@anthropic-ai/sdk breaking changes

Every breaking API change we have recorded in @anthropic-ai/sdk on npm: 264 breaking changes in 10 versions. Below are its newest 6 versions, removals and renames first, each with its source.

Newest change October 21, 2026

On this page

1.0.0

1 breaking change, first published October 21, 2026.

Signature changed messages.create
Code that passes temperature, top_p and top_k fails once it upgrades to 1.0.0 or later. Recommended replacement: Omit and use prompting to guide model behavior. platform.claude.com

0.68.0

8 breaking changes, first published October 28, 2025.

Signature changed Anthropic.Beta.BetaContextManagementConfig.edits
Was edits?: Array<BetaClearToolUses20250919Edit>; now edits?: Array<BetaClearToolUses20250919Edit | BetaClearThinking20251015Edit>. npmjs.com
Signature changed Anthropic.Beta.BetaContextManagementResponse.applied_edits
Was applied_edits: Array<BetaClearToolUses20250919EditResponse>; now applied_edits: Array<BetaClearToolUses20250919EditResponse | BetaClearThinking20251015EditResponse>. npmjs.com
Signature changed Anthropic.Beta.Messages.BetaContextManagementConfig.edits
Was edits?: Array<BetaClearToolUses20250919Edit>; now edits?: Array<BetaClearToolUses20250919Edit | BetaClearThinking20251015Edit>. npmjs.com
Signature changed Anthropic.Beta.Messages.BetaContextManagementResponse.applied_edits
Was applied_edits: Array<BetaClearToolUses20250919EditResponse>; now applied_edits: Array<BetaClearToolUses20250919EditResponse | BetaClearThinking20251015EditResponse>. npmjs.com
Signature changed default.Beta.BetaContextManagementConfig.edits
Was edits?: Array<BetaClearToolUses20250919Edit>; now edits?: Array<BetaClearToolUses20250919Edit | BetaClearThinking20251015Edit>. npmjs.com
Signature changed default.Beta.BetaContextManagementResponse.applied_edits
Was applied_edits: Array<BetaClearToolUses20250919EditResponse>; now applied_edits: Array<BetaClearToolUses20250919EditResponse | BetaClearThinking20251015EditResponse>. npmjs.com
Signature changed default.Beta.Messages.BetaContextManagementConfig.edits
Was edits?: Array<BetaClearToolUses20250919Edit>; now edits?: Array<BetaClearToolUses20250919Edit | BetaClearThinking20251015Edit>. npmjs.com
Signature changed default.Beta.Messages.BetaContextManagementResponse.applied_edits
Was applied_edits: Array<BetaClearToolUses20250919EditResponse>; now applied_edits: Array<BetaClearToolUses20250919EditResponse | BetaClearThinking20251015EditResponse>. npmjs.com

0.67.0

24 breaking changes, first published October 16, 2025.

Signature changed Anthropic.AnthropicBeta
Was type AnthropicBeta = (string & {}) | 'message-batches-2024-09-24' | 'prompt-caching-2024-07-31' | 'computer-use-2024-10-22' | 'computer-use-2025-01-24' | 'pdfs-2024-09-25' | 'token-counting-2024-11-01' |... npmjs.com
Signature changed Anthropic.Beta.AnthropicBeta
Was type AnthropicBeta = (string & {}) | 'message-batches-2024-09-24' | 'prompt-caching-2024-07-31' | 'computer-use-2024-10-22' | 'computer-use-2025-01-24' | 'pdfs-2024-09-25' | 'token-counting-2024-11-01' |... npmjs.com
Signature changed Anthropic.Beta.MessageCreateParams.MessageCreateParamsNonStreaming.container
Was container?: string | null; now container?: BetaContainerParams | string | null. npmjs.com
Signature changed Anthropic.Beta.MessageCreateParams.MessageCreateParamsStreaming.container
Was container?: string | null; now container?: BetaContainerParams | string | null. npmjs.com
Signature changed Anthropic.Beta.MessageCreateParamsNonStreaming.container
Was container?: string | null; now container?: BetaContainerParams | string | null. npmjs.com
Signature changed Anthropic.Beta.MessageCreateParamsStreaming.container
Was container?: string | null; now container?: BetaContainerParams | string | null. npmjs.com
Signature changed Anthropic.Beta.Messages.BetaToolRunnerParams.container
Was container?: string | null; now container?: BetaContainerParams | string | null. npmjs.com
Signature changed Anthropic.Beta.Messages.MessageCreateParams.MessageCreateParamsNonStreaming.container
Was container?: string | null; now container?: BetaContainerParams | string | null. npmjs.com
Signature changed Anthropic.Beta.Messages.MessageCreateParams.MessageCreateParamsStreaming.container
Was container?: string | null; now container?: BetaContainerParams | string | null. npmjs.com
Signature changed Anthropic.Beta.Messages.MessageCreateParamsNonStreaming.container
Was container?: string | null; now container?: BetaContainerParams | string | null. npmjs.com

And 14 more in this version.

0.66.0

6 breaking changes, first published October 15, 2025.

Signature changed Anthropic.AnthropicBeta
Was type AnthropicBeta = (string & {}) | 'message-batches-2024-09-24' | 'prompt-caching-2024-07-31' | 'computer-use-2024-10-22' | 'computer-use-2025-01-24' | 'pdfs-2024-09-25' | 'token-counting-2024-11-01' |... npmjs.com
Signature changed Anthropic.Beta.AnthropicBeta
Was type AnthropicBeta = (string & {}) | 'message-batches-2024-09-24' | 'prompt-caching-2024-07-31' | 'computer-use-2024-10-22' | 'computer-use-2025-01-24' | 'pdfs-2024-09-25' | 'token-counting-2024-11-01' |... npmjs.com
Signature changed Anthropic.Messages.Model
Was type Model = 'claude-3-7-sonnet-latest' | 'claude-3-7-sonnet-20250219' | 'claude-3-5-haiku-latest' | 'claude-3-5-haiku-20241022' | 'claude-sonnet-4-20250514' | 'claude-sonnet-4-0' | 'claude-4-sonnet-20250514' | 'claude-sonnet-4-5' |... npmjs.com
Signature changed Anthropic.Model
Was type Model = 'claude-3-7-sonnet-latest' | 'claude-3-7-sonnet-20250219' | 'claude-3-5-haiku-latest' | 'claude-3-5-haiku-20241022' | 'claude-sonnet-4-20250514' | 'claude-sonnet-4-0' | 'claude-4-sonnet-20250514' | 'claude-sonnet-4-5' |... npmjs.com
Signature changed default.Beta.AnthropicBeta
Was type AnthropicBeta = (string & {}) | 'message-batches-2024-09-24' | 'prompt-caching-2024-07-31' | 'computer-use-2024-10-22' | 'computer-use-2025-01-24' | 'pdfs-2024-09-25' | 'token-counting-2024-11-01' |... npmjs.com
Signature changed default.Messages.Model
Was type Model = 'claude-3-7-sonnet-latest' | 'claude-3-7-sonnet-20250219' | 'claude-3-5-haiku-latest' | 'claude-3-5-haiku-20241022' | 'claude-sonnet-4-20250514' | 'claude-sonnet-4-0' | 'claude-4-sonnet-20250514' | 'claude-sonnet-4-5' |... npmjs.com

0.50.1

88 breaking changes, first published May 9, 2025.

Signature changed Anthropic
Was class Anthropic extends Core.APIClient; now class Anthropic extends BaseAnthropic. npmjs.com
Signature changed Anthropic.Anthropic
Was static Anthropic: typeof Anthropic; now static Anthropic: typeof BaseAnthropic. npmjs.com
Signature changed Anthropic.apiKeyAuth
Was protected apiKeyAuth(opts: Core.FinalRequestOptions): Core.Headers; now protected apiKeyAuth(opts: FinalRequestOptions): NullableHeaders | undefined. npmjs.com
Signature changed Anthropic.authHeaders
Was protected authHeaders(opts: Core.FinalRequestOptions): Core.Headers; now protected authHeaders(opts: FinalRequestOptions): NullableHeaders | undefined. npmjs.com
Signature changed Anthropic.bearerAuth
Was protected bearerAuth(opts: Core.FinalRequestOptions): Core.Headers; now protected bearerAuth(opts: FinalRequestOptions): NullableHeaders | undefined. npmjs.com
Signature changed Anthropic.Beta._client
Was protected _client: Core.APIClient; now protected _client: BaseAnthropic. npmjs.com
Signature changed Anthropic.Beta.BetaModelInfosPage
Was class BetaModelInfosPage extends Page<BetaModelInfo>; now type BetaModelInfosPage = Page<BetaModelInfo>. npmjs.com
Signature changed Anthropic.Beta.Messages._client
Was protected _client: Core.APIClient; now protected _client: BaseAnthropic. npmjs.com
Signature changed Anthropic.Beta.Messages.Batches._client
Was protected _client: Core.APIClient; now protected _client: BaseAnthropic. npmjs.com
Signature changed Anthropic.Beta.Messages.Batches.BetaMessageBatchesPage
Was class BetaMessageBatchesPage extends Page<BetaMessageBatch>; now type BetaMessageBatchesPage = Page<BetaMessageBatch>. npmjs.com

And 78 more in this version.

0.41.0

67 breaking changes, first published May 7, 2025.

Signature changed Anthropic.Beta.BetaCitationsDelta.citation
Was citation: BetaCitationCharLocation | BetaCitationPageLocation | BetaCitationContentBlockLocation; now citation: BetaCitationCharLocation | BetaCitationPageLocation | BetaCitationContentBlockLocation |... npmjs.com
Signature changed Anthropic.Beta.BetaContentBlock
Was type BetaContentBlock = BetaTextBlock | BetaToolUseBlock | BetaThinkingBlock | BetaRedactedThinkingBlock; now type BetaContentBlock = BetaTextBlock | BetaToolUseBlock | BetaServerToolUseBlock | BetaWebSearchToolResultBlock |... npmjs.com
Signature changed Anthropic.Beta.BetaContentBlockParam
Was type BetaContentBlockParam = BetaTextBlockParam | BetaImageBlockParam | BetaToolUseBlockParam | BetaToolResultBlockParam | BetaBase64PDFBlock | BetaThinkingBlockParam | BetaRedactedThinkingBlockParam; now type BetaContentBlockParam =... npmjs.com
Signature changed Anthropic.Beta.BetaRawContentBlockStartEvent.content_block
Was content_block: BetaTextBlock | BetaToolUseBlock | BetaThinkingBlock | BetaRedactedThinkingBlock; now content_block: BetaTextBlock | BetaToolUseBlock | BetaServerToolUseBlock | BetaWebSearchToolResultBlock | BetaThinkingBlock |... npmjs.com
Signature changed Anthropic.Beta.BetaStopReason
Was type BetaStopReason = 'end_turn' | 'max_tokens' | 'stop_sequence' | 'tool_use'; now type BetaStopReason = 'end_turn' | 'max_tokens' | 'stop_sequence' | 'tool_use' | 'pause_turn' | 'refusal'. npmjs.com
Signature changed Anthropic.Beta.BetaTextCitation
Was type BetaTextCitation = BetaCitationCharLocation | BetaCitationPageLocation | BetaCitationContentBlockLocation; now type BetaTextCitation = BetaCitationCharLocation | BetaCitationPageLocation | BetaCitationContentBlockLocation |... npmjs.com
Signature changed Anthropic.Beta.BetaTextCitationParam
Was type BetaTextCitationParam = BetaCitationCharLocationParam | BetaCitationPageLocationParam | BetaCitationContentBlockLocationParam; now type BetaTextCitationParam = BetaCitationCharLocationParam | BetaCitationPageLocationParam |... npmjs.com
Signature changed Anthropic.Beta.BetaToolUnion
Was type BetaToolUnion = BetaTool | BetaToolComputerUse20241022 | BetaToolBash20241022 | BetaToolTextEditor20241022 | BetaToolComputerUse20250124 | BetaToolBash20250124 | BetaToolTextEditor20250124; now type BetaToolUnion = BetaTool |... npmjs.com
Signature changed Anthropic.Beta.MessageCountTokensParams.tools
Was tools?: Array<BetaTool | BetaToolComputerUse20241022 | BetaToolBash20241022 | BetaToolTextEditor20241022 | BetaToolComputerUse20250124 | BetaToolBash20250124 | BetaToolTextEditor20250124>; now tools?: Array<BetaTool |... npmjs.com
Signature changed Anthropic.Beta.Messages.BetaCitationsDelta.citation
Was citation: BetaCitationCharLocation | BetaCitationPageLocation | BetaCitationContentBlockLocation; now citation: BetaCitationCharLocation | BetaCitationPageLocation | BetaCitationContentBlockLocation |... npmjs.com

And 57 more in this version.

Check your code

These are the changes. To see which of them reach your code, scan a public repository, or have your coding agent call check_code with your manifest or lockfile over MCP. The API reads every change in every version, not only the newest. On Team and up, a fix pull request opens for the changes that reach a connected repository. Nothing merges or deploys.

Put your code on continuous management.

Scan a public repository now, or give your agent one line.

See how out of date your code is.

Tell your agent what changed since it was trained.

claude mcp add --transport http since https://api.since.dev/mcp