What Is HTTP? The Protocol Behind Web Requests

HTTP, the Hypertext Transfer Protocol, is the request-response language browsers, APIs, and CI pipelines use to ask a server for data and receive an answer.

Every time a pipeline downloads a package, calls a deployment API, or pings a health check, it speaks HTTP. The protocol defines how a client phrases a request, how a server replies, and what the status, headers, and body of each message mean. Understanding HTTP makes pipeline failures far easier to read, because most network errors in CI surface as HTTP responses.

How a request and response are structured

An HTTP request has a method (GET, POST, PUT, DELETE), a path, a set of headers, and an optional body. The server replies with a status code, response headers, and usually a body. This request-response pairing is the unit of nearly all web communication.

HTTP methods

GET retrieves data without changing server state.
POST creates or submits data.
PUT and PATCH update existing resources.
DELETE removes a resource.

Stateless by design

HTTP is stateless: each request stands alone and the server keeps no memory of prior requests unless you add cookies or tokens. That is why API calls in CI must send credentials with every request rather than logging in once.

HTTP versions

HTTP/1.1 opens a connection per request stream, HTTP/2 multiplexes many requests over one connection, and HTTP/3 runs over QUIC for lower latency. Most CI tooling negotiates the best version automatically, but mismatches can occasionally cause confusing hangs.

Where HTTP shows up in CI/CD

Package installs, container registry pulls, artifact uploads, webhook deliveries, and deploy-API calls are all HTTP under the hood. When one fails, the HTTP status code is your first clue: a 4xx points at your request, a 5xx points at the server, and a connection error points at the network.

Transient HTTP failures in pipelines

A momentary blip can drop a connection mid-request, producing a timeout or reset rather than a clean status code. These transient HTTP failures are usually safe to retry. On Latchkey managed runners, brief network blips to common endpoints are automatically retried so a single dropped request does not fail the whole job.

Key takeaways

HTTP is the stateless request-response protocol behind almost all web and API traffic.
Methods describe intent and status codes describe the outcome of each request.
In CI, most network operations are HTTP, so the status code is the first debugging clue.