Add AWS cross-region inference toggle

src/api/providers/bedrock.ts

@@ -25,8 +25,28 @@ export class AwsBedrockHandler implements ApiHandler {
 	}
 
 	async *createMessage(systemPrompt: string, messages: Anthropic.Messages.MessageParam[]): ApiStream {
+		// cross region inference requires prefixing the model id with the region
+		let modelId: string
+		if (this.options.awsUseCrossRegionInference) {
+			let regionPrefix = (this.options.awsRegion || "").slice(0, 3)
+			switch (regionPrefix) {
+				case "us-":
+					modelId = `us.${this.getModel().id}`
+					break
+				case "eu-":
+					modelId = `eu.${this.getModel().id}`
+					break
+				default:
+					// cross region inference is not supported in this region, falling back to default model
+					modelId = this.getModel().id
+					break
+			}
+		} else {
+			modelId = this.getModel().id
+		}
+
 		const stream = await this.client.messages.create({
-			model: this.getModel().id,
+			model: modelId,
 			max_tokens: this.getModel().info.maxTokens || 8192,
 			temperature: 0,
 			system: systemPrompt,