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Models and Providers

Claude Code has a built-in list of 22 models. It also knows the model names of each cloud provider, and a set of short aliases such as opus. You choose a model with a flag, an environment variable, a setting, or the /model command. This page lists every model, alias, and provider switch. For how the choice is made at run time, read Models.

At a Glance​

QuestionAnswer
Can you use it?✅ Yes. Run claude --model opus or type /model in a session.
Can you change it?✅ Yes. Use --model, ANTHROPIC_MODEL, ANTHROPIC_DEFAULT_*_MODEL, or the model and modelOverrides settings.
Can you turn it on or off?Pick a provider with CLAUDE_CODE_USE_BEDROCK and its siblings. Limit choices with availableModels.
Where does it live?~/.claude/settings.json (user), .claude/settings.json (project), managed settings, and your shell environment.
StatusDocumented Undocumented

Choose a Model​

The list runs from highest to lowest priority. Source: Model Configuration: Setting Your Model.

ItemStatusWhat it does
/model <alias|name>DocumentedSwitches now. With no argument it opens the picker. Enter saves your choice as the default. s switches for this session only.
--model <model>DocumentedSets the model for one session.
ANTHROPIC_MODELDocumentedSets the model with the same values as --model.
modelDocumentedThe settings key that stores the default.
ANTHROPIC_DEFAULT_MODELDocumentedSets the default for new sessions.
availableModelsDocumentedAn allowlist in managed settings. It limits /model, --model, the env vars, and alias resolution. Entries can be a family (sonnet), a version prefix (claude-sonnet-4-5), or a full ID.
modelOverridesDocumentedMaps an Anthropic model ID to the provider string Claude Code sends, such as a Bedrock inference profile ARN.
modelPickerDocumentedLists your own rows for the /model picker, in your order and labels.
ANTHROPIC_CUSTOM_MODEL_OPTIONDocumentedAdds one custom entry to the picker. The ID is not validated. Add _NAME and _DESCRIPTION for a label.
CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERYDocumentedFills the picker from the gateway /v1/models endpoint. Off by default.
CLAUDE_CODE_GATEWAY_MODEL_DISCOVERY_TIMEOUT_MSDocumentedTimeout of that request. Default 3000.
CLAUDE_CODE_SUBAGENT_MODELDocumentedThe default model for subagents, teammates, and workflow agents with no model set.
--include-unsupported-modelsUndocumentedOffers models your account can use that this version does not know.
PreModelSwitch, PostModelSwitch hooksDocumentedRun around a switch. PreModelSwitch can block it.

Aliases​

An alias is a short name for the newest model of a family. The catalog holds opus, sonnet, haiku, and fable. The help text of --model names fable, opus, and sonnet.

AliasStatusResolves toExceptions
defaultDocumentedClears the override. The model is the runtime default for your account.Not an alias in the strict sense.
opusDocumentedclaude-opus-5-5Foundry uses claude-opus-4-6. Gateways use claude-opus-4-7.
sonnetDocumentedclaude-sonnet-5-5Bedrock, Vertex, Foundry, and Mantle use claude-sonnet-4-5. Claude Platform on AWS and gateways use claude-sonnet-4-6.
haikuDocumentedclaude-haiku-5-5Every other provider uses claude-haiku-4-5.
fableDocumentedclaude-fable-5-1Gateways use claude-fable-5. In Claude apps gateway sessions, fable and best resolve to Fable 5.
bestDocumentedThe model fable resolves to, where you have Fable. Otherwise the same as opus.
opusplanDocumentedopus in plan mode, then sonnet to run the plan.
sonnet[1m], opus[1m], fable[1m]DocumentedThe alias with a 1M window.No effect when the alias already has a native 1M window.

Sources: Model Configuration for the aliases, and the program for the exceptions. Opus 5.5 needs Claude Code v2.1.280 or later, Sonnet 5.5 needs v2.1.284, Haiku 5.5 needs v2.1.293, and Fable 5.1 needs v2.1.257.

Pin the Models Behind an Alias​

Environment variableStatusEffect
ANTHROPIC_DEFAULT_OPUS_MODELDocumentedThe model for opus, and for opusplan in plan mode.
ANTHROPIC_DEFAULT_SONNET_MODELDocumentedThe model for sonnet, and for opusplan outside plan mode.
ANTHROPIC_DEFAULT_HAIKU_MODELDocumentedThe model for haiku and for background work.
ANTHROPIC_DEFAULT_FABLE_MODELDocumentedThe model for fable. It also marks the ID as a Fable model for fallback.
⛔ ANTHROPIC_SMALL_FAST_MODELDocumentedDeprecated. Use ANTHROPIC_DEFAULT_HAIKU_MODEL.
ANTHROPIC_DEFAULT_<FAMILY>_MODEL_NAMEDocumentedThe display name of the pinned model in the picker. Works on third-party providers and gateways.
ANTHROPIC_DEFAULT_<FAMILY>_MODEL_DESCRIPTIONDocumentedThe description in the picker.
ANTHROPIC_DEFAULT_<FAMILY>_MODEL_SUPPORTED_CAPABILITIESDocumentedA comma list that tells Claude Code what the pinned model supports. Values: effort, xhigh_effort, max_effort, thinking, adaptive_thinking, interleaved_thinking.

<FAMILY> is OPUS, SONNET, HAIKU, or FABLE. The _NAME, _DESCRIPTION, and _SUPPORTED_CAPABILITIES suffixes also work with ANTHROPIC_CUSTOM_MODEL_OPTION. Pin versions before you roll Claude Code out on a third-party provider, because the alias default can lag the newest model. A native 1M model runs with 1M with no suffix when the pinned ID contains its Anthropic API ID. For a model that reaches 1M through [1m] (Opus 4.6, Sonnet 4.6), add [1m] to the variable.

Catalog​

The catalog is a JavaScript object in the program with the comment Hand-maintained baked-in model catalog. It holds the provider names, the window, the output limits, the price, and the capability flags of each model. A row is Documented when an official docs page names the model. It is Undocumented when no page names it. The docs do not list the catalog fields, so the window, the limits, and the prices are program facts for all rows.

"Larger window" says how to get a bigger one: native 1M means the model has 1M already, context-1m is the beta that asks the API for it, and [1m] is the suffix for --model. "Output" shows the default and the highest output limit in tokens. "Price" shows dollars for one million input and output tokens.

idStatusNameKnowledge cutoffWindowLarger windowOutputDefault effortPrice
claude-3-5-haikuUndocumentedHaiku 3.5-not set-8,192 / 8,192-$0.8 / $4
claude-haiku-4-5DocumentedHaiku 4.5February 2025200,000[1m] suffix32,000 / 64,000-$1 / $5
claude-haiku-5-5DocumentedHaiku 5.5June 20261,000,000native 1M, context-1m128,000 / 128,000medium$0.1 / $0.5
claude-3-5-sonnetUndocumentedSonnet 3.5-not set-8,192 / 8,192-$3 / $15
claude-3-7-sonnetUndocumentedSonnet 3.7-not set-32,000 / 64,000-$3 / $15
claude-sonnet-4-0UndocumentedSonnet 4January 2025200,000context-1m, [1m]32,000 / 64,000-$3 / $15
claude-sonnet-4-5DocumentedSonnet 4.5January 2025200,000context-1m, [1m]32,000 / 64,000-$3 / $15
claude-sonnet-4-6DocumentedSonnet 4.6August 2025200,000context-1m, [1m]32,000 / 128,000-$3 / $15
claude-sonnet-5DocumentedSonnet 5January 20261,000,000native 1M, context-1m64,000 / 128,000high$2 / $10
claude-sonnet-5-5DocumentedSonnet 5.5June 20261,000,000native 1M, context-1m128,000 / 128,000medium$2 / $10
claude-opus-4-0UndocumentedOpus 4January 2025200,000[1m] suffix32,000 / 32,000-$15 / $75
claude-opus-4-1DocumentedOpus 4.1January 2025200,000[1m] suffix32,000 / 32,000-$15 / $75
claude-opus-4-5DocumentedOpus 4.5May 2025200,000[1m] suffix32,000 / 64,000-$5 / $25
claude-opus-4-6DocumentedOpus 4.6May 2025200,000context-1m, [1m]64,000 / 128,000-$5 / $25
claude-opus-4-7DocumentedOpus 4.7January 20261,000,000native 1M, context-1m, [1m]64,000 / 128,000xhigh$5 / $25
claude-opus-4-8DocumentedOpus 4.8January 20261,000,000native 1M, context-1m, [1m]64,000 / 128,000high$5 / $25
claude-opus-5DocumentedOpus 5May 20261,000,000native 1M, context-1m, [1m]64,000 / 128,000high$5 / $25
claude-opus-5-5DocumentedOpus 5.5June 20261,000,000native 1M, context-1m, [1m]128,000 / 128,000medium$4 / $20
claude-fable-5DocumentedFable 5January 20261,000,000native 1M, context-1m64,000 / 128,000high$10 / $50
claude-fable-5-1DocumentedFable 5.1June 20261,000,000native 1M, context-1m64,000 / 128,000high$10 / $50
claude-mythos-5DocumentedMythos 5January 20261,000,000native 1M, context-1m64,000 / 128,000-$10 / $50
claude-mythos-5-1UndocumentedMythos 5.1June 20261,000,000native 1M, context-1m64,000 / 128,000high$10 / $50

Notes:

  • A model with no window in the table has no context entry in the catalog.
  • The catalog keeps a rank for each model for the advisor tool (--advisor). The ranks run from 1 for claude-haiku-4-5 to 9 for claude-fable-5-1 and claude-mythos-5-1.
  • A model can name a model to use instead on a third-party provider. For example, claude-opus-5-5 falls back to claude-opus-5, and claude-fable-5-1 falls back to claude-fable-5.
  • The Mythos models have a name on the Anthropic API only, and none on the cloud providers.

Pricing​

Prices are in US dollars for each million tokens. A search request costs 0.01 in every group. Haiku 5.5 costs 0.5 for input and 2.5 for output above 100,000 prompt tokens. All rows are Undocumented.

ModelsInputOutputCache write 5mCache write 1hCache read
claude-sonnet-52102.540.2
claude-sonnet-5-52102.540.1
claude-3-5-sonnet, claude-3-7-sonnet, claude-sonnet-4-0, claude-sonnet-4-5, claude-sonnet-4-63153.7560.3
claude-opus-4-5, claude-opus-4-6, claude-opus-4-7, claude-opus-4-8, claude-opus-55256.25100.5
claude-opus-4-0, claude-opus-4-1157518.75301.5
claude-fable-5, claude-mythos-5105012.5201
claude-fable-5-1, claude-mythos-5-1105012.5200.25
claude-opus-5-5420580.2
claude-3-5-haiku0.8411.60.08
claude-haiku-4-5151.2520.1
claude-haiku-5-50.10.50.1250.20.01

Effort​

The effort levels are low, medium, high, xhigh, and max. A level the model does not accept runs as the highest accepted level below it. The effort cost index scales the cost of a level against high, which is 1. It comes from the catalog (Undocumented). claude-opus-4-7 has the default xhigh and no index. Other models not listed have no default effort in the catalog.

ItemStatusWhat it does
--effort <level>DocumentedSets the effort for a session. ultracode sets xhigh and turns on the workflow mode.
CLAUDE_CODE_EFFORT_LEVELDocumentedSets the effort. It wins over --effort, /effort, and settings. auto uses the model default.
effortLevel, maxEffortLevel, modelSettingsDocumentedSettings for the default level and a cap.
ultrathinkDocumentedA word in a prompt that asks for deeper thinking on that turn only.
idDefault effortIndex (low, medium, high, xhigh, max)
claude-fable-5high0.6, 0.77, 1, 1.74, 1.91
claude-fable-5-1high0.75, 0.86, 1, 1.38, 1.74
claude-haiku-5-5medium0.38, 0.52, 1, 2.03, 4.34
claude-mythos-5-1high0.75, 0.86, 1, 1.38, 1.74
claude-opus-4-7xhighnone
claude-opus-4-8high0.72, 0.9, 1, 1.65, 1.88
claude-opus-5high0.67, 0.76, 1, 1.6, 1.7
claude-opus-5-5medium0.48, 0.66, 1, 1.66, 3.44
claude-sonnet-5high0.47, 0.74, 1, 2.41, 5.59
claude-sonnet-5-5medium0.49, 0.54, 1, 1.87, 5.5

Thinking​

ItemStatusWhat it does
MAX_THINKING_TOKENSDocumentedSets a fixed thinking budget. 0 turns thinking off on the Anthropic API. It cannot turn thinking off on Opus 5.5, Sonnet 5.5, Haiku 5.5, and the Fable models.
CLAUDE_CODE_DISABLE_ADAPTIVE_THINKINGDocumentedGoes back to the fixed budget on Opus 4.6 and Sonnet 4.6. No effect on newer models.
CLAUDE_CODE_DISABLE_THINKINGDocumentedLeaves out the thinking field, for proxies that reject it.
alwaysThinkingEnabled, showThinkingSummariesDocumentedSettings for thinking. Option+T or Alt+T toggles it.
--thinking <enabled|adaptive|disabled>UndocumentedHidden print-mode flag. enabled equals adaptive.
--thinking-display <summarized|omitted|highlights>UndocumentedHidden flag. Sets how thinking text comes back.
--max-thinking-tokensUndocumentedHidden and deprecated. Use --thinking.

Fallback and Retries​

ItemStatusWhat it does
--fallback-model <model...>, fallbackModelDocumentedA chain of up to three models for overload and server errors.
CLAUDE_CODE_NO_MODEL_FALLBACKUndocumentedForbids the substitution of a model.
CLAUDE_CODE_MAX_RETRIESDocumentedNumber of retries. Default 10, up to 15.
CLAUDE_CODE_RETRY_WATCHDOGDocumentedRetries 429 and 529 without end.
CLAUDE_CODE_OVERLOADED_RETRY_BASE_DELAY_MS, CLAUDE_CODE_OVERLOADED_RETRY_MAX_DELAY_MSDocumentedStart and longest wait after a 529. Defaults 500 and 32000.
API_TIMEOUT_MSDocumentedRequest timeout. Default 600000.
CLAUDE_STREAM_IDLE_TIMEOUT_MS, CLAUDE_STREAM_FIRST_BYTE_TIMEOUT_MSDocumentedStream silence and first-byte deadlines.
CLAUDE_CODE_DISABLE_NONSTREAMING_FALLBACKDocumentedStops the retry without streaming.

The rules for these are on Models.

Providers​

The program knows these provider keys: first_party, bedrock, vertex, foundry, anthropic_aws, anthropic_google_cloud, mantle, and gateway. These environment variables choose the provider. The order when several are set is: gateway, Bedrock, Foundry, Claude Platform on AWS, Google Cloud, Mantle, Vertex.

Env varStatusProvider
CLAUDE_CODE_USE_BEDROCKDocumentedAmazon Bedrock.
CLAUDE_CODE_USE_VERTEXDocumentedGoogle Cloud Agent Platform (Vertex).
CLAUDE_CODE_USE_FOUNDRYDocumentedMicrosoft Foundry.
CLAUDE_CODE_USE_MANTLEDocumentedThe Mantle endpoint of Amazon Bedrock. With Bedrock on, anthropic.* model IDs route to Mantle.
CLAUDE_CODE_USE_ANTHROPIC_AWSDocumentedClaude Platform on AWS.
CLAUDE_CODE_USE_ANTHROPIC_GOOGLE_CLOUDUndocumentedClaude Platform on Google Cloud.
CLAUDE_CODE_USE_GATEWAYUndocumentedA host-managed gateway. Needs ANTHROPIC_BASE_URL and a token.

The Anthropic API, anthropic_aws, anthropic_google_cloud, and gateway providers use the first-party names, so the name tables below leave them out.

Endpoint and Region Variables​

Env varStatusProviderEffect
ANTHROPIC_BEDROCK_BASE_URLDocumentedBedrockOverrides the endpoint URL.
ANTHROPIC_BEDROCK_MANTLE_BASE_URLDocumentedMantleOverrides the Mantle endpoint. Default https://bedrock-mantle.<region>.api.aws.
ANTHROPIC_BEDROCK_REGION_PREFIXDocumentedBedrockCross-region profile prefix that Claude Code tries first.
ANTHROPIC_BEDROCK_SERVICE_TIERDocumentedBedrockSent in the X-Amzn-Bedrock-Service-Tier header.
ANTHROPIC_SMALL_FAST_MODEL_AWS_REGIONDocumentedBedrock, MantleRegion of the Haiku-class model.
AWS_REGION, AWS_DEFAULT_REGION, AWS_PROFILEDocumentedBedrockStandard AWS region and profile. Region order: AWS_REGION, AWS_DEFAULT_REGION, shared config, us-east-1.
ANTHROPIC_VERTEX_BASE_URLDocumentedVertexOverrides the endpoint URL.
ANTHROPIC_VERTEX_PROJECT_IDDocumentedVertexThe GCP project. Last choice after GCLOUD_PROJECT and GOOGLE_CLOUD_PROJECT.
ANTHROPIC_FOUNDRY_BASE_URLDocumentedFoundryFull base URL of the resource. Wins over the resource name.
ANTHROPIC_FOUNDRY_RESOURCEDocumentedFoundryResource name. Builds https://<resource>.services.ai.azure.com.
ANTHROPIC_AWS_BASE_URL, ANTHROPIC_AWS_WORKSPACE_IDDocumentedClaude Platform on AWSEndpoint and workspace.
ANTHROPIC_GOOGLE_CLOUD_BASE_URL, _LOCATION, _PROJECT, _WORKSPACE_IDUndocumentedClaude Platform on Google CloudEndpoint, location, project, and workspace (full names start with ANTHROPIC_GOOGLE_CLOUD).
CLAUDE_CODE_SKIP_BEDROCK_AUTH, CLAUDE_CODE_SKIP_VERTEX_AUTH, CLAUDE_CODE_SKIP_FOUNDRY_AUTH, CLAUDE_CODE_SKIP_MANTLE_AUTH, CLAUDE_CODE_SKIP_ANTHROPIC_AWS_AUTHDocumentedEach providerSkip client-side auth, for a gateway that signs requests itself.
CLAUDE_CODE_SKIP_ANTHROPIC_GOOGLE_CLOUD_AUTHUndocumentedClaude Platform on Google CloudThe same, for that provider.

Provider Names​

Each cell is the model name for that provider. A dash means the provider has none. A row is Documented when a docs page such as Amazon Bedrock or Model Configuration names the model, and Undocumented when only the program has the names.

idStatusfirst_partybedrockvertexfoundrymantle
claude-3-5-haikuUndocumentedclaude-3-5-haiku-20241022us.anthropic.claude-3-5-haiku-20241022-v1:0claude-3-5-haiku@20241022claude-3-5-haiku-
claude-haiku-4-5Documentedclaude-haiku-4-5-20251001us.anthropic.claude-haiku-4-5-20251001-v1:0claude-haiku-4-5@20251001claude-haiku-4-5anthropic.claude-haiku-4-5
claude-haiku-5-5Documentedclaude-haiku-5-5us.anthropic.claude-haiku-5-5claude-haiku-5-5claude-haiku-5-5anthropic.claude-haiku-5-5
claude-3-5-sonnetUndocumentedclaude-3-5-sonnet-20241022us.anthropic.claude-3-5-sonnet-20241022-v2:0claude-3-5-sonnet-v2@20241022claude-3-5-sonnet-
claude-3-7-sonnetUndocumentedclaude-3-7-sonnet-20250219us.anthropic.claude-3-7-sonnet-20250219-v1:0claude-3-7-sonnet@20250219claude-3-7-sonnet-
claude-sonnet-4-0Undocumentedclaude-sonnet-4-20250514us.anthropic.claude-sonnet-4-20250514-v1:0claude-sonnet-4@20250514claude-sonnet-4-
claude-sonnet-4-5Documentedclaude-sonnet-4-5-20250929us.anthropic.claude-sonnet-4-5-20250929-v1:0claude-sonnet-4-5@20250929claude-sonnet-4-5-
claude-sonnet-4-6Documentedclaude-sonnet-4-6us.anthropic.claude-sonnet-4-6claude-sonnet-4-6claude-sonnet-4-6-
claude-sonnet-5Documentedclaude-sonnet-5us.anthropic.claude-sonnet-5claude-sonnet-5claude-sonnet-5anthropic.claude-sonnet-5
claude-sonnet-5-5Documentedclaude-sonnet-5-5us.anthropic.claude-sonnet-5-5claude-sonnet-5-5claude-sonnet-5-5anthropic.claude-sonnet-5-5
claude-opus-4-0Undocumentedclaude-opus-4-20250514us.anthropic.claude-opus-4-20250514-v1:0claude-opus-4@20250514claude-opus-4-
claude-opus-4-1Documentedclaude-opus-4-1-20250805us.anthropic.claude-opus-4-1-20250805-v1:0claude-opus-4-1@20250805claude-opus-4-1-
claude-opus-4-5Documentedclaude-opus-4-5-20251101us.anthropic.claude-opus-4-5-20251101-v1:0claude-opus-4-5@20251101claude-opus-4-5-
claude-opus-4-6Documentedclaude-opus-4-6us.anthropic.claude-opus-4-6-v1claude-opus-4-6claude-opus-4-6-
claude-opus-4-7Documentedclaude-opus-4-7us.anthropic.claude-opus-4-7claude-opus-4-7claude-opus-4-7anthropic.claude-opus-4-7
claude-opus-4-8Documentedclaude-opus-4-8us.anthropic.claude-opus-4-8claude-opus-4-8claude-opus-4-8anthropic.claude-opus-4-8
claude-opus-5Documentedclaude-opus-5us.anthropic.claude-opus-5claude-opus-5claude-opus-5anthropic.claude-opus-5
claude-opus-5-5Documentedclaude-opus-5-5us.anthropic.claude-opus-5-5claude-opus-5-5claude-opus-5-5anthropic.claude-opus-5-5
claude-fable-5Documentedclaude-fable-5us.anthropic.claude-fable-5claude-fable-5claude-fable-5anthropic.claude-fable-5
claude-fable-5-1Documentedclaude-fable-5-1us.anthropic.claude-fable-5-1claude-fable-5-1claude-fable-5-1anthropic.claude-fable-5-1
claude-mythos-5Documentedclaude-mythos-5----
claude-mythos-5-1Undocumentedclaude-mythos-5-1----

Vertex Region Variables​

Each model has an environment variable that sets its region on Vertex. Environment Variables in the official docs lists them. The Mythos models have none, because they have no Vertex name.

idStatusEnv var
claude-3-5-haikuDocumentedVERTEX_REGION_CLAUDE_3_5_HAIKU
claude-haiku-4-5DocumentedVERTEX_REGION_CLAUDE_HAIKU_4_5
claude-haiku-5-5DocumentedVERTEX_REGION_CLAUDE_HAIKU_5_5
claude-3-5-sonnetDocumentedVERTEX_REGION_CLAUDE_3_5_SONNET
claude-3-7-sonnetDocumentedVERTEX_REGION_CLAUDE_3_7_SONNET
claude-sonnet-4-0DocumentedVERTEX_REGION_CLAUDE_4_0_SONNET
claude-sonnet-4-5DocumentedVERTEX_REGION_CLAUDE_4_5_SONNET
claude-sonnet-4-6DocumentedVERTEX_REGION_CLAUDE_4_6_SONNET
claude-sonnet-5DocumentedVERTEX_REGION_CLAUDE_5_SONNET
claude-sonnet-5-5DocumentedVERTEX_REGION_CLAUDE_5_5_SONNET
claude-opus-4-0DocumentedVERTEX_REGION_CLAUDE_4_0_OPUS
claude-opus-4-1DocumentedVERTEX_REGION_CLAUDE_4_1_OPUS
claude-opus-4-5DocumentedVERTEX_REGION_CLAUDE_4_5_OPUS
claude-opus-4-6DocumentedVERTEX_REGION_CLAUDE_4_6_OPUS
claude-opus-4-7DocumentedVERTEX_REGION_CLAUDE_4_7_OPUS
claude-opus-4-8DocumentedVERTEX_REGION_CLAUDE_4_8_OPUS
claude-opus-5DocumentedVERTEX_REGION_CLAUDE_5_OPUS
claude-opus-5-5DocumentedVERTEX_REGION_CLAUDE_5_5_OPUS
claude-fable-5DocumentedVERTEX_REGION_CLAUDE_FABLE_5
claude-fable-5-1DocumentedVERTEX_REGION_CLAUDE_FABLE_5_1

Gateways​

A gateway is a server between Claude Code and a model API. Set ANTHROPIC_BASE_URL to point at it. That variable changes where requests go, not which model answers. Pin the model IDs the gateway serves with the ANTHROPIC_DEFAULT_*_MODEL variables, and let the picker find them with CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY=1. A gateway that does not serve claude-fable-5-1 rejects it, so the fable alias falls to claude-fable-5 on gateways.

Capabilities​

Each catalog model has capability flags, for example effort, max_effort, adaptive_thinking, lean_prompt, per_turn_effort, and fast_mode. They switch features on for a model. The full list with counts is on Models. For pinned models on third-party providers, you can state the capabilities yourself with _SUPPORTED_CAPABILITIES (see above).

Example​

Pin Opus and Sonnet on Amazon Bedrock, then start Claude Code on a 1M window of Opus.

export CLAUDE_CODE_USE_BEDROCK=1
export AWS_REGION=us-east-1
export ANTHROPIC_DEFAULT_OPUS_MODEL='us.anthropic.claude-opus-4-8'
export ANTHROPIC_DEFAULT_SONNET_MODEL='us.anthropic.claude-sonnet-4-5-20250929-v1:0'
claude --model opus[1m] --effort high

Limit what users can pick in managed settings:

managed-settings.json
{
  "availableModels": ["sonnet", "claude-opus-4-8"],
  "modelOverrides": {
    "claude-opus-4-8": "arn:aws:bedrock:us-east-2:123456789012:application-inference-profile/opus-prod"
  }
}