refactor(translator): remove session ID logic from signature caching and associated tests

internal/translator/antigravity/claude/antigravity_claude_request.go

@@ -7,8 +7,6 @@ package claude
 
 import (
 	"bytes"
-	"crypto/sha256"
-	"encoding/hex"
 	"strings"
 
 	"github.com/router-for-me/CLIProxyAPI/v6/internal/cache"
@@ -19,33 +17,6 @@ import (
 	"github.com/tidwall/sjson"
 )
 
-// deriveSessionID generates a stable session ID from the request.
-// Uses the hash of the first user message to identify the conversation.
-func deriveSessionID(rawJSON []byte) string {
-	userIDResult := gjson.GetBytes(rawJSON, "metadata.user_id")
-	if userIDResult.Exists() {
-		userID := userIDResult.String()
-		idx := strings.Index(userID, "session_")
-		if idx != -1 {
-			return userID[idx+8:]
-		}
-	}
-	messages := gjson.GetBytes(rawJSON, "messages")
-	if !messages.IsArray() {
-		return ""
-	}
-	for _, msg := range messages.Array() {
-		if msg.Get("role").String() == "user" {
-			content := msg.Get("content").Raw
-			if content != "" {
-				h := sha256.Sum256([]byte(content))
-				return hex.EncodeToString(h[:16])
-			}
-		}
-	}
-	return ""
-}
-
 // ConvertClaudeRequestToAntigravity parses and transforms a Claude Code API request into Gemini CLI API format.
 // It extracts the model name, system instruction, message contents, and tool declarations
 // from the raw JSON request and returns them in the format expected by the Gemini CLI API.
@@ -68,9 +39,6 @@ func ConvertClaudeRequestToAntigravity(modelName string, inputRawJSON []byte, _
 	enableThoughtTranslate := true
 	rawJSON := bytes.Clone(inputRawJSON)
 
-	// Derive session ID for signature caching
-	sessionID := deriveSessionID(rawJSON)
-
 	// system instruction
 	systemInstructionJSON := ""
 	hasSystemInstruction := false
@@ -133,7 +101,7 @@ func ConvertClaudeRequestToAntigravity(modelName string, inputRawJSON []byte, _
 						// Always try cached signature first (more reliable than client-provided)
 						// Client may send stale or invalid signatures from different sessions
 						signature := ""
-						if sessionID != "" && thinkingText != "" {
+						if thinkingText != "" {
 							if cachedSig := cache.GetCachedSignature(modelName, thinkingText); cachedSig != "" {
 								signature = cachedSig
 								// log.Debugf("Using cached signature for thinking block")

internal/translator/antigravity/claude/antigravity_claude_request_test.go

@@ -98,10 +98,7 @@ func TestConvertClaudeRequestToAntigravity_ThinkingBlocks(t *testing.T) {
 		]
 	}`)
 
-	// Derive session ID and cache the signature
+	cache.CacheSignature("claude-sonnet-4-5-thinking", thinkingText, validSignature)
-	sessionID := deriveSessionID(inputJSON)
-	cache.CacheSignature("claude-sonnet-4-5-thinking", sessionID, thinkingText, validSignature)
-	defer cache.ClearSignatureCache(sessionID)
 
 	output := ConvertClaudeRequestToAntigravity("claude-sonnet-4-5-thinking", inputJSON, false)
 	outputStr := string(output)
@@ -266,10 +263,7 @@ func TestConvertClaudeRequestToAntigravity_ToolUse_WithSignature(t *testing.T) {
 		]
 	}`)
 
-	// Derive session ID and cache the signature
+	cache.CacheSignature("claude-sonnet-4-5-thinking", thinkingText, validSignature)
-	sessionID := deriveSessionID(inputJSON)
-	cache.CacheSignature("claude-sonnet-4-5-thinking", sessionID, thinkingText, validSignature)
-	defer cache.ClearSignatureCache(sessionID)
 
 	output := ConvertClaudeRequestToAntigravity("claude-sonnet-4-5-thinking", inputJSON, false)
 	outputStr := string(output)
@@ -306,10 +300,7 @@ func TestConvertClaudeRequestToAntigravity_ReorderThinking(t *testing.T) {
 		]
 	}`)
 
-	// Derive session ID and cache the signature
+	cache.CacheSignature("claude-sonnet-4-5-thinking", thinkingText, validSignature)
-	sessionID := deriveSessionID(inputJSON)
-	cache.CacheSignature("claude-sonnet-4-5-thinking", sessionID, thinkingText, validSignature)
-	defer cache.ClearSignatureCache(sessionID)
 
 	output := ConvertClaudeRequestToAntigravity("claude-sonnet-4-5-thinking", inputJSON, false)
 	outputStr := string(output)
@@ -517,10 +508,7 @@ func TestConvertClaudeRequestToAntigravity_TrailingSignedThinking_Kept(t *testin
 		]
 	}`)
 
-	// Derive session ID and cache the signature
+	cache.CacheSignature("claude-sonnet-4-5-thinking", thinkingText, validSignature)
-	sessionID := deriveSessionID(inputJSON)
-	cache.CacheSignature("claude-sonnet-4-5-thinking", sessionID, thinkingText, validSignature)
-	defer cache.ClearSignatureCache(sessionID)
 
 	output := ConvertClaudeRequestToAntigravity("claude-sonnet-4-5-thinking", inputJSON, false)
 	outputStr := string(output)

internal/translator/antigravity/claude/antigravity_claude_response.go

@@ -70,7 +70,6 @@ func ConvertAntigravityResponseToClaude(_ context.Context, _ string, originalReq
 			HasFirstResponse: false,
 			ResponseType:     0,
 			ResponseIndex:    0,
-			SessionID:        deriveSessionID(originalRequestRawJSON),
 		}
 	}
 	modelName := gjson.GetBytes(requestRawJSON, "model").String()

internal/translator/antigravity/claude/antigravity_claude_response_test.go

@@ -144,7 +144,7 @@ func TestConvertAntigravityResponseToClaude_SignatureCached(t *testing.T) {
 	ConvertAntigravityResponseToClaude(ctx, "claude-sonnet-4-5-thinking", requestJSON, requestJSON, signatureChunk, &param)
 
 	// Verify signature was cached
-	cachedSig := cache.GetCachedSignature("claude-sonnet-4-5-thinking", sessionID, thinkingText)
+	cachedSig := cache.GetCachedSignature("claude-sonnet-4-5-thinking", thinkingText)
 	if cachedSig != validSignature {
 		t.Errorf("Expected cached signature '%s', got '%s'", validSignature, cachedSig)
 	}
@@ -223,13 +223,12 @@ func TestConvertAntigravityResponseToClaude_MultipleThinkingBlocks(t *testing.T)
 	// Process first thinking block
 	ConvertAntigravityResponseToClaude(ctx, "claude-sonnet-4-5-thinking", requestJSON, requestJSON, block1Thinking, &param)
 	params := param.(*Params)
-	sessionID := params.SessionID
 	firstThinkingText := params.CurrentThinkingText.String()
 
 	ConvertAntigravityResponseToClaude(ctx, "claude-sonnet-4-5-thinking", requestJSON, requestJSON, block1Sig, &param)
 
 	// Verify first signature cached
-	if cache.GetCachedSignature("claude-sonnet-4-5-thinking", sessionID, firstThinkingText) != validSig1 {
+	if cache.GetCachedSignature("claude-sonnet-4-5-thinking", firstThinkingText) != validSig1 {
 		t.Error("First thinking block signature should be cached")
 	}
 
@@ -243,76 +242,7 @@ func TestConvertAntigravityResponseToClaude_MultipleThinkingBlocks(t *testing.T)
 	ConvertAntigravityResponseToClaude(ctx, "claude-sonnet-4-5-thinking", requestJSON, requestJSON, block2Sig, &param)
 
 	// Verify second signature cached
-	if cache.GetCachedSignature("claude-sonnet-4-5-thinking", sessionID, secondThinkingText) != validSig2 {
+	if cache.GetCachedSignature("claude-sonnet-4-5-thinking", secondThinkingText) != validSig2 {
 		t.Error("Second thinking block signature should be cached")
 	}
 }
-
-func TestDeriveSessionIDFromRequest(t *testing.T) {
-	tests := []struct {
-		name      string
-		input     []byte
-		wantEmpty bool
-	}{
-		{
-			name:      "valid user message",
-			input:     []byte(`{"messages": [{"role": "user", "content": "Hello"}]}`),
-			wantEmpty: false,
-		},
-		{
-			name:      "user message with content array",
-			input:     []byte(`{"messages": [{"role": "user", "content": [{"type": "text", "text": "Hello"}]}]}`),
-			wantEmpty: false,
-		},
-		{
-			name:      "no user message",
-			input:     []byte(`{"messages": [{"role": "assistant", "content": "Hi"}]}`),
-			wantEmpty: true,
-		},
-		{
-			name:      "empty messages",
-			input:     []byte(`{"messages": []}`),
-			wantEmpty: true,
-		},
-		{
-			name:      "no messages field",
-			input:     []byte(`{}`),
-			wantEmpty: true,
-		},
-	}
-
-	for _, tt := range tests {
-		t.Run(tt.name, func(t *testing.T) {
-			result := deriveSessionID(tt.input)
-			if tt.wantEmpty && result != "" {
-				t.Errorf("Expected empty session ID, got '%s'", result)
-			}
-			if !tt.wantEmpty && result == "" {
-				t.Error("Expected non-empty session ID")
-			}
-		})
-	}
-}
-
-func TestDeriveSessionIDFromRequest_Deterministic(t *testing.T) {
-	input := []byte(`{"messages": [{"role": "user", "content": "Same message"}]}`)
-
-	id1 := deriveSessionID(input)
-	id2 := deriveSessionID(input)
-
-	if id1 != id2 {
-		t.Errorf("Session ID should be deterministic: '%s' != '%s'", id1, id2)
-	}
-}
-
-func TestDeriveSessionIDFromRequest_DifferentMessages(t *testing.T) {
-	input1 := []byte(`{"messages": [{"role": "user", "content": "Message A"}]}`)
-	input2 := []byte(`{"messages": [{"role": "user", "content": "Message B"}]}`)
-
-	id1 := deriveSessionID(input1)
-	id2 := deriveSessionID(input2)
-
-	if id1 == id2 {
-		t.Error("Different messages should produce different session IDs")
-	}
-}