What is an API Endpoint? URIs, Paths, and Query Parameters

Overview #

An API endpoint is a specific digital location or URL where an API receives requests for a particular resource or service, typically consisting of a base URL, a path, and optional query parameters.

Anatomy of an Endpoint URL #

An endpoint is structured into distinct segments:
https://api.apihundred.com/v1/chat/completions?stream=true
• Protocol: https:// (encrypted communication)
• Host / Domain: api.apihundred.com (server destination)
• API Version: /v1 (enables backwards-compatible changes)
• Resource Path: /chat/completions (the specific capability requested)
• Query String: ?stream=true (optional filtering or behavior flags).

RESTful Endpoint Naming Best Practices #

Professional APIs use plural nouns rather than verbs for resource naming:
• Good: GET /v1/models, POST /v1/keys, DELETE /v1/keys/{id}
• Bad: GET /v1/getModels, POST /v1/createNewKey
Because HTTP methods (GET, POST, DELETE) already act as verbs, path names should strictly denote the entity being operated on.

Dynamic Path Parameters vs. Query Parameters #

Path parameters identify specific unique entities (e.g. /v1/keys/key_12345). Query parameters filter, sort, or paginate collections (e.g. /v1/models?limit=10&category=reasoning).

Code Example: Querying Endpoints with Dynamic Parameters in Node.js #

const BASE_URL = "https://api.apihundred.com/v1";

// 1. Static endpoint
const modelsEndpoint = `${BASE_URL}/models`;

// 2. Dynamic path parameter endpoint
const specificKeyId = "key_982410";
const keyDetailsEndpoint = `${BASE_URL}/keys/${specificKeyId}`;

// 3. Query parameter endpoint
const filteredEndpoint = `${BASE_URL}/models?category=multimodal&limit=5`;

console.log("Endpoint constructed:", filteredEndpoint);

Frequently Asked Questions #

Q: What is the difference between an API and an API endpoint?

The API is the entire software system and documentation. An endpoint is a single specific URL within that system dedicated to one particular operation.

Q: Why do endpoints include version numbers (/v1, /v2)?

Version prefixes ensure that when a provider updates response fields or schemas, existing production applications using /v1 do not break.

Q: Can an endpoint accept both GET and POST requests?

Yes. For example, GET /v1/keys might list your API keys, while POST /v1/keys creates a new API key on the same path.