--- title: Models url: https://platform.claude.com/docs/en/api/go/beta/models --- # Models ## List Models `client.Beta.Models.List(ctx, params) (*Page[BetaModelInfo], error)` **GET** `/v1/models` List available models. The Models API response can be used to determine which models are available for use in the API. More recently released models are listed first. ### Parameters - `params BetaModelListParams` - `AfterID param.Opt[string] Optional` (query parameter) ID of the object to use as a cursor for pagination. When provided, returns the page of results immediately after this object. - `BeforeID param.Opt[string] Optional` (query parameter) ID of the object to use as a cursor for pagination. When provided, returns the page of results immediately before this object. - `Lifecycle []string Optional` (query parameter) Filter the list to models in any of the given lifecycle stages (`active`, `deprecated`, or `retired`). Up to 3 values. When omitted, the list contains the `active` and `deprecated` models; `retired` models appear only when `retired` is requested explicitly. maxItems: 3 - `const BetaModelListParamsLifecycleActive BetaModelListParamsLifecycle = "active"` - `const BetaModelListParamsLifecycleDeprecated BetaModelListParamsLifecycle = "deprecated"` - `const BetaModelListParamsLifecycleRetired BetaModelListParamsLifecycle = "retired"` - `Limit param.Opt[int64] Optional` (query parameter) Number of items to return per page. Defaults to `20`. Ranges from `1` to `1000`. minimum: 1, maximum: 1000 - `Betas []AnthropicBeta Optional` (header parameter) Optional header to specify the beta version(s) you want to use. - `const AnthropicBetaMessageBatches2024_09_24 AnthropicBeta = "message-batches-2024-09-24"` - `const AnthropicBetaPromptCaching2024_07_31 AnthropicBeta = "prompt-caching-2024-07-31"` - `const AnthropicBetaComputerUse2024_10_22 AnthropicBeta = "computer-use-2024-10-22"` - `const AnthropicBetaComputerUse2025_01_24 AnthropicBeta = "computer-use-2025-01-24"` - `const AnthropicBetaPDFs2024_09_25 AnthropicBeta = "pdfs-2024-09-25"` - `const AnthropicBetaTokenCounting2024_11_01 AnthropicBeta = "token-counting-2024-11-01"` - `const AnthropicBetaTokenEfficientTools2025_02_19 AnthropicBeta = "token-efficient-tools-2025-02-19"` - `const AnthropicBetaOutput128k2025_02_19 AnthropicBeta = "output-128k-2025-02-19"` - `const AnthropicBetaFilesAPI2025_04_14 AnthropicBeta = "files-api-2025-04-14"` - `const AnthropicBetaMCPClient2025_04_04 AnthropicBeta = "mcp-client-2025-04-04"` - `const AnthropicBetaMCPClient2025_11_20 AnthropicBeta = "mcp-client-2025-11-20"` - `const AnthropicBetaDevFullThinking2025_05_14 AnthropicBeta = "dev-full-thinking-2025-05-14"` - `const AnthropicBetaInterleavedThinking2025_05_14 AnthropicBeta = "interleaved-thinking-2025-05-14"` - `const AnthropicBetaCodeExecution2025_05_22 AnthropicBeta = "code-execution-2025-05-22"` - `const AnthropicBetaExtendedCacheTTL2025_04_11 AnthropicBeta = "extended-cache-ttl-2025-04-11"` - `const AnthropicBetaContext1m2025_08_07 AnthropicBeta = "context-1m-2025-08-07"` - `const AnthropicBetaContextManagement2025_06_27 AnthropicBeta = "context-management-2025-06-27"` - `const AnthropicBetaModelContextWindowExceeded2025_08_26 AnthropicBeta = "model-context-window-exceeded-2025-08-26"` - `const AnthropicBetaSkills2025_10_02 AnthropicBeta = "skills-2025-10-02"` - `const AnthropicBetaFastMode2026_02_01 AnthropicBeta = "fast-mode-2026-02-01"` - `const AnthropicBetaOutput300k2026_03_24 AnthropicBeta = "output-300k-2026-03-24"` - `const AnthropicBetaUserProfiles2026_03_24 AnthropicBeta = "user-profiles-2026-03-24"` - `const AnthropicBetaUserProfiles2026_08_18 AnthropicBeta = "user-profiles-2026-08-18"` - `const AnthropicBetaUserProfiles2026_09_04 AnthropicBeta = "user-profiles-2026-09-04"` - `const AnthropicBetaAdvisorTool2026_03_01 AnthropicBeta = "advisor-tool-2026-03-01"` - `const AnthropicBetaManagedAgents2026_04_01 AnthropicBeta = "managed-agents-2026-04-01"` - `const AnthropicBetaCacheDiagnosis2026_04_07 AnthropicBeta = "cache-diagnosis-2026-04-07"` - `const AnthropicBetaDreaming2026_04_21 AnthropicBeta = "dreaming-2026-04-21"` - `const AnthropicBetaThinkingTokenCount2026_05_13 AnthropicBeta = "thinking-token-count-2026-05-13"` - `const AnthropicBetaServerSideFallback2026_06_01 AnthropicBeta = "server-side-fallback-2026-06-01"` - `const AnthropicBetaServerSideFallback2026_07_01 AnthropicBeta = "server-side-fallback-2026-07-01"` - `const AnthropicBetaFallbackCredit2026_06_01 AnthropicBeta = "fallback-credit-2026-06-01"` - `const AnthropicBetaFallbackCredit2026_07_01 AnthropicBeta = "fallback-credit-2026-07-01"` - `const AnthropicBetaAgentMemory2026_07_22 AnthropicBeta = "agent-memory-2026-07-22"` - `const AnthropicBetaMidConversationToolChanges2026_07_01 AnthropicBeta = "mid-conversation-tool-changes-2026-07-01"` - `const AnthropicBetaCompact2026_01_12 AnthropicBeta = "compact-2026-01-12"` - `const AnthropicBetaComputerUse2025_11_24 AnthropicBeta = "computer-use-2025-11-24"` - `const AnthropicBetaMCPTunnels2026_06_22 AnthropicBeta = "mcp-tunnels-2026-06-22"` - `const AnthropicBetaStructuredOutputs2025_11_13 AnthropicBeta = "structured-outputs-2025-11-13"` - `const AnthropicBetaTaskBudgets2026_03_13 AnthropicBeta = "task-budgets-2026-03-13"` - `const AnthropicBetaThinkingDisplayUpdates2026_08_18 AnthropicBeta = "thinking-display-updates-2026-08-18"` - `const AnthropicBetaCEUserManagement2026_07_13 AnthropicBeta = "ce-user-management-2026-07-13"` - `const AnthropicBetaMidConversationOutputConfig2026_07_01 AnthropicBeta = "mid-conversation-output-config-2026-07-01"` - `const AnthropicBetaThinkingBindingControls2026_08_01 AnthropicBeta = "thinking-binding-controls-2026-08-01"` - `const AnthropicBetaMidConversationSystemClearAt2026_08_21 AnthropicBeta = "mid-conversation-system-clear-at-2026-08-21"` - `const AnthropicBetaCompact2026_09_04 AnthropicBeta = "compact-2026-09-04"` - `const AnthropicBetaInlineTools2026_09_15 AnthropicBeta = "inline-tools-2026-09-15"` - `const AnthropicBetaMCPClient2026_09_15 AnthropicBeta = "mcp-client-2026-09-15"` - `const AnthropicBetaCEPlugins2026_09_01 AnthropicBeta = "ce-plugins-2026-09-01"` - `const AnthropicBetaSpendLimitReads2026_09_26 AnthropicBeta = "spend-limit-reads-2026-09-26"` - `const AnthropicBetaTelemetryDestinations2026_08_11 AnthropicBeta = "telemetry-destinations-2026-08-11"` - `WorkspaceID param.Opt[string] Optional` (header parameter) Optional header to select the Workspace for this request. The value is a Workspace ID (for example, `wrkspc_011CZkZaBF1tNoB5wlCeusgy`). Only needed for credentials that can act on more than one Workspace. A credential that belongs to a specific Workspace may omit it; if sent, it must match that Workspace. ### Returns - `type BetaModelInfo` - `Type Model` Object type. For Models, this is always `"model"`. default: model - `ID string` Unique model identifier. - `AllowedFallbackModels []string` Model IDs this model accepts as `fallbacks[i].model` on the Messages API. An empty list means the `fallbacks` parameter is not supported for this model as primary. - `Capabilities BetaModelCapabilities` Object mapping capability names to their support details. Keys are always present for all known capabilities. - `Batch BetaCapabilitySupport` Whether the model supports the Batch API. - `Supported bool` Whether this capability is supported by the model. - `Citations BetaCapabilitySupport` Whether the model supports citation generation. - `CodeExecution BetaCapabilitySupport` Whether code that the model runs in the code execution tool can call the request's other tools, as in programmatic tool calling and dynamic filtering for web search and web fetch. Support for the code execution tool itself is in `server_tools.code_execution`. - `Compaction BetaCompactionCapability` Server-side compaction support (the top-level `compaction` parameter) and the accepted `compaction.type` values. - `Summarize BetaCapabilitySupport` Whether the summarize compaction type is supported. - `Supported bool` Whether this capability is supported by the model. - `ContextManagement BetaContextManagementCapability` Context management support and available strategies. - `ClearThinking20251015 BetaCapabilitySupport` Whether the clear_thinking_20251015 strategy is supported. - `ClearToolUses20250919 BetaCapabilitySupport` Whether the clear_tool_uses_20250919 strategy is supported. - `Compact20260112 BetaCapabilitySupport` Whether the compact_20260112 strategy is supported. - `Supported bool` Whether this capability is supported by the model. - `Effort BetaEffortCapability` Effort (reasoning_effort) support and available levels. - `High BetaCapabilitySupport` Whether the model supports high effort level. - `Low BetaCapabilitySupport` Whether the model supports low effort level. - `Max BetaCapabilitySupport` Whether the model supports max effort level. - `Medium BetaCapabilitySupport` Whether the model supports medium effort level. - `Supported bool` Whether this capability is supported by the model. - `Xhigh BetaCapabilitySupport` Whether the model supports xhigh effort level. - `ImageInput BetaCapabilitySupport` Whether the model accepts image content blocks. - `PDFInput BetaCapabilitySupport` Whether the model accepts PDF content blocks. - `ServerTools BetaServerToolsCapability` Whether this model supports the web search and code execution server tools. `supported` is true when the model supports at least one of the tools. A supported tool can still be rejected for your organization, for example when an admin has turned web search off. - `CodeExecution BetaCapabilitySupport` Whether the model supports the code execution tool: true when the model supports at least one version of the tool, not necessarily every version. - `Supported bool` Whether this capability is supported by the model. - `WebSearch BetaCapabilitySupport` Whether the model supports the web search tool: true when the model supports at least one version of the tool, not necessarily every version. - `StructuredOutputs BetaCapabilitySupport` Whether the model supports structured output / JSON mode / strict tool schemas. - `Thinking BetaThinkingCapability` Thinking capability and supported type configurations. - `Supported bool` Whether this capability is supported by the model. - `Types BetaThinkingTypes` Supported thinking type configurations. - `Adaptive BetaCapabilitySupport` Whether the model accepts thinking with type 'adaptive' (the model decides whether and how much to think). - `Disabled BetaCapabilitySupport` Whether the model accepts thinking with type 'disabled' (thinking turned off). False exactly when a request that sends it gets a 400 from this model. True on a model that does not support thinking. - `Enabled BetaCapabilitySupport` Whether the model accepts thinking with type 'enabled' (extended thinking with a caller-set `budget_tokens`). - `CreatedAt Time` RFC 3339 datetime string representing the time at which the model was released. May be set to an epoch value if the release date is unknown. format: date-time - `DeprecatedAt Time` RFC 3339 datetime string representing the time of the model's most recent deprecation. Populated for `deprecated` and `retired` models; `null` while the model is `active`. format: date-time - `DisplayName string` A human-readable name for the model. - `Lifecycle BetaModelInfoLifecycle` The model's current lifecycle stage. - `active`: The model is available for use, open to new adopters, and not scheduled for retirement. - `deprecated`: The model remains callable for organizations with existing access, but is headed for retirement and closed to new adopters. - `retired`: The model is no longer available for use; inference requests naming it fail. It remains in the catalogue as the historical record of its retirement. default: active - `const BetaModelInfoLifecycleActive BetaModelInfoLifecycle = "active"` - `const BetaModelInfoLifecycleDeprecated BetaModelInfoLifecycle = "deprecated"` - `const BetaModelInfoLifecycleRetired BetaModelInfoLifecycle = "retired"` - `Line BetaModelLine` The model line this model belongs to, such as `opus` for both Claude Opus 4.5 and Claude Opus 4.6. More lines may be added. `null` when the model belongs to no line; do not infer a line from the `id`. - `const BetaModelLineHaiku BetaModelLine = "haiku"` - `const BetaModelLineSonnet BetaModelLine = "sonnet"` - `const BetaModelLineOpus BetaModelLine = "opus"` - `const BetaModelLineFable BetaModelLine = "fable"` - `const BetaModelLineMythos BetaModelLine = "mythos"` - `MaxInputTokens int64` Maximum input context window size in tokens for this model. - `MaxTokens int64` Maximum value for the `max_tokens` parameter when using this model. - `RetiresAt Time` RFC 3339 datetime string representing the model's currently scheduled retirement date. The schedule can be revised until retirement occurs; `null` while the model is `active` or while no retirement is scheduled. A past date on a `deprecated` model means retirement is overdue, not that it has occurred: `lifecycle` is the retirement signal. format: date-time ### Example ```go package main import ( "context" "fmt" "github.com/anthropics/anthropic-sdk-go" "github.com/anthropics/anthropic-sdk-go/option" ) func main() { client := anthropic.NewClient( option.WithAPIKey("my-anthropic-api-key"), ) page, err := client.Beta.Models.List(context.TODO(), anthropic.BetaModelListParams{}) if err != nil { panic(err.Error()) } fmt.Printf("%+v\n", page) } ``` #### Response (200) ```json { "data": [ { "id": "claude-opus-5-5", "allowed_fallback_models": [ "string" ], "capabilities": { "batch": { "supported": true }, "citations": { "supported": true }, "code_execution": { "supported": true }, "compaction": { "summarize": { "supported": true }, "supported": true }, "context_management": { "clear_thinking_20251015": { "supported": true }, "clear_tool_uses_20250919": { "supported": true }, "compact_20260112": { "supported": true }, "supported": true }, "effort": { "high": { "supported": true }, "low": { "supported": true }, "max": { "supported": true }, "medium": { "supported": true }, "supported": true, "xhigh": { "supported": true } }, "image_input": { "supported": true }, "pdf_input": { "supported": true }, "server_tools": { "code_execution": { "supported": true }, "supported": true, "web_search": { "supported": true } }, "structured_outputs": { "supported": true }, "thinking": { "supported": true, "types": { "adaptive": { "supported": true }, "disabled": { "supported": true }, "enabled": { "supported": true } } } }, "created_at": "2026-09-21T00:00:00Z", "deprecated_at": "2019-12-27T18:11:19.117Z", "display_name": "Claude Opus 5.5", "lifecycle": "active", "line": "haiku", "max_input_tokens": 0, "max_tokens": 0, "retires_at": "2019-12-27T18:11:19.117Z", "type": "model" } ], "first_id": "first_id", "has_more": true, "last_id": "last_id" } ``` ## Get a Model `client.Beta.Models.Get(ctx, modelID, query) (*BetaModelInfo, error)` **GET** `/v1/models/{model_id}` Get a specific model. The Models API response can be used to determine information about a specific model or resolve a model alias to a model ID. ### Parameters - `modelID string` (path parameter) Model identifier or alias. - `query BetaModelGetParams` - `Betas []AnthropicBeta Optional` (header parameter) Optional header to specify the beta version(s) you want to use. - `const AnthropicBetaMessageBatches2024_09_24 AnthropicBeta = "message-batches-2024-09-24"` - `const AnthropicBetaPromptCaching2024_07_31 AnthropicBeta = "prompt-caching-2024-07-31"` - `const AnthropicBetaComputerUse2024_10_22 AnthropicBeta = "computer-use-2024-10-22"` - `const AnthropicBetaComputerUse2025_01_24 AnthropicBeta = "computer-use-2025-01-24"` - `const AnthropicBetaPDFs2024_09_25 AnthropicBeta = "pdfs-2024-09-25"` - `const AnthropicBetaTokenCounting2024_11_01 AnthropicBeta = "token-counting-2024-11-01"` - `const AnthropicBetaTokenEfficientTools2025_02_19 AnthropicBeta = "token-efficient-tools-2025-02-19"` - `const AnthropicBetaOutput128k2025_02_19 AnthropicBeta = "output-128k-2025-02-19"` - `const AnthropicBetaFilesAPI2025_04_14 AnthropicBeta = "files-api-2025-04-14"` - `const AnthropicBetaMCPClient2025_04_04 AnthropicBeta = "mcp-client-2025-04-04"` - `const AnthropicBetaMCPClient2025_11_20 AnthropicBeta = "mcp-client-2025-11-20"` - `const AnthropicBetaDevFullThinking2025_05_14 AnthropicBeta = "dev-full-thinking-2025-05-14"` - `const AnthropicBetaInterleavedThinking2025_05_14 AnthropicBeta = "interleaved-thinking-2025-05-14"` - `const AnthropicBetaCodeExecution2025_05_22 AnthropicBeta = "code-execution-2025-05-22"` - `const AnthropicBetaExtendedCacheTTL2025_04_11 AnthropicBeta = "extended-cache-ttl-2025-04-11"` - `const AnthropicBetaContext1m2025_08_07 AnthropicBeta = "context-1m-2025-08-07"` - `const AnthropicBetaContextManagement2025_06_27 AnthropicBeta = "context-management-2025-06-27"` - `const AnthropicBetaModelContextWindowExceeded2025_08_26 AnthropicBeta = "model-context-window-exceeded-2025-08-26"` - `const AnthropicBetaSkills2025_10_02 AnthropicBeta = "skills-2025-10-02"` - `const AnthropicBetaFastMode2026_02_01 AnthropicBeta = "fast-mode-2026-02-01"` - `const AnthropicBetaOutput300k2026_03_24 AnthropicBeta = "output-300k-2026-03-24"` - `const AnthropicBetaUserProfiles2026_03_24 AnthropicBeta = "user-profiles-2026-03-24"` - `const AnthropicBetaUserProfiles2026_08_18 AnthropicBeta = "user-profiles-2026-08-18"` - `const AnthropicBetaUserProfiles2026_09_04 AnthropicBeta = "user-profiles-2026-09-04"` - `const AnthropicBetaAdvisorTool2026_03_01 AnthropicBeta = "advisor-tool-2026-03-01"` - `const AnthropicBetaManagedAgents2026_04_01 AnthropicBeta = "managed-agents-2026-04-01"` - `const AnthropicBetaCacheDiagnosis2026_04_07 AnthropicBeta = "cache-diagnosis-2026-04-07"` - `const AnthropicBetaDreaming2026_04_21 AnthropicBeta = "dreaming-2026-04-21"` - `const AnthropicBetaThinkingTokenCount2026_05_13 AnthropicBeta = "thinking-token-count-2026-05-13"` - `const AnthropicBetaServerSideFallback2026_06_01 AnthropicBeta = "server-side-fallback-2026-06-01"` - `const AnthropicBetaServerSideFallback2026_07_01 AnthropicBeta = "server-side-fallback-2026-07-01"` - `const AnthropicBetaFallbackCredit2026_06_01 AnthropicBeta = "fallback-credit-2026-06-01"` - `const AnthropicBetaFallbackCredit2026_07_01 AnthropicBeta = "fallback-credit-2026-07-01"` - `const AnthropicBetaAgentMemory2026_07_22 AnthropicBeta = "agent-memory-2026-07-22"` - `const AnthropicBetaMidConversationToolChanges2026_07_01 AnthropicBeta = "mid-conversation-tool-changes-2026-07-01"` - `const AnthropicBetaCompact2026_01_12 AnthropicBeta = "compact-2026-01-12"` - `const AnthropicBetaComputerUse2025_11_24 AnthropicBeta = "computer-use-2025-11-24"` - `const AnthropicBetaMCPTunnels2026_06_22 AnthropicBeta = "mcp-tunnels-2026-06-22"` - `const AnthropicBetaStructuredOutputs2025_11_13 AnthropicBeta = "structured-outputs-2025-11-13"` - `const AnthropicBetaTaskBudgets2026_03_13 AnthropicBeta = "task-budgets-2026-03-13"` - `const AnthropicBetaThinkingDisplayUpdates2026_08_18 AnthropicBeta = "thinking-display-updates-2026-08-18"` - `const AnthropicBetaCEUserManagement2026_07_13 AnthropicBeta = "ce-user-management-2026-07-13"` - `const AnthropicBetaMidConversationOutputConfig2026_07_01 AnthropicBeta = "mid-conversation-output-config-2026-07-01"` - `const AnthropicBetaThinkingBindingControls2026_08_01 AnthropicBeta = "thinking-binding-controls-2026-08-01"` - `const AnthropicBetaMidConversationSystemClearAt2026_08_21 AnthropicBeta = "mid-conversation-system-clear-at-2026-08-21"` - `const AnthropicBetaCompact2026_09_04 AnthropicBeta = "compact-2026-09-04"` - `const AnthropicBetaInlineTools2026_09_15 AnthropicBeta = "inline-tools-2026-09-15"` - `const AnthropicBetaMCPClient2026_09_15 AnthropicBeta = "mcp-client-2026-09-15"` - `const AnthropicBetaCEPlugins2026_09_01 AnthropicBeta = "ce-plugins-2026-09-01"` - `const AnthropicBetaSpendLimitReads2026_09_26 AnthropicBeta = "spend-limit-reads-2026-09-26"` - `const AnthropicBetaTelemetryDestinations2026_08_11 AnthropicBeta = "telemetry-destinations-2026-08-11"` - `WorkspaceID param.Opt[string] Optional` (header parameter) Optional header to select the Workspace for this request. The value is a Workspace ID (for example, `wrkspc_011CZkZaBF1tNoB5wlCeusgy`). Only needed for credentials that can act on more than one Workspace. A credential that belongs to a specific Workspace may omit it; if sent, it must match that Workspace. ### Returns - `type BetaModelInfo` - `Type Model` Object type. For Models, this is always `"model"`. default: model - `ID string` Unique model identifier. - `AllowedFallbackModels []string` Model IDs this model accepts as `fallbacks[i].model` on the Messages API. An empty list means the `fallbacks` parameter is not supported for this model as primary. - `Capabilities BetaModelCapabilities` Object mapping capability names to their support details. Keys are always present for all known capabilities. - `Batch BetaCapabilitySupport` Whether the model supports the Batch API. - `Supported bool` Whether this capability is supported by the model. - `Citations BetaCapabilitySupport` Whether the model supports citation generation. - `CodeExecution BetaCapabilitySupport` Whether code that the model runs in the code execution tool can call the request's other tools, as in programmatic tool calling and dynamic filtering for web search and web fetch. Support for the code execution tool itself is in `server_tools.code_execution`. - `Compaction BetaCompactionCapability` Server-side compaction support (the top-level `compaction` parameter) and the accepted `compaction.type` values. - `Summarize BetaCapabilitySupport` Whether the summarize compaction type is supported. - `Supported bool` Whether this capability is supported by the model. - `ContextManagement BetaContextManagementCapability` Context management support and available strategies. - `ClearThinking20251015 BetaCapabilitySupport` Whether the clear_thinking_20251015 strategy is supported. - `ClearToolUses20250919 BetaCapabilitySupport` Whether the clear_tool_uses_20250919 strategy is supported. - `Compact20260112 BetaCapabilitySupport` Whether the compact_20260112 strategy is supported. - `Supported bool` Whether this capability is supported by the model. - `Effort BetaEffortCapability` Effort (reasoning_effort) support and available levels. - `High BetaCapabilitySupport` Whether the model supports high effort level. - `Low BetaCapabilitySupport` Whether the model supports low effort level. - `Max BetaCapabilitySupport` Whether the model supports max effort level. - `Medium BetaCapabilitySupport` Whether the model supports medium effort level. - `Supported bool` Whether this capability is supported by the model. - `Xhigh BetaCapabilitySupport` Whether the model supports xhigh effort level. - `ImageInput BetaCapabilitySupport` Whether the model accepts image content blocks. - `PDFInput BetaCapabilitySupport` Whether the model accepts PDF content blocks. - `ServerTools BetaServerToolsCapability` Whether this model supports the web search and code execution server tools. `supported` is true when the model supports at least one of the tools. A supported tool can still be rejected for your organization, for example when an admin has turned web search off. - `CodeExecution BetaCapabilitySupport` Whether the model supports the code execution tool: true when the model supports at least one version of the tool, not necessarily every version. - `Supported bool` Whether this capability is supported by the model. - `WebSearch BetaCapabilitySupport` Whether the model supports the web search tool: true when the model supports at least one version of the tool, not necessarily every version. - `StructuredOutputs BetaCapabilitySupport` Whether the model supports structured output / JSON mode / strict tool schemas. - `Thinking BetaThinkingCapability` Thinking capability and supported type configurations. - `Supported bool` Whether this capability is supported by the model. - `Types BetaThinkingTypes` Supported thinking type configurations. - `Adaptive BetaCapabilitySupport` Whether the model accepts thinking with type 'adaptive' (the model decides whether and how much to think). - `Disabled BetaCapabilitySupport` Whether the model accepts thinking with type 'disabled' (thinking turned off). False exactly when a request that sends it gets a 400 from this model. True on a model that does not support thinking. - `Enabled BetaCapabilitySupport` Whether the model accepts thinking with type 'enabled' (extended thinking with a caller-set `budget_tokens`). - `CreatedAt Time` RFC 3339 datetime string representing the time at which the model was released. May be set to an epoch value if the release date is unknown. format: date-time - `DeprecatedAt Time` RFC 3339 datetime string representing the time of the model's most recent deprecation. Populated for `deprecated` and `retired` models; `null` while the model is `active`. format: date-time - `DisplayName string` A human-readable name for the model. - `Lifecycle BetaModelInfoLifecycle` The model's current lifecycle stage. - `active`: The model is available for use, open to new adopters, and not scheduled for retirement. - `deprecated`: The model remains callable for organizations with existing access, but is headed for retirement and closed to new adopters. - `retired`: The model is no longer available for use; inference requests naming it fail. It remains in the catalogue as the historical record of its retirement. default: active - `const BetaModelInfoLifecycleActive BetaModelInfoLifecycle = "active"` - `const BetaModelInfoLifecycleDeprecated BetaModelInfoLifecycle = "deprecated"` - `const BetaModelInfoLifecycleRetired BetaModelInfoLifecycle = "retired"` - `Line BetaModelLine` The model line this model belongs to, such as `opus` for both Claude Opus 4.5 and Claude Opus 4.6. More lines may be added. `null` when the model belongs to no line; do not infer a line from the `id`. - `const BetaModelLineHaiku BetaModelLine = "haiku"` - `const BetaModelLineSonnet BetaModelLine = "sonnet"` - `const BetaModelLineOpus BetaModelLine = "opus"` - `const BetaModelLineFable BetaModelLine = "fable"` - `const BetaModelLineMythos BetaModelLine = "mythos"` - `MaxInputTokens int64` Maximum input context window size in tokens for this model. - `MaxTokens int64` Maximum value for the `max_tokens` parameter when using this model. - `RetiresAt Time` RFC 3339 datetime string representing the model's currently scheduled retirement date. The schedule can be revised until retirement occurs; `null` while the model is `active` or while no retirement is scheduled. A past date on a `deprecated` model means retirement is overdue, not that it has occurred: `lifecycle` is the retirement signal. format: date-time ### Example ```go package main import ( "context" "fmt" "github.com/anthropics/anthropic-sdk-go" "github.com/anthropics/anthropic-sdk-go/option" ) func main() { client := anthropic.NewClient( option.WithAPIKey("my-anthropic-api-key"), ) betaModelInfo, err := client.Beta.Models.Get( context.TODO(), "model_id", anthropic.BetaModelGetParams{}, ) if err != nil { panic(err.Error()) } fmt.Printf("%+v\n", betaModelInfo.ID) } ``` #### Response (200) ```json { "id": "claude-opus-5-5", "allowed_fallback_models": [ "string" ], "capabilities": { "batch": { "supported": true }, "citations": { "supported": true }, "code_execution": { "supported": true }, "compaction": { "summarize": { "supported": true }, "supported": true }, "context_management": { "clear_thinking_20251015": { "supported": true }, "clear_tool_uses_20250919": { "supported": true }, "compact_20260112": { "supported": true }, "supported": true }, "effort": { "high": { "supported": true }, "low": { "supported": true }, "max": { "supported": true }, "medium": { "supported": true }, "supported": true, "xhigh": { "supported": true } }, "image_input": { "supported": true }, "pdf_input": { "supported": true }, "server_tools": { "code_execution": { "supported": true }, "supported": true, "web_search": { "supported": true } }, "structured_outputs": { "supported": true }, "thinking": { "supported": true, "types": { "adaptive": { "supported": true }, "disabled": { "supported": true }, "enabled": { "supported": true } } } }, "created_at": "2026-09-21T00:00:00Z", "deprecated_at": "2019-12-27T18:11:19.117Z", "display_name": "Claude Opus 5.5", "lifecycle": "active", "line": "haiku", "max_input_tokens": 0, "max_tokens": 0, "retires_at": "2019-12-27T18:11:19.117Z", "type": "model" } ``` ## Domain types ### Beta Capability Support - `type BetaCapabilitySupport` Indicates whether a capability is supported. - `Supported bool` Whether this capability is supported by the model. ### Beta Compaction Capability - `type BetaCompactionCapability` Compaction capability details: whether the model accepts the top-level `compaction` request parameter, with one entry per supported `compaction.type` value. - `Summarize BetaCapabilitySupport` Whether the summarize compaction type is supported. - `Supported bool` Whether this capability is supported by the model. - `Supported bool` Whether this capability is supported by the model. ### Beta Context Management Capability - `type BetaContextManagementCapability` Context management capability details. - `ClearThinking20251015 BetaCapabilitySupport` Whether the clear_thinking_20251015 strategy is supported. - `Supported bool` Whether this capability is supported by the model. - `ClearToolUses20250919 BetaCapabilitySupport` Whether the clear_tool_uses_20250919 strategy is supported. - `Compact20260112 BetaCapabilitySupport` Whether the compact_20260112 strategy is supported. - `Supported bool` Whether this capability is supported by the model. ### Beta Effort Capability - `type BetaEffortCapability` Effort (reasoning_effort) capability details. - `High BetaCapabilitySupport` Whether the model supports high effort level. - `Supported bool` Whether this capability is supported by the model. - `Low BetaCapabilitySupport` Whether the model supports low effort level. - `Max BetaCapabilitySupport` Whether the model supports max effort level. - `Medium BetaCapabilitySupport` Whether the model supports medium effort level. - `Supported bool` Whether this capability is supported by the model. - `Xhigh BetaCapabilitySupport` Whether the model supports xhigh effort level. ### Beta Model Capabilities - `type BetaModelCapabilities` Model capability information. - `Batch BetaCapabilitySupport` Whether the model supports the Batch API. - `Supported bool` Whether this capability is supported by the model. - `Citations BetaCapabilitySupport` Whether the model supports citation generation. - `CodeExecution BetaCapabilitySupport` Whether code that the model runs in the code execution tool can call the request's other tools, as in programmatic tool calling and dynamic filtering for web search and web fetch. Support for the code execution tool itself is in `server_tools.code_execution`. - `Compaction BetaCompactionCapability` Server-side compaction support (the top-level `compaction` parameter) and the accepted `compaction.type` values. - `Summarize BetaCapabilitySupport` Whether the summarize compaction type is supported. - `Supported bool` Whether this capability is supported by the model. - `ContextManagement BetaContextManagementCapability` Context management support and available strategies. - `ClearThinking20251015 BetaCapabilitySupport` Whether the clear_thinking_20251015 strategy is supported. - `ClearToolUses20250919 BetaCapabilitySupport` Whether the clear_tool_uses_20250919 strategy is supported. - `Compact20260112 BetaCapabilitySupport` Whether the compact_20260112 strategy is supported. - `Supported bool` Whether this capability is supported by the model. - `Effort BetaEffortCapability` Effort (reasoning_effort) support and available levels. - `High BetaCapabilitySupport` Whether the model supports high effort level. - `Low BetaCapabilitySupport` Whether the model supports low effort level. - `Max BetaCapabilitySupport` Whether the model supports max effort level. - `Medium BetaCapabilitySupport` Whether the model supports medium effort level. - `Supported bool` Whether this capability is supported by the model. - `Xhigh BetaCapabilitySupport` Whether the model supports xhigh effort level. - `ImageInput BetaCapabilitySupport` Whether the model accepts image content blocks. - `PDFInput BetaCapabilitySupport` Whether the model accepts PDF content blocks. - `ServerTools BetaServerToolsCapability` Whether this model supports the web search and code execution server tools. `supported` is true when the model supports at least one of the tools. A supported tool can still be rejected for your organization, for example when an admin has turned web search off. - `CodeExecution BetaCapabilitySupport` Whether the model supports the code execution tool: true when the model supports at least one version of the tool, not necessarily every version. - `Supported bool` Whether this capability is supported by the model. - `WebSearch BetaCapabilitySupport` Whether the model supports the web search tool: true when the model supports at least one version of the tool, not necessarily every version. - `StructuredOutputs BetaCapabilitySupport` Whether the model supports structured output / JSON mode / strict tool schemas. - `Thinking BetaThinkingCapability` Thinking capability and supported type configurations. - `Supported bool` Whether this capability is supported by the model. - `Types BetaThinkingTypes` Supported thinking type configurations. - `Adaptive BetaCapabilitySupport` Whether the model accepts thinking with type 'adaptive' (the model decides whether and how much to think). - `Disabled BetaCapabilitySupport` Whether the model accepts thinking with type 'disabled' (thinking turned off). False exactly when a request that sends it gets a 400 from this model. True on a model that does not support thinking. - `Enabled BetaCapabilitySupport` Whether the model accepts thinking with type 'enabled' (extended thinking with a caller-set `budget_tokens`). ### Beta Model Info - `type BetaModelInfo` - `Type Model` Object type. For Models, this is always `"model"`. default: model - `ID string` Unique model identifier. - `AllowedFallbackModels []string` Model IDs this model accepts as `fallbacks[i].model` on the Messages API. An empty list means the `fallbacks` parameter is not supported for this model as primary. - `Capabilities BetaModelCapabilities` Object mapping capability names to their support details. Keys are always present for all known capabilities. - `Batch BetaCapabilitySupport` Whether the model supports the Batch API. - `Supported bool` Whether this capability is supported by the model. - `Citations BetaCapabilitySupport` Whether the model supports citation generation. - `CodeExecution BetaCapabilitySupport` Whether code that the model runs in the code execution tool can call the request's other tools, as in programmatic tool calling and dynamic filtering for web search and web fetch. Support for the code execution tool itself is in `server_tools.code_execution`. - `Compaction BetaCompactionCapability` Server-side compaction support (the top-level `compaction` parameter) and the accepted `compaction.type` values. - `Summarize BetaCapabilitySupport` Whether the summarize compaction type is supported. - `Supported bool` Whether this capability is supported by the model. - `ContextManagement BetaContextManagementCapability` Context management support and available strategies. - `ClearThinking20251015 BetaCapabilitySupport` Whether the clear_thinking_20251015 strategy is supported. - `ClearToolUses20250919 BetaCapabilitySupport` Whether the clear_tool_uses_20250919 strategy is supported. - `Compact20260112 BetaCapabilitySupport` Whether the compact_20260112 strategy is supported. - `Supported bool` Whether this capability is supported by the model. - `Effort BetaEffortCapability` Effort (reasoning_effort) support and available levels. - `High BetaCapabilitySupport` Whether the model supports high effort level. - `Low BetaCapabilitySupport` Whether the model supports low effort level. - `Max BetaCapabilitySupport` Whether the model supports max effort level. - `Medium BetaCapabilitySupport` Whether the model supports medium effort level. - `Supported bool` Whether this capability is supported by the model. - `Xhigh BetaCapabilitySupport` Whether the model supports xhigh effort level. - `ImageInput BetaCapabilitySupport` Whether the model accepts image content blocks. - `PDFInput BetaCapabilitySupport` Whether the model accepts PDF content blocks. - `ServerTools BetaServerToolsCapability` Whether this model supports the web search and code execution server tools. `supported` is true when the model supports at least one of the tools. A supported tool can still be rejected for your organization, for example when an admin has turned web search off. - `CodeExecution BetaCapabilitySupport` Whether the model supports the code execution tool: true when the model supports at least one version of the tool, not necessarily every version. - `Supported bool` Whether this capability is supported by the model. - `WebSearch BetaCapabilitySupport` Whether the model supports the web search tool: true when the model supports at least one version of the tool, not necessarily every version. - `StructuredOutputs BetaCapabilitySupport` Whether the model supports structured output / JSON mode / strict tool schemas. - `Thinking BetaThinkingCapability` Thinking capability and supported type configurations. - `Supported bool` Whether this capability is supported by the model. - `Types BetaThinkingTypes` Supported thinking type configurations. - `Adaptive BetaCapabilitySupport` Whether the model accepts thinking with type 'adaptive' (the model decides whether and how much to think). - `Disabled BetaCapabilitySupport` Whether the model accepts thinking with type 'disabled' (thinking turned off). False exactly when a request that sends it gets a 400 from this model. True on a model that does not support thinking. - `Enabled BetaCapabilitySupport` Whether the model accepts thinking with type 'enabled' (extended thinking with a caller-set `budget_tokens`). - `CreatedAt Time` RFC 3339 datetime string representing the time at which the model was released. May be set to an epoch value if the release date is unknown. format: date-time - `DeprecatedAt Time` RFC 3339 datetime string representing the time of the model's most recent deprecation. Populated for `deprecated` and `retired` models; `null` while the model is `active`. format: date-time - `DisplayName string` A human-readable name for the model. - `Lifecycle BetaModelInfoLifecycle` The model's current lifecycle stage. - `active`: The model is available for use, open to new adopters, and not scheduled for retirement. - `deprecated`: The model remains callable for organizations with existing access, but is headed for retirement and closed to new adopters. - `retired`: The model is no longer available for use; inference requests naming it fail. It remains in the catalogue as the historical record of its retirement. default: active - `const BetaModelInfoLifecycleActive BetaModelInfoLifecycle = "active"` - `const BetaModelInfoLifecycleDeprecated BetaModelInfoLifecycle = "deprecated"` - `const BetaModelInfoLifecycleRetired BetaModelInfoLifecycle = "retired"` - `Line BetaModelLine` The model line this model belongs to, such as `opus` for both Claude Opus 4.5 and Claude Opus 4.6. More lines may be added. `null` when the model belongs to no line; do not infer a line from the `id`. - `const BetaModelLineHaiku BetaModelLine = "haiku"` - `const BetaModelLineSonnet BetaModelLine = "sonnet"` - `const BetaModelLineOpus BetaModelLine = "opus"` - `const BetaModelLineFable BetaModelLine = "fable"` - `const BetaModelLineMythos BetaModelLine = "mythos"` - `MaxInputTokens int64` Maximum input context window size in tokens for this model. - `MaxTokens int64` Maximum value for the `max_tokens` parameter when using this model. - `RetiresAt Time` RFC 3339 datetime string representing the model's currently scheduled retirement date. The schedule can be revised until retirement occurs; `null` while the model is `active` or while no retirement is scheduled. A past date on a `deprecated` model means retirement is overdue, not that it has occurred: `lifecycle` is the retirement signal. format: date-time ### Beta Model Line - `type BetaModelLine string` A Claude model line, such as `opus` or `sonnet`. More lines may be added as new values. - `const BetaModelLineHaiku BetaModelLine = "haiku"` - `const BetaModelLineSonnet BetaModelLine = "sonnet"` - `const BetaModelLineOpus BetaModelLine = "opus"` - `const BetaModelLineFable BetaModelLine = "fable"` - `const BetaModelLineMythos BetaModelLine = "mythos"` ### Beta Server Tools Capability - `type BetaServerToolsCapability` Web search and code execution tool support, with one entry per tool. - `CodeExecution BetaCapabilitySupport` Whether the model supports the code execution tool: true when the model supports at least one version of the tool, not necessarily every version. - `Supported bool` Whether this capability is supported by the model. - `Supported bool` Whether this capability is supported by the model. - `WebSearch BetaCapabilitySupport` Whether the model supports the web search tool: true when the model supports at least one version of the tool, not necessarily every version. ### Beta Thinking Capability - `type BetaThinkingCapability` Thinking capability details. - `Supported bool` Whether this capability is supported by the model. - `Types BetaThinkingTypes` Supported thinking type configurations. - `Adaptive BetaCapabilitySupport` Whether the model accepts thinking with type 'adaptive' (the model decides whether and how much to think). - `Supported bool` Whether this capability is supported by the model. - `Disabled BetaCapabilitySupport` Whether the model accepts thinking with type 'disabled' (thinking turned off). False exactly when a request that sends it gets a 400 from this model. True on a model that does not support thinking. - `Enabled BetaCapabilitySupport` Whether the model accepts thinking with type 'enabled' (extended thinking with a caller-set `budget_tokens`). ### Beta Thinking Types - `type BetaThinkingTypes` Which `thinking.type` values the model accepts on requests. Read each key on its own: for example, `enabled` can be false while `disabled` is true. - `Adaptive BetaCapabilitySupport` Whether the model accepts thinking with type 'adaptive' (the model decides whether and how much to think). - `Supported bool` Whether this capability is supported by the model. - `Disabled BetaCapabilitySupport` Whether the model accepts thinking with type 'disabled' (thinking turned off). False exactly when a request that sends it gets a 400 from this model. True on a model that does not support thinking. - `Enabled BetaCapabilitySupport` Whether the model accepts thinking with type 'enabled' (extended thinking with a caller-set `budget_tokens`).