> ## Documentation Index
> Fetch the complete documentation index at: https://code.claude.com/docs/llms.txt
> Use this file to discover all available pages before exploring further.

# Model configuration

> Learn about the Claude Code model configuration, including model aliases like `opusplan`

## Available models

For the `model` setting in Claude Code, you can configure either:

* A **model alias**
* A **model name**
  * Anthropic API: A full **[model name](https://platform.claude.com/docs/en/about-claude/models/overview)**
  * Bedrock: an inference profile ARN
  * Foundry: a deployment name
  * Vertex: a version name

<Note>
  `ANTHROPIC_BASE_URL` changes where requests are sent, not which model answers them. To route Claude through an LLM gateway, see [LLM gateway configuration](/en/llm-gateway).
</Note>

### Model aliases

Model aliases provide a convenient way to select model settings without
remembering exact version numbers:

| Model alias      | Behavior                                                                                                                                                             |
| ---------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **`default`**    | Special value that clears any model override and reverts to the recommended model for your account type. Not itself a model alias                                    |
| **`best`**       | Uses the most capable available model, currently equivalent to `opus`                                                                                                |
| **`sonnet`**     | Uses the latest Sonnet model for daily coding tasks                                                                                                                  |
| **`opus`**       | Uses the latest Opus model for complex reasoning tasks                                                                                                               |
| **`haiku`**      | Uses the fast and efficient Haiku model for simple tasks                                                                                                             |
| **`sonnet[1m]`** | Uses Sonnet with a [1 million token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows#1m-token-context-window) for long sessions |
| **`opus[1m]`**   | Uses Opus with a [1 million token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows#1m-token-context-window) for long sessions   |
| **`opusplan`**   | Special mode that uses `opus` during plan mode, then switches to `sonnet` for execution                                                                              |

On the Anthropic API and [Claude Platform on AWS](/en/claude-platform-on-aws), `opus` resolves to Opus 4.7 and `sonnet` resolves to Sonnet 4.6. On Bedrock, Vertex, and Foundry, `opus` resolves to Opus 4.6 and `sonnet` resolves to Sonnet 4.5; newer models are available on those providers by selecting the full model name explicitly or setting `ANTHROPIC_DEFAULT_OPUS_MODEL` or `ANTHROPIC_DEFAULT_SONNET_MODEL`.

Aliases point to the recommended version for your provider and update over time. To pin to a specific version, use the full model name (for example, `claude-opus-4-7`) or set the corresponding environment variable like `ANTHROPIC_DEFAULT_OPUS_MODEL`.

<Note>
  Opus 4.7 requires Claude Code v2.1.111 or later. Run `claude update` to upgrade.
</Note>

### Setting your model

You can configure your model in several ways, listed in order of priority:

1. **During session** - Use `/model <alias|name>` to switch immediately, or run `/model` with no argument to open the picker. The picker asks for confirmation when the conversation has prior output, since the next response re-reads the full history without cached context
2. **At startup** - Launch with `claude --model <alias|name>`
3. **Environment variable** - Set `ANTHROPIC_MODEL=<alias|name>`
4. **Settings** - Configure permanently in your settings file using the `model`
   field.

Your `/model` selection is saved to user settings and persists across restarts. As of v2.1.117, if the project's `.claude/settings.json` pins a different model, Claude Code also writes your choice to `.claude/settings.local.json` so it continues to apply in that project after a restart. Managed settings take precedence and reapply on the next launch.

The `--model` flag and `ANTHROPIC_MODEL` environment variable apply only to the session you launch with them and are not saved. To run different models in different terminals at the same time, launch each one with its own `--model` flag rather than switching with `/model`.

When the active model at startup comes from project or managed settings rather than your own selection, the startup header shows which settings file set it. Run `/model` to override for the current session.

Example usage:

```bash theme={null}
# Start with Opus
claude --model opus

# Switch to Sonnet during session
/model sonnet
```

Example settings file:

```json theme={null}
{
    "permissions": {
        ...
    },
    "model": "opus"
}
```

## Restrict model selection

Enterprise administrators can use `availableModels` in [managed or policy settings](/en/settings#settings-files) to restrict which models users can select.

When `availableModels` is set, users cannot switch to models not in the list via `/model`, `--model` flag, or `ANTHROPIC_MODEL` environment variable.

```json theme={null}
{
  "availableModels": ["sonnet", "haiku"]
}
```

### Default model behavior

The Default option in the model picker is not affected by `availableModels`. It always remains available and represents the system's runtime default [based on the user's subscription tier](#default-model-setting).

Even with `availableModels: []`, users can still use Claude Code with the Default model for their tier.

### Control the model users run on

The `model` setting is an initial selection, not enforcement. It sets which model is active when a session starts, but users can still open `/model` and pick Default, which resolves to the system default for their tier regardless of what `model` is set to.

To fully control the model experience, combine three settings:

* **`availableModels`**: restricts which named models users can switch to
* **`model`**: sets the initial model selection when a session starts
* **`ANTHROPIC_DEFAULT_SONNET_MODEL`** / **`ANTHROPIC_DEFAULT_OPUS_MODEL`** / **`ANTHROPIC_DEFAULT_HAIKU_MODEL`**: control what the Default option and the `sonnet`, `opus`, and `haiku` aliases resolve to

This example starts users on Sonnet 4.5, limits the picker to Sonnet and Haiku, and pins Default to resolve to Sonnet 4.5 rather than the latest release:

```json theme={null}
{
  "model": "claude-sonnet-4-5",
  "availableModels": ["claude-sonnet-4-5", "haiku"],
  "env": {
    "ANTHROPIC_DEFAULT_SONNET_MODEL": "claude-sonnet-4-5"
  }
}
```

Without the `env` block, a user who selects Default in the picker would get the latest Sonnet release, bypassing the version pin in `model` and `availableModels`.

### Merge behavior

When `availableModels` is set at multiple levels, such as user settings and project settings, arrays are merged and deduplicated. To enforce a strict allowlist, set `availableModels` in managed or policy settings which take highest priority.

### Mantle model IDs

When the [Bedrock Mantle endpoint](/en/amazon-bedrock#use-the-mantle-endpoint) is enabled, entries in `availableModels` that start with `anthropic.` are added to the `/model` picker as custom options and routed to the Mantle endpoint. This is an exception to the alias-only matching described in [Pin models for third-party deployments](#pin-models-for-third-party-deployments). The setting still restricts the picker to listed entries, so include the standard aliases alongside any Mantle IDs.

## Special model behavior

### `default` model setting

The behavior of `default` depends on your account type:

* **Max and Team Premium**: defaults to Opus 4.7
* **Pro, Team Standard, Enterprise, and Anthropic API**: defaults to Sonnet 4.6
* **Bedrock, Vertex, and Foundry**: defaults to Sonnet 4.5

Claude Code may automatically fall back to Sonnet if you hit a usage threshold with Opus.

<Note>
  On April 23, 2026, the default model for Enterprise pay-as-you-go and Anthropic API users will change to Opus 4.7. To keep a different default, set `ANTHROPIC_MODEL` or the `model` field in [server-managed settings](/en/server-managed-settings).
</Note>

### `opusplan` model setting

The `opusplan` model alias provides an automated hybrid approach:

* **In plan mode** - Uses `opus` for complex reasoning and architecture
  decisions
* **In execution mode** - Automatically switches to `sonnet` for code generation
  and implementation

This gives you the best of both worlds: Opus's superior reasoning for planning,
and Sonnet's efficiency for execution.

The plan-mode Opus phase runs with the standard 200K context window. The automatic 1M upgrade described in [Extended context](#extended-context) applies to the `opus` model setting and does not extend to `opusplan`.

### Adjust effort level

[Effort levels](https://platform.claude.com/docs/en/build-with-claude/effort) control adaptive reasoning, which lets the model decide whether and how much to think on each step based on task complexity. Lower effort is faster and cheaper for straightforward tasks, while higher effort provides deeper reasoning for complex problems.

Effort is supported on Opus 4.7, Opus 4.6, and Sonnet 4.6. The available levels depend on the model:

| Model                   | Levels                                  |
| :---------------------- | :-------------------------------------- |
| Opus 4.7                | `low`, `medium`, `high`, `xhigh`, `max` |
| Opus 4.6 and Sonnet 4.6 | `low`, `medium`, `high`, `max`          |

If you set a level the active model does not support, Claude Code falls back to the highest supported level at or below the one you set. For example, `xhigh` runs as `high` on Opus 4.6.

As of v2.1.117, the default effort is `xhigh` on Opus 4.7 and `high` on Opus 4.6 and Sonnet 4.6.

When you first run Opus 4.7, Claude Code applies `xhigh` even if you previously set a different effort level for Opus 4.6 or Sonnet 4.6. Run `/effort` again to choose a different level after switching.

`low`, `medium`, `high`, and `xhigh` persist across sessions. `max` provides the deepest reasoning with no constraint on token spending and applies to the current session only, except when set through the `CLAUDE_CODE_EFFORT_LEVEL` environment variable.

#### Choose an effort level

Each level trades token spend against capability. The default suits most coding tasks; adjust when you want a different balance.

| Level    | When to use it                                                                                                                         |
| :------- | :------------------------------------------------------------------------------------------------------------------------------------- |
| `low`    | Reserve for short, scoped, latency-sensitive tasks that are not intelligence-sensitive                                                 |
| `medium` | Reduces token usage for cost-sensitive work that can trade off some intelligence                                                       |
| `high`   | Balances token usage and intelligence. Use as a minimum for intelligence-sensitive work, or to reduce token spend relative to `xhigh`  |
| `xhigh`  | Best results for most coding and agentic tasks. Recommended default on Opus 4.7                                                        |
| `max`    | Can improve performance on demanding tasks but may show diminishing returns and is prone to overthinking. Test before adopting broadly |

The effort scale is calibrated per model, so the same level name does not represent the same underlying value across models.

#### Use ultrathink for one-off deep reasoning

Include `ultrathink` anywhere in your prompt to request deeper reasoning on that turn without changing your session effort setting. Claude Code recognizes the keyword and adds an in-context instruction. The effort level sent to the API is unchanged. Other phrases such as "think", "think hard", and "think more" are passed through as ordinary prompt text and are not recognized as keywords.

#### Set the effort level

You can change effort through any of the following:

* **`/effort`**: run `/effort` with no arguments to open an interactive slider, `/effort` followed by a level name to set it directly, or `/effort auto` to reset to the model default
* **In `/model`**: use left/right arrow keys to adjust the effort slider when selecting a model
* **`--effort` flag**: pass a level name to set it for a single session when launching Claude Code
* **Environment variable**: set `CLAUDE_CODE_EFFORT_LEVEL` to a level name or `auto`
* **Settings**: set `effortLevel` to `low`, `medium`, `high`, or `xhigh` in your settings file. `max` is [session-only](#adjust-effort-level) and is not accepted here
* **Skill and subagent frontmatter**: set `effort` in a [skill](/en/skills#frontmatter-reference) or [subagent](/en/sub-agents#supported-frontmatter-fields) markdown file to override the effort level when that skill or subagent runs

The environment variable takes precedence over all other methods, then your configured level, then the model default. Frontmatter effort applies when that skill or subagent is active, overriding the session level but not the environment variable.

The effort slider appears in `/model` when a supported model is selected. The current effort level is also displayed next to the logo and spinner, for example "with low effort", so you can confirm which setting is active without opening `/model`.

#### Adaptive reasoning and fixed thinking budgets

Adaptive reasoning makes thinking optional on each step, so Claude can respond faster to routine prompts and reserve deeper thinking for steps that benefit from it. If you want Claude to think more or less often than the current level produces, you can say so directly in your prompt or in `CLAUDE.md`; the model responds to that guidance within its effort setting.

Opus 4.7 always uses adaptive reasoning. The fixed thinking budget mode and `CLAUDE_CODE_DISABLE_ADAPTIVE_THINKING` do not apply to it.

On Opus 4.6 and Sonnet 4.6, you can set `CLAUDE_CODE_DISABLE_ADAPTIVE_THINKING=1` to revert to the previous fixed thinking budget controlled by `MAX_THINKING_TOKENS`. See [environment variables](/en/env-vars).

### Extended thinking

Extended thinking is the reasoning Claude emits before responding. On models that support [adaptive reasoning](#adjust-effort-level), the effort level is the primary control for how much thinking happens; the settings below turn thinking on or off and control how it displays.

| Control                        | How to set it                                                                                                                                       |
| :----------------------------- | :-------------------------------------------------------------------------------------------------------------------------------------------------- |
| Toggle for the current session | Press `Option+T` on macOS or `Alt+T` on Windows and Linux                                                                                           |
| Set the global default         | Run `/config` and toggle thinking mode. Saved as `alwaysThinkingEnabled` in `~/.claude/settings.json`                                               |
| Disable regardless of effort   | Set [`MAX_THINKING_TOKENS=0`](/en/env-vars). Other values apply only with a [fixed thinking budget](#adaptive-reasoning-and-fixed-thinking-budgets) |

Thinking output is collapsed by default. Press `Ctrl+O` to toggle verbose mode and see the reasoning as gray italic text. Interactive sessions on the Anthropic API receive redacted thinking blocks by default, so set `showThinkingSummaries: true` in [settings](/en/settings) if you want the full summaries available when you expand. You are charged for all thinking tokens generated, even when collapsed or redacted.

### Extended context

Opus 4.7, Opus 4.6, and Sonnet 4.6 support a [1 million token context window](https://platform.claude.com/docs/en/build-with-claude/context-windows#1m-token-context-window) for long sessions with large codebases.

Availability varies by model and plan. On Max, Team, and Enterprise plans, Opus is automatically upgraded to 1M context with no additional configuration. This applies to both Team Standard and Team Premium seats. Sonnet with 1M context is not part of the automatic upgrade and requires [usage credits](https://support.claude.com/en/articles/12429409-extra-usage-for-paid-claude-plans) on every subscription plan, including Max.

| Plan                      | Opus with 1M context                                                                                        | Sonnet with 1M context                                                                                      |
| ------------------------- | ----------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------------------------------------------------- |
| Max, Team, and Enterprise | Included with subscription                                                                                  | Requires [usage credits](https://support.claude.com/en/articles/12429409-extra-usage-for-paid-claude-plans) |
| Pro                       | Requires [usage credits](https://support.claude.com/en/articles/12429409-extra-usage-for-paid-claude-plans) | Requires [usage credits](https://support.claude.com/en/articles/12429409-extra-usage-for-paid-claude-plans) |
| API and pay-as-you-go     | Full access                                                                                                 | Full access                                                                                                 |

To disable 1M context entirely, set `CLAUDE_CODE_DISABLE_1M_CONTEXT=1`. This removes 1M model variants from the model picker. See [environment variables](/en/env-vars).

The 1M context window uses standard model pricing with no premium for tokens beyond 200K. For plans where extended context is included with your subscription, usage remains covered by your subscription. For plans that access extended context through usage credits, tokens are billed to usage credits.

If your account supports 1M context, the option appears in the model picker (`/model`) in the latest versions of Claude Code. If you don't see it, try restarting your session.

You can also use the `[1m]` suffix with model aliases or full model names:

```bash theme={null}
# Use the opus[1m] or sonnet[1m] alias
/model opus[1m]
/model sonnet[1m]

# Or append [1m] to a full model name
/model claude-opus-4-7[1m]
```

## Checking your current model

You can see which model you're currently using in several ways:

1. In [status line](/en/statusline) (if configured)
2. In `/status`, which also displays your account information.

## Add a custom model option

Use `ANTHROPIC_CUSTOM_MODEL_OPTION` to add a single custom entry to the `/model` picker without replacing the built-in aliases. This is useful for testing model IDs that Claude Code does not list by default. For LLM gateway deployments, Claude Code can populate the picker from the gateway's `/v1/models` endpoint when `CLAUDE_CODE_ENABLE_GATEWAY_MODEL_DISCOVERY=1` is set, so this variable is needed only when discovery is disabled or does not return the model you want. See [LLM gateway model selection](/en/llm-gateway#model-selection).

This example sets all three variables to make a gateway-routed Opus deployment selectable:

```bash theme={null}
export ANTHROPIC_CUSTOM_MODEL_OPTION="my-gateway/claude-opus-4-7"
export ANTHROPIC_CUSTOM_MODEL_OPTION_NAME="Opus via Gateway"
export ANTHROPIC_CUSTOM_MODEL_OPTION_DESCRIPTION="Custom deployment routed through the internal LLM gateway"
```

The custom entry appears at the bottom of the `/model` picker. `ANTHROPIC_CUSTOM_MODEL_OPTION_NAME` and `ANTHROPIC_CUSTOM_MODEL_OPTION_DESCRIPTION` are optional. If omitted, the model ID is used as the name and the description defaults to `Custom model (<model-id>)`.

Claude Code skips validation for the model ID set in `ANTHROPIC_CUSTOM_MODEL_OPTION`, so you can use any string your API endpoint accepts.

## Environment variables

You can use the following environment variables, which must be full **model
names** (or equivalent for your API provider), to control the model names that the aliases map to.

| Environment variable             | Description                                                                                                                                                                |
| -------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| `ANTHROPIC_DEFAULT_OPUS_MODEL`   | The model to use for `opus`, or for `opusplan` when Plan Mode is active.                                                                                                   |
| `ANTHROPIC_DEFAULT_SONNET_MODEL` | The model to use for `sonnet`, or for `opusplan` when Plan Mode is not active.                                                                                             |
| `ANTHROPIC_DEFAULT_HAIKU_MODEL`  | The model to use for `haiku`, or [background functionality](/en/costs#background-token-usage)                                                                              |
| `CLAUDE_CODE_SUBAGENT_MODEL`     | The model to use for all [subagents](/en/sub-agents#choose-a-model). Overrides both the per-invocation `model` parameter and the subagent definition's `model` frontmatter |

Note: `ANTHROPIC_SMALL_FAST_MODEL` is deprecated in favor of
`ANTHROPIC_DEFAULT_HAIKU_MODEL`.

### Pin models for third-party deployments

When deploying Claude Code through [Bedrock](/en/amazon-bedrock), [Vertex AI](/en/google-vertex-ai), [Foundry](/en/microsoft-foundry), or [Claude Platform on AWS](/en/claude-platform-on-aws), pin model versions before rolling out to users.

Without pinning, Claude Code uses model aliases (`sonnet`, `opus`, `haiku`) that resolve to the latest version. When Anthropic releases a new model that isn't yet enabled in a user's account, Bedrock and Vertex AI users see a notice and fall back to the previous version for that session, while Foundry users see errors because Foundry has no equivalent startup check.

<Warning>
  Set all three model environment variables to specific version IDs as part of your initial setup. Pinning lets you control when your users move to a new model.
</Warning>

Use the following environment variables with version-specific model IDs for your provider:

| Provider  | Example                                                              |
| :-------- | :------------------------------------------------------------------- |
| Bedrock   | `export ANTHROPIC_DEFAULT_OPUS_MODEL='us.anthropic.claude-opus-4-7'` |
| Vertex AI | `export ANTHROPIC_DEFAULT_OPUS_MODEL='claude-opus-4-7'`              |
| Foundry   | `export ANTHROPIC_DEFAULT_OPUS_MODEL='claude-opus-4-7'`              |

Apply the same pattern for `ANTHROPIC_DEFAULT_SONNET_MODEL` and `ANTHROPIC_DEFAULT_HAIKU_MODEL`. For current and legacy model IDs across all providers, see [Models overview](https://platform.claude.com/docs/en/about-claude/models/overview). To upgrade users to a new model version, update these environment variables and redeploy.

To enable [extended context](#extended-context) for a pinned model, append `[1m]` to the model ID in `ANTHROPIC_DEFAULT_OPUS_MODEL` or `ANTHROPIC_DEFAULT_SONNET_MODEL`:

```bash theme={null}
export ANTHROPIC_DEFAULT_OPUS_MODEL='claude-opus-4-7[1m]'
```

The `[1m]` suffix applies the 1M context window to all usage of that alias, including `opusplan`.

* Claude Code strips the suffix before sending the model ID to your provider.
* Only append `[1m]` when the underlying model [supports 1M context](https://platform.claude.com/docs/en/build-with-claude/context-windows#1m-token-context-window).
* The suffix is read per variable, not per model. On Bedrock, Vertex, and Foundry, a model ID without `[1m]` in one variable uses 200K context even if another variable sets the same model with the suffix.

<Note>
  The `settings.availableModels` allowlist still applies when using third-party providers. Filtering matches on the model alias (`opus`, `sonnet`, `haiku`), not the provider-specific model ID.
</Note>

### Customize pinned model display and capabilities

When you pin a model on a third-party provider, the provider-specific ID appears as-is in the `/model` picker and Claude Code may not recognize which features the model supports. You can override the display name and declare capabilities with companion environment variables for each pinned model.

These variables take effect on third-party providers such as Bedrock, Vertex AI, and Foundry. The `_NAME` and `_DESCRIPTION` variables also take effect when `ANTHROPIC_BASE_URL` points to an [LLM gateway](/en/llm-gateway). They have no effect when connecting directly to `api.anthropic.com`.

| Environment variable                                  | Description                                                                                                        |
| ----------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------ |
| `ANTHROPIC_DEFAULT_OPUS_MODEL_NAME`                   | Display name for the pinned Opus model in the `/model` picker. Defaults to the model ID when not set               |
| `ANTHROPIC_DEFAULT_OPUS_MODEL_DESCRIPTION`            | Display description for the pinned Opus model in the `/model` picker. Defaults to `Custom Opus model` when not set |
| `ANTHROPIC_DEFAULT_OPUS_MODEL_SUPPORTED_CAPABILITIES` | Comma-separated list of capabilities the pinned Opus model supports                                                |

The same `_NAME`, `_DESCRIPTION`, and `_SUPPORTED_CAPABILITIES` suffixes are available for `ANTHROPIC_DEFAULT_SONNET_MODEL`, `ANTHROPIC_DEFAULT_HAIKU_MODEL`, and `ANTHROPIC_CUSTOM_MODEL_OPTION`.

Claude Code enables features like [effort levels](#adjust-effort-level) and [extended thinking](#extended-thinking) by matching the model ID against known patterns. Provider-specific IDs such as Bedrock ARNs or custom deployment names often don't match these patterns, leaving supported features disabled. Set `_SUPPORTED_CAPABILITIES` to tell Claude Code which features the model actually supports:

| Capability value       | Enables                                                                         |
| ---------------------- | ------------------------------------------------------------------------------- |
| `effort`               | [Effort levels](#adjust-effort-level) and the `/effort` command                 |
| `xhigh_effort`         | {/* min-version: 2.1.111 */}The `xhigh` effort level                            |
| `max_effort`           | The `max` effort level                                                          |
| `thinking`             | [Extended thinking](#extended-thinking)                                         |
| `adaptive_thinking`    | Adaptive reasoning that dynamically allocates thinking based on task complexity |
| `interleaved_thinking` | Thinking between tool calls                                                     |

When `_SUPPORTED_CAPABILITIES` is set, listed capabilities are enabled and unlisted capabilities are disabled for the matching pinned model. When the variable is unset, Claude Code falls back to built-in detection based on the model ID.

This example pins Opus to a Bedrock custom model ARN, sets a friendly name, and declares its capabilities:

```bash theme={null}
export ANTHROPIC_DEFAULT_OPUS_MODEL='arn:aws:bedrock:us-east-1:123456789012:custom-model/abc'
export ANTHROPIC_DEFAULT_OPUS_MODEL_NAME='Opus via Bedrock'
export ANTHROPIC_DEFAULT_OPUS_MODEL_DESCRIPTION='Opus 4.7 routed through a Bedrock custom endpoint'
export ANTHROPIC_DEFAULT_OPUS_MODEL_SUPPORTED_CAPABILITIES='effort,xhigh_effort,max_effort,thinking,adaptive_thinking,interleaved_thinking'
```

### Override model IDs per version

The family-level environment variables above configure one model ID per family alias. If you need to map several versions within the same family to distinct provider IDs, use the `modelOverrides` setting instead.

`modelOverrides` maps individual Anthropic model IDs to the provider-specific strings that Claude Code sends to your provider's API. When a user selects a mapped model in the `/model` picker, Claude Code uses your configured value instead of the built-in default.

This lets enterprise administrators route each model version to a specific Bedrock inference profile ARN, Vertex AI version name, or Foundry deployment name for governance, cost allocation, or regional routing.

Set `modelOverrides` in your [settings file](/en/settings#settings-files):

```json theme={null}
{
  "modelOverrides": {
    "claude-opus-4-7": "arn:aws:bedrock:us-east-2:123456789012:application-inference-profile/opus-prod",
    "claude-opus-4-6": "arn:aws:bedrock:us-east-2:123456789012:application-inference-profile/opus-46-prod",
    "claude-sonnet-4-6": "arn:aws:bedrock:us-east-2:123456789012:application-inference-profile/sonnet-prod"
  }
}
```

Keys must be Anthropic model IDs as listed in the [Models overview](https://platform.claude.com/docs/en/about-claude/models/overview). For dated model IDs, include the date suffix exactly as it appears there. Unknown keys are ignored.

Overrides replace the built-in model IDs that back each entry in the `/model` picker. On Bedrock, overrides take precedence over any inference profiles that Claude Code discovers automatically at startup. Values you supply directly through `ANTHROPIC_MODEL`, `--model`, or the `ANTHROPIC_DEFAULT_*_MODEL` environment variables are passed to the provider as-is and are not transformed by `modelOverrides`.

`modelOverrides` works alongside `availableModels`. The allowlist is evaluated against the Anthropic model ID, not the override value, so an entry like `"opus"` in `availableModels` continues to match even when Opus versions are mapped to ARNs.

### Prompt caching configuration

Claude Code automatically uses [prompt caching](https://platform.claude.com/docs/en/build-with-claude/prompt-caching) to optimize performance and reduce costs. You can disable prompt caching globally or for specific model tiers:

| Environment variable            | Description                                                                                    |
| ------------------------------- | ---------------------------------------------------------------------------------------------- |
| `DISABLE_PROMPT_CACHING`        | Set to `1` to disable prompt caching for all models (takes precedence over per-model settings) |
| `DISABLE_PROMPT_CACHING_HAIKU`  | Set to `1` to disable prompt caching for Haiku models only                                     |
| `DISABLE_PROMPT_CACHING_SONNET` | Set to `1` to disable prompt caching for Sonnet models only                                    |
| `DISABLE_PROMPT_CACHING_OPUS`   | Set to `1` to disable prompt caching for Opus models only                                      |

These environment variables give you fine-grained control over prompt caching behavior. The global `DISABLE_PROMPT_CACHING` setting takes precedence over the model-specific settings, allowing you to quickly disable all caching when needed. The per-model settings are useful for selective control, such as when debugging specific models or working with cloud providers that may have different caching implementations.