A place to start

Build a reliable API

A fast API is useful only when clients understand its behavior. Start with HTTP methods and headers, then choose cache rules and retry conditions. These tables and worked guides help you reason about repeat requests, stale responses, and browser protections.

5 datasets
3 guides
Free · CC0 data

The reference tables

HTTP Status CodesHTTP Cache-Control DirectivesCache-Control directives for browser and shared caches, with example values, intended behavior, and common configuration mistakes.12entries
HTTP Status CodesHTTP Conditional Requests and ValidatorsConditional request headers, comparison rules, and response outcomes for safe caching and lost-update protection.8entries
HTTP Status CodesHTTP Retry Decision ReferenceFailure scenarios and retry decisions for HTTP clients, including idempotency, backoff, deadlines, and ambiguous writes.12entries
HTTP Status CodesHTTP Methods ReferenceStandard HTTP request methods: GET, POST, PUT, PATCH, DELETE, HEAD, OPTIONS, TRACE with safety, idempotency, and body characteristics.9entries
Web TechnologiesHTTP Response HeadersCommon HTTP response headers and their purposes.22entries

Put it into practice

Practical guide

HTTP Caching with ETags and Cache-Control

A worked HTTP caching example: freshness, ETag validation, 304 responses, and a safe cache policy for public reference files.

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Practical guide

API Retries: Backoff, Deadlines, and Idempotency

Build bounded API retries that respect Retry-After, avoid duplicate writes, and distinguish transport failures from invalid requests.

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Practical guide

Security Headers Without Breaking Your Site

Roll out CSP and browser security headers with a resource inventory, report-only checks, and concrete compatibility tests.

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Explore another path

02

Give an agent better context

Ground answers in compact reference data, validate the shape, and measure the failures.

5 datasets · 4 guides 03

Query data with confidence

Choose joins, windows, indexes, and transaction boundaries from the question you need to answer.

6 datasets · 3 guides 04

Work safely in the terminal

Find files, recover Git work, and write shell commands that handle real filenames.

5 datasets · 1 guide 05

Make the web work for everyone

Build usable layouts, keyboard interactions, text search, and time handling.

5 datasets · 4 guides 06

Measure, evaluate, and operate

Connect service signals, background jobs, probability, and experiment design to real decisions.

6 datasets · 4 guides