UK Office for National Statistics API boundary

Evidence-backed facts

1. The ONS API exposes datasets, editions, versions, observations, and filtered downloads through HTTP endpoints. informative
2. The documented beta API is open without API keys but may introduce breaking changes while functionality is developed. informative
3. Single observations and filtered dataset exports use different request workflows, including POST-based filter construction for complex slices. informative
4. A latest dataset version can be revised or corrected, so clients must retain edition and version identity instead of treating titles as immutable series. informative

Primary sources