API Documentation
Embed this diagram in your API docs to show consumers exactly how authentication and request routing work. It replaces paragraphs of prose with a single glanceable flow.
AI Chart Template
API Call Sequence Diagram Template
Visualize the complete lifecycle of an API request — from client to gateway, auth service, backend, and database — in a clear, numbered sequence diagram.
Chart preview
API Call Sequence Diagram Template
Visualize the complete lifecycle of an API request — from client to gateway, auth service, backend, and database — in a clear, numbered sequence diagram.
fontSize13
enableZoomtrue
mirrorActorsfalse
showSequenceNumberstrue
Template
What This Template Offers
A production-ready sequence diagram showing a full API call flow: JWT validation at the gateway, request forwarding with user context, transactional database writes, and structured JSON responses.
- 5 participants: Client App, API Gateway, Auth Service, Backend API, and Database
- 9 numbered messages tracing the full request-response lifecycle
- Activation bars showing which service is processing at each step
- Annotated notes for JWT validation logic and transactional DB writes
- Zoom and pan enabled for detailed review in presentations or docs
Use cases
Perfect Use Cases
Onboarding New Engineers
Give backend engineers joining your team a visual map of how services communicate. Sequence numbers make it easy to follow the call order step by step.
Architecture Review
Use this template in design reviews or RFC documents to illustrate how a new endpoint will behave across your service layer before writing a single line of code.
Security Audits
Clearly show where JWT validation happens and how user context is propagated, making it straightforward for security reviewers to identify trust boundaries.
Customize
How to Customize
Edit Participants
Rename or add participants to match your actual services — swap 'Auth Service' for 'Okta' or add a 'Cache' layer between the API and Database.
Update Messages
Change message text to reflect your real endpoint paths, headers, and payloads. Adjust arrow types to distinguish sync calls from async events or error returns.
Add Notes and Context
Attach notes to explain rate limiting at the gateway, retry logic in the client, or rollback behavior in the database layer — right where reviewers need it.
Key Benefits
- Pre-built with realistic API patterns — JWT auth, header forwarding, transactional writes
- Sequence numbers make call order unambiguous for engineers and non-technical stakeholders
- Activation bars visually communicate which service holds control at any moment
- Ready to embed in docs, wikis, or slide decks without extra formatting
Pro Tips
- Enable 'Mirror actors at bottom' in Display Settings to make long diagrams easier to read without scrolling back to the top.
- Use '-->> dotted arrows' for all response messages to visually distinguish replies from requests at a glance.
- Add a note 'over gateway, client' to document SLA or timeout expectations at the entry point of your API.
Start now
Create Your Own API Sequence Diagram
Map your API call flow in minutes — no diagramming tools or sign-up required.
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