
• A restart. Anything held only in memory is gone when the panel or the Xray child restarts, and the cron jobs in internal/web/job/ then fire against whatever survived.
• A second actor at the same instant. Two panel requests, a request racing a cron job, or a sub-node syncing while the master writes. Read-modify-write on the same row is where this surfaces.
• The same operation twice. A retried request, a re-sent sync, a job that ran late and then again on schedule. Traffic and quota resets and Xray API calls have to survive being applied a second time.
• Absent, empty and extreme input. An inbound with no clients, a client with no traffic, an expired or disabled one, a nil settings blob — and the other end, the operator with thousands of clients whose loop or query this change sits inside.
• A dependency that is down. The Xray gRPC API refusing a call, the mtg-multi management API unreachable, a sub-node offline, PIA or LDAP timing out. What the caller sees, and what state is left behind.

Running a case is not reporting it. Each one still has to clear the verification bar below — the code path that mishandles it, cited — and a case the code already handles is not a finding at all.

Do not report

• Anything CI already enforces: golangci-lint and gofumpt, oxlint, format and typecheck, govulncheck, and npm audit --omit=dev --audit-level=high. A dev-dependency advisory is out of scope on purpose: it ships to nobody.
• The contents of generated files (frontend/src/generated/, frontend/public/openapi.json, docs/public/openapi.json) or lock files. Those files being STALE after a source change is reportable; their style is not.
• Missing tests for getters, constants, renames or pure map lookups — CLAUDE.md rejects such tests outright.
• A missing or unreferenced i18n key. frontend/src/test/i18n-dead-keys.test.ts pins the 13 locale files in internal/web/translation/ in both directions, so the frontend job is already red. Report the failing check, not the key.

A higher bar, not silence

Everything named under "What HIGH means here" gets full scrutiny. Two areas do not — they earn review, but report there only what you are near-certain about and that actually breaks something:

• docs/ — the standalone Fumadocs site, with its own CI and its own dependency tree. docs/lib/xray/ is the exception and gets full scrutiny: it is the third link implementation.
• internal/web/translation/ — the key set is CI's job and the wording of a translation is nobody's here.

Verification bar

• A claim about behaviour needs a file:line citation from this repository, not an inference from a name.
• Reading code establishes what it says, not what it does when it runs. Keep apart what was read, what a test or command reproduced, and what is inferred, and say which one a finding rests on. "This races" or "this breaks clients" with no reproduction behind it is an inference, and reads as one.
• A performance finding needs evidence, not complexity or intuition: a benchmark, a query plan, a measured timing, an allocation count, or an invariant this repository already holds.
• A security finding traces the trust boundary the change sits on — who reaches the code, and what authorization, validation, escaping and privilege it assumes — against the existing code, not the hunk.
• A claim about what the change does to a caller or a callee needs that file read, not inferred from the hunk. A dispatch-rule violation rarely shows inside the diff — the changed line calls an innocuous helper and the internal/xray/api.go call sits a frame outside it.
• A claim that a downstream client rejects or requires a wire-format detail — a config key, JSON tag, URI query parameter, YAML or TOML key, an encoding or hash choice — must name the upstream symbol that decides it (repository, file, identifier). If you cannot verify it, keep the finding but say explicitly that it is unverified instead of asserting it.
• "CI passed" is a claim too, and needs the same evidence: say it only of a run you actually read. A green one proves less here than it looks — only postgres-durable-first runs against PostgreSQL, go-test and race are SQLite, and XRAY_E2E_BINARY and XUI_SCALE_TEST are set by no job, so those tests have never run in CI at all. Where a change touches dialect, migration or Xray gRPC code that no job exercised, say it is unverified rather than repeating a green tick as proof.

Cap the volume

CRITICAL, HIGH and MEDIUM findings this pull request introduced or made worse are never capped. Report every one.

Report at most five LOW and at most three pre-existing findings, whatever their severity. Past that, say "plus N similar" in the summary instead of posting them.

A cap decides WHICH ones survive, so choose rather than truncate: the same LOW repeated across files is ONE finding with a count, not five slots; one in code this pull request wrote outranks one in code it only moved; and one nobody would act on does not deserve a slot at all.

After the first review of a pull request, report MEDIUM and above only: a one-line fix must not reach round seven on style.

What the comment must show

Open with a one-line tally — 1 HIGH / 2 MEDIUM / 1 LOW, 1 pre-existing, where a pre-existing finding counts only in its own bucket — so the author sees the shape of the review before the detail. When nothing is blocking, lead with No blocking issues and put the tally after it.

Say each finding once. Where it already sits in an inline comment on its line, the summary gives it one line — severity, file:line, what breaks — and the reasoning stays in the inline comment.

Nothing pads the comment: no "Strengths" section, no restatement of what the pull request does, no praise, no closing pleasantry. Padding is not neutral — it buries the two lines someone actually has to act on.

The posted comment is the only part of a review anyone sees, so a bare "no issues found" is a receipt, not a review: nothing in it says whether the diff was read or the run died early. Every comment therefore ends with a short coverage list — one line per area actually checked, naming what was examined and what it turned out to be, plus the head SHA and the size of the diff it covers. Say which claims could not be verified and why, including a check this environment blocked. Keep that coverage list under ten lines; it is evidence, not a retelling of the pull request.

A finding is a report, not a patch

A finding says what is wrong, where (file:line), what triggers it and what breaks. It never carries the fix: no suggestion block, no patch, no replacement snippet, no rewritten function, no "suggested fix" section — in the summary and in an inline comment alike. It does not say where the fix belongs either: no closing "The fix belongs in …" line. The file:line already locates the defect, and a location set beside the missing piece the finding just named — "the fix belongs in the capability set" after naming the two capabilities it lacks — is the fix. Prose is a patch too the moment a verb describes the change: "move the lookup inside the body", "spend the comment on the invariant instead" hand it over as surely as a diff would, and so does holding up an existing symbol as the model to copy. A clause the maintainer could apply as written is the fix, however it is punctuated. The maintainer decides the change; a review that writes it out puts unreviewed code one click from the branch.

A finding that is not pre-existing also says, in one clause, what this pull request did to the code it is about — the line it added, the call it moved, the guard it dropped — the way a pre-existing one says that it predates the change. That clause reports what the change did, never what it should have done. Nothing else in the comment shows the marker was earned.