docs: add Mistral AI model provider page for kagent 1.x (#517)

docs-site/content/kagent/1.x/setup/model-providers/about-model-providers.md

@@ -68,7 +68,8 @@ When a request is made to a provider, the gateway puts the credential in the hea
 | `Foundry` API key in Anthropic format | `x-api-key: <key>` |
 | `Gemini` API key | `x-goog-api-key: <key>` |
 | `Bedrock` bearer token | `authorization: Bearer <token>` |
-| `Ollama` API key, for an Ollama Cloud model | `authorization: Bearer <key>` |
+| `Ollama` API key, for an Ollama Cloud model | `authorization: Bearer *** |
+| `Mistral` API key | `authorization: Bearer *** |
 | A Secret-backed `RemoteMCPServer` header | The header that the server names |
 
 Substrate matches a destination on the exact DNS hostname, without path, port, or scheme. Two credentials that target the same hostname and header are rejected, including a conflict between an agent's model, a memory embedding model, and an MCP server. Give such origins distinct DNS names. A destination given as an IP address cannot carry an injected credential at all.

docs-site/content/kagent/1.x/setup/model-providers/mistral.md

@@ -0,0 +1,79 @@
+---
+title: Mistral
+description: Configure kagent to use Mistral models by creating a ModelConfig for the Mistral provider.
+weight: 20
+author: kagent.dev
+---
+
+The `Mistral` provider calls the Mistral API directly. Mistral speaks the OpenAI-compatible wire protocol, but kagent exposes it as its own `provider: Mistral` value rather than routing it through the `OpenAI` provider.
+
+> [!NOTE]
+> This provider works on the `kagent` and `byo` runtimes, but not on `codex` or `claude`. For more information, see [Agent harness]({{< link path="agents/agent-harness#model-provider-support" >}}).
+
+## Create the ModelConfig
+
+1. Save your [Mistral API key](https://console.mistral.ai/api-keys) as an environment variable.
+   ```bash
+   export MISTRAL_API_KEY=<your_api_key>
+   ```
+
+2. Create a Kubernetes Secret that stores the API key. Create it in the same namespace as the AgentTemplates that use it, such as `kagent`.
+   ```bash
+   kubectl create secret generic kagent-mistral -n kagent --from-literal MISTRAL_API_KEY=$MISTRAL_API_KEY
+   ```
+
+3. Create a `ModelConfig` that references the Secret. Every field in the `mistral` block is optional, and an empty block is valid.
+   ```yaml
+   kubectl apply -f - <<EOF
+   apiVersion: api.kagent.dev/v1alpha3
+   kind: ModelConfig
+   metadata:
+     name: mistral-model-config
+     namespace: kagent
+   spec:
+     apiKeySecret: kagent-mistral
+     apiKeySecretKey: MISTRAL_API_KEY
+     model: mistral-large-latest
+     provider: Mistral
+     mistral: {}
+   EOF
+   ```
+
+   | Field | Description |
+   | ----- | ----------- |
+   | `apiKeySecret` | The name of the Kubernetes Secret that stores the API key, in the same namespace as this ModelConfig. |
+   | `apiKeySecretKey` | The key within that Secret that holds the API key. |
+   | `model` | The model to use. For the available models, see the [Mistral model docs](https://docs.mistral.ai/models). |
+   | `provider` | The provider to use, `Mistral`. |
+   | `mistral` | Settings that only the Mistral provider takes. An empty block is valid. A CEL rule rejects a `mistral` block on any other provider. |
+
+## Mistral provider settings
+
+The `mistral` block takes the following optional settings. For every field, including its type, default, and validation rules, see the [API reference]({{< link path="reference/api-ref#mistralconfig" >}}).
+
+| Field | Description |
+| ----- | ----------- |
+| `baseUrl` | An alternative Mistral API endpoint. Defaults to `https://api.mistral.ai/v1`. |
+| `temperature` | How much randomness the model applies when it picks the next token, written as a string. |
+| `topP` | The nucleus sampling cutoff, written as a string. |
+| `maxTokens` | A cap on the tokens generated in one response. Minimum 1. |
+| `timeout` | How long to wait on a request to the provider, in seconds. Minimum 1. |
+
+Mistral embeddings (`mistral-embed`) are out of scope for this page.
+
+## Use the ModelConfig
+
+Reference the ModelConfig by name from an AgentTemplate in the same namespace.
+
+```yaml
+spec:
+  modelConfig:
+    name: mistral-model-config
+```
+
+## Next steps
+
+{{< cards >}}
+  {{< card link=`{{< link path="get-started/your-first-agent" >}}` title="Your first agent" subtitle="Create an agent that uses this model, and hold a conversation with it." >}}
+  {{< card link=`{{< link path="setup/model-providers/byo-openai" >}}` title="BYO OpenAI-compatible endpoint" subtitle="Point the OpenAI provider at a different service." >}}
+{{< /cards >}}