Claude docs changelog
We periodically re-check Anthropic's official docs and record every case where a fact our guides relied on has changed — with the date, previous value, current value and source. This is our own verified log, not Anthropic's official change history.
23 entries · "changed" = official date, "verified on" = date we confirmed it when the exact change date is unknown · How we verify (editorial principles)
September 18, 2026
- Claude appverified on
Artifact sharing article revised — Share dialog in the new Claude experience (chat + Cowork merged)
- Before
- Only Publish (Free/Pro/Max, no account needed to open) vs Share (Team/Enterprise); explicit note that the Remix button was removed
- Now
- Artifacts made in the new Claude experience (incl. Design, Slides, Docs, Claude Code) are shared via the Share dialog and viewers need a Claude account; Publish, embed codes and code copy remain only for chat artifacts on the previous experience. The Remix note is gone; only "build on a published artifact" (copy the code) remains
September 17, 2026
- Modelsverified on
Minimum Claude Code version for Fable 5.1 — 2.1.255 or later
- Before
- 2.1.250 or later (as recorded on September 2)
- Now
- The official support article now says 2.1.255 or later (Fable 5: 2.1.170+). Whether the article changed or the September 2 record was wrong is unconfirmed; four articles corrected to the current wording
September 14, 2026
- Pricingchanged
Claude Code weekly limits — temporary 50% boost ends, standard limit permanently +25%
- Before
- Temporary 50% increase from 2026-05-13 to 09-13 (extended four times)
- Now
- From September 14 the standard weekly limit is permanently 25% above the old baseline. Per Anthropic, that is about 17% lower than today (with the 50% boost). Applies to Pro, Max, Team and seat-based Enterprise; 5-hour limits not mentioned
September 9, 2026
- Claude appverified on
Voice mode availability
- Before
- Two-way voice conversation limited
- Now
- Two-way voice mode on mobile, desktop and web, all plans. Non-English in beta; counts toward usage limits
- Claude appverified on
Chat file upload limits
- Before
- 30MB per file
- Now
- 500MB per file, up to 20 files, PDFs up to 1,000 pages (visual analysis up to 100). Project files remain 30MB
- Claude appverified on
Artifacts Remix button
- Before
- Signed-in users can Remix into an editable copy
- Now
- Remix button removed. Copy the published artifact code into a new chat and ask for changes (Free, Pro, Max)
- APIverified on
Streaming fallback content block
- Now
- When a request is served by a different model, a fallback block (start/stop pair, no deltas) appears at each model boundary
- APIverified on
What a 429 means
- Before
- Rate limit exceeded; follow retry-after
- Now
- Also returned at the tier monthly spend cap, with no retry-after header (SDK auto-retries keep failing). A self-set spend limit returns 400
- Modelsverified on
API model aliases
- Before
- One-word aliases like opus / sonnet resolve to the recommended version
- Now
- One-word names are Claude Code /model shortcuts. API aliases exist only for pre-4.6 models (claude-haiku-4-5 form); from 4.6 the dateless ID is the snapshot
- APIverified on
Previous-turn thinking blocks in context
- Before
- Stripped automatically by the API
- Now
- Kept by default on Opus 4.5+, Sonnet 4.6+ and Fable (count as input tokens); stripped only on older Opus/Sonnet and all Haiku
- APIverified on
Structured outputs generally available
- Before
- Beta header required, parameter output_format
- Now
- GA. No beta header; parameter is output_config.format. Python SDK 1.0+ raises TypeError if output_format is passed to beta create()
- APIverified on
How extended thinking is enabled
- Before
- type: enabled + budget_tokens
- Now
- Current models think by default. Manual mode is deprecated on 4.6 and rejected (400) on 4.7+; steer with type: adaptive + effort
September 2, 2026
- Pricingchanged
Claude Sonnet 5 API pricing
- Before
- Announced September increase ($3/$15)
- Now
- Increase withdrawn; $2/$10 confirmed as standard
September 1, 2026
- Modelschanged
Claude Fable 5.1 released; Fable 5 becomes legacy
- Before
- Fable 5 as the current top tier
- Now
- Fable 5.1 is the current top tier; Fable 5 is legacy (retirement no sooner than June 9, 2027). Same plan terms for both; the $100 credit applied only to the Fable 5 transition
July 28, 2026
- MCPchanged
MCP Python SDK 2.0 server class
- Before
- from mcp.server.fastmcp import FastMCP
- Now
- SDK 2.0 required; from mcp.server import MCPServer. uv add "mcp[cli]" installs 2.x
July 24, 2026
- Modelschanged
Claude Opus 5 released
- Before
- Opus 4.8 as top general model
- Now
- Opus 5 launched at the same price as 4.8 ($5/$25); default on Max, top model on Pro. Fast mode (~2.5× speed, 2× price)
July 20, 2026
- Pricingchanged
Fable 5 subscription terms finalized
- Before
- Temporary inclusion extended July 7 → 12 → 19
- Now
- Max and Team Premium include Fable within 50% of weekly limits; Pro and Team Standard use usage credits (one-time $100 credit)
July 13, 2026
- Claude appchanged
Artifacts sharing expanded
- Now
- Multiplayer editing for Team/Enterprise; artifacts created in Claude Code and Claude Tag (Slack) shareable via public link
July 1, 2026
- Modelschanged
Claude Fable 5 available again
- Before
- Paused since June 12
- Now
- Back on July 1 after export controls lifted June 30, with a stronger cyber classifier and per-request fallback (bio/chem to Opus 5, offensive cyber to Opus 4.8)
- Claude Codechanged
Node.js requirement for Claude Code install
- Before
- Node.js 18 or later required
- Now
- Native install needs no Node.js. Only npm installs (v2.1.198+) require Node 22+; lower versions print an EBADENGINE warning but still run
June 30, 2026
- Modelschanged
Claude Sonnet 5 released
- Before
- Sonnet 4.6 as Free/Pro default
- Now
- Sonnet 5 becomes the default for Free and Pro. Introductory API price $2/$10
June 15, 2026
- APIchanged
Agent SDK subscription credit change
- Before
- From June 15, Agent SDK usage on subscription plans draws from a separate monthly credit
- Now
- Paused on June 15. Agent SDK, claude -p and third-party apps still draw from subscription limits; no credit
June 9, 2026
- Modelschanged
Claude Fable 5 released
- Now
- Fable 5 launched as the tier above Opus at $10/$50 API. Distribution paused on June 12 under US export controls