RowShield vs Probely: black-box DAST vs white-box policy checks

Head to head: Probely vs RowShield

Column claims about Probely are sourced below. Where the edge is theirs, the page says so — and the sections that follow explain why Supabase teams still pick RowShield.

What Probely does

Probely builds a dynamic scanner aimed explicitly at developers rather than security departments, and that developer-first stance is its real strength. Applications and APIs are described once, authentication is configured, and the platform then crawls, probes and reports with an emphasis on reducing false positives and fitting existing engineering workflows.

Continuous modes revisit targets regularly, and an API supports automation, which places Probely comfortably inside modern delivery pipelines. Among dynamic scanners it speaks the most fluent developer dialect, and teams that want DAST without ceremony often settle here, treating findings much like any other review feedback.

Where the scopes differ

Every Probely conclusion derives from responses it elicits. On a Supabase backend that imposes a hard epistemic limit: PostgREST answers succeed identically whether a table is protected by strict policies, readable by everyone, or simply empty. Policy-filtered rows and absent rows share one representation, so no amount of external cleverness resolves authorisation quality from the wire.

Changes compound the problem. A migration disabling protection alters nothing observable until probed just so, and between continuous-mode passes the alteration travels unnoticed. White-box inspection of the catalog resolves instantly what black-box inference cannot, which is exactly the gap RowShield occupies.

Restated through the recurring lens: Probely samples behaviour; RowShield holds posture, semantics and drift by reading the source of truth. Choose the method that matches the question.

Why Supabase teams choose RowShield over Probely

If Probely appeals to you, RowShield will feel familiar in temperament, automated, low-ceremony, developer-first, while aiming at the layer Probely cannot inspect. Rules such as RLS_DISABLED, ANON_TABLE_READABLE and SERVICE_ROLE_KEY_EXPOSED are checked against live catalog state on every merge.

Findings cite the rule, the object and the offending definition, so fixes happen in the same sitting as the migration that caused them. Filtered-versus-empty ambiguity disappears because policy text is the evidence. Latency-to-alert drops to minutes, triage nearly vanishes, and pricing reflects a focused utility.

For Supabase authorisation, white-box specificity outperforms even well-executed inference, however polished the automation delivering it.

Where Probely is the right choice

Applications with substantial non-database surface, custom servers, third-party frameworks and intricate front-end logic benefit from the broader technique library and comfortable workflow, and teams seeking continuous DAST with minimal fuss are well served. It finds injection points and misconfigurations across stacks that RowShield deliberately ignores.

The concession mirrors the compliment: fluency with HTTP is not fluency with Postgres. However refined the probing, responses alone cannot certify row level security or notice its quiet removal. Keep it for the surfaces it understands; assign the data layer to instrumentation that reads the source of truth.

Using both

Because temperaments align, the combination is smooth. Wire RowShield into the repository so every merge receives authorisation verification, and let Probely continue its continuous probing of the broader application. Findings regarding API endpoints can be interpreted quickly against the RowShield catalog picture, separating genuine authorisation defects from behavioural quirks.

Conversely, when RowShield reports drift, Probely history helps characterise what the exposed window looked like in practice. Developers get one coherent experience: dynamic testing where appropriate, semantic verification underneath, and neither asked to substitute for the other.

Frequently asked

Is RowShield affiliated with Probely?

No. RowShield is produced by Veristria independently and has no affiliation with, endorsement from or sponsorship by Probely. Any product names mentioned are trademarks of their respective owners and appear for identification and comparison only.

We already run Probely continuously. Is RowShield redundant?

It is complementary rather than redundant. Continuous DAST still reasons from HTTP responses and cannot resolve filtered-versus-empty ambiguity, inspect policies, or tie findings to migrations. RowShield reads catalog and policy state directly and verifies on every merge, covering the authorisation layer that dynamic scanning samples only indirectly.

Which tool tells us faster that a policy regressed?

RowShield, decisively. Posture changes are detected when the migration lands, reported with rule and object identified, typically minutes after merge. Behavioural scanners register regressions only when a later probe produces a recognisably anomalous result, and many policy changes produce no externally recognisable anomaly at any time.