Anthropic
This page shows Anthropic's complete history in The Diff. Each entry documents a detected change. Unchanged documents are verified each week but shown only in the full diff summary.
2026-10-24 · anthropic — Anthropic reorders high-risk use case sections in the Usage Policy
Anthropic Usage Policy · detected weekly pass, 2026-10-24
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Pricing Log in to Claude Models Mythos Fable Opus Sonnet Haiku Solutions AI agents Code modernization Coding Commerce Customer support Cybersecurity Enterprise Financial advisors Financial services Government Healthcare Higher education K-12 teachers Legal Life sciences Nonprofits Sales Small business Claude Platform Overview Developer docs Pricing Ecosystem Marketplace Regional compliance Claude on AWS Google Cloud Microsoft Foundry Console login Resources Blog Claude partner network Community Connectors Courses Customer stories Developer blog Engineering at Anthropic Events Plugins Powered by Claude Service partners Tutorials Use cases Programs Campus Frontier Academy Scientists Startups Help and security Availability Status Support center Company Anthropic Careers Leadership Policy
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mental health safeguards on Claude.ai. Research Policy Commitments Company Products Models Solutions Help and security Terms and policies Our mission AI research and products
The Usage Policy's "High-risk Use Case Requirements" and "Additional Use Case Guidelines" sections were relocated relative to "Do Not Violate" in the document's structure; the page's header metadata and global footer navigation were also restyled. 5 changed spans on the page; the excerpt shows the largest. Main content: changed. Last unchanged 2026-10-17.
2026-10-24 · anthropic — Anthropic adds a Claude Haiku 5.5 model report section to the Transparency page
Anthropic Transparency page · detected weekly pass, 2026-10-24
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describe our safeguards further in our most recent Risk Report . Claude Opus 5.5 Summary Table Model description Claude Opus 5.5 is our new
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describe our safeguards further in our most recent Risk Report . Claude Haiku 5.5 Summary Table See Claude Haiku 5.5 System Card Model description Claude Haiku 5.5 is our fastest, most capable small model, built for high-volume work like summarization, subagents, and browser use Benchmarked Capabilities See our Claude Haiku 5.5 system card ’s Section 8 on capabilities. Acceptable Uses See our Usage Policy Release date October 2026 Modalities Claude Haiku 5.5 can understand both text (including voice dictation) and image inputs, engaging in conversation, analysis, coding, and creative tasks. Claude can output text, including text-based artifacts, and diagrams. Model architecture and training methodology Claude Haiku 5.5 was pretrained on large, diverse datasets to acquire language capabilities. After the pretraining process, Haiku 5.5 underwent substantial post-training, with the goal of making it an effective assistant whose behavior aligns with the values described in Claude’s constitution . Training Data Claude Haiku 5.5 was trained on a proprietary mix of publicly available information from the internet, public and private datasets, user data included in feedback or bugs or which users have explicitly permitted for training, and other sources, such as synthetic data generated by other models. In the course of its training, we used several data cleaning and filtering methods, including deduplication and classification. Testing Methods and Results Based on our assessments, w
A new Claude Haiku 5.5 summary table was added to the Model Report, covering its described capabilities, release date (October 2026), modalities, training methodology, training data sources, and testing methods. 37 changed spans in the main content; the excerpt shows the largest. Main content: changed. Last unchanged 2026-10-17.
2026-10-24 · anthropic — Anthropic removes temperature, top_p, and top_k parameters in API version 2026-10-21
Anthropic model deprecations · detected weekly pass, 2026-10-24
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Anthropic occasionally deprecates request parameters that no longer apply to current models. How the API treats a deprecated parameter depends on the model, as the following table shows. Most SDKs keep deprecated parameters in their request types so existing code continues to type-check. The Python SDK (v1.0 and later) removes temperature , top_p , and top_k , so passing them raises a TypeError . Parameter Status Behavior Recommended replacement temperature , top_p , top_k Deprecated (Claude 4.7 and later models) Returns a 400 error when set to a non-default value on Claude 4.7 and later models
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Anthropic occasionally deprecates request parameters that no longer apply to current models. A new model can reject a deprecated parameter, and a new API version can remove it for every model. Parameter Status Behavior Recommended replacement temperature , top_p , top_k Removed in API version 2026-10-21 Returns a 400 error . Earlier API versions return it when set to a non-default value on Claude 4.7 and later models
The temperature, top_p, and top_k parameters moved from deprecated to removed in API version 2026-10-21, where they now return a 400 error unconditionally; earlier API versions still return that error only when the parameters are set to a non-default value on Claude 4.7 and later models. 15 changed spans in the main content; the excerpt shows the largest. Main content: changed. Last unchanged 2026-10-17.
2026-10-10 · anthropic — Anthropic Usage Policy revises its effective date and multiple use-case provisions
Anthropic Usage Policy · detected weekly pass, 2026-10-10
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related to using our products or services to automatically generate content and publish it for external consumption Additional Use Case Guidelines The below use cases
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or behavior, including through disciplining, suspending, or terminating a worker. Education and credentials — admitting, rejecting, or ranking applicants; grading an exam or assessment that determines admission, graduation, licensure, or certification (outside of multiple-choice testing); granting, denying, or revoking a professional license or certification; making a determination of academic misconduct or suspending or expelling a student. Healthcare access — setting triage or waitlist priority; determining eligibility for, denying, or discontinuing a treatment, service, or care program. Public benefits and services — determining eligibility for, or the amount of, government benefits, assistance, or essential services, including suspension and termination. Legal status and adjudication — deciding or recommending the outcome of a civil, administrative, or arbitral matter; determining immigration, asylum, or citizenship status. Prohibition Reminder: Use of our products or services to make or suggest decisions in law enforcement or criminal justice processes is prohibited under our Universal Usage Standards and is not a High-risk AI Recommendation. High-risk Physical Actions When connecting our models to hardware that can take physical actions, users should assess and understand 1) the range of possible outcomes if something goes wrong, 2) the nature and extent of potential impact to individuals, groups or populations, and 3) the degree of control the user maintains relative t
The policy's stated effective date changes from September 15, 2025 to November 12, 2026. The listed spans show revised wording throughout the Universal Usage Standards and Additional Use Case Guidelines sections, including the excerpted High-risk AI Recommendation categories (employment, education, healthcare, public benefits, and legal adjudication) and changes to the illegal-activity, unauthorized-access, weapons, discrimination, child-safety, and fraud provisions. 15 changed spans in the main content; the excerpt shows the largest. Main content: changed. Last unchanged 2026-10-03.
2026-10-10 · anthropic — Anthropic model-deprecations table adds claude-haiku-5-5 and renames a listed replacement model
Anthropic model deprecations · detected weekly pass, 2026-10-10
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2026 June 15, 2026 claude-3-7-sonnet-20250219 Retired October 28, 2025 February 19, 2026 claude-haiku-4-5-20251001 Active N/A Not sooner than October 15, 2026 claude-3-5-haiku-20241022 Retired December
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2026 June 15, 2026 claude-3-7-sonnet-20250219 Retired October 28, 2025 February 19, 2026 claude-haiku-5-5 Active N/A Not sooner than October 7, 2027 claude-haiku-4-5-20251001 Active N/A Not sooner than October 15, 2026 claude-3-5-haiku-20241022 Retired December
The table adds a claude-haiku-5-5 row (Active, retirement not sooner than October 7, 2027) ahead of the existing claude-haiku-4-5-20251001 row, and five rows' listed replacement model changes from claude-sonnet-4-6 to claude-sonnet-5-5. The top_k deprecation note's stated applicability also changes from "Claude Opus 4.7 and later" to "Claude 4.7 and later models." 6 changed spans in the main content; the excerpt shows the largest. Main content: changed. Last unchanged 2026-10-03.
2026-10-03 · anthropic — Transparency page adds Claude Sonnet 5.5 and Claude Opus 5.5
Anthropic Transparency page · detected weekly pass, 2026-10-03
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Claude Opus 4 and Sonnet 4 Claude Opus 4.1 Claude Sonnet 3.7 Claude Fable 5.1 Summary Table Model description Claude Fable 5.1 is the
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Claude Opus 4 and Sonnet 4 Claude Opus 4.1 Claude Sonnet 3.7 Claude Sonnet 5.5 Summary Table Model description Claude Sonnet 5.5 is a faster, lower-cost complement to Claude Opus 5.5, and is strongest at well-scoped everyday tasks, fixing bugs, and creating polished documents, slides, and spreadsheets. Benchmarked Capabilities See our Claude Sonnet 5.5 system card ’s Section 8 on capabilities. Acceptable Uses See our Usage Policy Release date September 2026 Modalities Claude Sonnet 5.5 can understand both text (including voice dictation) and image inputs, engaging in conversation, analysis, coding, and creative tasks. Claude can output text, including text-based artifacts, and diagrams. Model architecture and training methodology Claude Sonnet 5.5 was pretrained on large, diverse datasets to acquire language capabilities. After the pretraining process, Sonnet 5.5 underwent substantial post-training, with the goal of making it an effective assistant whose behavior aligns with the values described in Claude’s constitution . Training Data Claude Sonnet 5.5 was trained on a proprietary mix of publicly available information from the internet, public and private datasets, and other sources, such as synthetic data generated by other models. The mix may also include user data from feedback or bug reports, or data that users have explicitly permitted for training. In the course of its training, we used several data cleaning and filtering methods, including deduplication and classifica
The page's Model Report date moved from August 17, 2026 to October 2, 2026, and Claude Sonnet 5.5 and Claude Opus 5.5 were added to the model list. A new summary-table entry describes Claude Sonnet 5.5, with a stated release date of September 2026. 3 changed spans in the main content; the excerpt shows the largest. Main content: changed. Last unchanged 2026-09-26.
2026-10-03 · anthropic — Model deprecations page adds Claude Sonnet 4.5 retirement notice
Anthropic model deprecations · detected weekly pass, 2026-10-03
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are listed in the following sections, with the most recent announcements first. 2026-06-05: Claude Opus 4.1 model This model was retired August
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are listed in the following sections, with the most recent announcements first. 2026-09-30: Claude Sonnet 4.5 model On September 30, 2026, Anthropic notified developers using Claude Sonnet 4.5 of its upcoming retirement on the Claude API. Retirement date Deprecated model Recommended replacement November 30, 2026 claude-sonnet-4-5-20250929 claude-sonnet-5-5 2026-06-05: Claude Opus 4.1 model This model was retired August
The active-models table added a claude-sonnet-5-5 row and changed claude-sonnet-4-5-20250929's status from Active to Deprecated. A new notice dated 2026-09-30 announces claude-sonnet-4-5-20250929's retirement from the API on November 30, 2026, with claude-sonnet-5-5 as the recommended replacement. 2 changed spans in the main content; the excerpt shows the largest. Main content: changed. Last unchanged 2026-09-26.
2026-09-26 · anthropic — Anthropic adds claude-opus-5-5 to the model status table and removes the Mythos Preview deprecation notice
Anthropic model deprecations · detected weekly pass, 2026-09-26
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Model status Claude Mythos Preview ( claude-mythos-preview ) is deprecated. To migrate to Claude Mythos 5 ( claude-mythos-5 ), see the migration guide . Current and recently retired models are listed in the following table with their status: API model name Current state Deprecated Tentative retirement date claude-fable-5-1 Active N/A Not sooner than September 1, 2027 claude-mythos-5-1 Active N/A Not sooner than September 1, 2027 claude-fable-5 Active N/A Not sooner than June 9, 2027 claude-mythos-5 Active N/A Not sooner than June 9, 2027 claude-mythos-preview Deprecated June 9, 2026 To be announced claude-opus-5 Active N/A Not sooner than July 24, 2027
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Model status Current and recently retired models are listed in the following table with their status: API model name Current state Deprecated Tentative retirement date claude-fable-5-1 Active N/A Not sooner than September 1, 2027 claude-mythos-5-1 Active N/A Not sooner than September 1, 2027 claude-fable-5 Active N/A Not sooner than June 9, 2027 claude-mythos-5 Active N/A Not sooner than June 9, 2027 claude-mythos-preview Deprecated June 9, 2026 To be announced claude-opus-5-5 Active N/A Not sooner than September 22, 2027 claude-opus-5 Active N/A Not sooner than July 24, 2027
A row for claude-opus-5-5 was added to the model status table as Active, with a tentative retirement date of "Not sooner than September 22, 2027." The notice above the table stating that Claude Mythos Preview is deprecated, with a pointer to a migration guide for Claude Mythos 5, was removed; the claude-mythos-preview row is unchanged. Last unchanged 2026-09-19.
2026-09-19 · anthropic — Anthropic publishes Claude Fable 5.1 and Mythos 5.1 model cards, both deployed under ASL-3
Transparency & Annual Report · detected weekly pass, 2026-09-19
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how we're addressing potential risks. Claude Opus 5 Claude Sonnet 5 Claude Fable 5 Claude Mythos 5 Claude Opus 4.8 Claude Opus 4.7
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how we're addressing potential risks. Claude Fable 5.1 Claude Mythos 5.1 Claude Opus 5 Claude Sonnet 5 Claude Fable 5 Claude Mythos 5 Claude Opus 4.8 Claude Opus 4.7
The page grew from 18,124 to 20,410 words. A 2,279-word insertion adds full model cards for Claude Fable 5.1 and Claude Mythos 5.1, stating a September 2026 release date, that both were deployed with ASL-3 protections and treated as having CB-1 capabilities, and that the two are the same underlying model differing only in safeguards, with Mythos 5.1 restricted to trusted access programs and Claude Security. The insertion reports RSP evaluation conclusions for chemical and biological weapons, novel weapons development, and automated AI research and development; safeguards evaluation results in the suicide and self-harm domain, including a stated pre-launch change to the claude.ai system prompt; computer-use attack success rates; and ExploitGym cyber and protein-design bio results. The alignment risk assessment is stated as moved "from very low to low" in the August 2026 Risk Report. Last unchanged 2026-09-12.
2026-09-19 · anthropic — Anthropic adds Claude Mythos models to the deprecation table, one already deprecated
Model Deprecations · detected weekly pass, 2026-09-19
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API model name Current state Deprecated Tentative retirement date claude-fable-5-1 Active N/A Not sooner than September 1, 2027 claude-fable-5 Active N/A Not sooner than June 9, 2027 claude-opus-5 Active N/A Not sooner than July 24, 2027
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API model name Current state Deprecated Tentative retirement date claude-fable-5-1 Active N/A Not sooner than September 1, 2027 claude-mythos-5-1 Active N/A Not sooner than September 1, 2027 claude-fable-5 Active N/A Not sooner than June 9, 2027 claude-mythos-5 Active N/A Not sooner than June 9, 2027 claude-mythos-preview Deprecated June 9, 2026 To be announced claude-opus-5 Active N/A Not sooner than July 24, 2027
Three rows were added to the model status table: claude-mythos-5-1 and claude-mythos-5, both Active, with tentative retirement dates of September 1, 2027 and June 9, 2027; and claude-mythos-preview, listed as Deprecated on June 9, 2026 with a retirement date of "To be announced." No existing row changed. Last unchanged 2026-09-12.
2026-09-12 · anthropic — Anthropic adds Korea-specific privacy compliance disclosures
Privacy Policy · detected weekly pass, 2026-09-12
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Privacy Policy Effective July 8, 2026 Previous Version English Anthropic is an AI safety and research company working to build reliable, interpretable, and steerable AI systems.
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Privacy Policy Effective September 10, 2026 Previous Version English Anthropic is an AI safety and research company working to build reliable, interpretable, and steerable AI systems. Supplemental Disclosures for Residents of the Republic of Korea This section applies to the extent that Anthropic is subject to the Personal Information Protection Act ("PIPA"), and supplements the information in the Privacy Policy. Items of Personal Data Collected and Purpose of Use: Name, birthdate, sex, native-foreigner-code, and DI (duplication information). Purpose: Identity verification, Fraud and abuse monitoring.
Effective date changed from July 8, 2026 to September 10, 2026. New section added governing PIPA compliance for Republic of Korea residents, including requirements for collecting identity verification data and managing cross-border personal data transfers. Last unchanged between 2026-08-28 and 2026-09-12.
2026-09-05 · anthropic — claude-fable-5-1 added to the model lifecycle table
Claude Model Deprecations · detected weekly pass, 2026-09-05
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API model name Current state Deprecated Tentative retirement date claude-fable-5 Active N/A Not sooner than June 9, 2027 claude-opus-5 Active N/A Not sooner than July 24, 2027
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API model name Current state Deprecated Tentative retirement date claude-fable-5-1 Active N/A Not sooner than September 1, 2027 claude-fable-5 Active N/A Not sooner than June 9, 2027 claude-opus-5 Active N/A Not sooner than July 24, 2027
One row added; no existing row's state or retirement date changed. Change interval 2026-08-31 to 2026-09-05. The pass counted 40 changed spans for this source, but the other 39 are navigation chrome and the disappearance of sixteen "Loading" placeholders present in the 2026-08-28 capture, not document text.
All Anthropic governance documents in The Diff, whether changed or not:
About this archive: The Diff is a dated, externally anchored record of AI operators' published governance documents. Captures are retained verbatim; nothing is paraphrased or normalized. View the weekly summary or return home.