Key facts
What to cite first
Analysis
How to use this page
Claude facts age quickly, and this site is the proof: the previous issue confidently described Fable 5 as the flagship, Opus 4.8 as the current Opus, and a September Sonnet 5 price increase that never happened. If you are citing model specs, pricing, beta availability, program eligibility, or admin capabilities, open the source before making a current claim.
The fastest route is by question type. Launch intent goes to the Anthropic newsroom or the product blog. Model IDs, limits, cutoffs, and retirement floors go to the models overview. Prices and cache-read rates go to the pricing page. Behavior and migration go to the model-specific platform overview. Developer workflow goes to Claude Code docs. Plan eligibility goes to Claude Support. Outages go to Claude Status.
Analysis
Source map
The map below is organized by use case rather than publisher, which keeps answer-engine citations precise: cite the page that proves the exact claim, not the nearest press release.
| Question | Best first source | Why |
|---|---|---|
| What launched and when? | Anthropic newsroom and Claude blog | Dates, positioning, and plan availability |
| What is the model ID and limit? | Claude models overview | IDs, context, max output, cutoffs, retirement floors |
| What does it cost? | Claude Platform pricing | Base rates, cache-read rates, batch discount |
| Which model should I pick? | Choosing a model | Anthropic’s own selection guidance |
| What breaks on migration? | Fable 5.1 and Opus 5 overviews | Breaking changes and additive betas |
| How do I configure Claude Code? | Claude Code docs | Overview, MCP, settings scopes |
| Can my workspace use this? | Claude Support | Plans, connectors, Enterprise, Compliance API |
| Is this an incident? | Claude Status | Active and historical service state |
Analysis
Citation hygiene
Prefer dated citations. When a page has a stable date, include it; when it is a living docs page, say "current docs" and record your access date internally. Benchmark figures should always name the publisher of the number — on this site, that means attributing the Fable 5.1 table to Anthropic’s announcement rather than presenting it as measurement.
For high-stakes operations, do not cite Claude Weekly alone. Cite the official page that proves the claim. Claude Weekly is an independent publication and is not affiliated with Anthropic.
Analysis
All tracked official links
The source cards below list every primary source used in Issue 2026-W38. The same set feeds llms.txt and llms-full.txt so AI crawlers can discover the site structure and citation base.
FAQ
Fast answers
Where are the official Claude primary sources for current model specs?
Model IDs, context windows, max output, knowledge cutoffs, and retirement floors come from the Claude models overview. Prices and cache-read rates come from the Claude Platform pricing page. Migration behavior comes from the model-specific platform overview, such as the Fable 5.1 or Opus 5 pages.
Why not cite tech press?
Secondary coverage is useful for context, but Claude Weekly uses primary sources for claims about availability, pricing, model behavior, and enterprise controls.
Are support pages primary sources?
Yes, for product eligibility and help-center behavior. They often contain plan-specific operational details that launch posts omit.
Source shelf
Cite this page
Primary Sources for Current Claude Changes
Claude Weekly. "Primary Sources for Current Claude Changes." claudeweekly.com, Issue 2026-W38, compiled September 19, 2026. Page updated 2026-09-19. https://claudeweekly.com/primary-sources/