Sequence Diagramapisequencearchitecture

API Request Sequence

Use this Mermaid sequence diagram to explain how a client request moves through gateway, auth, services, cache, and database layers.

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Use Cases

Show request and response order during an API review

Document auth checks and cache lookup behavior

Align frontend and backend teams on integration timing

Explain alternate paths such as cache hits, cache misses, retries, and downstream failures

How This Workflow Works

Step	Purpose
Client request	Begins the interaction when the client sends a request to the gateway or API boundary.
Token validation	Shows the authentication check that must succeed before the request reaches business logic.
Route to service	Moves the valid request from the gateway to the domain service responsible for the work.
Cache lookup	Branches the sequence between fast cached responses and slower database-backed responses.
Return response	Completes the sequence by sending the assembled service response back through the gateway.

How To Customize

Rename participants to match your services

Add alternate paths for errors, retries, or cache misses

Change messages to the real method names or API endpoints

Add latency, timeout, or ownership notes to calls that are important during incident review

Split one domain service into multiple participants when the integration spans several teams

Edit This Template Visually

Open this template in the editor to work from the rendered diagram and the Mermaid source together. Click a node in supported flowchart and sequence diagrams to locate the matching code, select source lines to find the related shape, or ask AI to rename, expand, restyle, or rewrite the selected part of the workflow.

Mermaid Source

sequenceDiagram
    participant Client
    participant Gateway as API Gateway
    participant Auth as Auth Service
    participant Service as Domain Service
    participant Cache
    participant DB as Database

    Client->>Gateway: Send request
    Gateway->>Auth: Validate token
    Auth-->>Gateway: Token valid
    Gateway->>Service: Route request
    Service->>Cache: Read cached result
    alt Cache hit
      Cache-->>Service: Return cached data
    else Cache miss
      Service->>DB: Query records
      DB-->>Service: Return records
      Service->>Cache: Store result
    end
    Service-->>Gateway: Build response
    Gateway-->>Client: Return response