diff --git a/dist/providers/google-gemini-cli.js b/dist/providers/google-gemini-cli.js
index 12540bb1069087a0d0a2967f792008627b9f79d9..f30b525620e6d8e45146b439ec3733e4053c9d2a 100644
--- a/dist/providers/google-gemini-cli.js
+++ b/dist/providers/google-gemini-cli.js
@@ -248,6 +248,11 @@ export const streamGoogleGeminiCli = (model, context, options) => {
                         break; // Success, exit retry loop
                     }
                     const errorText = await response.text();
+                    // Fail immediately on 429 for Antigravity to let callers rotate accounts.
+                    // Antigravity rate limits can have very long retry delays (10+ minutes).
+                    if (isAntigravity && response.status === 429) {
+                        throw new Error(`Cloud Code Assist API error (${response.status}): ${errorText}`);
+                    }
                     // Check if retryable
                     if (attempt < MAX_RETRIES && isRetryableError(response.status, errorText)) {
                         // Use server-provided delay or exponential backoff
diff --git a/dist/providers/google-shared.js b/dist/providers/google-shared.js
index ae4710b0f134ac4a48f5b7053f454d1068bee71f..b1b5bd94586f68461ccc44e4a9cdf3acb4e0d084 100644
--- a/dist/providers/google-shared.js
+++ b/dist/providers/google-shared.js
@@ -42,6 +42,8 @@ export function retainThoughtSignature(existing, incoming) {
 export function convertMessages(model, context) {
     const contents = [];
     const transformedMessages = transformMessages(context.messages, model);
+    const shouldStripFunctionId = typeof model.provider === "string" &&
+        model.provider.startsWith("google");
     for (const msg of transformedMessages) {
         if (msg.role === "user") {
             if (typeof msg.content === "string") {
@@ -113,6 +115,9 @@ export function convertMessages(model, context) {
                             args: block.arguments,
                         },
                     };
+                    if (shouldStripFunctionId && part?.functionCall?.id) {
+                        delete part.functionCall.id; // Google Gemini/Vertex do not support 'id' in functionCall
+                    }
                     if (block.thoughtSignature) {
                         part.thoughtSignature = block.thoughtSignature;
                     }
@@ -155,6 +160,9 @@ export function convertMessages(model, context) {
                     ...(hasImages && supportsMultimodalFunctionResponse && { parts: imageParts }),
                 },
             };
+            if (shouldStripFunctionId && functionResponsePart.functionResponse?.id) {
+                delete functionResponsePart.functionResponse.id; // Google Gemini/Vertex do not support 'id' in functionResponse
+            }
             // Cloud Code Assist API requires all function responses to be in a single user turn.
             // Check if the last content is already a user turn with function responses and merge.
             const lastContent = contents[contents.length - 1];
diff --git a/dist/providers/openai-codex-responses.js b/dist/providers/openai-codex-responses.js
index ad0a2aabbe10382cee4e463b68a02864dd235e57..8c001acfd0b4e0743181c246f1bedcf8cd2ffb02 100644
--- a/dist/providers/openai-codex-responses.js
+++ b/dist/providers/openai-codex-responses.js
@@ -517,7 +517,7 @@ function convertTools(tools) {
         name: tool.name,
         description: tool.description,
         parameters: tool.parameters,
-        strict: null,
+        strict: false,
     }));
 }
 function mapStopReason(status) {
diff --git a/dist/providers/openai-responses.js b/dist/providers/openai-responses.js
index f07085c64390b211340d6a826b28ea9c2e77302f..7f758532246cc7b062df48e9cec4e6c904b76a99 100644
--- a/dist/providers/openai-responses.js
+++ b/dist/providers/openai-responses.js
@@ -396,10 +396,16 @@ function convertMessages(model, context) {
         }
         else if (msg.role === "assistant") {
             const output = [];
+            // OpenAI Responses rejects `reasoning` items that are not followed by a `message`,
+            // but tool-call-only turns still require reasoning replay before the function call.
+            const hasTextBlock = msg.content.some((b) => b.type === "text");
+            const hasToolCallBlock = msg.content.some((b) => b.type === "toolCall");
             for (const block of msg.content) {
                 // Do not submit thinking blocks if the completion had an error (i.e. abort)
                 if (block.type === "thinking" && msg.stopReason !== "error") {
                     if (block.thinkingSignature) {
+                        if (!hasTextBlock && !hasToolCallBlock)
+                            continue;
                         const reasoningItem = JSON.parse(block.thinkingSignature);
                         output.push(reasoningItem);
                     }
@@ -434,6 +440,16 @@ function convertMessages(model, context) {
                     });
                 }
             }
+            const hasAssistantMessage = output.some((item) => item.type === "message");
+            const hasFunctionCall = output.some((item) => item.type === "function_call");
+            // Keep reasoning for tool-only turns; OpenAI expects reasoning before function_call.
+            if (!hasAssistantMessage && !hasFunctionCall) {
+                for (let i = output.length - 1; i >= 0; i -= 1) {
+                    if (output[i].type === "reasoning") {
+                        output.splice(i, 1);
+                    }
+                }
+            }
             if (output.length === 0)
                 continue;
             messages.push(...output);