Does stateless mean a website cannot remember a user?

No. Application-managed state can sit above HTTP's request semantics.

Does 202 mean processing succeeded?

No. It reports acceptance while processing remains incomplete, and completion is not guaranteed by that response.

Is an HTTPS response automatically trustworthy content?

No. Secure transport and the accuracy of the application output are different properties.

AI Glossary / Mathematics and optimization / Beginner

Hypertext Transfer Protocol

Definition

Hypertext Transfer Protocol, or HTTP, is the application-level request-and-response protocol family used to communicate with web resources and many online services. A client requests an operation, and a server returns a response with a status code and, where appropriate, content. HTTP provides communication semantics; it does not perform the AI reasoning behind an AI service.

What it means

When a website sends a question to an AI service, several different jobs occur. The application decides what question to send. HTTP carries a structured exchange with the service. The service runs its own processing and returns information that the application must interpret.
Keeping these roles separate helps explain failures. A request can reach a server successfully while the requested model operation fails later. Conversely, the operation might succeed even though a network interruption prevents the client from seeing its response. User-facing software must handle both situations rather than treating every communication problem as proof that nothing happened.

How it works

An HTTP request identifies a target resource and a method, such as GET or POST, and can include fields and content. A response reports a status and may include its own fields and content. The application defines how these exchanges support a particular workflow.
HTTP is stateless at the protocol level, but applications can maintain accounts, sessions, and job histories. The protocol does not require an application to forget previous requests. Different HTTP versions provide different message-transport mechanisms while sharing core semantics. HTTPS uses secure communication for HTTP; it does not establish that the returned content is true.

Three practical examples

A glossary website can retrieve the stored explanation for a selected term through an HTTP request.
A writing application can submit text to a summarization endpoint and interpret the response according to that service's contract.
A batch-processing dashboard can ask for the current state of a previously submitted job and display progress to the user.

Think of it this way

Think of HTTP as a standardized exchange of service forms: a request names the action, and a reply reports how that request was handled. The analogy is limited because network exchanges can be interrupted, repeated, cached, or routed through intermediaries. A form being received is also different from the requested work being completed.

Worked example

Consider an original, fictional summarization service. A client submits a document using POST to https://example.com/summary-jobs. The service replies with status 202 and a body containing job identifier J17 and a status address. Here, 202 means the request has been accepted for processing; it does not announce a finished summary.
The client next sends GET to https://example.com/summary-jobs/J17. Suppose the response status is 200 and the body says state=running. The GET successfully retrieved the job representation, but the represented job is still running. HTTP success for this lookup and application completion are two different facts.
Later, another GET returns 200 with state=completed and a result address. The application can now fetch the result. If the body instead says state=failed, a successful lookup has retrieved information about an unsuccessful job. The client must inspect the documented application fields as well as the HTTP status.
Now suppose the first POST reaches the server, creates J17, and its response is lost. Blindly repeating that POST might create J18 and duplicate the work. An application could provide a documented deduplication key or a recovery lookup, but neither is automatically supplied by the word HTTP. Its actual service contract determines the recovery behavior.
All addresses, identifiers, and body fields here are illustrative. HTTP does not prescribe these endpoint paths, state names, polling intervals, or job-retention rules. Those details belong to the imagined API.

Illustrative case study

In a fictional example, Pine Editorial adds an AI article-processing feature to its website. The first interface displays Finished whenever it receives any response in the successful status range. Editors become confused because accepted jobs still have no result.
The team changes the interface to display Submitted, Processing, Completed, or Failed from the documented job representation. It also retains the job identifier so a refreshed page can recover the current state. This invented case shows how protocol-level and application-level information work together; it makes no claim about a particular service's implementation.

Common misconceptions and mistakes

HTTP is not the same thing as an API. An API is an interface contract; HTTP is one way that contract can be exposed over a network. Nor does every HTTP exchange contain HTML: an application may exchange structured data or other representations.
Do not assume a successful status proves an AI answer is accurate. The server may have correctly processed a request and still produced a poor model output. Content validation remains an application concern.
Idempotence concerns the intended effect of repeating a request, not whether repeated responses have identical bytes. PUT, DELETE, and safe methods have idempotent semantics, while POST is not generally idempotent. An application-specific retry policy must respect the operation's actual behavior.

Business use

For an AI website, HTTP understanding helps product teams specify reliable progress messages, failure recovery, and integrations. A useful integration agreement states what submission means, how results become available, which failures can be retried, and how duplicate work is prevented.
Testing should include interrupted responses and application failures, not only a successful demonstration. For example, verify that a browser refresh can recover an existing job rather than resubmitting the original document unintentionally. Track service errors separately from model-quality issues so that the team fixes the right layer. An unavailable endpoint and an inaccurate summary call for different remedies.

Check your understanding

A job-status GET returns 200 with state=failed. Did the status lookup succeed?

Answer: Yes, in this example it successfully retrieved a representation. The represented processing job failed, so the interface should report that application outcome rather than treating 200 as proof of a completed summary.

Related terms

API
client
server
HTTPS
request method
status code
idempotence
resource
asynchronous processing
authentication

Learn next

Draw the fictional job's submission, status lookup, and result retrieval as three separate exchanges. For each, state what a successful response proves and what it does not prove. Then add the lost-response case and specify an application-level recovery rule before implementing retries.

Sources

Primary specification: RFC 9110, HTTP Semantics, especially request/response structure, statelessness, idempotent methods, and 202 Accepted: https://www.rfc-editor.org/rfc/rfc9110.html . The job workflow, paths, identifiers, and interface examples above are original and are not standardized HTTP requirements.

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