Build JWTs with Pre-made Templates
Generate JWTs quickly using templates for OpenID Connect, OAuth 2.0, and API authentication. Customize standard claims and sign tokens instantly for your testing scenarios.
Building JWTs with Pre-Made Templates
The template builder provides starting points for common JWT scenarios. Instead of manually typing claims like iss, sub, and aud, you select a template and customize the values.
Each template pre-fills standard claims with sensible defaults. The OAuth template includes scope and azp claims. The microservice template adds roles arrays and tenant_id for multi-tenant architectures.
Available templates:
- Basic auth - Simple user authentication with issuer, subject, audience, expiry
- OAuth 2.0 - Includes scope, authorized party (azp), and OAuth-specific claims
- API gateway - Service-to-service tokens with permissions arrays and rate limits
- Microservice - Multi-tenant setups with roles, tenant IDs, and active flags
After selecting a template, you can add custom claims with typed values (string, number, boolean, array). The builder validates JSON syntax for array claims before generating the final token.
When Templates Save You Time
Setting up a new authentication system
You're implementing JWT auth from scratch. The basic template gives you the standard claims structure, so you don't have to look up what each claim name means.
Creating service account tokens
Your microservices need to authenticate with each other. The API template includes permissions arrays and rate limit claims that match your service mesh requirements.
Testing OAuth integrations
Before connecting to the real OAuth provider, you generate test tokens with the OAuth template. Your code can parse and validate them without hitting the actual auth server.
Documenting expected token structure
Your API docs need example JWTs. Generate tokens from templates to show developers exactly what claims they'll receive and what format each claim uses.
Onboarding new team members
Junior developers learning JWTs can experiment with templates to see how different claims affect token structure. It's faster than reading the RFC spec.
Prototyping multi-tenant features
You're adding tenant isolation. The microservice template includes tenant_id claims, letting you quickly test how your code handles tenant-scoped data.
What to Know Before Using
Templates generate unsigned tokens.The builder creates the payload structure but doesn't sign tokens with a secret key. Use these for testing and documentation, not production authentication.
Custom claims are your responsibility.Templates include common claims, but your application may need additional ones. Add custom claims carefully—every claim increases token size.
Array claims require valid JSON.When adding array-type claims, enter valid JSON syntax: ["read", "write"] not [read, write]. The builder validates before generating.
Expiry times are in seconds.The exp claim uses Unix timestamps. Templates show relative expiry (3600 = 1 hour), but actual tokens get absolute timestamps.
Important: Never use template-generated tokens in production without proper signing. Unsigned tokens provide zero security—anyone can modify the payload.
Common Questions
What's the difference between iss and sub?
iss (issuer) identifies who created the token (e.g., "auth.example.com"). sub (subject) identifies the principal (user ID, email, or service account name).
When should I use the aud claim?
Always, if your tokens might be used by multiple services. aud (audience) prevents token confusion attacks where a token meant for Service A is used with Service B.
How long should JWTs be valid?
Short-lived access tokens: 15 minutes to 1 hour. Long-lived refresh tokens: 7-30 days. The template defaults to 3600 seconds (1 hour) as a reasonable starting point.
Can I add nested objects as claims?
Yes, JWT payloads support any valid JSON. However, keep claims flat when possible. Deep nesting increases parsing complexity and token size.
What's the maximum JWT size?
HTTP headers typically limit to 8-16KB. Aim for tokens under 4KB to leave room for other headers. If your token exceeds this, move data to your database and use the token as a reference.
Do I need all the standard claims?
Only sub is technically required by the JWT spec. However, iss, exp, and iat are strongly recommended for security. aud is critical for multi-service architectures.
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