Add reverse mappings for original tool names and improve error logging

- Introduced reverse mapping logic for tool names in translators to restore original names when shortened.
- Enhanced error handling by logging API response errors consistently across handlers.
- Refactored request and response loggers to include API error details, improving debugging capabilities.
- Integrated robust tool name shortening and uniqueness mechanisms for OpenAI, Gemini, and Claude requests.
- Improved handler retry logic to properly capture and respond to errors.

internal/api/handlers/claude/code_handlers.go

@@ -139,12 +139,13 @@ func (h *ClaudeCodeAPIHandler) handleStreamingResponse(c *gin.Context, rawJSON [
 			}
 		}
 	}()
+
+	var errorResponse *interfaces.ErrorMessage
 	retryCount := 0
 	// Main client rotation loop with quota management
 	// This loop implements a sophisticated load balancing and failover mechanism
 outLoop:
 	for retryCount <= h.Cfg.RequestRetry {
-		var errorResponse *interfaces.ErrorMessage
 		cliClient, errorResponse = h.GetClient(modelName)
 		if errorResponse != nil {
 			c.Status(errorResponse.StatusCode)
@@ -185,6 +186,8 @@ outLoop:
 			// This manages various error conditions and implements retry logic
 			case errInfo, okError := <-errChan:
 				if okError {
+					errorResponse = errInfo
+					h.LoggingAPIResponseError(cliCtx, errInfo)
 					// Special handling for quota exceeded errors
 					// If configured, attempt to switch to a different project/client
 					switch errInfo.StatusCode {
@@ -221,4 +224,12 @@ outLoop:
 			}
 		}
 	}
+
+	if errorResponse != nil {
+		c.Status(errorResponse.StatusCode)
+		_, _ = fmt.Fprint(c.Writer, errorResponse.Error.Error())
+		flusher.Flush()
+		cliCancel(errorResponse.Error)
+		return
+	}
 }

internal/api/handlers/gemini/gemini-cli_handlers.go

@@ -169,10 +169,10 @@ func (h *GeminiCLIAPIHandler) handleInternalStreamGenerateContent(c *gin.Context
 		}
 	}()
 
+	var errorResponse *interfaces.ErrorMessage
 	retryCount := 0
 outLoop:
 	for retryCount <= h.Cfg.RequestRetry {
-		var errorResponse *interfaces.ErrorMessage
 		cliClient, errorResponse = h.GetClient(modelName)
 		if errorResponse != nil {
 			c.Status(errorResponse.StatusCode)
@@ -208,6 +208,9 @@ outLoop:
 			// Handle errors from the backend.
 			case err, okError := <-errChan:
 				if okError {
+					errorResponse = err
+					h.LoggingAPIResponseError(cliCtx, err)
+
 					switch err.StatusCode {
 					case 429:
 						if h.Cfg.QuotaExceeded.SwitchProject {
@@ -232,6 +235,13 @@ outLoop:
 			}
 		}
 	}
+	if errorResponse != nil {
+		c.Status(errorResponse.StatusCode)
+		_, _ = fmt.Fprint(c.Writer, errorResponse.Error.Error())
+		flusher.Flush()
+		cliCancel(errorResponse.Error)
+		return
+	}
 }
 
 // handleInternalGenerateContent handles non-streaming content generation requests.
@@ -252,9 +262,9 @@ func (h *GeminiCLIAPIHandler) handleInternalGenerateContent(c *gin.Context, rawJ
 		}
 	}()
 
+	var errorResponse *interfaces.ErrorMessage
 	retryCount := 0
 	for retryCount <= h.Cfg.RequestRetry {
-		var errorResponse *interfaces.ErrorMessage
 		cliClient, errorResponse = h.GetClient(modelName)
 		if errorResponse != nil {
 			c.Status(errorResponse.StatusCode)
@@ -265,6 +275,9 @@ func (h *GeminiCLIAPIHandler) handleInternalGenerateContent(c *gin.Context, rawJ
 
 		resp, err := cliClient.SendRawMessage(cliCtx, modelName, rawJSON, "")
 		if err != nil {
+			errorResponse = err
+			h.LoggingAPIResponseError(cliCtx, err)
+
 			switch err.StatusCode {
 			case 429:
 				if h.Cfg.QuotaExceeded.SwitchProject {
@@ -296,4 +309,11 @@ func (h *GeminiCLIAPIHandler) handleInternalGenerateContent(c *gin.Context, rawJ
 			break
 		}
 	}
+	if errorResponse != nil {
+		c.Status(errorResponse.StatusCode)
+		_, _ = c.Writer.Write([]byte(errorResponse.Error.Error()))
+		cliCancel(errorResponse.Error)
+		return
+	}
+
 }

internal/api/handlers/gemini/gemini_handlers.go

@@ -221,10 +221,10 @@ func (h *GeminiAPIHandler) handleStreamGenerateContent(c *gin.Context, modelName
 		}
 	}()
 
+	var errorResponse *interfaces.ErrorMessage
 	retryCount := 0
 outLoop:
 	for retryCount <= h.Cfg.RequestRetry {
-		var errorResponse *interfaces.ErrorMessage
 		cliClient, errorResponse = h.GetClient(modelName)
 		if errorResponse != nil {
 			c.Status(errorResponse.StatusCode)
@@ -263,6 +263,9 @@ outLoop:
 			// Handle errors from the backend.
 			case err, okError := <-errChan:
 				if okError {
+					errorResponse = err
+					h.LoggingAPIResponseError(cliCtx, err)
+
 					switch err.StatusCode {
 					case 429:
 						if h.Cfg.QuotaExceeded.SwitchProject {
@@ -287,6 +290,13 @@ outLoop:
 			}
 		}
 	}
+	if errorResponse != nil {
+		c.Status(errorResponse.StatusCode)
+		_, _ = fmt.Fprint(c.Writer, errorResponse.Error.Error())
+		flusher.Flush()
+		cliCancel(errorResponse.Error)
+		return
+	}
 }
 
 // handleCountTokens handles token counting requests for Gemini models.
@@ -365,9 +375,9 @@ func (h *GeminiAPIHandler) handleGenerateContent(c *gin.Context, modelName strin
 		}
 	}()
 
+	var errorResponse *interfaces.ErrorMessage
 	retryCount := 0
 	for retryCount <= h.Cfg.RequestRetry {
-		var errorResponse *interfaces.ErrorMessage
 		cliClient, errorResponse = h.GetClient(modelName)
 		if errorResponse != nil {
 			c.Status(errorResponse.StatusCode)
@@ -378,6 +388,9 @@ func (h *GeminiAPIHandler) handleGenerateContent(c *gin.Context, modelName strin
 
 		resp, err := cliClient.SendRawMessage(cliCtx, modelName, rawJSON, alt)
 		if err != nil {
+			errorResponse = err
+			h.LoggingAPIResponseError(cliCtx, err)
+
 			switch err.StatusCode {
 			case 429:
 				if h.Cfg.QuotaExceeded.SwitchProject {
@@ -409,4 +422,10 @@ func (h *GeminiAPIHandler) handleGenerateContent(c *gin.Context, modelName strin
 			break
 		}
 	}
+	if errorResponse != nil {
+		c.Status(errorResponse.StatusCode)
+		_, _ = c.Writer.Write([]byte(errorResponse.Error.Error()))
+		cliCancel(errorResponse.Error)
+		return
+	}
 }

internal/api/handlers/handlers.go

@@ -235,6 +235,22 @@ func (h *BaseAPIHandler) GetContextWithCancel(handler interfaces.APIHandler, c *
 	}
 }
 
+func (h *BaseAPIHandler) LoggingAPIResponseError(ctx context.Context, err *interfaces.ErrorMessage) {
+	if h.Cfg.RequestLog {
+		if ginContext, ok := ctx.Value("gin").(*gin.Context); ok {
+			if apiResponseErrors, isExist := ginContext.Get("API_RESPONSE_ERROR"); isExist {
+				if slicesAPIResponseError, isOk := apiResponseErrors.([]*interfaces.ErrorMessage); isOk {
+					slicesAPIResponseError = append(slicesAPIResponseError, err)
+					ginContext.Set("API_RESPONSE_ERROR", slicesAPIResponseError)
+				}
+			} else {
+				// Create new response data entry
+				ginContext.Set("API_RESPONSE_ERROR", []*interfaces.ErrorMessage{err})
+			}
+		}
+	}
+}
+
 // APIHandlerCancelFunc is a function type for canceling an API handler's context.
 // It can optionally accept parameters, which are used for logging the response.
 type APIHandlerCancelFunc func(params ...interface{})

internal/api/handlers/openai/openai_handlers.go

@@ -387,9 +387,9 @@ func (h *OpenAIAPIHandler) handleNonStreamingResponse(c *gin.Context, rawJSON []
 		}
 	}()
 
+	var errorResponse *interfaces.ErrorMessage
 	retryCount := 0
 	for retryCount <= h.Cfg.RequestRetry {
-		var errorResponse *interfaces.ErrorMessage
 		cliClient, errorResponse = h.GetClient(modelName)
 		if errorResponse != nil {
 			c.Status(errorResponse.StatusCode)
@@ -400,6 +400,9 @@ func (h *OpenAIAPIHandler) handleNonStreamingResponse(c *gin.Context, rawJSON []
 
 		resp, err := cliClient.SendRawMessage(cliCtx, modelName, rawJSON, "")
 		if err != nil {
+			errorResponse = err
+			h.LoggingAPIResponseError(cliCtx, err)
+
 			switch err.StatusCode {
 			case 429:
 				if h.Cfg.QuotaExceeded.SwitchProject {
@@ -431,6 +434,12 @@ func (h *OpenAIAPIHandler) handleNonStreamingResponse(c *gin.Context, rawJSON []
 			break
 		}
 	}
+	if errorResponse != nil {
+		c.Status(errorResponse.StatusCode)
+		_, _ = c.Writer.Write([]byte(errorResponse.Error.Error()))
+		cliCancel(errorResponse.Error)
+		return
+	}
 }
 
 // handleStreamingResponse handles streaming responses for Gemini models.
@@ -471,10 +480,10 @@ func (h *OpenAIAPIHandler) handleStreamingResponse(c *gin.Context, rawJSON []byt
 		}
 	}()
 
+	var errorResponse *interfaces.ErrorMessage
 	retryCount := 0
 outLoop:
 	for retryCount <= h.Cfg.RequestRetry {
-		var errorResponse *interfaces.ErrorMessage
 		cliClient, errorResponse = h.GetClient(modelName)
 		if errorResponse != nil {
 			c.Status(errorResponse.StatusCode)
@@ -511,6 +520,9 @@ outLoop:
 			// Handle errors from the backend.
 			case err, okError := <-errChan:
 				if okError {
+					errorResponse = err
+					h.LoggingAPIResponseError(cliCtx, err)
+
 					switch err.StatusCode {
 					case 429:
 						if h.Cfg.QuotaExceeded.SwitchProject {
@@ -535,6 +547,13 @@ outLoop:
 			}
 		}
 	}
+	if errorResponse != nil {
+		c.Status(errorResponse.StatusCode)
+		_, _ = fmt.Fprint(c.Writer, errorResponse.Error.Error())
+		flusher.Flush()
+		cliCancel(errorResponse.Error)
+		return
+	}
 }
 
 // handleCompletionsNonStreamingResponse handles non-streaming completions responses.
@@ -562,9 +581,9 @@ func (h *OpenAIAPIHandler) handleCompletionsNonStreamingResponse(c *gin.Context,
 		}
 	}()
 
+	var errorResponse *interfaces.ErrorMessage
 	retryCount := 0
 	for retryCount <= h.Cfg.RequestRetry {
-		var errorResponse *interfaces.ErrorMessage
 		cliClient, errorResponse = h.GetClient(modelName)
 		if errorResponse != nil {
 			c.Status(errorResponse.StatusCode)
@@ -576,6 +595,9 @@ func (h *OpenAIAPIHandler) handleCompletionsNonStreamingResponse(c *gin.Context,
 		// Send the converted chat completions request
 		resp, err := cliClient.SendRawMessage(cliCtx, modelName, chatCompletionsJSON, "")
 		if err != nil {
+			errorResponse = err
+			h.LoggingAPIResponseError(cliCtx, err)
+
 			switch err.StatusCode {
 			case 429:
 				if h.Cfg.QuotaExceeded.SwitchProject {
@@ -601,6 +623,13 @@ func (h *OpenAIAPIHandler) handleCompletionsNonStreamingResponse(c *gin.Context,
 			break
 		}
 	}
+	if errorResponse != nil {
+		c.Status(errorResponse.StatusCode)
+		_, _ = c.Writer.Write([]byte(errorResponse.Error.Error()))
+		cliCancel(errorResponse.Error)
+		return
+	}
+
 }
 
 // handleCompletionsStreamingResponse handles streaming completions responses.
@@ -644,10 +673,10 @@ func (h *OpenAIAPIHandler) handleCompletionsStreamingResponse(c *gin.Context, ra
 		}
 	}()
 
+	var errorResponse *interfaces.ErrorMessage
 	retryCount := 0
 outLoop:
 	for retryCount <= h.Cfg.RequestRetry {
-		var errorResponse *interfaces.ErrorMessage
 		cliClient, errorResponse = h.GetClient(modelName)
 		if errorResponse != nil {
 			c.Status(errorResponse.StatusCode)
@@ -689,6 +718,9 @@ outLoop:
 			// Handle errors from the backend.
 			case err, okError := <-errChan:
 				if okError {
+					errorResponse = err
+					h.LoggingAPIResponseError(cliCtx, err)
+
 					switch err.StatusCode {
 					case 429:
 						if h.Cfg.QuotaExceeded.SwitchProject {
@@ -713,4 +745,11 @@ outLoop:
 			}
 		}
 	}
+	if errorResponse != nil {
+		c.Status(errorResponse.StatusCode)
+		_, _ = fmt.Fprint(c.Writer, errorResponse.Error.Error())
+		flusher.Flush()
+		cliCancel(errorResponse.Error)
+		return
+	}
 }

internal/api/handlers/openai/openai_responses_handlers.go

@@ -115,9 +115,9 @@ func (h *OpenAIResponsesAPIHandler) handleNonStreamingResponse(c *gin.Context, r
 		}
 	}()
 
+	var errorResponse *interfaces.ErrorMessage
 	retryCount := 0
 	for retryCount <= h.Cfg.RequestRetry {
-		var errorResponse *interfaces.ErrorMessage
 		cliClient, errorResponse = h.GetClient(modelName)
 		if errorResponse != nil {
 			c.Status(errorResponse.StatusCode)
@@ -128,6 +128,9 @@ func (h *OpenAIResponsesAPIHandler) handleNonStreamingResponse(c *gin.Context, r
 
 		resp, err := cliClient.SendRawMessage(cliCtx, modelName, rawJSON, "")
 		if err != nil {
+			errorResponse = err
+			h.LoggingAPIResponseError(cliCtx, err)
+
 			switch err.StatusCode {
 			case 429:
 				if h.Cfg.QuotaExceeded.SwitchProject {
@@ -159,6 +162,13 @@ func (h *OpenAIResponsesAPIHandler) handleNonStreamingResponse(c *gin.Context, r
 			break
 		}
 	}
+	if errorResponse != nil {
+		c.Status(errorResponse.StatusCode)
+		_, _ = c.Writer.Write([]byte(errorResponse.Error.Error()))
+		cliCancel(errorResponse.Error)
+		return
+	}
+
 }
 
 // handleStreamingResponse handles streaming responses for Gemini models.
@@ -199,10 +209,10 @@ func (h *OpenAIResponsesAPIHandler) handleStreamingResponse(c *gin.Context, rawJ
 		}
 	}()
 
+	var errorResponse *interfaces.ErrorMessage
 	retryCount := 0
 outLoop:
 	for retryCount <= h.Cfg.RequestRetry {
-		var errorResponse *interfaces.ErrorMessage
 		cliClient, errorResponse = h.GetClient(modelName)
 		if errorResponse != nil {
 			c.Status(errorResponse.StatusCode)
@@ -238,6 +248,8 @@ outLoop:
 			// Handle errors from the backend.
 			case err, okError := <-errChan:
 				if okError {
+					errorResponse = err
+					h.LoggingAPIResponseError(cliCtx, err)
 					switch err.StatusCode {
 					case 429:
 						if h.Cfg.QuotaExceeded.SwitchProject {
@@ -262,4 +274,12 @@ outLoop:
 			}
 		}
 	}
+
+	if errorResponse != nil {
+		c.Status(errorResponse.StatusCode)
+		_, _ = fmt.Fprint(c.Writer, errorResponse.Error.Error())
+		flusher.Flush()
+		cliCancel(errorResponse.Error)
+		return
+	}
 }

internal/api/middleware/response_writer.go

@@ -8,6 +8,7 @@ import (
 	"strings"
 
 	"github.com/gin-gonic/gin"
+	"github.com/luispater/CLIProxyAPI/internal/interfaces"
 	"github.com/luispater/CLIProxyAPI/internal/logging"
 )
 
@@ -240,6 +241,16 @@ func (w *ResponseWriterWrapper) Finalize(c *gin.Context) error {
 			}
 		}
 
+		var slicesAPIResponseError []*interfaces.ErrorMessage
+		apiResponseError, isExist := c.Get("API_RESPONSE_ERROR")
+		if isExist {
+			var ok bool
+			slicesAPIResponseError, ok = apiResponseError.([]*interfaces.ErrorMessage)
+			if !ok {
+				slicesAPIResponseError = nil
+			}
+		}
+
 		// Log complete non-streaming response
 		return w.logger.LogRequest(
 			w.requestInfo.URL,
@@ -251,6 +262,7 @@ func (w *ResponseWriterWrapper) Finalize(c *gin.Context) error {
 			w.body.Bytes(),
 			apiRequestBody,
 			apiResponseBody,
+			slicesAPIResponseError,
 		)
 	}
 

internal/logging/request_logger.go

@@ -14,6 +14,8 @@ import (
 	"regexp"
 	"strings"
 	"time"
+
+	"github.com/luispater/CLIProxyAPI/internal/interfaces"
 )
 
 // RequestLogger defines the interface for logging HTTP requests and responses.
@@ -34,7 +36,7 @@ type RequestLogger interface {
 	//
 	// Returns:
 	//   - error: An error if logging fails, nil otherwise
-	LogRequest(url, method string, requestHeaders map[string][]string, body []byte, statusCode int, responseHeaders map[string][]string, response, apiRequest, apiResponse []byte) error
+	LogRequest(url, method string, requestHeaders map[string][]string, body []byte, statusCode int, responseHeaders map[string][]string, response, apiRequest, apiResponse []byte, apiResponseErrors []*interfaces.ErrorMessage) error
 
 	// LogStreamingRequest initiates logging for a streaming request and returns a writer for chunks.
 	//
@@ -139,7 +141,7 @@ func (l *FileRequestLogger) SetEnabled(enabled bool) {
 //
 // Returns:
 //   - error: An error if logging fails, nil otherwise
-func (l *FileRequestLogger) LogRequest(url, method string, requestHeaders map[string][]string, body []byte, statusCode int, responseHeaders map[string][]string, response, apiRequest, apiResponse []byte) error {
+func (l *FileRequestLogger) LogRequest(url, method string, requestHeaders map[string][]string, body []byte, statusCode int, responseHeaders map[string][]string, response, apiRequest, apiResponse []byte, apiResponseErrors []*interfaces.ErrorMessage) error {
 	if !l.enabled {
 		return nil
 	}
@@ -161,7 +163,7 @@ func (l *FileRequestLogger) LogRequest(url, method string, requestHeaders map[st
 	}
 
 	// Create log content
-	content := l.formatLogContent(url, method, requestHeaders, body, apiRequest, apiResponse, decompressedResponse, statusCode, responseHeaders)
+	content := l.formatLogContent(url, method, requestHeaders, body, apiRequest, apiResponse, decompressedResponse, statusCode, responseHeaders, apiResponseErrors)
 
 	// Write to file
 	if err = os.WriteFile(filePath, []byte(content), 0644); err != nil {
@@ -310,7 +312,7 @@ func (l *FileRequestLogger) sanitizeForFilename(path string) string {
 //
 // Returns:
 //   - string: The formatted log content
-func (l *FileRequestLogger) formatLogContent(url, method string, headers map[string][]string, body, apiRequest, apiResponse, response []byte, status int, responseHeaders map[string][]string) string {
+func (l *FileRequestLogger) formatLogContent(url, method string, headers map[string][]string, body, apiRequest, apiResponse, response []byte, status int, responseHeaders map[string][]string, apiResponseErrors []*interfaces.ErrorMessage) string {
 	var content strings.Builder
 
 	// Request info
@@ -320,6 +322,13 @@ func (l *FileRequestLogger) formatLogContent(url, method string, headers map[str
 	content.Write(apiRequest)
 	content.WriteString("\n\n")
 
+	for i := 0; i < len(apiResponseErrors); i++ {
+		content.WriteString("=== API ERROR RESPONSE ===\n")
+		content.WriteString(fmt.Sprintf("HTTP Status: %d\n", apiResponseErrors[i].StatusCode))
+		content.WriteString(apiResponseErrors[i].Error.Error())
+		content.WriteString("\n\n")
+	}
+
 	content.WriteString("=== API RESPONSE ===\n")
 	content.Write(apiResponse)
 	content.WriteString("\n\n")

internal/translator/codex/claude/codex_claude_request.go

@@ -8,6 +8,8 @@ package claude
 import (
 	"bytes"
 	"fmt"
+	"strconv"
+	"strings"
 
 	"github.com/luispater/CLIProxyAPI/internal/misc"
 	"github.com/tidwall/gjson"
@@ -94,7 +96,17 @@ func ConvertClaudeRequestToCodex(modelName string, inputRawJSON []byte, _ bool)
 						// Handle tool use content by creating function call message.
 						functionCallMessage := `{"type":"function_call"}`
 						functionCallMessage, _ = sjson.Set(functionCallMessage, "call_id", messageContentResult.Get("id").String())
-						functionCallMessage, _ = sjson.Set(functionCallMessage, "name", messageContentResult.Get("name").String())
+						{
+							// Shorten tool name if needed based on declared tools
+							name := messageContentResult.Get("name").String()
+							toolMap := buildReverseMapFromClaudeOriginalToShort(rawJSON)
+							if short, ok := toolMap[name]; ok {
+								name = short
+							} else {
+								name = shortenNameIfNeeded(name)
+							}
+							functionCallMessage, _ = sjson.Set(functionCallMessage, "name", name)
+						}
 						functionCallMessage, _ = sjson.Set(functionCallMessage, "arguments", messageContentResult.Get("input").Raw)
 						template, _ = sjson.SetRaw(template, "input.-1", functionCallMessage)
 					} else if contentType == "tool_result" {
@@ -130,10 +142,29 @@ func ConvertClaudeRequestToCodex(modelName string, inputRawJSON []byte, _ bool)
 		template, _ = sjson.SetRaw(template, "tools", `[]`)
 		template, _ = sjson.Set(template, "tool_choice", `auto`)
 		toolResults := toolsResult.Array()
+		// Build short name map from declared tools
+		var names []string
+		for i := 0; i < len(toolResults); i++ {
+			n := toolResults[i].Get("name").String()
+			if n != "" {
+				names = append(names, n)
+			}
+		}
+		shortMap := buildShortNameMap(names)
 		for i := 0; i < len(toolResults); i++ {
 			toolResult := toolResults[i]
 			tool := toolResult.Raw
 			tool, _ = sjson.Set(tool, "type", "function")
+			// Apply shortened name if needed
+			if v := toolResult.Get("name"); v.Exists() {
+				name := v.String()
+				if short, ok := shortMap[name]; ok {
+					name = short
+				} else {
+					name = shortenNameIfNeeded(name)
+				}
+				tool, _ = sjson.Set(tool, "name", name)
+			}
 			tool, _ = sjson.SetRaw(tool, "parameters", toolResult.Get("input_schema").Raw)
 			tool, _ = sjson.Delete(tool, "input_schema")
 			tool, _ = sjson.Delete(tool, "parameters.$schema")
@@ -170,3 +201,97 @@ func ConvertClaudeRequestToCodex(modelName string, inputRawJSON []byte, _ bool)
 
 	return []byte(template)
 }
+
+// shortenNameIfNeeded applies a simple shortening rule for a single name.
+func shortenNameIfNeeded(name string) string {
+	const limit = 64
+	if len(name) <= limit {
+		return name
+	}
+	if strings.HasPrefix(name, "mcp__") {
+		idx := strings.LastIndex(name, "__")
+		if idx > 0 {
+			cand := "mcp__" + name[idx+2:]
+			if len(cand) > limit {
+				return cand[:limit]
+			}
+			return cand
+		}
+	}
+	return name[:limit]
+}
+
+// buildShortNameMap ensures uniqueness of shortened names within a request.
+func buildShortNameMap(names []string) map[string]string {
+	const limit = 64
+	used := map[string]struct{}{}
+	m := map[string]string{}
+
+	baseCandidate := func(n string) string {
+		if len(n) <= limit {
+			return n
+		}
+		if strings.HasPrefix(n, "mcp__") {
+			idx := strings.LastIndex(n, "__")
+			if idx > 0 {
+				cand := "mcp__" + n[idx+2:]
+				if len(cand) > limit {
+					cand = cand[:limit]
+				}
+				return cand
+			}
+		}
+		return n[:limit]
+	}
+
+	makeUnique := func(cand string) string {
+		if _, ok := used[cand]; !ok {
+			return cand
+		}
+		base := cand
+		for i := 1; ; i++ {
+			suffix := "~" + strconv.Itoa(i)
+			allowed := limit - len(suffix)
+			if allowed < 0 {
+				allowed = 0
+			}
+			tmp := base
+			if len(tmp) > allowed {
+				tmp = tmp[:allowed]
+			}
+			tmp = tmp + suffix
+			if _, ok := used[tmp]; !ok {
+				return tmp
+			}
+		}
+	}
+
+	for _, n := range names {
+		cand := baseCandidate(n)
+		uniq := makeUnique(cand)
+		used[uniq] = struct{}{}
+		m[n] = uniq
+	}
+	return m
+}
+
+// buildReverseMapFromClaudeOriginalToShort builds original->short map, used to map tool_use names to short.
+func buildReverseMapFromClaudeOriginalToShort(original []byte) map[string]string {
+	tools := gjson.GetBytes(original, "tools")
+	m := map[string]string{}
+	if !tools.IsArray() {
+		return m
+	}
+	var names []string
+	arr := tools.Array()
+	for i := 0; i < len(arr); i++ {
+		n := arr[i].Get("name").String()
+		if n != "" {
+			names = append(names, n)
+		}
+	}
+	if len(names) > 0 {
+		m = buildShortNameMap(names)
+	}
+	return m
+}

internal/translator/codex/claude/codex_claude_response.go

@@ -122,7 +122,15 @@ func ConvertCodexResponseToClaude(_ context.Context, _ string, originalRequestRa
 			template = `{"type":"content_block_start","index":0,"content_block":{"type":"tool_use","id":"","name":"","input":{}}}`
 			template, _ = sjson.Set(template, "index", rootResult.Get("output_index").Int())
 			template, _ = sjson.Set(template, "content_block.id", itemResult.Get("call_id").String())
-			template, _ = sjson.Set(template, "content_block.name", itemResult.Get("name").String())
+			{
+				// Restore original tool name if shortened
+				name := itemResult.Get("name").String()
+				rev := buildReverseMapFromClaudeOriginalShortToOriginal(originalRequestRawJSON)
+				if orig, ok := rev[name]; ok {
+					name = orig
+				}
+				template, _ = sjson.Set(template, "content_block.name", name)
+			}
 
 			output = "event: content_block_start\n"
 			output += fmt.Sprintf("data: %s\n\n", template)
@@ -171,3 +179,27 @@ func ConvertCodexResponseToClaude(_ context.Context, _ string, originalRequestRa
 func ConvertCodexResponseToClaudeNonStream(_ context.Context, _ string, originalRequestRawJSON, requestRawJSON, _ []byte, _ *any) string {
 	return ""
 }
+
+// buildReverseMapFromClaudeOriginalShortToOriginal builds a map[short]original from original Claude request tools.
+func buildReverseMapFromClaudeOriginalShortToOriginal(original []byte) map[string]string {
+	tools := gjson.GetBytes(original, "tools")
+	rev := map[string]string{}
+	if !tools.IsArray() {
+		return rev
+	}
+	var names []string
+	arr := tools.Array()
+	for i := 0; i < len(arr); i++ {
+		n := arr[i].Get("name").String()
+		if n != "" {
+			names = append(names, n)
+		}
+	}
+	if len(names) > 0 {
+		m := buildShortNameMap(names)
+		for orig, short := range m {
+			rev[short] = orig
+		}
+	}
+	return rev
+}

internal/translator/codex/gemini/codex_gemini_request.go

@@ -10,6 +10,7 @@ import (
 	"crypto/rand"
 	"fmt"
 	"math/big"
+	"strconv"
 	"strings"
 
 	"github.com/luispater/CLIProxyAPI/internal/misc"
@@ -46,6 +47,27 @@ func ConvertGeminiRequestToCodex(modelName string, inputRawJSON []byte, _ bool)
 
 	root := gjson.ParseBytes(rawJSON)
 
+	// Pre-compute tool name shortening map from declared functionDeclarations
+	shortMap := map[string]string{}
+	if tools := root.Get("tools"); tools.IsArray() {
+		var names []string
+		tarr := tools.Array()
+		for i := 0; i < len(tarr); i++ {
+			fns := tarr[i].Get("functionDeclarations")
+			if !fns.IsArray() {
+				continue
+			}
+			for _, fn := range fns.Array() {
+				if v := fn.Get("name"); v.Exists() {
+					names = append(names, v.String())
+				}
+			}
+		}
+		if len(names) > 0 {
+			shortMap = buildShortNameMap(names)
+		}
+	}
+
 	// helper for generating paired call IDs in the form: call_<alphanum>
 	// Gemini uses sequential pairing across possibly multiple in-flight
 	// functionCalls, so we keep a FIFO queue of generated call IDs and
@@ -124,7 +146,13 @@ func ConvertGeminiRequestToCodex(modelName string, inputRawJSON []byte, _ bool)
 				if fc := p.Get("functionCall"); fc.Exists() {
 					fn := `{"type":"function_call"}`
 					if name := fc.Get("name"); name.Exists() {
-						fn, _ = sjson.Set(fn, "name", name.String())
+						n := name.String()
+						if short, ok := shortMap[n]; ok {
+							n = short
+						} else {
+							n = shortenNameIfNeeded(n)
+						}
+						fn, _ = sjson.Set(fn, "name", n)
 					}
 					if args := fc.Get("args"); args.Exists() {
 						fn, _ = sjson.Set(fn, "arguments", args.Raw)
@@ -185,7 +213,13 @@ func ConvertGeminiRequestToCodex(modelName string, inputRawJSON []byte, _ bool)
 				tool := `{}`
 				tool, _ = sjson.Set(tool, "type", "function")
 				if v := fn.Get("name"); v.Exists() {
-					tool, _ = sjson.Set(tool, "name", v.String())
+					name := v.String()
+					if short, ok := shortMap[name]; ok {
+						name = short
+					} else {
+						name = shortenNameIfNeeded(name)
+					}
+					tool, _ = sjson.Set(tool, "name", name)
 				}
 				if v := fn.Get("description"); v.Exists() {
 					tool, _ = sjson.Set(tool, "description", v.String())
@@ -227,3 +261,76 @@ func ConvertGeminiRequestToCodex(modelName string, inputRawJSON []byte, _ bool)
 
 	return []byte(out)
 }
+
+// shortenNameIfNeeded applies the simple shortening rule for a single name.
+func shortenNameIfNeeded(name string) string {
+	const limit = 64
+	if len(name) <= limit {
+		return name
+	}
+	if strings.HasPrefix(name, "mcp__") {
+		idx := strings.LastIndex(name, "__")
+		if idx > 0 {
+			cand := "mcp__" + name[idx+2:]
+			if len(cand) > limit {
+				return cand[:limit]
+			}
+			return cand
+		}
+	}
+	return name[:limit]
+}
+
+// buildShortNameMap ensures uniqueness of shortened names within a request.
+func buildShortNameMap(names []string) map[string]string {
+	const limit = 64
+	used := map[string]struct{}{}
+	m := map[string]string{}
+
+	baseCandidate := func(n string) string {
+		if len(n) <= limit {
+			return n
+		}
+		if strings.HasPrefix(n, "mcp__") {
+			idx := strings.LastIndex(n, "__")
+			if idx > 0 {
+				cand := "mcp__" + n[idx+2:]
+				if len(cand) > limit {
+					cand = cand[:limit]
+				}
+				return cand
+			}
+		}
+		return n[:limit]
+	}
+
+	makeUnique := func(cand string) string {
+		if _, ok := used[cand]; !ok {
+			return cand
+		}
+		base := cand
+		for i := 1; ; i++ {
+			suffix := "~" + strconv.Itoa(i)
+			allowed := limit - len(suffix)
+			if allowed < 0 {
+				allowed = 0
+			}
+			tmp := base
+			if len(tmp) > allowed {
+				tmp = tmp[:allowed]
+			}
+			tmp = tmp + suffix
+			if _, ok := used[tmp]; !ok {
+				return tmp
+			}
+		}
+	}
+
+	for _, n := range names {
+		cand := baseCandidate(n)
+		uniq := makeUnique(cand)
+		used[uniq] = struct{}{}
+		m[n] = uniq
+	}
+	return m
+}

internal/translator/codex/gemini/codex_gemini_response.go

@@ -80,7 +80,15 @@ func ConvertCodexResponseToGemini(_ context.Context, modelName string, originalR
 		if itemType == "function_call" {
 			// Create function call part
 			functionCall := `{"functionCall":{"name":"","args":{}}}`
-			functionCall, _ = sjson.Set(functionCall, "functionCall.name", itemResult.Get("name").String())
+			{
+				// Restore original tool name if shortened
+				n := itemResult.Get("name").String()
+				rev := buildReverseMapFromGeminiOriginal(originalRequestRawJSON)
+				if orig, ok := rev[n]; ok {
+					n = orig
+				}
+				functionCall, _ = sjson.Set(functionCall, "functionCall.name", n)
+			}
 
 			// Parse and set arguments
 			argsStr := itemResult.Get("arguments").String()
@@ -250,7 +258,14 @@ func ConvertCodexResponseToGeminiNonStream(_ context.Context, modelName string,
 						hasToolCall = true
 						functionCall := map[string]interface{}{
 							"functionCall": map[string]interface{}{
-								"name": value.Get("name").String(),
+								"name": func() string {
+									n := value.Get("name").String()
+									rev := buildReverseMapFromGeminiOriginal(originalRequestRawJSON)
+									if orig, ok := rev[n]; ok {
+										return orig
+									}
+									return n
+								}(),
 								"args": map[string]interface{}{},
 							},
 						}
@@ -292,6 +307,35 @@ func ConvertCodexResponseToGeminiNonStream(_ context.Context, modelName string,
 	return ""
 }
 
+// buildReverseMapFromGeminiOriginal builds a map[short]original from original Gemini request tools.
+func buildReverseMapFromGeminiOriginal(original []byte) map[string]string {
+	tools := gjson.GetBytes(original, "tools")
+	rev := map[string]string{}
+	if !tools.IsArray() {
+		return rev
+	}
+	var names []string
+	tarr := tools.Array()
+	for i := 0; i < len(tarr); i++ {
+		fns := tarr[i].Get("functionDeclarations")
+		if !fns.IsArray() {
+			continue
+		}
+		for _, fn := range fns.Array() {
+			if v := fn.Get("name"); v.Exists() {
+				names = append(names, v.String())
+			}
+		}
+	}
+	if len(names) > 0 {
+		m := buildShortNameMap(names)
+		for orig, short := range m {
+			rev[short] = orig
+		}
+	}
+	return rev
+}
+
 // mustMarshalJSON marshals a value to JSON, panicking on error.
 func mustMarshalJSON(v interface{}) string {
 	data, err := json.Marshal(v)

internal/translator/codex/openai/chat-completions/codex_openai_request.go

@@ -9,6 +9,9 @@ package chat_completions
 import (
 	"bytes"
 
+	"strconv"
+	"strings"
+
 	"github.com/luispater/CLIProxyAPI/internal/misc"
 	"github.com/tidwall/gjson"
 	"github.com/tidwall/sjson"
@@ -67,6 +70,31 @@ func ConvertOpenAIRequestToCodex(modelName string, inputRawJSON []byte, stream b
 	// Model
 	out, _ = sjson.Set(out, "model", modelName)
 
+	// Build tool name shortening map from original tools (if any)
+	originalToolNameMap := map[string]string{}
+	{
+		tools := gjson.GetBytes(rawJSON, "tools")
+		if tools.IsArray() && len(tools.Array()) > 0 {
+			// Collect original tool names
+			var names []string
+			arr := tools.Array()
+			for i := 0; i < len(arr); i++ {
+				t := arr[i]
+				if t.Get("type").String() == "function" {
+					fn := t.Get("function")
+					if fn.Exists() {
+						if v := fn.Get("name"); v.Exists() {
+							names = append(names, v.String())
+						}
+					}
+				}
+			}
+			if len(names) > 0 {
+				originalToolNameMap = buildShortNameMap(names)
+			}
+		}
+	}
+
 	// Extract system instructions from first system message (string or text object)
 	messages := gjson.GetBytes(rawJSON, "messages")
 	instructions := misc.CodexInstructions
@@ -177,7 +205,15 @@ func ConvertOpenAIRequestToCodex(modelName string, inputRawJSON []byte, stream b
 								funcCall := `{}`
 								funcCall, _ = sjson.Set(funcCall, "type", "function_call")
 								funcCall, _ = sjson.Set(funcCall, "call_id", tc.Get("id").String())
-								funcCall, _ = sjson.Set(funcCall, "name", tc.Get("function.name").String())
+								{
+									name := tc.Get("function.name").String()
+									if short, ok := originalToolNameMap[name]; ok {
+										name = short
+									} else {
+										name = shortenNameIfNeeded(name)
+									}
+									funcCall, _ = sjson.Set(funcCall, "name", name)
+								}
 								funcCall, _ = sjson.Set(funcCall, "arguments", tc.Get("function.arguments").String())
 								out, _ = sjson.SetRaw(out, "input.-1", funcCall)
 							}
@@ -249,7 +285,13 @@ func ConvertOpenAIRequestToCodex(modelName string, inputRawJSON []byte, stream b
 				fn := t.Get("function")
 				if fn.Exists() {
 					if v := fn.Get("name"); v.Exists() {
-						item, _ = sjson.Set(item, "name", v.Value())
+						name := v.String()
+						if short, ok := originalToolNameMap[name]; ok {
+							name = short
+						} else {
+							name = shortenNameIfNeeded(name)
+						}
+						item, _ = sjson.Set(item, "name", name)
 					}
 					if v := fn.Get("description"); v.Exists() {
 						item, _ = sjson.Set(item, "description", v.Value())
@@ -273,3 +315,81 @@ func ConvertOpenAIRequestToCodex(modelName string, inputRawJSON []byte, stream b
 	out, _ = sjson.Set(out, "store", store)
 	return []byte(out)
 }
+
+// shortenNameIfNeeded applies the simple shortening rule for a single name.
+// If the name length exceeds 64, it will try to preserve the "mcp__" prefix and last segment.
+// Otherwise it truncates to 64 characters.
+func shortenNameIfNeeded(name string) string {
+	const limit = 64
+	if len(name) <= limit {
+		return name
+	}
+	if strings.HasPrefix(name, "mcp__") {
+		// Keep prefix and last segment after '__'
+		idx := strings.LastIndex(name, "__")
+		if idx > 0 {
+			candidate := "mcp__" + name[idx+2:]
+			if len(candidate) > limit {
+				return candidate[:limit]
+			}
+			return candidate
+		}
+	}
+	return name[:limit]
+}
+
+// buildShortNameMap generates unique short names (<=64) for the given list of names.
+// It preserves the "mcp__" prefix with the last segment when possible and ensures uniqueness
+// by appending suffixes like "~1", "~2" if needed.
+func buildShortNameMap(names []string) map[string]string {
+	const limit = 64
+	used := map[string]struct{}{}
+	m := map[string]string{}
+
+	baseCandidate := func(n string) string {
+		if len(n) <= limit {
+			return n
+		}
+		if strings.HasPrefix(n, "mcp__") {
+			idx := strings.LastIndex(n, "__")
+			if idx > 0 {
+				cand := "mcp__" + n[idx+2:]
+				if len(cand) > limit {
+					cand = cand[:limit]
+				}
+				return cand
+			}
+		}
+		return n[:limit]
+	}
+
+	makeUnique := func(cand string) string {
+		if _, ok := used[cand]; !ok {
+			return cand
+		}
+		base := cand
+		for i := 1; ; i++ {
+			suffix := "~" + strconv.Itoa(i)
+			allowed := limit - len(suffix)
+			if allowed < 0 {
+				allowed = 0
+			}
+			tmp := base
+			if len(tmp) > allowed {
+				tmp = tmp[:allowed]
+			}
+			tmp = tmp + suffix
+			if _, ok := used[tmp]; !ok {
+				return tmp
+			}
+		}
+	}
+
+	for _, n := range names {
+		cand := baseCandidate(n)
+		uniq := makeUnique(cand)
+		used[uniq] = struct{}{}
+		m[n] = uniq
+	}
+	return m
+}

internal/translator/codex/openai/chat-completions/codex_openai_response.go

@@ -119,7 +119,16 @@ func ConvertCodexResponseToOpenAI(_ context.Context, modelName string, originalR
 			}
 			template, _ = sjson.SetRaw(template, "choices.0.delta.tool_calls", `[]`)
 			functionCallItemTemplate, _ = sjson.Set(functionCallItemTemplate, "id", itemResult.Get("call_id").String())
-			functionCallItemTemplate, _ = sjson.Set(functionCallItemTemplate, "function.name", itemResult.Get("name").String())
+			{
+				// Restore original tool name if it was shortened
+				name := itemResult.Get("name").String()
+				// Build reverse map on demand from original request tools
+				rev := buildReverseMapFromOriginalOpenAI(originalRequestRawJSON)
+				if orig, ok := rev[name]; ok {
+					name = orig
+				}
+				functionCallItemTemplate, _ = sjson.Set(functionCallItemTemplate, "function.name", name)
+			}
 			functionCallItemTemplate, _ = sjson.Set(functionCallItemTemplate, "function.arguments", itemResult.Get("arguments").String())
 			template, _ = sjson.Set(template, "choices.0.delta.role", "assistant")
 			template, _ = sjson.SetRaw(template, "choices.0.delta.tool_calls.-1", functionCallItemTemplate)
@@ -244,7 +253,12 @@ func ConvertCodexResponseToOpenAINonStream(_ context.Context, _ string, original
 					}
 
 					if nameResult := outputItem.Get("name"); nameResult.Exists() {
-						functionCallTemplate, _ = sjson.Set(functionCallTemplate, "function.name", nameResult.String())
+						n := nameResult.String()
+						rev := buildReverseMapFromOriginalOpenAI(originalRequestRawJSON)
+						if orig, ok := rev[n]; ok {
+							n = orig
+						}
+						functionCallTemplate, _ = sjson.Set(functionCallTemplate, "function.name", n)
 					}
 
 					if argsResult := outputItem.Get("arguments"); argsResult.Exists() {
@@ -289,3 +303,34 @@ func ConvertCodexResponseToOpenAINonStream(_ context.Context, _ string, original
 	}
 	return ""
 }
+
+// buildReverseMapFromOriginalOpenAI builds a map of shortened tool name -> original tool name
+// from the original OpenAI-style request JSON using the same shortening logic.
+func buildReverseMapFromOriginalOpenAI(original []byte) map[string]string {
+	tools := gjson.GetBytes(original, "tools")
+	rev := map[string]string{}
+	if tools.IsArray() && len(tools.Array()) > 0 {
+		var names []string
+		arr := tools.Array()
+		for i := 0; i < len(arr); i++ {
+			t := arr[i]
+			if t.Get("type").String() != "function" {
+				continue
+			}
+			fn := t.Get("function")
+			if !fn.Exists() {
+				continue
+			}
+			if v := fn.Get("name"); v.Exists() {
+				names = append(names, v.String())
+			}
+		}
+		if len(names) > 0 {
+			m := buildShortNameMap(names)
+			for orig, short := range m {
+				rev[short] = orig
+			}
+		}
+	}
+	return rev
+}