Verified history
This means HyperObserve has not found sufficient first-party evidence for a dated before-and-after event. It does not mean Anthropic API has never changed. Undated values are kept in the current baseline below instead of being presented as history.
Current monitored baseline
HyperObserve currently monitors 4 scoped observations for Anthropic API. The baseline covers Messages API limiters, Claude Fable 5, Opus 5, and Sonnet 5 context, Claude 5 family maximum output, Claude Haiku 4.5 context. Each value retains its plan, product, endpoint, region, account, or runtime qualifier so a future change can be compared against the correct scope.
| Constraint | Current value | Scope | Verified source |
|---|---|---|---|
| Messages API limitersThe API uses a token bucket, and limits can be enforced over shorter intervals than one minute. | RPM + input TPM + output TPM | Usage-tier and model specific | AnthropicAug 22, 2026 |
| Claude Fable 5, Opus 5, and Sonnet 5 contextAPI model specification; model availability can differ by provider. | 1,000,000 tokens | Claude 5 family | AnthropicAug 22, 2026 |
| Claude 5 family maximum outputSeparate maximum output for the listed Claude 5 API models. | 128,000 tokens | Claude 5 family | AnthropicAug 22, 2026 |
| Claude Haiku 4.5 contextModel-specific API context window. | 200,000 tokens | Claude Haiku 4.5 | AnthropicAug 22, 2026 |
Tracked constraints and impact
Claude model context windows and organization-level API rate controls. A change is recorded only when it alters a constraint developers can act on, such as capacity planning, request shaping, model selection, deployment configuration, storage design, retry behavior, or account budgeting.
Anthropic API rate limits
How Claude API organization, workspace, model, and token-bucket rate limits work, with current official-source guidance.
Claude context windows
Current Claude API context-window and output constraints by model family, with official model documentation and practical caveats.
How a change is verified
- Compare the current first-party statement with the previously stored observation, including the exact plan, model, runtime, endpoint, region, and account scope.
- Separate a true product change from documentation clarification, temporary capacity, configurable account state, or a limit that applies to a different execution path.
- Preserve the old and new values, official source, effective date when disclosed, detection date, and practical impact. If those elements cannot be supported, no historical event is published.
Official sources monitored
These first-party documents support the current Anthropic API baseline. HyperObserve links directly to them so you can confirm the live wording before making a production decision.
Messages API rate limits and response headers
Current Claude model context and output limits