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.Field[string] Optional

Query param: ID of the object to use as a cursor for pagination. When provided, returns the page of results immediately after this object.

BeforeID param.Field[string] Optional

Query param: ID of the object to use as a cursor for pagination. When provided, returns the page of results immediately before this object.

Limit param.Field[int64] Optional

Query param: Number of items to return per page.

Defaults to 20. Ranges from 1 to 1000.

maximum1000

minimum1

Betas param.Field[[]AnthropicBeta] Optional

Header param: Optional header to specify the beta version(s) you want to use.

string

type AnthropicBeta string

One of the following:

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 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"

Returns

type BetaModelInfo struct{…}

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

Model capability information.

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.

formatdate-time

DisplayName string

A human-readable name for the model.

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.

Type Model

Object type.

For Models, this is always "model".

defaultmodel

List Models

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)
}

{
  "data": [
    {
      "id": "claude-opus-5",
      "allowed_fallback_models": [
        "string"
      ],
      "capabilities": {
        "batch": {
          "supported": true
        },
        "citations": {
          "supported": true
        },
        "code_execution": {
          "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
        },
        "structured_outputs": {
          "supported": true
        },
        "thinking": {
          "supported": true,
          "types": {
            "adaptive": {
              "supported": true
            },
            "enabled": {
              "supported": true
            }
          }
        }
      },
      "created_at": "2026-07-24T00:00:00Z",
      "display_name": "Claude Opus 5",
      "max_input_tokens": 0,
      "max_tokens": 0,
      "type": "model"
    }
  ],
  "first_id": "first_id",
  "has_more": true,
  "last_id": "last_id"
}

Returns Examples

{
  "data": [
    {
      "id": "claude-opus-5",
      "allowed_fallback_models": [
        "string"
      ],
      "capabilities": {
        "batch": {
          "supported": true
        },
        "citations": {
          "supported": true
        },
        "code_execution": {
          "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
        },
        "structured_outputs": {
          "supported": true
        },
        "thinking": {
          "supported": true,
          "types": {
            "adaptive": {
              "supported": true
            },
            "enabled": {
              "supported": true
            }
          }
        }
      },
      "created_at": "2026-07-24T00:00:00Z",
      "display_name": "Claude Opus 5",
      "max_input_tokens": 0,
      "max_tokens": 0,
      "type": "model"
    }
  ],
  "first_id": "first_id",
  "has_more": true,
  "last_id": "last_id"
}