Introduction — Why Supabase JWT Claims Matter
As soon as you move beyond simple authenticated apps and start building SaaS platforms, teams, or role-based access workflows, understanding how Supabase JWT Claims work becomes essential. JWT claims allow you to store extra identity information — such as organization membership, role level, or tenant ID — inside the user token and use that information to enforce Row Level Security (RLS) rules.
Without JWT claims, RLS logic often becomes:
❌ Hard-coded
❌ Dependent on additional queries
❌ Slower or overly complex
❌ Unscalable for multi-tenant systems
With JWT claims, Supabase can enforce authorization directly inside SQL, making your access model:
✔ Faster
✔ Cleaner
✔ More secure
✔ Easier to scale
This guide walks you step-by-step through how to use JWT claims correctly in Supabase — particularly for RLS.
What Are JWT Claims?
JWT (JSON Web Token) claims are pieces of information stored inside the user’s authentication token. Supabase automatically generates standard JWT values, such as:
| Claim | Description |
|---|---|
sub | The user ID |
email | User’s email |
role | Supabase auth role (not app role) |
But the real power comes from custom JWT claims, which allow you to store:
- Organization ID
- Team memberships
- Application roles (admin, viewer, member)
- Feature flags
- Subscription or billing status
Supabase exposes JWT claims inside SQL using:
auth.jwt()Why Use JWT Claims With RLS?
When building secure RLS rules, you often need contextual information beyond just auth.uid().
For example:
- Is this user an admin or standard user?
- Which tenant do they belong to?
- Does the user have write, read-only, or no access?
JWT claims allow you to answer those questions without querying another table.
This makes:
⚡ Queries faster
🔐 Policies clearer
🏗 Scalability easier
Adding Custom Claims
Supabase stores custom claims inside the auth.users metadata object.
Example (Node or client-side):
await supabase.auth.updateUser({
data: {
app_role: "admin",
organization_id: "org_abc123"
}
});Once updated, Supabase includes them in the JWT.
Accessing JWT Claims in SQL
select auth.jwt()->>'app_role';
select auth.jwt()->>'organization_id';Using JWT Claims in RLS Policies
Here’s how to build real-world RLS rules using JWT claims.
1 — Role-Based Access Using JWT Claims
create policy "Admins can read everything"
on users
for select
using (auth.jwt()->>'app_role' = 'admin');2 — Multi-Tenant Access Using organization_id
create policy "Read only own tenant data"
on tasks
for select
using (
organization_id = auth.jwt()->>'organization_id'
);3 — Mixed Rule (Tenant Matching + Role Override)
create policy "Tenant-level RBAC"
on tasks
for select
using (
organization_id = auth.jwt()->>'organization_id'
or auth.jwt()->>'app_role' = 'admin'
);Refreshing JWT Claims (Important)
JWT claims do not update immediately after metadata changes.
Users must:
👉 Log out and log back in
or
👉 Refresh the token programmatically:
await supabase.auth.refreshSession()Common Mistakes When Implementing JWT Claims
| Mistake | Fix |
|---|---|
| Forgetting to refresh JWT after updating metadata | Use .refreshSession() |
| Storing large objects in metadata | Keep claims lightweight |
| Using service_role key in client | Never do this |
| Using JWT claims instead of database references | Claims should mirror, not replace data |
Best Practices for Secure App Architecture
✔ Store only what is required for security
✔ Keep naming consistent (organization_id, role)
✔ Combine claims + RLS patterns for multi-tenant SaaS
✔ Refresh tokens after metadata changes
✔ Test user flows with multiple user types
Summary — JWT Claims Make RLS Powerful and Scalable
Using Supabase JWT Claims gives you the ability to:
- Secure multi-tenant systems
- Add role-based access
- Avoid unnecessary database joins
- Build fast, secure authorization rules
JWT claims aren’t just a feature — they’re the backbone of scalable RLS design.
Want JWT Claims and RLS Done Automatically?
Instead of writing custom claims, update handlers, and policies manually, PromptXL gives you:
- Prebuilt JWT claim automation
- Multi-tenant + role-based policy sets
- Secure RLS templates
- Fully working SaaS access architecture
No guessing. | No debugging. | No broken permissions.
🚀 Build fast
🔐 Deploy secure
⚡ Scale without rewriting auth logic
👉 Try PromptXL — secure Supabase apps start here.