Deep security review patterns for authorization logic, data access boundaries, action isolation, rate limiting, and protecting sensitive operations

Convex security audit Produces a written findings report covering every public function, every table, and every entry point (HTTP routes, file storage, scheduler). The one rule: every exported query , mutation , and action is a public endpoint anyone on the internet can call with any arguments, so each one must prove who the caller is and what they may touch. For a ten minute pass, use convex security check instead. This skill is the slow, complete version. When to reach for this Before a production launch or a major release After an incident, a leaked key, or suspicious data access When the codebase has grown past a handful of public functions and nobody has mapped who can call what When adding multi tenant, admin, or billing features When the user asks for "a full audit", "security review", or "check the whole backend" Reference files [references/authorization patterns.md](references/authorization patterns.md): open when fixing findings, it has the getCurrentUser helper, customQuery and customMutation wrappers for authed, admin, and tenant scoped access, ownership checks through indexes, and role checks. [references/attack surface.md](references/attack surface.md): open during steps 4 through 7, it covers HTTP actions, storage URL leakage, scheduler trust, rate limiting with @convex dev/rate limiter , secrets in env, and client supplied IDs. [references/audit report template.md](references/audit report template.md): open at step 8, it is the findings template and the per table data access matrix to fill in. Audit procedure Work through the steps in order. Record every finding as you go. Do not fix anything until the inventory is complete; fixing early hides the shape of the problem. 1. Inventory public functions List every exported query , mutation , and action . These are the attack surface. For each one write down: file, name, type, whether a client needs to call it, and whether it is costly (sends email, calls an LLM, creates records) and so needs a rate limit. Anything only called by other Convex functions, crons, or the scheduler should be internalQuery , internalMutation , or internalAction . Flag each of those as a finding. 2. Map auth per function For every public function from step 1, answer: does it call ctx.auth.getUserIdentity() (or a helper that does) before reading or writing? Which functions are intentionally anonymous? Files that print here contain public functions with no auth call anywhere in the file. Read each one. Anonymous is fine for a public blog list. It is a critical finding for anything that returns or writes user data. Check that auth helpers throw or return early on a missing identity, and that role checks read the role from your users table, not from client arguments. 3. Map data access per table For every table in convex/schema.ts , list which public functions read it, which write it, and what condition scopes the access (owner ID, org membership, role, public flag). Fill in the data access matrix from the report template. Look for: Reads with no scoping: ctx.db.query("table").collect() inside a public function ctx.db.get(args.someId) followed by a return or patch with no ownership comparison Ownership compared against a spoofable value (email, display name) instead of user. id .filter() used for scoping instead of .withIndex() ; this usually means the scoping was an afterthought Return validators that leak fields: v.any() , or spreading a full document that carries passwordHash , stripeCustomerId , or internal flags 4. Review http.ts Every route in convex/http.ts is reachable without a Convex client. For each route check: how is the caller verified (webhook signature, bearer token, ctx.auth.getUserIdentity() ), is the body validated before use, and does it call only internal. functions with data it has already verified? Webhook handlers that skip signature verification are critical. Routes that call api. functions from inside an httpAction may be bypassing auth those functions assume they have. 5. Review file storage Find where upload URLs are generated and where file URLs are returned. generateUploadUrl in a public mutation with no auth lets anyone fill your storage. A query that returns ctx.storage.getUrl(args.fileId) for any ID the client passes is a data leak; the URL works for anyone who holds it. 6. Review scheduled and internal boundaries Internal functions skip auth by design. The question is whether anything schedules them with unverified input. Scheduling an api. function is a finding: use internal. . Then trace each internal. call site back to the public function or route that triggered it and confirm the caller validated ownership before scheduling. 7. Review env and secrets Secrets belong in Convex environment variables ( npx convex env set NAME value ), read through process.env in the action or HTTP action that makes the external call. A secret literal in source is critical. Anything read from process.env in client code ( src/ ) is public; only non secret VITE or NEXT PUBLIC values belong there. Confirm dev and prod deployments use different keys. 8. Write the report Fill in [references/audit report template.md](references/audit report template.md). One finding per issue, ordered by severity, each with location, evidence, and a concrete fix. Include the data access matrix. Finish with the list of public functions reviewed and judged correctly anonymous, so the next auditor does not repeat that work. Severity scale Severity Meaning Examples Critical Any anonymous caller can read or change other users' data, or a secret is exposed Public mutation patches a document by client supplied ID with no ownership check; API key in source; webhook with no signature check High An authenticated user can reach data or actions outside their scope Missing org membership check in a multi tenant query; admin function reads role from client args Medium Defense in depth gap with no direct exploit today Public function that should be internal; no rate limit on a costly action; upload URL with no auth Low Hygiene v.any() on a non sensitive arg; missing return validator; .filter() where an index exists Example finding Common mistakes Mistake Why it breaks Do this instead Treating internalMutation as safe without tracing callers The public function that schedules it may pass unverified IDs Audit the scheduling call site, not just the internal function Checking auth only in the UI Anyone can call the function from the dashboard or a script Every public handler checks identity itself Comparing ownership to identity.email Emails can be reused or unverified across providers Compare to user. id looked up via tokenIdentifier Mixing return null and throw for the same case Leaks record existence through response differences In queries, return null for both "not found" and "not yours" Rate limiting only in the client Attackers skip the client Use @convex dev/rate limiter inside the mutation or action Signing off after fixes without re running the greps Fixes often move the problem Re run steps 1 through 7 after remediation Checklist [ ] Every exported query , mutation , action is listed with its intended caller [ ] Every function that should be internal is internal [ ] Every public function either checks identity or is documented as intentionally anonymous [ ] Every table has a filled row in the data access matrix [ ] Every http.ts route verifies its caller and validates its body [ ] Upload URL generation and file URL reads are gated by ownership [ ] No api. reference inside scheduler, cron, or ctx.run calls [ ] No secret literals in source; dev and prod use different keys [ ] Costly or abusable mutations and actions are rate limited [ ] Report written with severity, location, evidence, and fix for each finding Docs https://docs.convex.dev/llms.txt https://docs.convex.dev/auth/functions auth https://docs.convex.dev/functions/internal functions https://docs.convex.dev/functions/http actions https://docs.convex.dev/production/environment variables

convex-security-audit