diff --git a/src/backend/src/modules/puterai/AIChatService.js b/src/backend/src/modules/puterai/AIChatService.js
index e995947d..0009ab39 100644
--- a/src/backend/src/modules/puterai/AIChatService.js
+++ b/src/backend/src/modules/puterai/AIChatService.js
@@ -409,6 +409,7 @@ class AIChatService extends BaseService {
                 const available = await svc_cost.get_available_amount();
                 const model_input_cost = this.detail_model_map[model_used].cost.input;
                 const model_output_cost = this.detail_model_map[model_used].cost.output;
+                const model_max_tokens = this.detail_model_map[model_used].max_tokens;
                 const text = Messages.extract_text(parameters.messages);
                 const approximate_input_cost = text.length / 4 * model_input_cost;
                 const usageAllowed = await svc_cost.get_funding_allowed({
@@ -440,10 +441,13 @@ class AIChatService extends BaseService {
                 const max_allowed_output_tokens =
                     max_allowed_output_amount / model_output_cost;
                 
-                parameters.max_tokens = Math.min(
-                    parameters.max_tokens ?? Number.POSITIVE_INFINITY,
-                    max_allowed_output_tokens,
-                );
+                if ( model_max_tokens ) {
+                    parameters.max_tokens = Math.floor(Math.min(
+                        parameters.max_tokens ?? Number.POSITIVE_INFINITY,
+                        max_allowed_output_tokens,
+                        model_max_tokens,
+                    ));
+                }
 
                 this.log.noticeme('AI PARAMETERS', parameters);
 
diff --git a/src/backend/src/modules/puterai/ClaudeService.js b/src/backend/src/modules/puterai/ClaudeService.js
index d8fbe49b..39b78b4b 100644
--- a/src/backend/src/modules/puterai/ClaudeService.js
+++ b/src/backend/src/modules/puterai/ClaudeService.js
@@ -111,7 +111,11 @@ class ClaudeService extends BaseService {
                 
                 const sdk_params = {
                     model: model ?? this.get_default_model(),
-                    max_tokens: max_tokens || (model === 'claude-3-5-sonnet-20241022' || model === 'claude-3-5-sonnet-20240620') ? 8192 : 4096, //required
+                    max_tokens: Math.floor(max_tokens) ||
+                        ((
+                            model === 'claude-3-5-sonnet-20241022'
+                            || model === 'claude-3-5-sonnet-20240620'
+                        ) ? 8192 : 4096), //required
                     temperature: temperature || 0, // required
                     ...(system_prompts ? {
                         system: system_prompts.length > 1
diff --git a/src/backend/src/modules/puterai/OpenAICompletionService.js b/src/backend/src/modules/puterai/OpenAICompletionService.js
index 02e2aa7a..7155eca5 100644
--- a/src/backend/src/modules/puterai/OpenAICompletionService.js
+++ b/src/backend/src/modules/puterai/OpenAICompletionService.js
@@ -106,6 +106,7 @@ class OpenAICompletionService extends BaseService {
             },
             {
                 id: 'gpt-4o-mini',
+                max_tokens: 16384,
                 cost: {
                     currency: 'usd-cents',
                     tokens: 1_000_000,
@@ -169,6 +170,7 @@ class OpenAICompletionService extends BaseService {
             },
             {
                 id: 'o4-mini',
+                max_tokens: 100000,
                 cost: {
                     currency: 'usd-cents',
                     tokens: 1_000_000,
@@ -335,7 +337,7 @@ class OpenAICompletionService extends BaseService {
             messages: messages,
             model: model,
             ...(tools ? { tools } : {}),
-            ...(max_tokens ? { max_tokens } : {}),
+            ...(max_tokens ? { max_completion_tokens: max_tokens } : {}),
             ...(temperature ? { temperature } : {}),
             stream,
             ...(stream ? {
diff --git a/src/backend/src/modules/puterai/OpenRouterService.js b/src/backend/src/modules/puterai/OpenRouterService.js
index 1e7f8094..62791f7d 100644
--- a/src/backend/src/modules/puterai/OpenRouterService.js
+++ b/src/backend/src/modules/puterai/OpenRouterService.js
@@ -172,6 +172,7 @@ class OpenRouterService extends BaseService {
             coerced_models.push({
                 id: 'openrouter:' + model.id,
                 name: model.name + ' (OpenRouter)',
+                max_tokens: model.max_completion_tokens,
                 cost: {
                     currency: 'usd-cents',
                     tokens: 1_000_000,