# Choosing a model and reasoning effort (/models/choosing-a-model)





This page shows you where models are turned on, how to pick a model and reasoning effort for a session, and what each provider needs before a session can use it.

<img alt="Settings, Models: the Anthropic section with a toggle per model and an Enable all link" src="__img0" title="Settings › Models decides which models appear in the model picker." />

## Enable models in Settings › Models [#enable-models-in-settings--models]

Settings › Models lists every model in the catalog, grouped by provider, under the heading **Enabled Models**. Toggle a model on or off, or use **Enable all** and **Disable all** on a group. Changes save automatically and apply to the model selector across the web app and the Slack bot. You cannot disable the last enabled model.

| Group            | Enabled by default |
| ---------------- | ------------------ |
| Anthropic        | Yes                |
| OpenAI           | Yes                |
| OpenCode Zen     | No                 |
| OpenCode Go      | No                 |
| xAI / SuperGrok  | No                 |
| Z.AI Coding Plan | No                 |
| DeepSeek         | No                 |

The deployment default model is Claude Sonnet 4.6 (`anthropic/claude-sonnet-4-6`). It is used when nothing else (a session, an integration setting, or an automation) picks a model.

## Pick a model and effort in the composer [#pick-a-model-and-effort-in-the-composer]

The composer shows one control that reads `<harness>: <model> <effort>`. Open it to see up to three rows:

| Row        | What it does                                                                                                                                                           |
| ---------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| **Agent**  | Chooses the harness (OpenCode or Claude Agent). Shown only when you create a session; the harness is fixed afterwards. See [Agent harnesses](/models/agent-harnesses). |
| **Model**  | Lists the enabled models the chosen harness can run, grouped by provider, with each model's display name and one-line description.                                     |
| **Effort** | Lists **Default** plus the efforts the model supports (None, Low, Medium, High, XHigh, Max). Hidden for models without reasoning controls.                             |

**Default** effort means the model's own default from the table below. Choosing a specific effort applies it to the prompts you send.

You can change the model and effort for each follow-up; the harness cannot change. The list therefore only contains models the session's harness can run. If a message override names a model the harness cannot run, the prompt is rejected with an error such as `Model "openai/gpt-5.5" cannot run on the Claude Agent harness.` It is never silently replaced with another model.

## Model catalog [#model-catalog]

Reasoning efforts and defaults below come from the shared model catalog. A model with no reasoning efforts has no Effort row in the composer.

### Anthropic [#anthropic]

Runs on both harnesses. Credential: `ANTHROPIC_API_KEY` as a global secret, or on Claude Agent sessions a connected Claude account (see [Provider accounts](/models/provider-accounts)).

| Model ID                      | Display name      | Reasoning efforts             | Default effort |
| ----------------------------- | ----------------- | ----------------------------- | -------------- |
| `anthropic/claude-haiku-4-5`  | Claude Haiku 4.5  | high, max                     | max            |
| `anthropic/claude-sonnet-4-5` | Claude Sonnet 4.5 | high, max                     | max            |
| `anthropic/claude-sonnet-4-6` | Claude Sonnet 4.6 | low, medium, high, max        | high           |
| `anthropic/claude-sonnet-5`   | Claude Sonnet 5   | low, medium, high, xhigh, max | high           |
| `anthropic/claude-opus-4-5`   | Claude Opus 4.5   | high, max                     | max            |
| `anthropic/claude-opus-4-6`   | Claude Opus 4.6   | low, medium, high, max        | high           |
| `anthropic/claude-opus-4-7`   | Claude Opus 4.7   | low, medium, high, xhigh, max | high           |
| `anthropic/claude-opus-4-8`   | Claude Opus 4.8   | low, medium, high, xhigh, max | high           |
| `anthropic/claude-opus-5`     | Claude Opus 5     | low, medium, high, xhigh, max | high           |
| `anthropic/claude-opus-5-5`   | Claude Opus 5.5   | low, medium, high, xhigh, max | high           |
| `anthropic/claude-fable-5`    | Claude Fable 5    | low, medium, high, xhigh, max | high           |
| `anthropic/claude-fable-5-1`  | Claude Fable 5.1  | low, medium, high, xhigh, max | high           |

### OpenAI [#openai]

Runs on OpenCode only. Credential: a connected ChatGPT account, or `OPENAI_API_KEY` in the session's secret scope when the session uses API-key mode.

| Model ID                     | Display name        | Reasoning efforts                   | Default effort |
| ---------------------------- | ------------------- | ----------------------------------- | -------------- |
| `openai/gpt-5.4`             | GPT 5.4             | none, low, medium, high, xhigh      | Not set        |
| `openai/gpt-5.5`             | GPT 5.5             | none, low, medium, high, xhigh      | Not set        |
| `openai/gpt-5.6-sol`         | GPT 5.6 Sol         | none, low, medium, high, xhigh      | medium         |
| `openai/gpt-5.6-terra`       | GPT 5.6 Terra       | none, low, medium, high, xhigh      | medium         |
| `openai/gpt-5.6-luna`        | GPT 5.6 Luna        | none, low, medium, high, xhigh, max | medium         |
| `openai/gpt-6-astra`         | GPT-6 Astra         | low, medium, high, xhigh, max       | medium         |
| `openai/gpt-6-sol`           | GPT-6 Sol           | none, low, medium, high, xhigh, max | medium         |
| `openai/gpt-6-luna`          | GPT-6 Luna          | none, low, medium, high, xhigh, max | medium         |
| `openai/gpt-5.3-codex`       | GPT 5.3 Codex       | low, medium, high, xhigh            | high           |
| `openai/gpt-5.3-codex-spark` | GPT 5.3 Codex Spark | low, medium, high, xhigh            | high           |

"Not set" means the composer shows **Default** and sends no effort unless you choose one.

### xAI / SuperGrok [#xai--supergrok]

Runs on OpenCode only. Opt-in group. Credential: a connected SuperGrok account, or `XAI_API_KEY` in API-key mode. Entitlement to a given Grok model is decided by xAI for the connected account.

| Model ID             | Display name   | Reasoning efforts        | Default effort |
| -------------------- | -------------- | ------------------------ | -------------- |
| `xai/grok-4.5`       | Grok 4.5       | low, medium, high        | high           |
| `xai/grok-4.6`       | Grok 4.6       | low, medium, high, xhigh | high           |
| `xai/grok-4.7`       | Grok 4.7       | low, medium, high, xhigh | high           |
| `xai/grok-build-0.1` | Grok Build 0.1 | Not configurable         | N/A            |

### OpenCode Zen [#opencode-zen]

Runs on OpenCode only. Opt-in group. Credential: `OPENCODE_API_KEY` as a global or repository secret. Zen is billed per token.

| Model ID                | Display name | Reasoning efforts | Default effort |
| ----------------------- | ------------ | ----------------- | -------------- |
| `opencode/kimi-k2.5`    | Kimi K2.5    | Not supported     | N/A            |
| `opencode/kimi-k2.6`    | Kimi K2.6    | Not supported     | N/A            |
| `opencode/kimi-k3`      | Kimi K3      | Not supported     | N/A            |
| `opencode/minimax-m2.5` | MiniMax M2.5 | Not supported     | N/A            |
| `opencode/qwen3.7-max`  | Qwen3.7 Max  | Not supported     | N/A            |
| `opencode/glm-5`        | GLM 5        | Not supported     | N/A            |
| `opencode/glm-5.1`      | GLM 5.1      | Not supported     | N/A            |
| `opencode/glm-5.2`      | GLM 5.2      | Not supported     | N/A            |

### OpenCode Go [#opencode-go]

Runs on OpenCode only. Opt-in group. Credential: the same `OPENCODE_API_KEY` secret as Zen, but the key must carry an active OpenCode Go subscription. Go bills against the subscription's rolling allowance instead of per token, so a key without a Go subscription fails on `opencode-go/*` models while `opencode/*` models keep working.

<Callout type="warn" title="Rolling allowance and unattended sessions">
  Go usage is capped on three rolling windows: 20% of the monthly allowance per 5 hours, 50% per
  week, and 100% per month. Allowances differ per model. An unattended session pinned to a Go model
  can exhaust its window and fail mid-run, so keep Go models off Slack, GitHub, Linear, and
  automation launches unless you accept that.
</Callout>

| Model ID                                   | Display name                 | Reasoning efforts | Default effort |
| ------------------------------------------ | ---------------------------- | ----------------- | -------------- |
| `opencode-go/grok-4.6`                     | Grok 4.6                     | Not supported     | N/A            |
| `opencode-go/gpt-5.6-luna`                 | GPT 5.6 Luna                 | Not supported     | N/A            |
| `opencode-go/glm-5.3-flash`                | GLM 5.3 Flash                | Not supported     | N/A            |
| `opencode-go/glm-5.3`                      | GLM 5.3                      | Not supported     | N/A            |
| `opencode-go/glm-5.2`                      | GLM 5.2                      | Not supported     | N/A            |
| `opencode-go/glm-5.1`                      | GLM 5.1                      | Not supported     | N/A            |
| `opencode-go/kimi-k3`                      | Kimi K3                      | Not supported     | N/A            |
| `opencode-go/kimi-k2.7-code`               | Kimi K2.7 Code               | Not supported     | N/A            |
| `opencode-go/kimi-k2.6`                    | Kimi K2.6                    | Not supported     | N/A            |
| `opencode-go/longcat-2.0`                  | LongCat 2.0                  | Not supported     | N/A            |
| `opencode-go/deepseek-v4.1-flash`          | DeepSeek V4.1 Flash          | Not supported     | N/A            |
| `opencode-go/deepseek-v4-pro`              | DeepSeek V4 Pro              | Not supported     | N/A            |
| `opencode-go/deepseek-v4-flash`            | DeepSeek V4 Flash            | Not supported     | N/A            |
| `opencode-go/deepseek-v4-flash-vision-exp` | DeepSeek V4 Flash Vision Exp | Not supported     | N/A            |
| `opencode-go/mimo-v2.5`                    | MiMo V2.5                    | Not supported     | N/A            |
| `opencode-go/mimo-v2.5-pro`                | MiMo V2.5 Pro                | Not supported     | N/A            |
| `opencode-go/minimax-m3`                   | MiniMax M3                   | Not supported     | N/A            |
| `opencode-go/minimax-m2.7`                 | MiniMax M2.7                 | Not supported     | N/A            |
| `opencode-go/muse-spark-1.3-contributor`   | Muse Spark 1.3 Contributor   | Not supported     | N/A            |
| `opencode-go/muse-spark-1.2-contributor`   | Muse Spark 1.2 Contributor   | Not supported     | N/A            |
| `opencode-go/qwen3.8-max`                  | Qwen3.8 Max                  | Not supported     | N/A            |
| `opencode-go/qwen3.8-flash`                | Qwen3.8 Flash                | Not supported     | N/A            |
| `opencode-go/qwen3.7-max`                  | Qwen3.7 Max                  | Not supported     | N/A            |
| `opencode-go/qwen3.7-plus`                 | Qwen3.7 Plus                 | Not supported     | N/A            |
| `opencode-go/qwen3.6-plus`                 | Qwen3.6 Plus                 | Not supported     | N/A            |
| `opencode-go/hy4-preview`                  | Hy4 Preview                  | Not supported     | N/A            |
| `opencode-go/hy3`                          | Hy3                          | Not supported     | N/A            |

Go also publishes `minimax-m2.5`, but the pinned OpenCode release does not resolve it on the Go gateway, so it is left out of the catalog. Use `opencode/minimax-m2.5` on Zen instead.

### Z.AI Coding Plan [#zai-coding-plan]

Runs on OpenCode only. Opt-in group. Credential: `ZHIPU_API_KEY` as a global or repository secret.

| Model ID                  | Display name | Reasoning efforts | Default effort |
| ------------------------- | ------------ | ----------------- | -------------- |
| `zai-coding-plan/glm-5.2` | GLM 5.2      | Not supported     | N/A            |
| `zai-coding-plan/glm-5.3` | GLM 5.3      | Not supported     | N/A            |

### DeepSeek [#deepseek]

Runs on OpenCode only. Opt-in group. Credential: `DEEPSEEK_API_KEY` as a global or repository secret.

| Model ID                     | Display name      | Reasoning efforts | Default effort |
| ---------------------------- | ----------------- | ----------------- | -------------- |
| `deepseek/deepseek-v4-flash` | DeepSeek V4 Flash | Not supported     | N/A            |
| `deepseek/deepseek-v4-pro`   | DeepSeek V4 Pro   | Not supported     | N/A            |

## The same model behind several gateways [#the-same-model-behind-several-gateways]

Some models appear more than once because they are reachable through more than one provider, each billed against a different credential. `opencode-go/grok-4.6` and `xai/grok-4.6` are the same Grok model behind two gateways. `opencode-go/glm-5.2`, `opencode/glm-5.2`, and `zai-coding-plan/glm-5.2` are the same GLM model behind three. Pick the entry whose billing you want.

## Defaults for integrations and automations [#defaults-for-integrations-and-automations]

Sessions started by Slack, GitHub, and Linear always run on the OpenCode harness. Automations run on the harness chosen in the automation editor (OpenCode by default). Each surface picks its model from these settings:

| Surface     | Where the default lives                                                                                                                                                                                                                                                                 |
| ----------- | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| GitHub      | Settings › Integrations › GitHub: **Default model** and **Default reasoning effort**, plus per-repository **Repository Overrides**. Falls back to the deployment default model.                                                                                                         |
| Linear      | Settings › Integrations › Linear: **Default model and effort** and **Repository Overrides**. A `model:*` issue label wins when **Allow model labels** is on, then a Linear user preference (when allowed), then the repository override or global default, then the deployment default. |
| Slack       | Each Slack user sets **Model** and **Reasoning effort** in the app's **Home** tab. A request can start with `!model` and `!reasoning` flags to override them; on a request that starts a session the flags become that session's defaults.                                              |
| Automations | The automation editor picks a model and effort per automation. The list is limited to enabled models the automation's harness can run.                                                                                                                                                  |

All of these selectors show only models enabled in Settings › Models. Reasoning values must be ones the selected model supports.

```text
@OpenInspect !model anthropic/claude-sonnet-4-6 !reasoning max investigate the flaky test
```

## Troubleshooting [#troubleshooting]

<Accordions>
  <Accordion title="&#x22;Model not found&#x22; when a prompt runs">
    The sandbox has no usable credential for the selected model. Check the session's authentication
    mode first. In provider-account mode, verify the account and confirm it is entitled to the
    model. In API-key mode, add the provider's key to the session's secret scope:
    `ANTHROPIC_API_KEY`, `OPENAI_API_KEY`, `XAI_API_KEY`, `DEEPSEEK_API_KEY`, `ZHIPU_API_KEY`, or
    `OPENCODE_API_KEY` (an `opencode-go/*` model additionally needs an active Go subscription on
    that key). See [Secrets](/configure/secrets).
  </Accordion>

  <Accordion title="A model is missing from the selector">
    Its group is opt-in or the model was toggled off. Enable it in Settings › Models. Slack falls
    back to the default enabled set if it cannot load the enabled list.
  </Accordion>

  <Accordion title="&#x22;No enabled models can run on Claude Agent.&#x22;">
    Claude Agent runs Anthropic models only, and every Anthropic model is disabled. Enable at least
    one Anthropic model, or switch the Agent row to OpenCode.
  </Accordion>

  <Accordion title="A per-message model override was rejected">
    The override named a model the session's harness cannot run (for example an OpenAI model on a
    Claude Agent session). Send the message with a compatible model, or start a new session on the
    other harness.
  </Accordion>
</Accordions>

## Next steps [#next-steps]

* [Agent harnesses: OpenCode and Claude Agent](/models/agent-harnesses)
* [Provider accounts and API keys](/models/provider-accounts)
* [Secrets](/configure/secrets)