Documents – Page 11 – Memorres Information Center

Template: Error Handling Strategy Document

Purpose

To define a consistent error handling strategy across services, ensuring predictable responses, easier debugging, and better user experience.

Scope

Applies to all backend services (APIs, microservices, serverless).
Used by Backend Developers, QA, Frontend Developers, and DevOps.
Covers error classification, format, codes, retry logic, and logging standards.

Structure

Section 1 – Error Classification

Category	Description	Example (SaaS)	Example (B2C)
Validation Errors	Invalid input or missing fields	Email format invalid	Booking date missing
Authentication/Authorization	Identity or role issues	Invalid JWT token	User not logged in
Business Logic Errors	Domain-specific failures	User already onboarded	Cleaner not available
Resource Errors	Missing entities or duplicates	User not found	Booking not found
System Errors	Infra or dependency failure	DB connection timeout	Payment gateway down
Rate Limits	Too many requests	429 Too Many Requests	App spamming API

Section 2 – Error Format (REST & GraphQL)

Aspect	REST Example	GraphQL Example
Envelope	`{ "error": { "code": 400, "message": "Invalid email" } }`	`{ "errors": [ { "message": "Invalid email", "path": ["createUser"] } ] }`
Fields	`code`, `message`, `details`, `traceId`	`message`, `path`, `extensions.code`
Traceability	Include `traceId` in all errors	Extensions field for trace IDs

Section 3 – Error Codes

Code	Category	Description	Example
200	Success	Request processed successfully	`GET /users`
400	Validation Error	Invalid/missing input	Wrong email format
401	Unauthorized	Missing/invalid token	Expired JWT
403	Forbidden	User lacks permission	Non-admin updating roles
404	Not Found	Entity doesn’t exist	Booking ID invalid
409	Conflict	Duplicate or state conflict	Email already in use
429	Rate Limit	Too many requests	Throttled client
500	Server Error	Unexpected failure	DB crash
502/503	Dependency Error	Downstream service unavailable	Stripe API down

Section 4 – Retry & Recovery Guidelines

Error Category	Should Retry?	Client Action	Server Action
Validation	❌	Fix input	N/A
Auth	❌	Refresh token / login	N/A
Business Logic	❌	Adjust request	Log & notify
System (5xx)	✅ (with backoff)	Retry with exponential backoff	Circuit breaker / fallback
Rate Limit (429)	✅ (after wait)	Respect Retry-After header	Include rate-limit headers

Section 5 – Logging & Monitoring

Requirement	Standard
Log Level	WARN for client errors, ERROR for server failures
Context	Include `traceId`, userId (if available), requestId
Storage	Centralized log collector (e.g., ELK, Datadog)
Alerts	Trigger alerts on repeated 5xx or spikes in 4xx
Redaction	Strip sensitive data (PII, tokens) before logging

Section 6 – User Messaging (Frontend Integration)

Category	Developer-Facing Message	User-Facing Message
Validation Error	`"Invalid email format"`	“Please enter a valid email.”
Auth Error	`"Expired JWT"`	“Your session expired. Please log in again.”
System Error	`"DB timeout on query X"`	“Something went wrong. Try again later.”

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Error Classification

| Category | Description | Example |

Error Format

| Aspect | Contract |

Error Codes

Retry & Recovery

Logging & Monitoring

| Requirement | Standard |

User Messaging

| Category | Developer-Facing Message | User-Facing Message |

Template: Database Schema Documentation Template

Purpose

To provide a standardized template for documenting database schemas, ensuring developers, QA, and analysts have a clear, up-to-date reference for entities, relationships, constraints, and data governance.

Scope

Applies to all SQL and NoSQL databases.
Used by Developers, DBAs, Architects, and QA Engineers.
Covers tables/collections, fields, types, constraints, relationships, and indexing.

Structure

Section 1 – Database Metadata

Field	Example (B2B SaaS)	Example (B2C App)
Database Name	onboarding_db	ecoclean_app_db
Engine/Type	PostgreSQL 14	Firestore (NoSQL)
Owner	Backend Team A	Mobile API Team
Versioning	Liquibase Migration v12	Firestore Rules v2

Section 2 – Entities / Collections

Entity/Table	Purpose	Example (SaaS)	Example (B2C)
users	Store user accounts	id, email, password, role	uid, email, phone, role
companies	Store org details	id, name, plan_type	N/A
bookings	Store service bookings	N/A	booking_id, user_id, date, status
payments	Track payments	txn_id, user_id, amount	txn_id, booking_id, amount

Section 3 – Fields Definition

Table/Collection	Field	Type	Constraints	Example
users	id	UUID	Primary Key	`d33f…`
users	email	VARCHAR(255)	Unique, Not Null	`test@abc.com`
users	password	HASH	Not Null	`****`
bookings	booking_id	UUID	Primary Key	`a12b…`
bookings	status	ENUM(active,cancelled,completed)	Default=active	`active`

Section 4 – Relationships

Source	Target	Type	Cardinality	Notes
users.id	companies.id	FK	Many-to-One	A user belongs to a company
users.id	bookings.user_id	FK	One-to-Many	User can have many bookings
bookings.booking_id	payments.booking_id	FK	One-to-One	Each booking has one payment

Section 5 – Indexing & Performance

Table	Field(s)	Index Type	Purpose
users	email	Unique Index	Fast login lookup
bookings	user_id, date	Composite Index	Query bookings per user per date
payments	txn_id	Unique Index	Ensure transaction uniqueness

Section 6 – Data Governance

Aspect	Standard
PII Storage	Encrypt sensitive fields (email, phone)
Retention	Archive data older than 2 years
Compliance	GDPR: data deletion on request
Backup	Daily snapshots + point-in-time recovery
Access Control	Read-only for QA, full for DevOps/DBA

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Database Metadata

Field	Entry
Database Name
Engine/Type
Owner
Versioning

Entities / Collections

| Entity/Table | Purpose |

Fields Definition

Relationships

Indexing & Performance

Data Governance

| Aspect | Standard |

Template: API Contract Document (REST & GraphQL)

Section 1 – API Metadata (Rebuilt)

The metadata section provides context about the API contract before diving into endpoints. It ensures that anyone consuming the API — whether internal developers, QA, or external partners — immediately understands the scope, ownership, authentication, and environments. A well-written metadata section prevents confusion, ensures accountability, and acts as a quick reference for governance.

Metadata Table

Field	Description	Example (REST – SaaS App)	Example (GraphQL – B2C App)
API Name	Human-readable name of the API	User Onboarding API	Booking Service Schema
Version	Semantic version number (major.minor.patch)	v1.2.0	2025-08 schema
Owner	Squad/team responsible for API maintenance	Backend Team – SaaS Squad A	Mobile API Team
Point of Contact	Escalation contact (Slack channel, email)	#api-squad-a, api-support@company.com	#mobile-api, mobile-support@company.com
Base URL – Production	Endpoint for production environment	https://api.saasapp.com/v1	https://api.ecoclean.com/graphql
Base URL – Staging	Endpoint for testing environment	https://staging.api.saasapp.com/v1	https://staging.api.ecoclean.com/graphql
Base URL – Development	Endpoint for dev sandbox	http://localhost:8080/api/v1	http://localhost:4000/graphql
Auth Mechanism	Authentication standard used	OAuth2 (Bearer Token)	Firebase Auth (JWT)
Scopes / Roles	Role-based access or OAuth scopes required	`users.read`, `users.write`	`booking:read`, `booking:write`
Rate Limits	Allowed requests per client	100 requests/min	60 queries/min
Timeout Policy	API request timeout (ms)	30,000 ms	20,000 ms
Deprecation Policy	Rules for version retirement	90-day notice, /v1 sunset in 2026	Schema changes flagged in changelog
Change Tracking	Where changes are logged	ADR Doc 12	ADR Doc 12
Monitoring & Logging	Tools and dashboards used	Datadog, Kibana	Grafana, ELK Stack
Error Logging Contact	Who monitors errors	DevOps Squad A	Mobile DevOps Squad

Section 2 – Endpoints / Operations (Rebuilt)

Purpose of This Section

The Endpoints/Operations section defines the actual API contract. Unlike generic notes, this must include URLs, methods, authentication rules, required parameters, request/response bodies, and error codes. For REST APIs, endpoints are URI + HTTP method–driven; for GraphQL APIs, operations are schema-based queries and mutations. This section ensures frontend, backend, QA, and third-party consumers all speak the same language before development begins.

Table A – REST Endpoints (20 rows)

Endpoint	Method	Description	Auth Required	Request Params	Request Body Example	Success Response (200)	Error Codes
`/users`	POST	Create new user	Yes (Bearer)	None	`{ "name": "John", "email": "john@x.com", "password": "123456" }`	`{ "id": 101, "name": "John", "email": "john@x.com" }`	400 Invalid Email, 409 Conflict
`/users/{id}`	GET	Get user profile	Yes	Path: `id`	None	`{ "id": 101, "name": "John", "status": "active" }`	404 Not Found
`/users/{id}`	PUT	Update user profile	Yes	Path: `id`	`{ "name": "John D", "status": "inactive" }`	`{ "id": 101, "updatedAt": "2025-09-18T10:00:00Z" }`	400 Invalid Input
`/users/{id}`	DELETE	Delete user	Admin Only	Path: `id`	None	`{ "message": "User deleted" }`	403 Forbidden, 404 Not Found
`/auth/login`	POST	Authenticate user	No	None	`{ "email": "john@x.com", "password": "123456" }`	`{ "token": "jwt-token", "expiresIn": 3600 }`	401 Unauthorized
`/auth/refresh`	POST	Refresh access token	Yes (Refresh Token)	None	`{ "refreshToken": "abcd1234" }`	`{ "token": "new-jwt-token" }`	401 Invalid Token
`/projects`	GET	List projects	Yes	Query: `page`, `limit`	None	`{ "data": [ { "id": 1, "name": "Alpha" } ], "meta": { "page": 1 } }`	401 Unauthorized
`/projects`	POST	Create project	Yes	None	`{ "name": "Project Alpha" }`	`{ "id": 201, "name": "Project Alpha" }`	400 Bad Request
`/projects/{id}`	GET	Get project detail	Yes	Path: `id`	None	`{ "id": 201, "name": "Alpha", "status": "active" }`	404 Not Found
`/projects/{id}`	PUT	Update project	Yes	Path: `id`	`{ "status": "archived" }`	`{ "id": 201, "status": "archived" }`	400 Invalid Input
`/tasks`	GET	List tasks	Yes	Query: `projectId`, `status`	None	`{ "data": [ { "id": 301, "title": "Design UI" } ] }`	401 Unauthorized
`/tasks`	POST	Create task	Yes	None	`{ "title": "Design UI", "projectId": 201 }`	`{ "id": 301, "title": "Design UI" }`	400 Bad Request
`/tasks/{id}`	GET	Get task detail	Yes	Path: `id`	None	`{ "id": 301, "title": "Design UI", "status": "open" }`	404 Not Found
`/tasks/{id}`	PUT	Update task	Yes	Path: `id`	`{ "status": "done" }`	`{ "id": 301, "status": "done" }`	400 Invalid Input
`/tasks/{id}`	DELETE	Delete task	Yes	Path: `id`	None	`{ "message": "Task deleted" }`	404 Not Found
`/reports`	GET	Generate report	Yes	Query: `from`, `to`	None	`{ "reportId": "rpt123", "status": "ready" }`	400 Invalid Dates
`/reports/{id}`	GET	Download report	Yes	Path: `id`	None	File stream (PDF/CSV)	404 Report Not Found
`/notifications`	GET	Fetch notifications	Yes	Query: `limit`	None	`{ "data": [ { "id": 401, "text": "Task due soon" } ] }`	401 Unauthorized
`/notifications/{id}`	PUT	Mark notification read	Yes	Path: `id`	None	`{ "id": 401, "status": "read" }`	404 Not Found
`/settings/profile`	PUT	Update user settings	Yes	None	`{ "timezone": "UTC", "language": "en" }`	`{ "id": 101, "updatedAt": "..." }`	400 Invalid Input

Table B – GraphQL Operations (10 rows)

Operation Type	Operation Name	Description	Example Query/Mutation	Success Response	Error Cases
Query	`getUser`	Fetch a user by ID	`query { getUser(id: "101") { id name email } }`	`{ "data": { "getUser": { "id": "101", "name": "John" } } }`	User not found
Mutation	`createUser`	Create a new user	`mutation { createUser(name:"John", email:"john@x.com") { id name } }`	`{ "data": { "createUser": { "id": "101", "name": "John" } } }`	Duplicate email
Mutation	`updateUser`	Update user details	`mutation { updateUser(id:"101", status:"inactive") { id status } }`	`{ "data": { "updateUser": { "id": "101", "status": "inactive" } } }`	Invalid input
Query	`listProjects`	List all projects	`query { listProjects(limit:10) { id name } }`	`{ "data": { "listProjects": [ { "id": "201", "name": "Alpha" } ] } }`	Unauthorized
Mutation	`createProject`	Add a new project	`mutation { createProject(name:"Alpha") { id name } }`	`{ "data": { "createProject": { "id": "201", "name": "Alpha" } } }`	Bad request
Query	`getProject`	Get project detail	`query { getProject(id:"201") { id name status } }`	`{ "data": { "getProject": { "id": "201", "name": "Alpha" } } }`	Not found
Mutation	`updateProject`	Update project detail	`mutation { updateProject(id:"201", status:"archived") { id status } }`	`{ "data": { "updateProject": { "id": "201", "status": "archived" } } }`	Invalid status
Query	`listTasks`	Fetch tasks for a project	`query { listTasks(projectId:"201") { id title status } }`	`{ "data": { "listTasks": [ { "id":"301", "title":"UI" } ] } }`	Unauthorized
Mutation	`createTask`	Add new task	`mutation { createTask(title:"UI", projectId:"201") { id title } }`	`{ "data": { "createTask": { "id":"301", "title":"UI" } } }`	Missing projectId
Mutation	`updateTask`	Update task status	`mutation { updateTask(id:"301", status:"done") { id status } }`	`{ "data": { "updateTask": { "id":"301", "status":"done" } } }`	Invalid taskId

Section 3 – Request/Response Standards (Rebuilt)

Purpose of This Section

Request/Response standards exist to enforce uniformity across APIs, so that frontend developers, QA engineers, and third-party integrators don’t have to guess what structure to expect from one endpoint to another. Without standards, APIs become inconsistent: some return raw objects, others wrap in data, some paginate differently, and error responses vary wildly. This creates friction, wasted time, and bugs. A proper specification establishes one way of doing things, covering pagination, filtering, sorting, success envelopes, and error handling. It ensures APIs are predictable, testable, and scalable across the product lifecycle.

Table A – REST Standards

Aspect	Contract	Example
HTTP Methods	Use correct verbs: GET (read), POST (create), PUT (update), DELETE (remove). PATCH for partial updates.	`PUT /users/{id}` updates full profile; `PATCH /users/{id}` updates status only.
Content Type	All requests and responses must use JSON with header `Content-Type: application/json`.	`POST /users` → `{"name":"John"}`
Headers	Standard headers: `Authorization: Bearer <token>`, `Accept: application/json`.	`curl -H "Authorization: Bearer token" -H "Accept: application/json"`
Pagination	Cursor-based preferred; fallback to page/limit. Always return pagination metadata.	`GET /users?page=2&limit=20` → `{ "data":[...], "meta":{"page":2,"limit":20,"total":55} }`
Filtering	Filters must be explicit query params; multiple filters allowed.	`/users?status=active&role=admin`
Sorting	Use query param `sort` with +/- prefix. Default ascending.	`/projects?sort=-createdAt`
Search	Use `q` param for free-text search.	`/tasks?q=design`
Success Envelope	Always wrap response in `{ "data":..., "meta":... }`. `meta` optional.	`{ "data":{"id":101,"name":"John"} }`
Error Format	Unified structure: `{ "error": { "code": <int>, "message": <string>, "details": <object> } }`	`{ "error":{ "code":400,"message":"Invalid Email","details":{"field":"email"} } }`
Timestamps	Always ISO 8601 UTC.	`"createdAt":"2025-09-18T10:00:00Z"`

Table B – GraphQL Standards

Aspect	Contract	Example
Schema	All operations must be strongly typed with nullable vs. non-nullable explicitly defined.	`type User { id: ID! name: String! email: String }`
Query Naming	Use descriptive names; avoid generic like `getData`.	`getUser`, `listTasks`
Mutation Naming	Use imperative verbs: `createX`, `updateX`, `deleteX`.	`mutation { createTask(...) }`
Pagination	Relay-style cursor-based (`edges`, `pageInfo`) recommended.	`tasks(first:10, after:"cursor123"){ edges{node{id title}} pageInfo{hasNextPage}}`
Filtering	Use input objects for multiple filters.	`users(filter:{status:"active", role:"admin"}) { id name }`
Sorting	Sorting fields must be explicit in schema.	`users(sort:{field:"createdAt", order:DESC}) { id name }`
Success Envelope	Always return under `"data"` key.	`{ "data": { "getUser": { "id":"101","name":"John"} } }`
Error Format	All errors under `"errors"` array, with `message`, `path`, `extensions`.	`{ "errors":[ { "message":"Invalid ID", "path":["getUser"], "extensions":{"code":"400"}} ] }`
Auth Context	Auth tokens must be passed via headers; resolvers must enforce role-level access.	`Authorization: Bearer token`
Timestamps	ISO 8601 UTC for all datetime fields.	`"updatedAt":"2025-09-18T10:05:00Z"`

Section 4 – Error Codes (Rebuilt)

Purpose of This Section

Error codes define how the API communicates problems to consumers. A weak error strategy leads to chaos: frontend developers can’t distinguish between a user mistake and a server crash, QA testers can’t automate edge cases, and third-party integrators waste time guessing what went wrong. A good error catalogue ensures that every error is predictable, consistent, and actionable. This section establishes both HTTP-level status codes and application-level error codes/messages that align with the request/response standards (see Section 3).

Table A – REST Error Codes (15 Rows)

HTTP Code	Meaning	When Used	Response Example
200 OK	Success	Standard for successful GET, PUT, DELETE	`{ "data": { "id":101,"status":"active" } }`
201 Created	Resource created	After successful POST	`{ "data": { "id":201,"name":"Project Alpha" } }`
202 Accepted	Request accepted for async processing	Report generation, background jobs	`{ "data": { "reportId":"rpt123","status":"processing" } }`
204 No Content	Success with no body	DELETE success	Empty body
400 Bad Request	Invalid input, missing params	Invalid JSON, missing `email`	`{ "error": { "code":400,"message":"Missing email" } }`
401 Unauthorized	Missing/invalid auth token	No `Authorization` header	`{ "error": { "code":401,"message":"Token missing/invalid" } }`
403 Forbidden	Valid token, insufficient rights	Non-admin trying to delete user	`{ "error": { "code":403,"message":"Insufficient role" } }`
404 Not Found	Resource doesn’t exist	Invalid `id`	`{ "error": { "code":404,"message":"User not found" } }`
405 Method Not Allowed	Wrong HTTP verb	`POST /reports/{id}`	`{ "error": { "code":405,"message":"Method not allowed" } }`
409 Conflict	Duplicate or conflicting state	Email already registered	`{ "error": { "code":409,"message":"Email exists" } }`
410 Gone	Deprecated resource	Old API version removed	`{ "error": { "code":410,"message":"This endpoint is deprecated" } }`
422 Unprocessable Entity	Semantic validation failure	Password too weak	`{ "error": { "code":422,"message":"Password must be 8+ chars" } }`
429 Too Many Requests	Rate limit exceeded	101st request in a minute	`{ "error": { "code":429,"message":"Rate limit exceeded, retry in 60s" } }`
500 Internal Server Error	Unexpected server error	Null pointer exception	`{ "error": { "code":500,"message":"Unexpected server error" } }`
503 Service Unavailable	Temporary downtime	DB offline	`{ "error": { "code":503,"message":"Service temporarily unavailable" } }`

Table B – GraphQL Error Handling (10 Rows)

Unlike REST, GraphQL always returns 200 OK at HTTP level — errors are inside an errors array. We standardize error codes with extensions.code.

Error Code	Meaning	When Used	Example Response
GRAPHQL_VALIDATION_FAILED	Invalid query syntax	Misspelled field	`{ "errors":[{ "message":"Cannot query field foo","extensions":{"code":"GRAPHQL_VALIDATION_FAILED"}}] }`
BAD_USER_INPUT	Invalid arguments	`email` missing in mutation	`{ "errors":[{ "message":"Email required","extensions":{"code":"BAD_USER_INPUT"}}] }`
UNAUTHENTICATED	No/invalid token	Missing auth header	`{ "errors":[{ "message":"Not authenticated","extensions":{"code":"UNAUTHENTICATED"}}] }`
FORBIDDEN	Role doesn’t allow operation	User without admin deleting project	`{ "errors":[{ "message":"Forbidden","extensions":{"code":"FORBIDDEN"}}] }`
NOT_FOUND	Entity not found	Non-existent project ID	`{ "errors":[{ "message":"Project not found","extensions":{"code":"NOT_FOUND"}}] }`
CONFLICT	Duplicate or inconsistent state	Duplicate email	`{ "errors":[{ "message":"Email exists","extensions":{"code":"CONFLICT"}}] }`
RATE_LIMITED	Too many requests	Over API quota	`{ "errors":[{ "message":"Rate limit exceeded","extensions":{"code":"RATE_LIMITED"}}] }`
INTERNAL_SERVER_ERROR	Generic backend error	Exception in resolver	`{ "errors":[{ "message":"Unexpected error","extensions":{"code":"INTERNAL_SERVER_ERROR"}}] }`
SERVICE_UNAVAILABLE	Downstream service unavailable	DB timeout	`{ "errors":[{ "message":"Database down","extensions":{"code":"SERVICE_UNAVAILABLE"}}] }`
DEPRECATED_FIELD	Querying removed field	Legacy schema	`{ "errors":[{ "message":"Field x deprecated","extensions":{"code":"DEPRECATED_FIELD"}}] }`

Section 5 – Security & Auth (Rebuilt)

Purpose of This Section

Security is not an afterthought in API design — it is the contractual backbone that ensures only authorized consumers can access resources safely. Weak documentation here leads to massive risks: developers may skip proper checks, third-party integrators may leak tokens, and testers may miss critical abuse scenarios. A strong API specification must define authentication flows, authorization rules, data protection practices, and rate-limiting policies clearly enough that no consumer can claim ignorance. This section establishes both mechanical security requirements (OAuth2, JWT, HTTPS) and behavioral policies (roles, scopes, logging, rotation, rate limits).

Table A – REST Security & Auth Standards

Area	Contract	Example
Transport Security	All endpoints must use HTTPS with TLS 1.2+; no plaintext HTTP allowed.	`https://api.saasapp.com/v1/users`
Auth Mechanism	Default auth via OAuth2 (Authorization Code / Client Credentials) or JWT (Bearer token).	`Authorization: Bearer <jwt-token>`
Token Format	JWT must include `sub`, `iat`, `exp`, and `roles` claims.	`{ "sub":"101", "exp":1695049200, "roles":["admin"] }`
Token Expiry	Access tokens expire in 1h; refresh tokens in 30d.	Frontend refreshes automatically before expiry.
Refresh Workflow	Token refresh via `/auth/refresh` with refresh token.	`POST /auth/refresh { "refreshToken":"xyz" }`
Scopes & Roles	Endpoints require explicit scopes (e.g., `users:read`, `projects:write`).	`/users/{id}` requires `users:read`.
Rate Limiting	Default: 100 requests/min per client. Higher tiers configurable.	Exceeding limit → 429 error.
Replay Protection	Nonces or `jti` (JWT ID) required for sensitive actions.	Prevents replay of `/payments`.
Logging Rules	Sensitive fields (passwords, tokens, PII) never logged in plaintext.	Log only `userId`, `endpoint`, `timestamp`.
Audit Trail	All admin-level actions logged with userId, role, timestamp.	Role change → audit entry in `security_audit` table.

Table B – GraphQL Security & Auth Standards

Area	Contract	Example
Transport Security	All queries and mutations over HTTPS/TLS only.	`POST https://api.ecoclean.com/graphql`
Auth Header	Every request must include `Authorization: Bearer <token>`.	`curl -H "Authorization: Bearer jwt" ...`
Field-Level Auth	Sensitive fields protected via resolver rules.	`User.email` accessible only to self or admin.
Role Enforcement	Mutations validated by roles/scopes.	`createProject` requires `projects:write`.
Rate Limiting	Limit queries per client: 60/min. Complex queries count extra.	`listUsers(first:1000)` = 10 ops cost.
Query Depth Limit	Max query depth = 5 to prevent DoS via nested queries.	`users → projects → tasks → comments → likes`.
Query Complexity Limit	Each field weighted; queries > 100 points rejected.	Weighted cost analysis.
Error Sanitization	Never expose stack traces; return generic error + code.	`{ "errors":[{ "message":"Internal Error"}] }`
Token Expiry & Refresh	Same as REST (1h expiry, 30d refresh).	Refresh via `/auth/refresh`.
Subscription Security	WebSocket subscriptions must revalidate token on connection + periodically.	`connection_init` must include JWT.

General Security Best Practices (Applies to REST + GraphQL)

Principle of Least Privilege – Default roles (e.g., user) should have only minimum access; admin privileges require explicit assignment.
CORS Policy – Allowed origins explicitly listed; no wildcard *.
Input Validation – All incoming data validated at API boundary to prevent injection attacks.
Data Masking – Sensitive outputs (tokens, partial card numbers, SSNs) masked before returning in API responses.
Secrets Management – Keys and tokens stored in secure vaults (HashiCorp Vault, AWS Secrets Manager).
Versioning Security – Old versions decommissioned with minimum 90-day notice. Security patches applied retroactively until sunset.
Monitoring & Alerts – Auth failures, rate limit violations, and suspicious traffic patterns automatically flagged to security team.
Penetration Testing – APIs undergo regular security tests before major releases.

Closing Note

This API Specification is designed as a living contract between teams — not a static document. It provides structure, consistency, and governance across REST and GraphQL APIs, but its true value lies in being actively maintained and adapted. Every product evolves: new endpoints are added, schemas change, authentication strategies harden, and integrations scale. As such, this document should always reflect the current reality of the API, not just the intent at launch.

Depending on your product type, architectural choices, or security requirements, sections of this template may need to be extended or refined. For example, a financial SaaS may require more rigorous audit trails, while a consumer mobile app may prioritize lightweight payloads and real-time subscriptions. What must remain non-negotiable is the discipline of consistency — ensuring that every API consumer can rely on predictable standards for requests, responses, errors, and security.

In practice, this means teams should treat the specification as part of their software lifecycle governance: version it alongside code, review it during design discussions, and update it whenever breaking or non-breaking changes are introduced. Used in this way, the API Specification stops being “just documentation” and becomes an operational safeguard — reducing bugs, avoiding miscommunication, and ensuring integrations succeed.

SOP: Architecture Review & Approval Process

Purpose

To define a standardized process for reviewing and approving system architecture designs, ensuring they meet business requirements, technical quality, and compliance standards before implementation begins.

Scope

Applies to all new projects, major feature builds, and infra changes.
Used by Developers, Tech Leads, Architects, DevOps, and QA leads.
Covers system architecture blueprints, infra diagrams, API contracts, and DB schema designs.

Objectives

Guarantee that architectures are scalable, secure, and cost-efficient.
Ensure designs align with company-wide standards (patterns, versioning, modularity).
Create a transparent approval workflow that avoids delays but enforces rigor.

Step-by-Step Process

Step 1 – Preparation (By Developer/Architect)

Draft the System Architecture Blueprint (Doc 1).
Create the Infrastructure Diagram (Doc 2).
Prepare supporting docs:
- API Contract (Doc 4).
- Database Schema (Doc 5).
- Error Handling Strategy (Doc 6).
- Logging & Observability Plan (Doc 10).
Log initial proposal in Architecture Decision Log (Doc 12).

Step 2 – Internal Peer Review

Share draft in Architecture Review channel (Slack/Teams).
Assign at least 2 peer reviewers (senior devs or leads).
Collect feedback on:
- Scalability.
- Security.
- Performance.
- Maintainability.
- Cost implications.
Update proposal before formal review.

Step 3 – Formal Review Session

Schedule a review meeting (within 5 working days of submission).
Attendees: Project Lead, Architect, DevOps, QA Lead, Security Rep (if required).
Presenter walks through:
- Business requirement → design rationale.
- Architecture diagrams + modules.
- Data flows + integration points.
- Risks & constraints.
Reviewers challenge assumptions, raise risks, and request changes.

Step 4 – Approval or Revision

Outcomes:
1. Approved: Architecture locked for implementation.
2. Approved with Changes: Minor adjustments required, no re-review.
3. Rejected: Major gaps → revise and resubmit.
Decision logged in ADR (Doc 12) with date & rationale.

Step 5 – Post-Approval Communication

Update Project Documentation Hub (Confluence/Notion).
Share approved blueprint & diagrams with all developers.
Mark relevant tickets as “Ready for Dev” in PM tool.
Archive all feedback for future audits.

Roles & Responsibilities

Role	Responsibility
Developer/Architect	Drafts blueprint + supporting docs
Peer Reviewers	Provide feedback during informal review
Project Lead	Chairs formal review, ensures timeline
DevOps Engineer	Validates infra feasibility + costs
QA Lead	Validates testability & quality criteria
Security Rep	Ensures compliance with security standards
Documentation Owner	Uploads & maintains approved artifacts

Governance

Review SLA: Every architecture must be reviewed within 5 working days.
Quorum: Minimum 3 reviewers (Lead + DevOps + QA) must sign-off.
Change Control: Any architecture changes post-approval require a new ADR entry and mini-review.
Audit Trail: All approved docs stored in central repository with versioning.

Template: Infrastructure Diagram Template

Purpose

To provide a standardized infrastructure diagram template that visually represents environments, components, and interactions across systems.

This ensures every project has a clear, visual map of infra layers (frontend, backend, DB, services, cloud resources, monitoring).

Scope

Applies to all new and existing projects.
Used by Developers, DevOps, Architects, and QA.
Covers staging, production, monitoring, and external integrations.

Diagram Conventions (Legend)

To maintain consistency, use the following symbols and shapes across all diagrams:

Shape/Icon	Meaning	Example
Rectangle	Service/Component	API Gateway, Backend Service
Cylinder	Database/Storage	PostgreSQL, Firestore
Circle	External Service	Stripe, Auth0
Rounded Rectangle	Client/User Interface	React App, Flutter App
Arrows	Data Flow	Request/Response, Event Stream
Padlock Icon	Security Layer	TLS/HTTPS, RBAC
Cloud Shape	Cloud Provider	AWS, GCP, Azure

Example – B2B SaaS Project

Frontend: React web app.
Backend: Node.js microservices on AWS ECS.
DB: PostgreSQL on AWS RDS.
Auth: Auth0 OIDC.
CI/CD: GitHub Actions → ECS Deploy.
Monitoring: Datadog + CloudWatch.

Diagram flow:

User → React (CloudFront) → API Gateway → Node Services (ECS) → PostgreSQL (RDS)
                                     ↘ Stripe, Auth0, SendGrid

Example – B2C Mobile App

Frontend: Flutter app (iOS + Android).
Backend: Firebase Functions.
DB: Firestore.
Auth: Firebase Auth.
Push Notifications: Firebase Cloud Messaging.
Payment: Razorpay.

Diagram flow:

User → Flutter App → Firebase Functions → Firestore DB
                     ↘ Firebase Auth
                     ↘ Razorpay
                     ↘ Cloud Messaging

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Section 1 – Project Metadata

Field	Entry
Project Name
Infra Owner
Date Last Updated
Environments Covered	Dev / Staging / Production

Section 2 – Infra Layers

Layer	Components	Notes
Client Interfaces		Web, Mobile
API Gateway / Backend		REST, GraphQL, Functions
Databases / Storage		SQL, NoSQL, Blob
Authentication / Security		IAM, OAuth, JWT
External Integrations		Payments, Analytics
CI/CD		Toolchain
Monitoring / Logging		Datadog, Grafana

Section 4 – Change Log

Date	Change Made	Author

Template: System Architecture Blueprint Template

Purpose

To provide a standardized architecture blueprint that documents how business and technical requirements are translated into a working system design.

This ensures developers, architects, and stakeholders have a shared, high-level view of system components, interactions, and constraints.

Structure

Section 1 – Project Context

Field	Example (B2B SaaS)	Example (B2C App)
Project Name	SaaS Onboarding Automation	EcoClean Booking App
Business Goal	Reduce churn by improving onboarding workflows	Enable families to book verified eco-friendly cleaners
Core Users	SaaS CTOs, Customer Success Managers	Urban families, busy professionals
Key Outcomes	Churn ↓ 30%, Adoption ↑ 40%	Time saved, Safer verified cleaning

Section 2 – High-Level Architecture Overview

Component	Description	Example (SaaS)	Example (B2C)
Frontend	User-facing app/web	React web app	Flutter mobile app
Backend	Core APIs & business logic	Node.js + Express	Firebase Functions
Database	Data storage layer	PostgreSQL	Firestore
Auth & Security	Identity management	Auth0 (OIDC)	Firebase Auth
Integrations	Third-party systems	Salesforce API	Google Maps API
Infrastructure	Hosting & runtime	AWS ECS + RDS	GCP Firebase Hosting

Section 3 – System Modules

Module	Function	Example (SaaS)	Example (B2C)
User Management	Auth, roles, profiles	Auth0 + RBAC	Firebase Auth
Core Feature	Main business logic	Workflow engine for onboarding	Booking engine
Payments	Billing & invoicing	Stripe API	Razorpay
Notifications	Email, SMS, Push	SendGrid, Twilio	Firebase Cloud Messaging
Analytics	Usage tracking & reporting	Mixpanel + BI dashboard	Google Analytics + custom reporting

Section 4 – Data Flows

Flow	Trigger	Source → Destination	Example
User Signup	New user registers	Frontend → Backend → DB	React form → Node API → PostgreSQL
Booking Request	User books service	App → API → DB → Notification	Flutter app → Firebase Function → Firestore → Push
Payment Flow	Checkout	Frontend → Payment Gateway → DB	Web → Stripe → RDS

Section 5 – Non-Functional Requirements

Category	Requirement	Example
Scalability	Handle 10K concurrent users	Horizontal scaling on AWS ECS
Availability	99.9% uptime	Multi-zone hosting
Security	Enforce RBAC, encrypt PII	GDPR & SOC2 alignment
Performance	<200ms API latency	API caching layer
Monitoring	Real-time logs + alerts	Datadog, Grafana

Section 6 – Risks & Constraints

Risk/Constraint	Impact	Mitigation
Vendor Lock-In	Tied to Auth0 for auth	Abstract auth layer
Budget Constraint	Infra costs high at scale	Optimize with reserved instances
Compliance	Must be GDPR-compliant	Use EU data region

Blank Reusable Template

Project Context

Field	Entry
Project Name
Business Goal
Core Users
Key Outcomes

High-Level Architecture Overview

Component	Description	Tool/Tech Stack

System Modules

Module	Function	Tool/Tech Stack

Data Flows

Flow	Trigger	Source → Destination	Notes

Non-Functional Requirements

Category	Requirement

Risks & Constraints

Risk/Constraint	Impact	Mitigation

SOP: Joining a Mid-Flight Project

Purpose

To provide a structured onboarding workflow for developers who join a project already in progress.

This ensures they quickly gain context, access, and alignment without slowing down the existing team or repeating past mistakes.

Scope

Applies to all developers joining ongoing projects (mid-sprint, mid-release, or maintenance).
Used by Project Leads, Tech Buddies, and Developers.
Covers context transfer, environment setup, and integration into rituals.

Objectives

Ensure fast context transfer without overwhelming the new joiner.
Minimize handoff friction for existing team members.
Get the developer contributing to real tickets within 3–5 days.

Step-by-Step Process

Step 1 – Pre-Onboarding (By Lead/PM)

Provide Developer Onboarding Kit (Doc 2).
Assign a tech buddy for the first 2 weeks.
Share the current sprint board with priority tickets.
Confirm repo + tool access is ready (per Access Policy, Doc 8).

Step 2 – Project Context Download (Day 1–2)

Lead/Tech Buddy walkthrough covering:
- Business context (what the client wants).
- System overview (arch diagram + API contracts).
- Active sprint scope (which features are in-flight).
- Known blockers/tech debt.
Review:
- Backlog + sprint board (Jira/ClickUp/Linear).
- Release notes (last 2–3).
- Team retro notes (if available).

Step 3 – Environment & Setup (Day 1–3)

Developer sets up local environment per:
- Web Stack Setup (Doc 3) or Mobile Stack Setup (Doc 4).
Run sample build and confirm staging connectivity.
Submit test PR (doc update or small bug fix) to verify CI/CD.

Step 4 – Knowledge Transfer

Tech buddy shares:
- Critical modules ownership (who owns what).
- Known pitfalls (common setup/build issues).
- Recent architectural decisions (ADR log).
The developer reviews at least 1 PR to understand the team’s coding style.

Step 5 – First Ticket Assignment (Day 3–5)

Assign a low-to-medium complexity ticket (bug fix, UI feature, test writing).
Buddy reviews PR → ensures style & process adherence.
Track performance in Developer Access & Onboarding Log (Doc 12).

Step 6 – Integration into Rituals

Developer joins:
- Daily standups.
- Sprint planning.
- Squad syncs.
The developer starts logging time/effort.

Roles & Responsibilities

Role	Responsibility
Project Lead	Provides context, assigns first sprint tasks
Tech Buddy	Guides setup, answers technical questions
Developer	Completes setup, reviews docs/PRs, executes first ticket
PM	Ensures backlog & sprint context is shared
QA Lead	Aligns on dev–QA handoff process

Governance

Onboarding SLA: Mid-flight joiners must be contributing within 5 working days.
Access Logs: All access must be tracked (per Access Policy).
Feedback Loop: Developer logs blockers in onboarding kit → updates quarterly.
Escalation: If the developer is idle >2 days → escalate to Lead & PM.

Checklist: Project Setup Readiness Checklist (Dev Perspective)

Purpose

To ensure all essential components of a project are in place and accessible before developers begin active work.

This prevents wasted cycles, blocked tasks, and inconsistent environments.

Checklist Structure

Section 1 – Repository & Codebase

Item	Status	Notes
Project repo created (GitHub/GitLab/Bitbucket)	⬜	Repo link:
Repo has README with setup instructions	⬜	Must include stack, env setup
`.gitignore` configured	⬜	Prevents committing secrets/node_modules/builds
Branching strategy documented (Doc: Git Strategy)	⬜	feature/*, develop, main
Sample commit & PR tested	⬜	Ensures CI/CD triggers

Section 2 – Environment Setup

Item	Status	Notes
`.env.example` file present	⬜	Contains placeholders for API keys, DB creds
Local build runs without errors	⬜	Run `npm run dev` or equivalent
Docker/DB setup tested	⬜	Containers spin up successfully
Default dev account provided	⬜	Username/password documented
Test API endpoint verified	⬜	`/health` or equivalent

Section 3 – Access & Tools

Item	Status	Notes
Repo access granted to all devs	⬜	Verify permissions
PM tool (Jira/ClickUp/Linear) configured	⬜	Backlog visible
CI/CD tool linked to repo	⬜	Build pipeline passes
Staging environment accessible	⬜	URL + credentials provided
Secrets manager configured (Vault/1Password)	⬜	Tokens not shared via chat

Section 4 – Documentation & Guidelines

Item	Status	Notes
System architecture diagram available	⬜	High-level overview
API contract/specification shared	⬜	Postman/Swagger file
Coding standards documented	⬜	ESLint/Prettier/Style guides
Dev–QA Handoff process documented	⬜	SOP link
Security guidelines shared	⬜	RBAC, access policy

Section 5 – Team Setup

Item	Status	Notes
Project lead assigned	⬜	Name/contact:
Tech buddy assigned (for new devs)	⬜	Name/contact:
QA lead assigned	⬜	Name/contact:
Slack/Teams channel created	⬜	Channel link:
First sprint backlog ready	⬜	At least 1 sprint planned

Usage Notes

Must be completed before the sprint start.
Devs/Leads own the checkmarks, PM/Lead validates readiness.
Any missing item must have a Jira ticket created before kickoff.

Outcome

Ensures developers never start work in a half-ready environment.
Reduces delays caused by missing access, env configs, or unclear guidelines.
Provides an audit trail of readiness for retros.

Policy: Developer Tool Access & Responsibility Policy

Purpose

To define a standardized policy for how developers are granted access to tools, environments, and credentials, and to outline their responsibility in using them securely and responsibly.

This prevents unauthorized access, data leaks, and misuse of critical development resources.

Scope

Applies to all developers, contractors, and interns who require access to organizational tools.
Covers:
- Source Code Repositories (GitHub/GitLab/Bitbucket).
- Project Management Tools (Jira, ClickUp, Linear).
- CI/CD Pipelines (GitHub Actions, CircleCI, Jenkins).
- Cloud Services & Environments (AWS/GCP/Azure, staging servers).
- Collaboration Tools (Slack, Teams, Confluence, Notion).
- Secrets & Tokens (API keys, database credentials).

Principles

Least Privilege Access – Developers only receive the minimum access required for their role.
Accountability – Every access action is logged, auditable, and traceable.
Separation of Duties – Sensitive access (e.g., production) is restricted to leads/DevOps, not all developers.
Time-Bound Access – Temporary roles (contractors, interns) receive time-limited credentials.
Revocation on Exit – Access is revoked immediately when a developer leaves or changes role.

Rules & Responsibilities

Developer Responsibilities

Use 2FA on all accounts (mandatory).
Never share credentials (passwords, tokens, keys).
Store sensitive credentials in approved vaults (e.g., 1Password, HashiCorp Vault, AWS Secrets Manager).
Always log out of shared machines/sessions.
Report any suspicious activity immediately to leads/IT.
Keep local dev machines updated with latest OS & security patches.
Respect code of conduct in collaboration tools (Slack/Teams).

Access Rules

Tool Category	Default Role	Elevated Role	Notes
Source Control (GitHub/GitLab)	Read + Write (project repos only)	Admin (Leads only)	No force-push to protected branches
Project Management (Jira/ClickUp)	Developer (ticket access)	Manager (create/edit workflows)	Must log work & updates
CI/CD (CircleCI, GitHub Actions)	Read logs	Trigger Deploy (Leads only)	Devs cannot modify pipelines without approval
Cloud Services (AWS/GCP/Azure)	Staging access only	Production (DevOps/Leads only)	All actions logged
Collaboration Tools (Slack/Confluence)	Member	Admin (HR/IT only)	No external sharing
Secrets/Tokens	Read (scoped)	Write (DevOps only)	Never hardcode tokens in code

Governance

Access Request Workflow: Must go through EPIC 1 – Doc 7 (Access Request SOP).
Access Reviews: Quarterly audits to ensure least privilege.
Revocation: Access revoked within 24 hours of role exit/change.
Violations: Any breach of this policy → disciplinary review + potential revocation of access.
Escalation: Security incidents are escalated to CTO + Security Lead immediately.

Outcome

Developers receive just enough access to do their jobs effectively.
Responsibility for tool usage is clear and enforceable.
Protects the organization from data loss, misuse, and compliance risks.
Supports smooth onboarding/offboarding (ties into Onboarding SOP – Doc 1).

Guide: Accessing & Using Internal Packages (Repo-Based Modules & Submodules)

Purpose

To provide a standardized workflow for accessing and using internal code that is managed as repo-based modules, submodules, or monorepos instead of package registries.

This ensures developers handle shared code consistently, with secure access, correct branching, and minimal duplication.

Scope

Applies to shared libraries, boilerplates, or modules stored in Git repos (not published as packages).
Covers:
- Git Submodules (linked repos inside parent).
- Git Subtrees (vendor code snapshots).
- Monorepo Workspaces (Nx, Turborepo, Yarn/PNPM Workspaces, Lerna).
Used by all developers and tech leads.

Objectives

Ensure developers can clone, update, and sync shared repo modules without breaking builds.
Define clear rules for versioning and contribution.
Reduce code duplication by encouraging reuse via submodules/workspaces.

Step-by-Step Usage

Step 1 – Access & Permissions

Request access through Access Request Workflow (Doc 7).
Repo must be added to developer’s GitHub/GitLab/Bitbucket account with correct role:
- Read for consumers.
- Write/Maintainer for contributors.
Confirm access via:
git ls-remote git@github.com:org/shared-lib.git

Step 2 – Adding Repo-Based Modules

A. Git Submodules

git submodule add git@github.com:org/shared-lib.git libs/shared-lib
git submodule update --init --recursive

Commits are locked to a specific SHA → ensures deterministic builds.

B. Git Subtrees (alternative)

git subtree add --prefix=libs/shared-lib git@github.com:org/shared-lib.git main --squash

Creates a snapshot inside repo (less overhead, harder to sync).

C. Monorepo (Nx/Turborepo/Yarn Workspaces)

Packages are linked under /packages or /libs.
Example package.json:

{"workspaces": ["apps/*","packages/*"]}

Consumers import like:

import { Button } from "@org/ui"

Step 3 – Syncing Updates

Submodules

git submodule update --remote --merge

Pulls latest changes from default branch.
Always commit updated submodule SHA.

Subtrees

git subtree pull --prefix=libs/shared-lib git@github.com:org/shared-lib.git main --squash

Monorepo

Run package manager install:

yarn install # or pnpm install

Internal dependencies auto-linked.

Step 4 – Versioning & Pinning

Submodules: Pin to specific commit SHA.
Subtrees: Pin to snapshot commit in logs.
Monorepos: Use workspace protocol ("ui-lib": "workspace:^1.2.0").
Never track “latest” — creates instability.

Step 5 – Contributing Back

Open PR against the shared repo, not local consumer project.
Update CHANGELOG.md + bump version in shared repo.
After merge:
- Update consumer project’s submodule/subtree.
- For monorepo: run yarn workspaces run build to verify changes.

Governance & Standards

Ownership: Every shared repo must have a listed maintainer.
Branching: Consumers must use main/develop only; no feature branches for submodules.
Code Review: PRs must be approved by shared repo maintainers.
Deprecation: Deprecated modules must be flagged in README + marked in internal catalog.
Security: Access must be revoked when developers roll off (EPIC 7).

Troubleshooting

Symptom	Likely Cause	Fix
Submodule repo empty	Forgot `--recursive`	Run `git submodule update --init --recursive`
Merge conflicts in submodule	SHA mismatch between teams	Reset to agreed commit → re-sync
Subtree pull fails	Divergence in history	Use `--squash` or re-add subtree
Monorepo package not linking	Workspace misconfig	Check `package.json` paths & lockfile
Build fails on update	Breaking change in shared repo	Rollback SHA; check CHANGELOG & migration notes

Do’s & Don’ts

Do’s

Always pin versions/commits for reproducibility.
Document every update in the consumer repo PR description.
Use monorepo workspaces for active, evolving libraries.
Keep the shared repo README updated with install & usage guides.

Don’ts

Don’t point submodules to developer forks.
Don’t track main/HEAD directly in consumer repos.
Don’t modify shared repo code inside consumer project → always contribute back upstream.
Don’t duplicate modules across projects — enforce reuse.