feat: add gpt-5 support (#1105)

* feat: add gpt-5 support

src/ai-providers/base-provider.js

@@ -61,8 +61,11 @@ export class BaseAIProvider {
 		) {
 			throw new Error('Temperature must be between 0 and 1');
 		}
-		if (params.maxTokens !== undefined && params.maxTokens <= 0) {
-			throw new Error('maxTokens must be greater than 0');
+		if (params.maxTokens !== undefined) {
+			const maxTokens = Number(params.maxTokens);
+			if (!Number.isFinite(maxTokens) || maxTokens <= 0) {
+				throw new Error('maxTokens must be a finite number greater than 0');
+			}
 		}
 	}
 
@@ -122,6 +125,37 @@ export class BaseAIProvider {
 		throw new Error('getRequiredApiKeyName must be implemented by provider');
 	}
 
+	/**
+	 * Determines if a model requires max_completion_tokens instead of maxTokens
+	 * Can be overridden by providers to specify their model requirements
+	 * @param {string} modelId - The model ID to check
+	 * @returns {boolean} True if the model requires max_completion_tokens
+	 */
+	requiresMaxCompletionTokens(modelId) {
+		return false; // Default behavior - most models use maxTokens
+	}
+
+	/**
+	 * Prepares token limit parameter based on model requirements
+	 * @param {string} modelId - The model ID
+	 * @param {number} maxTokens - The maximum tokens value
+	 * @returns {object} Object with either maxTokens or max_completion_tokens
+	 */
+	prepareTokenParam(modelId, maxTokens) {
+		if (maxTokens === undefined) {
+			return {};
+		}
+
+		// Ensure maxTokens is an integer
+		const tokenValue = Math.floor(Number(maxTokens));
+
+		if (this.requiresMaxCompletionTokens(modelId)) {
+			return { max_completion_tokens: tokenValue };
+		} else {
+			return { maxTokens: tokenValue };
+		}
+	}
+
 	/**
 	 * Generates text using the provider's model
 	 */
@@ -139,7 +173,7 @@ export class BaseAIProvider {
 			const result = await generateText({
 				model: client(params.modelId),
 				messages: params.messages,
-				maxTokens: params.maxTokens,
+				...this.prepareTokenParam(params.modelId, params.maxTokens),
 				temperature: params.temperature
 			});
 
@@ -175,7 +209,7 @@ export class BaseAIProvider {
 			const stream = await streamText({
 				model: client(params.modelId),
 				messages: params.messages,
-				maxTokens: params.maxTokens,
+				...this.prepareTokenParam(params.modelId, params.maxTokens),
 				temperature: params.temperature
 			});
 
@@ -216,7 +250,7 @@ export class BaseAIProvider {
 				messages: params.messages,
 				schema: zodSchema(params.schema),
 				mode: params.mode || 'auto',
-				maxTokens: params.maxTokens,
+				...this.prepareTokenParam(params.modelId, params.maxTokens),
 				temperature: params.temperature
 			});