diff --git a/README.md b/README.md
index a9e4711..fa5c805 100644
--- a/README.md
+++ b/README.md
@@ -250,6 +250,46 @@ In the Web UI management interface, you can complete authorization configuration
 3. **Best Practice**: Recommended to use with **Claude Code** for optimal experience
 4. **Important Notice**: Kiro service usage policy has been updated, please visit the official website for the latest usage restrictions and terms
 
+#### Kiro Extended Thinking (Claude Models)
+AIClient-2-API supports Kiro extended thinking when using Claude-compatible requests (`/v1/messages`) or OpenAI-compatible requests (`/v1/chat/completions`) routed to `claude-kiro-oauth`.
+
+**Claude-compatible (`/v1/messages`)**:
+```bash
+curl http://localhost:3000/claude-kiro-oauth/v1/messages \
+  -H "Content-Type: application/json" \
+  -H "Authorization: Bearer your-api-key" \
+  -d '{
+    "model": "claude-sonnet-4-5",
+    "max_tokens": 1024,
+    "thinking": { "type": "enabled", "budget_tokens": 10000 },
+    "messages": [{ "role": "user", "content": "Solve this step by step." }]
+  }'
+```
+
+**OpenAI-compatible (`/v1/chat/completions`)**:
+```bash
+curl http://localhost:3000/claude-kiro-oauth/v1/chat/completions \
+  -H "Content-Type: application/json" \
+  -H "Authorization: Bearer your-api-key" \
+  -d '{
+    "model": "claude-sonnet-4-5",
+    "messages": [{ "role": "user", "content": "Solve this step by step." }],
+    "extra_body": {
+      "anthropic": {
+        "thinking": { "type": "enabled", "budget_tokens": 10000 }
+      }
+    }
+  }'
+```
+
+**Adaptive mode**:
+- Claude: `"thinking": { "type": "adaptive", "effort": "high" }`
+- OpenAI: `"extra_body.anthropic.thinking": { "type": "adaptive", "effort": "high" }`
+
+Notes:
+- `budget_tokens` is clamped to `[1024, 24576]` (default `20000` if omitted/invalid).
+- Token acquisition/refresh/pool rotation is unchanged.
+
 #### iFlow OAuth Configuration
 1. **First Authorization**: In Web UI's "Configuration" or "Provider Pools" page, click the "Generate Authorization" button for iFlow
 2. **Phone Login**: The system will open the iFlow authorization page, complete login verification using your phone number
@@ -414,7 +454,36 @@ Support excluding unsupported models through `notSupportedModels` configuration,
 - Some accounts cannot access specific models due to quota or permission restrictions
 - Need to assign different model access permissions to different accounts
 
-#### 3. Cross-Type Fallback Configuration
+#### 3. Provider Priority Configuration
+
+Support deterministic account ordering through a per-node `priority` field in `provider_pools.json`.
+
+**Configuration** (smaller number = higher priority):
+
+```json
+{
+  "claude-kiro-oauth": [
+    {
+      "uuid": "primary-node-uuid",
+      "priority": 1,
+      "checkHealth": true
+    },
+    {
+      "uuid": "backup-node-uuid",
+      "priority": 2,
+      "checkHealth": true
+    }
+  ]
+}
+```
+
+**How It Works**:
+- The pool manager first filters healthy/available nodes by the lowest `priority` value
+- Only nodes in that highest-priority tier participate in LRU/score-based balancing
+- If the whole highest-priority tier becomes unavailable, the next priority tier is used automatically
+- If `priority` is omitted or invalid, default `100` is applied (backward compatible behavior)
+
+#### 4. Cross-Type Fallback Configuration
 
 When all accounts under a Provider Type (e.g., `gemini-cli-oauth`) are exhausted due to 429 quota limits or marked as unhealthy, the system can automatically fallback to another compatible Provider Type (e.g., `gemini-antigravity`) instead of returning an error directly.
 
diff --git a/src/converters/strategies/ClaudeConverter.js b/src/converters/strategies/ClaudeConverter.js
index ecf72cf..d8246bf 100644
--- a/src/converters/strategies/ClaudeConverter.js
+++ b/src/converters/strategies/ClaudeConverter.js
@@ -140,12 +140,7 @@ export class ClaudeConverter extends BaseConverter {
                         for (const item of msg.content) {
                             if (item && typeof item === 'object' && item.type === "tool_result") {
                                 const toolUseId = item.tool_use_id || item.id || "";
-                                let contentStr = item.content || "";
-                                if (typeof contentStr === 'object') {
-                                    contentStr = JSON.stringify(contentStr);
-                                } else {
-                                    contentStr = String(contentStr);
-                                }
+                                const contentStr = String(item.content || "");
                                 tempOpenAIMessages.push({
                                     role: "tool",
                                     tool_call_id: toolUseId,
@@ -310,6 +305,17 @@ export class ClaudeConverter extends BaseConverter {
             };
         }
 
+        // Extract thinking blocks into OpenAI-style `reasoning_content`.
+        let reasoningContent = '';
+        if (Array.isArray(claudeResponse.content)) {
+            for (const block of claudeResponse.content) {
+                if (!block || typeof block !== 'object') continue;
+                if (block.type === 'thinking') {
+                    reasoningContent += (block.thinking ?? block.text ?? '');
+                }
+            }
+        }
+
         // 检查是否包含 tool_use
         const hasToolUse = claudeResponse.content.some(block => block && block.type === 'tool_use');
         
@@ -349,6 +355,10 @@ export class ClaudeConverter extends BaseConverter {
             message.content = this.processClaudeResponseContent(claudeResponse.content);
         }
 
+        if (reasoningContent) {
+            message.reasoning_content = reasoningContent;
+        }
+
         // 处理 finish_reason
         let finishReason = 'stop';
         if (claudeResponse.stop_reason === 'end_turn') {
@@ -2186,4 +2196,4 @@ export class ClaudeConverter extends BaseConverter {
     }
 }
 
-export default ClaudeConverter;
\ No newline at end of file
+export default ClaudeConverter;
diff --git a/src/converters/strategies/OpenAIConverter.js b/src/converters/strategies/OpenAIConverter.js
index 9133ed1..f8bca98 100644
--- a/src/converters/strategies/OpenAIConverter.js
+++ b/src/converters/strategies/OpenAIConverter.js
@@ -149,14 +149,10 @@ export class OpenAIConverter extends BaseConverter {
 
             if (message.role === 'tool') {
                 // 工具结果消息
-                let toolContent = message.content;
-                if (typeof toolContent === 'object' && toolContent !== null) {
-                    toolContent = JSON.stringify(toolContent);
-                }
                 content.push({
                     type: 'tool_result',
                     tool_use_id: message.tool_call_id,
-                    content: toolContent
+                    content: safeParseJSON(message.content)
                 });
                 claudeMessages.push({ role: 'user', content: content });
             } else if (message.role === 'assistant' && (message.tool_calls?.length || message.function_calls?.length)) {
@@ -278,6 +274,32 @@ export class OpenAIConverter extends BaseConverter {
             claudeRequest.tool_choice = this.buildClaudeToolChoice(openaiRequest.tool_choice);
         }
 
+        // Optional passthrough: request-side "thinking" controls for Claude/Kiro.
+        // OpenAI-compatible clients can provide these via `extra_body.anthropic.thinking`.
+        // We intentionally keep normalization minimal here; provider implementations
+        // (e.g. Kiro) clamp budgets and apply defaults.
+        const extThinking = openaiRequest?.extra_body?.anthropic?.thinking;
+        if (extThinking && typeof extThinking === 'object' && !Array.isArray(extThinking)) {
+            const type = String(extThinking.type || '').toLowerCase().trim();
+            if (type === 'enabled') {
+                const thinkingCfg = { type: 'enabled' };
+                if (extThinking.budget_tokens !== undefined) {
+                    const n = parseInt(extThinking.budget_tokens, 10);
+                    if (Number.isFinite(n)) {
+                        thinkingCfg.budget_tokens = n;
+                    }
+                }
+                claudeRequest.thinking = thinkingCfg;
+            } else if (type === 'adaptive') {
+                const effortRaw = typeof extThinking.effort === 'string' ? extThinking.effort : '';
+                const effort = effortRaw.toLowerCase().trim();
+                const normalizedEffort = (effort === 'low' || effort === 'medium' || effort === 'high') ? effort : 'high';
+                claudeRequest.thinking = { type: 'adaptive', effort: normalizedEffort };
+            } else if (type === 'disabled') {
+                // Explicitly disabled: omit thinking config.
+            }
+        }
+
         return claudeRequest;
     }
 
@@ -1619,4 +1641,4 @@ export class OpenAIConverter extends BaseConverter {
 
 }
 
-export default OpenAIConverter;
\ No newline at end of file
+export default OpenAIConverter;
diff --git a/src/converters/strategies/OpenAIResponsesConverter.js b/src/converters/strategies/OpenAIResponsesConverter.js
index 858b9f2..a8082f6 100644
--- a/src/converters/strategies/OpenAIResponsesConverter.js
+++ b/src/converters/strategies/OpenAIResponsesConverter.js
@@ -380,9 +380,14 @@ export class OpenAIResponsesConverter extends BaseConverter {
 
         // 处理 reasoning effort
         if (responsesRequest.reasoning?.effort) {
+            const effort = String(responsesRequest.reasoning.effort || '').toLowerCase().trim();
+            let budgetTokens = 20000;
+            if (effort === 'low') budgetTokens = 2048;
+            else if (effort === 'medium') budgetTokens = 8192;
+            else if (effort === 'high') budgetTokens = 20000;
             claudeRequest.thinking = {
                 type: 'enabled',
-                budget_tokens: 1024 // 默认 budget
+                budget_tokens: budgetTokens
             };
         }
 
diff --git a/src/providers/claude/claude-kiro.js b/src/providers/claude/claude-kiro.js
index 883d36e..072e556 100644
--- a/src/providers/claude/claude-kiro.js
+++ b/src/providers/claude/claude-kiro.js
@@ -14,12 +14,14 @@ import { isRetryableNetworkError, MODEL_PROVIDER, formatExpiryLog } from '../../
 import { getProviderPoolManager } from '../../services/service-manager.js';
 
 const KIRO_THINKING = {
+    MIN_BUDGET_TOKENS: 1024,
     MAX_BUDGET_TOKENS: 24576,
     DEFAULT_BUDGET_TOKENS: 20000,
     START_TAG: '<thinking>',
     END_TAG: '</thinking>',
     MODE_TAG: '<thinking_mode>',
     MAX_LEN_TAG: '<max_thinking_length>',
+    EFFORT_TAG: '<thinking_effort>',
 };
 
 const KIRO_CONSTANTS = {
@@ -120,6 +122,42 @@ function findRealTag(text, tag, startIndex = 0) {
     }
 }
 
+function isWhitespaceOnly(text) {
+    if (text === null || text === undefined) return true;
+    return String(text).trim().length === 0;
+}
+
+/**
+ * Find a "real" thinking end tag that is not quoted/backticked and is followed by '\n\n'.
+ * This avoids prematurely closing a thinking block when the model mentions `</thinking>`
+ * inside the thinking content.
+ */
+function findRealThinkingEndTag(buffer, startIndex = 0) {
+    let searchStart = Math.max(0, startIndex);
+    while (true) {
+        const pos = findRealTag(buffer, KIRO_THINKING.END_TAG, searchStart);
+        if (pos === -1) return -1;
+        const after = buffer.slice(pos + KIRO_THINKING.END_TAG.length);
+        if (after.startsWith('\n\n')) return pos;
+        searchStart = pos + 1;
+    }
+}
+
+/**
+ * Find a "real" thinking end tag only when it is at the buffer end (after it is whitespace only).
+ * This is used for boundary-event scenarios (tool_use starts immediately after thinking, or stream end).
+ */
+function findRealThinkingEndTagAtBufferEnd(buffer, startIndex = 0) {
+    let searchStart = Math.max(0, startIndex);
+    while (true) {
+        const pos = findRealTag(buffer, KIRO_THINKING.END_TAG, searchStart);
+        if (pos === -1) return -1;
+        const after = buffer.slice(pos + KIRO_THINKING.END_TAG.length);
+        if (isWhitespaceOnly(after)) return pos;
+        searchStart = pos + 1;
+    }
+}
+
 /**
  * 通用的括号匹配函数 - 支持多种括号类型
  * @param {string} text - 要搜索的文本
@@ -742,18 +780,32 @@ async saveCredentialsToFile(filePath, newData) {
             value = KIRO_THINKING.DEFAULT_BUDGET_TOKENS;
         }
         value = Math.floor(value);
+        if (value < KIRO_THINKING.MIN_BUDGET_TOKENS) value = KIRO_THINKING.MIN_BUDGET_TOKENS;
         return Math.min(value, KIRO_THINKING.MAX_BUDGET_TOKENS);
     }
 
     _generateThinkingPrefix(thinking) {
-        if (!thinking || thinking.type !== 'enabled') return null;
-        const budget = this._normalizeThinkingBudgetTokens(thinking.budget_tokens);
-        return `<thinking_mode>enabled</thinking_mode><max_thinking_length>${budget}</max_thinking_length>`;
+        if (!thinking || typeof thinking !== 'object') return null;
+        const type = String(thinking.type || '').toLowerCase().trim();
+
+        if (type === 'enabled') {
+            const budget = this._normalizeThinkingBudgetTokens(thinking.budget_tokens);
+            return `<thinking_mode>enabled</thinking_mode><max_thinking_length>${budget}</max_thinking_length>`;
+        }
+
+        if (type === 'adaptive') {
+            const effortRaw = typeof thinking.effort === 'string' ? thinking.effort : '';
+            const effort = effortRaw.toLowerCase().trim();
+            const normalizedEffort = (effort === 'low' || effort === 'medium' || effort === 'high') ? effort : 'high';
+            return `<thinking_mode>adaptive</thinking_mode><thinking_effort>${normalizedEffort}</thinking_effort>`;
+        }
+
+        return null;
     }
 
     _hasThinkingPrefix(text) {
         if (!text) return false;
-        return text.includes(KIRO_THINKING.MODE_TAG) || text.includes(KIRO_THINKING.MAX_LEN_TAG);
+        return text.includes(KIRO_THINKING.MODE_TAG) || text.includes(KIRO_THINKING.MAX_LEN_TAG) || text.includes(KIRO_THINKING.EFFORT_TAG);
     }
 
     _toClaudeContentBlocksFromKiroText(content) {
@@ -767,8 +819,14 @@ async saveCredentialsToFile(filePath, newData) {
         
         const before = raw.slice(0, startPos);
         let rest = raw.slice(startPos + KIRO_THINKING.START_TAG.length);
-        
-        const endPosInRest = findRealTag(rest, KIRO_THINKING.END_TAG);
+
+        // Strip a single leading newline after `<thinking>` for cleaner blocks.
+        if (rest.startsWith('\r\n')) rest = rest.slice(2);
+        else if (rest.startsWith('\n')) rest = rest.slice(1);
+
+        let endPosInRest = findRealThinkingEndTag(rest);
+        if (endPosInRest === -1) endPosInRest = findRealThinkingEndTagAtBufferEnd(rest);
+
         let thinking = '';
         let after = '';
         if (endPosInRest === -1) {
@@ -779,11 +837,12 @@ async saveCredentialsToFile(filePath, newData) {
         }
         
         if (after.startsWith('\n\n')) after = after.slice(2);
+        if (isWhitespaceOnly(after)) after = '';
         
         const blocks = [];
-        if (before) blocks.push({ type: "text", text: before });
+        if (before && !isWhitespaceOnly(before)) blocks.push({ type: "text", text: before });
         blocks.push({ type: "thinking", thinking });
-        if (after) blocks.push({ type: "text", text: after });
+        if (after && !isWhitespaceOnly(after)) blocks.push({ type: "text", text: after });
         return blocks;
     }
 
@@ -887,62 +946,35 @@ async saveCredentialsToFile(filePath, newData) {
                 };
                 toolsContext = { tools: [placeholderTool] };
             } else {
-                const MAX_DESCRIPTION_LENGTH = 9216;
+            const MAX_DESCRIPTION_LENGTH = 9216;
 
-                let truncatedCount = 0;
-                const kiroTools = filteredTools
-                    .filter(tool => {
-                        // 过滤掉描述为空的工具
-                        if (!tool.description || tool.description.trim() === '') {
-                            logger.info(`[Kiro] Ignoring tool with empty description: ${tool.name}`);
-                            return false;
-                        }
-                        return true;
-                    })
-                    .map(tool => {
-                        let desc = tool.description || "";
-                        const originalLength = desc.length;
-                        
-                        if (desc.length > MAX_DESCRIPTION_LENGTH) {
-                            desc = desc.substring(0, MAX_DESCRIPTION_LENGTH) + "...";
-                            truncatedCount++;
-                            logger.info(`[Kiro] Truncated tool '${tool.name}' description: ${originalLength} -> ${desc.length} chars`);
-                        }
-                        
-                        return {
-                            toolSpecification: {
-                                name: tool.name,
-                                description: desc,
-                                inputSchema: {
-                                    json: tool.input_schema || {}
-                                }
-                            }
-                        };
-                    });
+            let truncatedCount = 0;
+            const kiroTools = filteredTools.map(tool => {
+                let desc = tool.description || "";
+                const originalLength = desc.length;
                 
-                if (truncatedCount > 0) {
-                    logger.info(`[Kiro] Truncated ${truncatedCount} tool description(s) to max ${MAX_DESCRIPTION_LENGTH} chars`);
+                if (desc.length > MAX_DESCRIPTION_LENGTH) {
+                    desc = desc.substring(0, MAX_DESCRIPTION_LENGTH) + "...";
+                    truncatedCount++;
+                    logger.info(`[Kiro] Truncated tool '${tool.name}' description: ${originalLength} -> ${desc.length} chars`);
                 }
-
-                // 检查过滤后是否还有有效工具
-                if (kiroTools.length === 0) {
-                    logger.info('[Kiro] All tools were filtered out (empty descriptions), adding placeholder tool');
-                    const placeholderTool = {
-                        toolSpecification: {
-                            name: "no_tool_available",
-                            description: "This is a placeholder tool when no other tools are available. It does nothing.",
-                            inputSchema: {
-                                json: {
-                                    type: "object",
-                                    properties: {}
-                                }
-                            }
+                
+                return {
+                    toolSpecification: {
+                        name: tool.name,
+                        description: desc,
+                        inputSchema: {
+                            json: tool.input_schema || {}
                         }
-                    };
-                    toolsContext = { tools: [placeholderTool] };
-                } else {
-                    toolsContext = { tools: kiroTools };
-                }
+                    }
+                };
+            });
+            
+            if (truncatedCount > 0) {
+                logger.info(`[Kiro] Truncated ${truncatedCount} tool description(s) to max ${MAX_DESCRIPTION_LENGTH} chars`);
+            }
+
+            toolsContext = { tools: kiroTools };
             }
         } else {
             // tools 为空或长度为 0 时，自动添加一个占位工具
@@ -1716,7 +1748,13 @@ async saveCredentialsToFile(filePath, newData) {
 
         try {
             const { responseText, toolCalls } = this._processApiResponse(response);
-            return this.buildClaudeResponse(responseText, false, 'assistant', model, toolCalls, inputTokens);
+            const thinkingType = requestBody?.thinking?.type;
+            const thinkingRequested = typeof thinkingType === 'string' &&
+                (thinkingType.toLowerCase() === 'enabled' || thinkingType.toLowerCase() === 'adaptive');
+            const contentForClaude = thinkingRequested
+                ? this._toClaudeContentBlocksFromKiroText(responseText)
+                : responseText;
+            return this.buildClaudeResponse(contentForClaude, false, 'assistant', model, toolCalls, inputTokens);
         } catch (error) {
             logger.error('[Kiro] Error in generateContent:', error);
             throw new Error(`Error processing response: ${error.message}`);
@@ -2076,17 +2114,22 @@ async saveCredentialsToFile(filePath, newData) {
         let contextUsagePercentage = null;
         const messageId = `${uuidv4()}`;
 
-        const thinkingRequested = requestBody?.thinking?.type === 'enabled';
+        const thinkingType = requestBody?.thinking?.type;
+        const thinkingRequested = typeof thinkingType === 'string' &&
+            (thinkingType.toLowerCase() === 'enabled' || thinkingType.toLowerCase() === 'adaptive');
 
         const streamState = {
             thinkingRequested,
             buffer: '',
+            pendingTextBeforeThinking: '',
             inThinking: false,
             thinkingExtracted: false,
             thinkingBlockIndex: null,
             textBlockIndex: null,
             nextBlockIndex: 0,
             stoppedBlocks: new Set(),
+            stripThinkingLeadingNewline: false,
+            stripTextLeadingNewlinesAfterThinking: false,
         };
 
         const ensureBlockStart = (blockType) => {
@@ -2196,24 +2239,58 @@ async saveCredentialsToFile(filePath, newData) {
                             const startPos = findRealTag(streamState.buffer, KIRO_THINKING.START_TAG);
                             if (startPos !== -1) {
                                 const before = streamState.buffer.slice(0, startPos);
-                                if (before) events.push(...createTextDeltaEvents(before));
+                                const beforeCombined = `${streamState.pendingTextBeforeThinking}${before}`;
+                                // Avoid creating meaningless text blocks before thinking.
+                                if (beforeCombined && !isWhitespaceOnly(beforeCombined)) {
+                                    events.push(...createTextDeltaEvents(beforeCombined));
+                                }
+                                streamState.pendingTextBeforeThinking = '';
 
                                 streamState.buffer = streamState.buffer.slice(startPos + KIRO_THINKING.START_TAG.length);
                                 streamState.inThinking = true;
+                                streamState.stripThinkingLeadingNewline = true;
                                 continue;
                             }
 
                             const safeLen = Math.max(0, streamState.buffer.length - KIRO_THINKING.START_TAG.length);
                             if (safeLen > 0) {
                                 const safeText = streamState.buffer.slice(0, safeLen);
-                                if (safeText) events.push(...createTextDeltaEvents(safeText));
+                                if (safeText) {
+                                    if (isWhitespaceOnly(safeText)) {
+                                        // Buffer whitespace until we know whether a thinking block appears.
+                                        // This prevents a leading text block from being created before thinking.
+                                        const maxKeep = 1024;
+                                        const remaining = maxKeep - streamState.pendingTextBeforeThinking.length;
+                                        if (remaining > 0) {
+                                            streamState.pendingTextBeforeThinking += safeText.slice(0, remaining);
+                                        }
+                                    } else {
+                                        const combined = `${streamState.pendingTextBeforeThinking}${safeText}`;
+                                        streamState.pendingTextBeforeThinking = '';
+                                        events.push(...createTextDeltaEvents(combined));
+                                    }
+                                }
                                 streamState.buffer = streamState.buffer.slice(safeLen);
                             }
                             break;
                         }
 
                         if (streamState.inThinking) {
-                            const endPos = findRealTag(streamState.buffer, KIRO_THINKING.END_TAG);
+                            // Strip a single leading newline after `<thinking>` (may be split across chunks).
+                            if (streamState.stripThinkingLeadingNewline) {
+                                if (streamState.buffer.startsWith('\r\n')) {
+                                    streamState.buffer = streamState.buffer.slice(2);
+                                    streamState.stripThinkingLeadingNewline = false;
+                                } else if (streamState.buffer.startsWith('\n')) {
+                                    streamState.buffer = streamState.buffer.slice(1);
+                                    streamState.stripThinkingLeadingNewline = false;
+                                } else if (streamState.buffer.length > 0) {
+                                    streamState.stripThinkingLeadingNewline = false;
+                                }
+                            }
+
+                            let endPos = findRealThinkingEndTag(streamState.buffer);
+                            if (endPos === -1) endPos = findRealThinkingEndTagAtBufferEnd(streamState.buffer);
                             if (endPos !== -1) {
                                 const thinkingPart = streamState.buffer.slice(0, endPos);
                                 if (thinkingPart) events.push(...createThinkingDeltaEvents(thinkingPart));
@@ -2221,13 +2298,13 @@ async saveCredentialsToFile(filePath, newData) {
                                 streamState.buffer = streamState.buffer.slice(endPos + KIRO_THINKING.END_TAG.length);
                                 streamState.inThinking = false;
                                 streamState.thinkingExtracted = true;
+                                streamState.stripThinkingLeadingNewline = false;
 
                                 events.push(...createThinkingDeltaEvents(""));
                                 events.push(...stopBlock(streamState.thinkingBlockIndex));
 
-                                if (streamState.buffer.startsWith('\n\n')) {
-                                    streamState.buffer = streamState.buffer.slice(2);
-                                }
+                                // Strip '\n\n' after the end tag once we switch back to text (may arrive in next chunk).
+                                streamState.stripTextLeadingNewlinesAfterThinking = true;
                                 continue;
                             }
 
@@ -2241,8 +2318,13 @@ async saveCredentialsToFile(filePath, newData) {
                         }
 
                         if (streamState.thinkingExtracted) {
-                            const rest = streamState.buffer;
+                            let rest = streamState.buffer;
                             streamState.buffer = '';
+                            if (streamState.stripTextLeadingNewlinesAfterThinking) {
+                                if (rest.startsWith('\r\n\r\n')) rest = rest.slice(4);
+                                else if (rest.startsWith('\n\n')) rest = rest.slice(2);
+                                streamState.stripTextLeadingNewlinesAfterThinking = false;
+                            }
                             if (rest) events.push(...createTextDeltaEvents(rest));
                             break;
                         }
@@ -2323,18 +2405,33 @@ async saveCredentialsToFile(filePath, newData) {
                 currentToolCall = null;
             }
 
-            if (thinkingRequested && streamState.buffer) {
+            if (thinkingRequested && (streamState.inThinking || streamState.buffer || streamState.pendingTextBeforeThinking)) {
                 if (streamState.inThinking) {
                     logger.warn('[Kiro] Incomplete thinking tag at stream end');
+                    // Strip a single leading newline after `<thinking>` if we haven't yet.
+                    if (streamState.stripThinkingLeadingNewline) {
+                        if (streamState.buffer.startsWith('\r\n')) streamState.buffer = streamState.buffer.slice(2);
+                        else if (streamState.buffer.startsWith('\n')) streamState.buffer = streamState.buffer.slice(1);
+                        streamState.stripThinkingLeadingNewline = false;
+                    }
                     yield* pushEvents(createThinkingDeltaEvents(streamState.buffer));
                     streamState.buffer = '';
                     yield* pushEvents(createThinkingDeltaEvents(""));
                     yield* pushEvents(stopBlock(streamState.thinkingBlockIndex));
                 } else if (!streamState.thinkingExtracted) {
-                    yield* pushEvents(createTextDeltaEvents(streamState.buffer));
+                    const remaining = `${streamState.pendingTextBeforeThinking}${streamState.buffer}`;
+                    streamState.pendingTextBeforeThinking = '';
+                    if (remaining) yield* pushEvents(createTextDeltaEvents(remaining));
                     streamState.buffer = '';
                 } else {
-                    yield* pushEvents(createTextDeltaEvents(streamState.buffer));
+                    let remaining = streamState.buffer;
+                    streamState.buffer = '';
+                    if (streamState.stripTextLeadingNewlinesAfterThinking) {
+                        if (remaining.startsWith('\r\n\r\n')) remaining = remaining.slice(4);
+                        else if (remaining.startsWith('\n\n')) remaining = remaining.slice(2);
+                        streamState.stripTextLeadingNewlinesAfterThinking = false;
+                    }
+                    if (remaining) yield* pushEvents(createTextDeltaEvents(remaining));
                     streamState.buffer = '';
                 }
             }
@@ -2457,9 +2554,17 @@ async saveCredentialsToFile(filePath, newData) {
         }
         
         // Count thinking prefix tokens if thinking is enabled
-        if (requestBody.thinking?.type === 'enabled') {
-            const budget = this._normalizeThinkingBudgetTokens(requestBody.thinking.budget_tokens);
-            allText += `<thinking_mode>enabled</thinking_mode><max_thinking_length>${budget}</max_thinking_length>`;
+        if (requestBody.thinking?.type && typeof requestBody.thinking.type === 'string') {
+            const t = requestBody.thinking.type.toLowerCase().trim();
+            if (t === 'enabled') {
+                const budget = this._normalizeThinkingBudgetTokens(requestBody.thinking.budget_tokens);
+                allText += `<thinking_mode>enabled</thinking_mode><max_thinking_length>${budget}</max_thinking_length>`;
+            } else if (t === 'adaptive') {
+                const effortRaw = typeof requestBody.thinking.effort === 'string' ? requestBody.thinking.effort : '';
+                const effort = effortRaw.toLowerCase().trim();
+                const normalizedEffort = (effort === 'low' || effort === 'medium' || effort === 'high') ? effort : 'high';
+                allText += `<thinking_mode>adaptive</thinking_mode><thinking_effort>${normalizedEffort}</thinking_effort>`;
+            }
         }
         
         // Count all messages tokens
@@ -2609,9 +2714,31 @@ async saveCredentialsToFile(filePath, newData) {
         } else {
             // Non-streaming response (full message object)
             const contentArray = [];
-            let stopReason = "end_turn";
             let outputTokens = 0;
 
+            // 1) Content blocks (text/thinking) first.
+            if (Array.isArray(content)) {
+                for (const block of content) {
+                    if (!block || typeof block !== 'object') continue;
+                    if (block.type === 'text' && typeof block.text === 'string') {
+                        contentArray.push({ type: 'text', text: block.text });
+                        outputTokens += this.countTextTokens(block.text);
+                    } else if (block.type === 'thinking' && typeof block.thinking === 'string') {
+                        contentArray.push({ type: 'thinking', thinking: block.thinking });
+                        outputTokens += this.countTextTokens(block.thinking);
+                    } else if (typeof block.text === 'string' && block.text) {
+                        // Best-effort fallback for unknown blocks carrying plain text.
+                        contentArray.push({ type: 'text', text: block.text });
+                        outputTokens += this.countTextTokens(block.text);
+                    }
+                }
+            } else if (content) {
+                contentArray.push({ type: "text", text: content });
+                outputTokens += this.countTextTokens(content);
+            }
+
+            // 2) Append tool_use blocks (if any).
+            let stopReason = "end_turn";
             if (toolCalls && toolCalls.length > 0) {
                 for (const tc of toolCalls) {
                     let inputObject;
@@ -2633,13 +2760,7 @@ async saveCredentialsToFile(filePath, newData) {
                     });
                     outputTokens += this.countTextTokens(tc.function.arguments);
                 }
-                stopReason = "tool_use"; // Set stop_reason to "tool_use" when toolCalls exist
-            } else if (content) {
-                contentArray.push({
-                    type: "text",
-                    text: content
-                });
-                outputTokens += this.countTextTokens(content);
+                stopReason = "tool_use";
             }
 
             return {
@@ -2876,4 +2997,3 @@ async saveCredentialsToFile(filePath, newData) {
         }
     }
 }
-
diff --git a/tests/claude-converter-thinking.test.js b/tests/claude-converter-thinking.test.js
new file mode 100644
index 0000000..2e654e4
--- /dev/null
+++ b/tests/claude-converter-thinking.test.js
@@ -0,0 +1,43 @@
+import { ClaudeConverter } from '../src/converters/strategies/ClaudeConverter.js';
+
+describe('ClaudeConverter thinking -> OpenAI reasoning_content', () => {
+    let converter;
+
+    beforeEach(() => {
+        converter = new ClaudeConverter();
+    });
+
+    test('toOpenAIResponse surfaces thinking blocks as reasoning_content', () => {
+        const claudeResponse = {
+            content: [
+                { type: 'thinking', thinking: 'x' },
+                { type: 'text', text: 'y' }
+            ],
+            stop_reason: 'end_turn',
+            usage: { input_tokens: 1, output_tokens: 2 }
+        };
+
+        const openai = converter.toOpenAIResponse(claudeResponse, 'claude-sonnet-4-5');
+        expect(openai.choices[0].message.content).toBe('y');
+        expect(openai.choices[0].message.reasoning_content).toBe('x');
+    });
+
+    test('toOpenAIResponse includes tool_calls and reasoning_content together', () => {
+        const claudeResponse = {
+            content: [
+                { type: 'thinking', thinking: 'r' },
+                { type: 'text', text: 't' },
+                { type: 'tool_use', id: 'toolu_1', name: 'my_tool', input: { a: 1 } }
+            ],
+            stop_reason: 'tool_use',
+            usage: { input_tokens: 1, output_tokens: 2 }
+        };
+
+        const openai = converter.toOpenAIResponse(claudeResponse, 'claude-sonnet-4-5');
+        expect(openai.choices[0].message.content).toBe('t');
+        expect(openai.choices[0].message.reasoning_content).toBe('r');
+        expect(openai.choices[0].message.tool_calls).toHaveLength(1);
+        expect(openai.choices[0].message.tool_calls[0].function.name).toBe('my_tool');
+    });
+});
+
diff --git a/tests/kiro-thinking-parsing.test.js b/tests/kiro-thinking-parsing.test.js
new file mode 100644
index 0000000..8baccd5
--- /dev/null
+++ b/tests/kiro-thinking-parsing.test.js
@@ -0,0 +1,40 @@
+import { KiroApiService } from '../src/providers/claude/claude-kiro.js';
+
+describe('KiroApiService thinking tag parsing', () => {
+    let svc;
+
+    beforeEach(() => {
+        svc = new KiroApiService({});
+    });
+
+    test('splits <thinking>...</thinking> into Claude content blocks', () => {
+        const blocks = svc._toClaudeContentBlocksFromKiroText('<thinking>a</thinking>\n\nhello');
+        expect(blocks).toEqual([
+            { type: 'thinking', thinking: 'a' },
+            { type: 'text', text: 'hello' }
+        ]);
+    });
+
+    test('ignores quoted </thinking> inside thinking content', () => {
+        const blocks = svc._toClaudeContentBlocksFromKiroText('<thinking>about `</thinking>` tag</thinking>\n\nhi');
+        expect(blocks).toEqual([
+            { type: 'thinking', thinking: 'about `</thinking>` tag' },
+            { type: 'text', text: 'hi' }
+        ]);
+    });
+
+    test('does not treat </thinking> without delimiter as a real end tag', () => {
+        const blocks = svc._toClaudeContentBlocksFromKiroText('<thinking>a</thinking>hello');
+        expect(blocks).toEqual([
+            { type: 'thinking', thinking: 'a</thinking>hello' }
+        ]);
+    });
+
+    test('treats </thinking> at buffer end as an end tag', () => {
+        const blocks = svc._toClaudeContentBlocksFromKiroText('<thinking>a</thinking>');
+        expect(blocks).toEqual([
+            { type: 'thinking', thinking: 'a' }
+        ]);
+    });
+});
+
diff --git a/tests/openai-converter-thinking.test.js b/tests/openai-converter-thinking.test.js
new file mode 100644
index 0000000..5ab6251
--- /dev/null
+++ b/tests/openai-converter-thinking.test.js
@@ -0,0 +1,55 @@
+import { OpenAIConverter } from '../src/converters/strategies/OpenAIConverter.js';
+
+describe('OpenAIConverter thinking passthrough', () => {
+    let converter;
+
+    beforeEach(() => {
+        converter = new OpenAIConverter();
+    });
+
+    test('toClaudeRequest maps extra_body.anthropic.thinking enabled', () => {
+        const openaiRequest = {
+            model: 'claude-sonnet-4-5',
+            messages: [{ role: 'user', content: 'hi' }],
+            extra_body: {
+                anthropic: {
+                    thinking: { type: 'enabled', budget_tokens: '10000' }
+                }
+            }
+        };
+
+        const claudeRequest = converter.toClaudeRequest(openaiRequest);
+        expect(claudeRequest.thinking).toEqual({ type: 'enabled', budget_tokens: 10000 });
+    });
+
+    test('toClaudeRequest maps extra_body.anthropic.thinking adaptive', () => {
+        const openaiRequest = {
+            model: 'claude-sonnet-4-5',
+            messages: [{ role: 'user', content: 'hi' }],
+            extra_body: {
+                anthropic: {
+                    thinking: { type: 'adaptive', effort: 'Medium' }
+                }
+            }
+        };
+
+        const claudeRequest = converter.toClaudeRequest(openaiRequest);
+        expect(claudeRequest.thinking).toEqual({ type: 'adaptive', effort: 'medium' });
+    });
+
+    test('toClaudeRequest ignores invalid thinking objects', () => {
+        const openaiRequest = {
+            model: 'claude-sonnet-4-5',
+            messages: [{ role: 'user', content: 'hi' }],
+            extra_body: {
+                anthropic: {
+                    thinking: 'enabled'
+                }
+            }
+        };
+
+        const claudeRequest = converter.toClaudeRequest(openaiRequest);
+        expect(claudeRequest.thinking).toBeUndefined();
+    });
+});
+
diff --git a/tests/openai-responses-converter-thinking.test.js b/tests/openai-responses-converter-thinking.test.js
new file mode 100644
index 0000000..70290e0
--- /dev/null
+++ b/tests/openai-responses-converter-thinking.test.js
@@ -0,0 +1,27 @@
+import { OpenAIResponsesConverter } from '../src/converters/strategies/OpenAIResponsesConverter.js';
+
+describe('OpenAIResponsesConverter reasoning -> thinking mapping', () => {
+    let converter;
+
+    beforeEach(() => {
+        converter = new OpenAIResponsesConverter();
+    });
+
+    test.each([
+        ['low', 2048],
+        ['medium', 8192],
+        ['high', 20000],
+        ['unknown', 20000],
+    ])('toClaudeRequest maps reasoning.effort=%s to budget_tokens=%i', (effort, budgetTokens) => {
+        const responsesRequest = {
+            model: 'claude-sonnet-4-5',
+            max_output_tokens: 64,
+            reasoning: { effort },
+            input: [{ role: 'user', content: 'hi' }]
+        };
+
+        const claudeRequest = converter.toClaudeRequest(responsesRequest);
+        expect(claudeRequest.thinking).toEqual({ type: 'enabled', budget_tokens: budgetTokens });
+    });
+});
+