Diagnose your API before your users do.
Inconsistent naming, misused status codes, semantic drift, and design smells that rule-based linters miss — found before they reach your consumers.
The bugs your linter never finds.
GET /users wraps its list in
{"{"} "data": [...] {"}"}. GET /orders
returns a bare array. Nobody noticed until the SDK broke.
POST /payments documents its error body under
200. Your consumers' retry logic never fires.
Someone renamed a field in a "minor" PR. Three downstream services broke on Friday.
Rule-based linters enforce the rules you write. Protonosis learns the conventions your spec already follows — and flags where it breaks them.
Three steps. One diagnosis.
Upload or paste
Drop your OpenAPI / Swagger spec, or point us at a URL. No install required.
Get a diagnosis
Convention outliers, naming drift, and REST anti-patterns — each with severity, a suggested fix, and a pointer to the exact location in your spec.
Share the report
Send a link to your team or drop it in the PR. The shareable report is built-in.
Deterministic checks infer your conventions; an AI pass catches drift in meaning. No evidence, no finding.
What a real diagnosis looks like.
-
WARNING
`DELETE /subscriptions/{id}` returns 200; 7 of 8 DELETE
endpoints return 204
↳ #/paths/~1subscriptions~1{id}/delete/responses
- WARNING `GET /invoices` returns `{ items, total }`; every other collection returns `{ data, next_cursor }`
- WARNING `customerId` and `customer_id` both used across 6 schemas; 31 of 37 fields are snake_case
- WARNING `Refund.amount` described as "amount in dollars"; `Charge.amount` described as "amount in cents"
- `GET /events` — unbounded array response; consider cursor pagination like other collections
Catch breaking changes before they ship.
Add Protonosis to your CI pipeline. Every PR that touches your API contract is diffed against your base branch and checked against your existing conventions.
Removed fields, changed types, narrowed enums, altered status codes — detected by diffing the PR against your base branch. Flagged before merge, not after the incident.
New endpoints that break your API's existing conventions are caught automatically.
Findings show up where developers already work — inline in the pull request.
Built for you. Scales to your team.
| For you | For your team |
|---|---|
| Spec diagnosis | CI checks on every PR |
| Learn REST best practices from real findings | Block breaking changes before merge |
| Shareable report links | Consistency enforcement across services |
| Severity-ranked findings with suggested fixes | History & drift tracking over time |
Get early access.
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