An Application Programming Interface (API) is a set of rules and protocols that allows two software applications to communicate and exchange data. It acts as a middleman, handling requests and responses between a client and a server. To understand and use an API effectively, you need to know some API Reference:
HTTP Verbs
- GET: Retrieve data from the server
- POST: Send data to the server to create a resource
- PUT: Send data to the server to update a resource
- PATCH: Send data to the server to update a resource partially
- DELETE: Delete a resource from the server
- TRACE: Returns the full HTTP request received by the server for debugging and diagnostic purposes
- OPTIONS: Returns the HTTP methods supported by the server for the requested URL
- CONNECT: Converts the request connection to a transparent TCP/IP tunnel for secure communication
- PURGE: Invalidates a cached resource
- LOCK: Locks the resource for exclusive use by the client
- UNLOCK: Unlocks the resource previously locked by the client
- MKCOL: Creates a new collection resource
- COPY: Copies the resource identified by the Request-URI to the destination URI.
HTTP Status Codes
- 1xx: Informational
- 2xx: Success
- 3xx: Redirection
- 4xx: Client Errors
- 5xx: Server Errors
Response Headers
- Content-Type: Specifies the MIME type of the data in the response body
- Content-Length: Specifies the length of the response body in bytes
- Cache-Control: Specifies the caching behavior of the response
- Location: Specifies the URI of a resource that can be used to retrieve the requested resource
- Server: Specifies the name and version of the server software that generated the response
- Access-Control-Allow-Origin: Specifies which origins are allowed to access the resource
- Set-Cookie: Specifies a cookie that should be stored by the client and sent back to the server with future requests
- Expires: Specifies the date and time after which the response is considered stale
- Last-Modified: Specifies the date and time the resource was last modified.
API Design
- REST: Representational State Transfer, a design pattern for building web services
- SOAP: Simple Object Access Protocol, a messaging protocol for exchanging structured data
- GraphQL: A query language and runtime for building APIs
- API Gateway: A service that manages, protects, and scales APIs
API Architectures
- SOA: Service-Oriented Architecture, an architectural style for building distributed systems
- Microservices: An architectural style for building complex applications as a suite of small, independent services
- Serverless: A cloud computing execution model where the cloud provider manages the infrastructure and automatically allocates resources as needed
- Event-Driven: An architectural style where the flow of data between components is triggered by events
- RESTful API: An architectural style that uses HTTP requests to GET, POST, PUT, and DELETE data.
API Design Patterns
- Adapter Pattern: A pattern that converts the interface of a class into another interface that clients expect
- Decorator Pattern: A pattern that adds behavior to an individual object dynamically
- Proxy Pattern: A pattern that provides a surrogate or placeholder for another object to control access to it
- Chain of Responsibility Pattern: A pattern that delegates commands to a chain of processing objects
- Observer Pattern: A pattern that defines a one-to-many dependency between objects so that when one object changes state, all its dependents are notified and updated automatically.
API Security
- OAuth: An open standard for authorization used for protecting APIs
- JWT: JSON Web Tokens, a standard for securely transmitting information between parties as a JSON object
- SSL/TLS: Secure Sockets Layer/Transport Layer Security, a protocol for establishing a secure connection between a client and a server
- API Key: A secret token used to authenticate API requests
- Rate Limiting: A technique used to limit the number of requests that can be made to an API over a specific period of time
- OpenID Connect: An authentication layer built on top of OAuth that allows users to be authenticated across multiple domains
- Cross-Origin Resource Sharing (CORS): A mechanism that allows many resources (e.g., fonts, JavaScript, etc.) on a web page to be requested from another domain outside the domain from which the resource originated
API Testing
- Postman: A popular tool for testing and debugging APIs
- SoapUI: A tool for testing SOAP and REST web services
- Swagger: A tool for designing, building, and testing APIs
- JMeter: A tool for testing the performance of APIs
- TestRail: A test management tool for planning, executing, and tracking API tests
- Dredd: A command-line tool for testing API documentation against its backend implementation
- REST Assured: A Java-based library for testing RESTful APIs
- Karate DSL: A testing framework for API testing using Gherkin syntax
- HttpMaster: A tool for testing and debugging APIs
- Assertible: A tool for testing and monitoring APIs with automated tests.
API Development
- Node.js: A JavaScript runtime for building server-side applications
- Express: A popular framework for building web applications and APIs with Node.js
- Django: A Python web framework for building web applications and APIs
- Flask: A lightweight Python web framework for building web applications and APIs
- Spring: A Java framework for building enterprise-level web applications and APIs
- Swagger Editor: A tool for designing and documenting APIs using the OpenAPI specification
- Postman: A tool for testing and debugging APIs
- Insomnia: A tool for designing, testing, and debugging APIs
- Paw: A tool for designing and testing APIs on Mac OS
- API Blueprint: A high-level API description language for building RESTful APIs.
API Implementation Platforms
- Firebase: A mobile and web application development platform developed by Google
- Backendless: A mobile and web application development platform that allows developers to build and deploy applications without backend coding
- Parse Server: An open-source version of the Parse backend that can be deployed to any infrastructure
- Amazon API Gateway: A fully managed service that makes it easy for developers to create, publish, maintain, monitor, and secure APIs
- Microsoft Azure API Management: A fully managed service that enables users to publish, secure, transform, maintain, and monitor APIs.
API Performance
- Caching: A technique for improving API performance by storing responses in a cache
- Throttling: A technique for limiting the rate of requests to an API to prevent overload
- Load Balancing: A technique for distributing traffic evenly across multiple servers to improve API performance
- Content Delivery Network (CDN): A distributed system of servers that delivers content to users based on their geographic location to improve API performance
- Edge Computing: A computing paradigm that brings computation and data storage closer to the location where it is needed to reduce latency and improve API performance.
API Monitoring
- Pingdom: A tool for monitoring the uptime and performance of APIs
- New Relic: A tool for monitoring the performance of APIs and other web applications
- Datadog: A monitoring and analytics platform for cloud-scale applications and APIs
- Sumo Logic: A cloud-based log management and analytics platform for APIs and other applications
- Loggly: A cloud-based log management platform for monitoring APIs and other applications
API Standards
- JSON API: A specification for building APIs that use JSON as the data format
- HAL: Hypertext Application Language, a standard for building hypermedia-driven APIs
- JSON-LD: A format for representing linked data on the web
- OData: Open Data Protocol, a standard for building and consuming RESTful APIs
- AsyncAPI: A specification for building event-driven APIs.
API Standards Organizations
- W3C: The World Wide Web Consortium, an international community that develops web standards
- IETF: The Internet Engineering Task Force, an open standards organization that develops and promotes Internet standards
- OASIS: Organization for the Advancement of Structured Information Standards, a nonprofit consortium that drives the development, convergence, and adoption of open standards for the global information society
- RESTful API Modeling Language (RAML): A YAML-based language for describing RESTful APIs developed by MuleSoft
- JSON API: A specification for building APIs that use JSON as the data format.
API Infrastructure
- Kubernetes: An open-source platform for managing containerized workloads and services
- OpenShift: A container application platform that builds on top of Kubernetes
- Docker Swarm: A native clustering and orchestration solution for Docker
- Consul: A service mesh solution that provides service discovery, configuration, and segmentation capabilities
- Istio: A service mesh solution that provides traffic management, security, and observability capabilities.
API Governance
- API Management: The process of creating, publishing, and monitoring APIs in a secure and scalable way
- API Monetization: The process of generating revenue from APIs by charging developers for usage
- API Versioning: The process of managing changes to APIs over time
- API Analytics: The process of collecting and analyzing data on API usage and performance
- API Gateway: A service that manages, protects, and scales APIs.
API Documentation
- OpenAPI: A specification for building APIs in YAML or JSON format
- API Blueprint: A high-level API description language for building RESTful APIs
- RAML: A YAML-based language for describing RESTful APIs
- Swagger UI: A tool for visualizing and interacting with APIs that have been described using the OpenAPI specification
- Slate: A tool for generating beautiful, responsive API documentation.
API Deployment
- Heroku: A cloud platform for deploying, managing, and scaling web applications and APIs
- AWS Elastic Beanstalk: A service for deploying and scaling web applications and APIs on AWS
- Azure App Service: A service for deploying and scaling web applications and APIs on Azure
- Google App Engine: A service for deploying and scaling web applications and APIs on GCP
- Docker: A containerization platform used for packaging and deploying applications
- AWS Lambda: A serverless compute service for running code in response to events
- Azure Functions: A serverless compute service for running code in response to events
- Google Cloud Functions: A serverless compute service for running code in response to events
- Netlify: A cloud platform for deploying and managing static websites and APIs
- Vercel: A cloud platform for deploying and managing static websites and APIs
API Security
- OAuth: An open standard for authorization used by many social media platforms and APIs
- OpenID Connect: An authentication layer built on top of OAuth that allows users to be authenticated across multiple domains
- JSON Web Tokens (JWT): A method for representing claims securely between two parties
- Cross-Origin Resource Sharing (CORS): A mechanism that allows many resources (e.g., fonts, JavaScript, etc.) on a web page to be requested from another domain outside the domain from which the resource originated
- API Keys: A secret token that identifies an API client to the server and allows the client to access resources.
API Best Practices
- Versioning: A technique for managing changes to APIs over time
- Pagination: A technique for breaking up large API responses into smaller, more manageable chunks
- Caching: A technique for improving API performance by storing responses in a cache
- Error Handling: A technique for returning meaningful error messages to API clients
- HATEOAS: Hypermedia as the Engine of Application State, a constraint of RESTful APIs that requires the API to provide links to related resources
API Tutorials
- Getting Started with RESTful APIs by Tania Rascia
- API Design Best Practices by Martin Fowler
- Testing RESTful Web Services Made Easy Using the REST Assured Framework by Dinesh Rajput
- API Gateway Concepts and Options by AWS
- Building Secure APIs by Auth0
- RESTful API Designing guidelines — The best practices by Mahesh Haldar
API Guides (Reference)
- REST API Tutorial by Guru99
- A Beginner’s Guide to HTTP and REST by Linode
- REST API Design: Resource Modeling by Oracle
- API Security Best Practices by Google Cloud
- API Governance Handbook by WSO2.
API Tools
- API Studio: A web-based IDE for designing and testing APIs
- Stoplight: A collaborative platform for designing, documenting, and testing APIs
- Apigee: A full lifecycle API management platform that allows developers to design, secure, deploy, and analyze APIs
- Azure API Management: A fully managed service that enables users to publish, secure, transform, maintain, and monitor APIs
- Postman Learning Center: A hub for learning how to use Postman to design, develop, and test APIs.
