Merge pull request #2896 from edlsh/fix/oauth-tool-rename-per-request-map

fix(amp): smart-mode tool name fixes + deep-mode response repair

internal/runtime/executor/claude_executor.go

@@ -65,14 +65,13 @@ var oauthToolRenameMap = map[string]string{
 	"notebookedit": "NotebookEdit",
 }
 
-// oauthToolRenameReverseMap is the inverse of oauthToolRenameMap for response decoding.
-var oauthToolRenameReverseMap = func() map[string]string {
-	m := make(map[string]string, len(oauthToolRenameMap))
-	for k, v := range oauthToolRenameMap {
-		m[v] = k
-	}
-	return m
-}()
+// The reverse map is now computed per-request in remapOAuthToolNames so that
+// only names the client actually caused us to rewrite are restored on the
+// response. A global reverse map — as used previously — corrupted responses
+// for clients that sent mixed casing (e.g. Amp CLI sends `Bash` TitleCase
+// alongside `glob` lowercase; the request flagged renames via `glob→Glob`,
+// then the global reverse map incorrectly rewrote every `Bash` in the
+// response to `bash`, causing Amp to reject the tool_use as unknown).
 
 // oauthToolsToRemove lists tool names that must be stripped from OAuth requests
 // even after remapping. Currently empty — all tools are mapped instead of removed.
@@ -192,15 +191,9 @@ func (e *ClaudeExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, r
 	bodyForTranslation := body
 	bodyForUpstream := body
 	oauthToken := isClaudeOAuthToken(apiKey)
-	oauthToolNamesRemapped := false
-	if oauthToken && !auth.ToolPrefixDisabled() {
-		bodyForUpstream = applyClaudeToolPrefix(body, claudeToolPrefix)
-	}
-	// Remap third-party tool names to Claude Code equivalents and remove
-	// tools without official counterparts. This prevents Anthropic from
-	// fingerprinting the request as third-party via tool naming patterns.
+	var oauthToolNamesReverseMap map[string]string
 	if oauthToken {
-		bodyForUpstream, oauthToolNamesRemapped = remapOAuthToolNames(bodyForUpstream)
+		bodyForUpstream, oauthToolNamesReverseMap = prepareClaudeOAuthToolNamesForUpstream(bodyForUpstream, claudeToolPrefix, auth.ToolPrefixDisabled())
 	}
 	// Enable cch signing by default for OAuth tokens (not just experimental flag).
 	// Claude Code always computes cch; missing or invalid cch is a detectable fingerprint.
@@ -298,13 +291,7 @@ func (e *ClaudeExecutor) Execute(ctx context.Context, auth *cliproxyauth.Auth, r
 	} else {
 		reporter.Publish(ctx, helps.ParseClaudeUsage(data))
 	}
-	if isClaudeOAuthToken(apiKey) && !auth.ToolPrefixDisabled() {
-		data = stripClaudeToolPrefixFromResponse(data, claudeToolPrefix)
-	}
-	// Reverse the OAuth tool name remap so the downstream client sees original names.
-	if isClaudeOAuthToken(apiKey) && oauthToolNamesRemapped {
-		data = reverseRemapOAuthToolNames(data)
-	}
+	data = restoreClaudeOAuthToolNamesFromResponse(data, claudeToolPrefix, auth.ToolPrefixDisabled(), oauthToolNamesReverseMap)
 	var param any
 	out := sdktranslator.TranslateNonStream(
 		ctx,
@@ -379,15 +366,9 @@ func (e *ClaudeExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.A
 	bodyForTranslation := body
 	bodyForUpstream := body
 	oauthToken := isClaudeOAuthToken(apiKey)
-	oauthToolNamesRemapped := false
-	if oauthToken && !auth.ToolPrefixDisabled() {
-		bodyForUpstream = applyClaudeToolPrefix(body, claudeToolPrefix)
-	}
-	// Remap third-party tool names to Claude Code equivalents and remove
-	// tools without official counterparts. This prevents Anthropic from
-	// fingerprinting the request as third-party via tool naming patterns.
+	var oauthToolNamesReverseMap map[string]string
 	if oauthToken {
-		bodyForUpstream, oauthToolNamesRemapped = remapOAuthToolNames(bodyForUpstream)
+		bodyForUpstream, oauthToolNamesReverseMap = prepareClaudeOAuthToolNamesForUpstream(bodyForUpstream, claudeToolPrefix, auth.ToolPrefixDisabled())
 	}
 	// Enable cch signing by default for OAuth tokens (not just experimental flag).
 	if oauthToken || experimentalCCHSigningEnabled(e.cfg, auth) {
@@ -478,12 +459,7 @@ func (e *ClaudeExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.A
 				if detail, ok := helps.ParseClaudeStreamUsage(line); ok {
 					reporter.Publish(ctx, detail)
 				}
-				if isClaudeOAuthToken(apiKey) && !auth.ToolPrefixDisabled() {
-					line = stripClaudeToolPrefixFromStreamLine(line, claudeToolPrefix)
-				}
-				if isClaudeOAuthToken(apiKey) && oauthToolNamesRemapped {
-					line = reverseRemapOAuthToolNamesFromStreamLine(line)
-				}
+				line = restoreClaudeOAuthToolNamesFromStreamLine(line, claudeToolPrefix, auth.ToolPrefixDisabled(), oauthToolNamesReverseMap)
 				// Forward the line as-is to preserve SSE format
 				cloned := make([]byte, len(line)+1)
 				copy(cloned, line)
@@ -515,12 +491,7 @@ func (e *ClaudeExecutor) ExecuteStream(ctx context.Context, auth *cliproxyauth.A
 			if detail, ok := helps.ParseClaudeStreamUsage(line); ok {
 				reporter.Publish(ctx, detail)
 			}
-			if isClaudeOAuthToken(apiKey) && !auth.ToolPrefixDisabled() {
-				line = stripClaudeToolPrefixFromStreamLine(line, claudeToolPrefix)
-			}
-			if isClaudeOAuthToken(apiKey) && oauthToolNamesRemapped {
-				line = reverseRemapOAuthToolNamesFromStreamLine(line)
-			}
+			line = restoreClaudeOAuthToolNamesFromStreamLine(line, claudeToolPrefix, auth.ToolPrefixDisabled(), oauthToolNamesReverseMap)
 			chunks := sdktranslator.TranslateStream(
 				ctx,
 				to,
@@ -635,12 +606,8 @@ func (e *ClaudeExecutor) CountTokens(ctx context.Context, auth *cliproxyauth.Aut
 	// Extract betas from body and convert to header (for count_tokens too)
 	var extraBetas []string
 	extraBetas, body = extractAndRemoveBetas(body)
-	if isClaudeOAuthToken(apiKey) && !auth.ToolPrefixDisabled() {
-		body = applyClaudeToolPrefix(body, claudeToolPrefix)
-	}
-	// Remap tool names for OAuth token requests to avoid third-party fingerprinting.
 	if isClaudeOAuthToken(apiKey) {
-		body, _ = remapOAuthToolNames(body)
+		body, _ = prepareClaudeOAuthToolNamesForUpstream(body, claudeToolPrefix, auth.ToolPrefixDisabled())
 	}
 
 	url := fmt.Sprintf("%s/v1/messages/count_tokens?beta=true", baseURL)
@@ -1080,6 +1047,36 @@ func isClaudeOAuthToken(apiKey string) bool {
 	return strings.Contains(apiKey, "sk-ant-oat")
 }
 
+// prepareClaudeOAuthToolNamesForUpstream applies the Claude OAuth tool-name
+// transforms in the same order across request paths. Remap runs before prefixing
+// so any future non-empty prefix still composes correctly with the per-request
+// reverse map.
+func prepareClaudeOAuthToolNamesForUpstream(body []byte, prefix string, prefixDisabled bool) ([]byte, map[string]string) {
+	body, reverseMap := remapOAuthToolNames(body)
+	if !prefixDisabled {
+		body = applyClaudeToolPrefix(body, prefix)
+	}
+	return body, reverseMap
+}
+
+// restoreClaudeOAuthToolNamesFromResponse undoes the Claude OAuth tool-name
+// transforms for non-stream responses in reverse order.
+func restoreClaudeOAuthToolNamesFromResponse(body []byte, prefix string, prefixDisabled bool, reverseMap map[string]string) []byte {
+	if !prefixDisabled {
+		body = stripClaudeToolPrefixFromResponse(body, prefix)
+	}
+	return reverseRemapOAuthToolNames(body, reverseMap)
+}
+
+// restoreClaudeOAuthToolNamesFromStreamLine undoes the Claude OAuth tool-name
+// transforms for SSE lines in reverse order.
+func restoreClaudeOAuthToolNamesFromStreamLine(line []byte, prefix string, prefixDisabled bool, reverseMap map[string]string) []byte {
+	if !prefixDisabled {
+		line = stripClaudeToolPrefixFromStreamLine(line, prefix)
+	}
+	return reverseRemapOAuthToolNamesFromStreamLine(line, reverseMap)
+}
+
 // remapOAuthToolNames renames third-party tool names to Claude Code equivalents
 // and removes tools without an official counterpart. This prevents Anthropic from
 // fingerprinting the request as a third-party client via tool naming patterns.
@@ -1087,8 +1084,25 @@ func isClaudeOAuthToken(apiKey string) bool {
 // It operates on: tools[].name, tool_choice.name, and all tool_use/tool_reference
 // references in messages. Removed tools' corresponding tool_result blocks are preserved
 // (they just become orphaned, which is safe for Claude).
-func remapOAuthToolNames(body []byte) ([]byte, bool) {
-	renamed := false
+//
+// The returned map is keyed on the upstream (TitleCase) name and maps to the
+// client-supplied original name. Callers MUST pass this map to the reverse
+// functions so only names the client actually caused us to rewrite are restored
+// on the response. A global reverse map (the previous implementation) incorrectly
+// rewrote names the client originally sent in TitleCase (e.g. Amp CLI's `Bash`)
+// when any OTHER tool in the same request triggered a forward rename (e.g.
+// Amp's `glob`→`Glob`), because the global reverse map contained `Bash`→`bash`
+// regardless of what the client originally sent.
+func remapOAuthToolNames(body []byte) ([]byte, map[string]string) {
+	reverseMap := make(map[string]string, len(oauthToolRenameMap))
+	recordRename := func(original, renamed string) {
+		// Preserve the first-seen original name if the same upstream name is
+		// produced from multiple call sites; they all map back identically.
+		if _, exists := reverseMap[renamed]; !exists {
+			reverseMap[renamed] = original
+		}
+	}
+
 	// 1. Rewrite tools array in a single pass (if present).
 	// IMPORTANT: do not mutate names first and then rebuild from an older gjson
 	// snapshot. gjson results are snapshots of the original bytes; rebuilding from a
@@ -1121,7 +1135,7 @@ func remapOAuthToolNames(body []byte) ([]byte, bool) {
 				updatedTool, err := sjson.Set(toolJSON, "name", newName)
 				if err == nil {
 					toolJSON = updatedTool
-					renamed = true
+					recordRename(name, newName)
 				}
 			}
 
@@ -1146,7 +1160,7 @@ func remapOAuthToolNames(body []byte) ([]byte, bool) {
 			body, _ = sjson.DeleteBytes(body, "tool_choice")
 		} else if newName, ok := oauthToolRenameMap[tcName]; ok && newName != tcName {
 			body, _ = sjson.SetBytes(body, "tool_choice.name", newName)
-			renamed = true
+			recordRename(tcName, newName)
 		}
 	}
 
@@ -1166,14 +1180,14 @@ func remapOAuthToolNames(body []byte) ([]byte, bool) {
 					if newName, ok := oauthToolRenameMap[name]; ok && newName != name {
 						path := fmt.Sprintf("messages.%d.content.%d.name", msgIndex.Int(), contentIndex.Int())
 						body, _ = sjson.SetBytes(body, path, newName)
-						renamed = true
+						recordRename(name, newName)
 					}
 				case "tool_reference":
 					toolName := part.Get("tool_name").String()
 					if newName, ok := oauthToolRenameMap[toolName]; ok && newName != toolName {
 						path := fmt.Sprintf("messages.%d.content.%d.tool_name", msgIndex.Int(), contentIndex.Int())
 						body, _ = sjson.SetBytes(body, path, newName)
-						renamed = true
+						recordRename(toolName, newName)
 					}
 				case "tool_result":
 					// Handle nested tool_reference blocks inside tool_result.content[]
@@ -1187,7 +1201,7 @@ func remapOAuthToolNames(body []byte) ([]byte, bool) {
 								if newName, ok := oauthToolRenameMap[nestedToolName]; ok && newName != nestedToolName {
 									nestedPath := fmt.Sprintf("messages.%d.content.%d.content.%d.tool_name", msgIndex.Int(), contentIndex.Int(), nestedIndex.Int())
 									body, _ = sjson.SetBytes(body, nestedPath, newName)
-									renamed = true
+									recordRename(nestedToolName, newName)
 								}
 							}
 							return true
@@ -1200,13 +1214,16 @@ func remapOAuthToolNames(body []byte) ([]byte, bool) {
 		})
 	}
 
-	return body, renamed
+	return body, reverseMap
 }
 
-// reverseRemapOAuthToolNames reverses the tool name mapping for non-stream responses.
-// It maps Claude Code TitleCase names back to the original lowercase names so the
-// downstream client receives tool names it recognizes.
-func reverseRemapOAuthToolNames(body []byte) []byte {
+// reverseRemapOAuthToolNames reverses the tool name mapping for non-stream responses
+// using the per-request map produced by remapOAuthToolNames. Names the client sent
+// that were NOT forward-renamed are passed through unchanged.
+func reverseRemapOAuthToolNames(body []byte, reverseMap map[string]string) []byte {
+	if len(reverseMap) == 0 {
+		return body
+	}
 	content := gjson.GetBytes(body, "content")
 	if !content.Exists() || !content.IsArray() {
 		return body
@@ -1216,13 +1233,13 @@ func reverseRemapOAuthToolNames(body []byte) []byte {
 		switch partType {
 		case "tool_use":
 			name := part.Get("name").String()
-			if origName, ok := oauthToolRenameReverseMap[name]; ok {
+			if origName, ok := reverseMap[name]; ok {
 				path := fmt.Sprintf("content.%d.name", index.Int())
 				body, _ = sjson.SetBytes(body, path, origName)
 			}
 		case "tool_reference":
 			toolName := part.Get("tool_name").String()
-			if origName, ok := oauthToolRenameReverseMap[toolName]; ok {
+			if origName, ok := reverseMap[toolName]; ok {
 				path := fmt.Sprintf("content.%d.tool_name", index.Int())
 				body, _ = sjson.SetBytes(body, path, origName)
 			}
@@ -1232,8 +1249,12 @@ func reverseRemapOAuthToolNames(body []byte) []byte {
 	return body
 }
 
-// reverseRemapOAuthToolNamesFromStreamLine reverses the tool name mapping for SSE stream lines.
-func reverseRemapOAuthToolNamesFromStreamLine(line []byte) []byte {
+// reverseRemapOAuthToolNamesFromStreamLine reverses the tool name mapping for SSE
+// stream lines, using the per-request reverseMap produced by remapOAuthToolNames.
+func reverseRemapOAuthToolNamesFromStreamLine(line []byte, reverseMap map[string]string) []byte {
+	if len(reverseMap) == 0 {
+		return line
+	}
 	payload := helps.JSONPayload(line)
 	if len(payload) == 0 || !gjson.ValidBytes(payload) {
 		return line
@@ -1251,7 +1272,7 @@ func reverseRemapOAuthToolNamesFromStreamLine(line []byte) []byte {
 	switch blockType {
 	case "tool_use":
 		name := contentBlock.Get("name").String()
-		if origName, ok := oauthToolRenameReverseMap[name]; ok {
+		if origName, ok := reverseMap[name]; ok {
 			updated, err = sjson.SetBytes(payload, "content_block.name", origName)
 			if err != nil {
 				return line
@@ -1261,7 +1282,7 @@ func reverseRemapOAuthToolNamesFromStreamLine(line []byte) []byte {
 		}
 	case "tool_reference":
 		toolName := contentBlock.Get("tool_name").String()
-		if origName, ok := oauthToolRenameReverseMap[toolName]; ok {
+		if origName, ok := reverseMap[toolName]; ok {
 			updated, err = sjson.SetBytes(payload, "content_block.tool_name", origName)
 			if err != nil {
 				return line

internal/runtime/executor/claude_executor_test.go

@@ -2096,19 +2096,16 @@ func TestNormalizeClaudeTemperatureForThinking_AfterForcedToolChoiceKeepsOrigina
 func TestRemapOAuthToolNames_TitleCase_NoReverseNeeded(t *testing.T) {
 	body := []byte(`{"tools":[{"name":"Bash","description":"Run shell commands","input_schema":{"type":"object","properties":{"cmd":{"type":"string"}}}}],"messages":[{"role":"user","content":[{"type":"text","text":"hi"}]}]}`)
 
-	out, renamed := remapOAuthToolNames(body)
-	if renamed {
-		t.Fatalf("renamed = true, want false")
+	out, reverseMap := remapOAuthToolNames(body)
+	if len(reverseMap) != 0 {
+		t.Fatalf("reverseMap = %v, want empty", reverseMap)
 	}
 	if got := gjson.GetBytes(out, "tools.0.name").String(); got != "Bash" {
 		t.Fatalf("tools.0.name = %q, want %q", got, "Bash")
 	}
 
 	resp := []byte(`{"content":[{"type":"tool_use","id":"toolu_01","name":"Bash","input":{"cmd":"ls"}}]}`)
-	reversed := resp
-	if renamed {
-		reversed = reverseRemapOAuthToolNames(resp)
-	}
+	reversed := reverseRemapOAuthToolNames(resp, reverseMap)
 	if got := gjson.GetBytes(reversed, "content.0.name").String(); got != "Bash" {
 		t.Fatalf("content.0.name = %q, want %q", got, "Bash")
 	}
@@ -2117,20 +2114,150 @@ func TestRemapOAuthToolNames_TitleCase_NoReverseNeeded(t *testing.T) {
 func TestRemapOAuthToolNames_Lowercase_ReverseApplied(t *testing.T) {
 	body := []byte(`{"tools":[{"name":"bash","description":"Run shell commands","input_schema":{"type":"object","properties":{"cmd":{"type":"string"}}}}],"messages":[{"role":"user","content":[{"type":"text","text":"hi"}]}]}`)
 
-	out, renamed := remapOAuthToolNames(body)
-	if !renamed {
-		t.Fatalf("renamed = false, want true")
+	out, reverseMap := remapOAuthToolNames(body)
+	if reverseMap["Bash"] != "bash" {
+		t.Fatalf("reverseMap = %v, want entry Bash->bash", reverseMap)
 	}
 	if got := gjson.GetBytes(out, "tools.0.name").String(); got != "Bash" {
 		t.Fatalf("tools.0.name = %q, want %q", got, "Bash")
 	}
 
 	resp := []byte(`{"content":[{"type":"tool_use","id":"toolu_01","name":"Bash","input":{"cmd":"ls"}}]}`)
-	reversed := resp
-	if renamed {
-		reversed = reverseRemapOAuthToolNames(resp)
-	}
+	reversed := reverseRemapOAuthToolNames(resp, reverseMap)
 	if got := gjson.GetBytes(reversed, "content.0.name").String(); got != "bash" {
 		t.Fatalf("content.0.name = %q, want %q", got, "bash")
 	}
 }
+
+// TestRemapOAuthToolNames_MixedCase_OnlyRenamedToolsReversed is the regression
+// test for a case where a single request contains both a TitleCase tool (which
+// must pass through unchanged) and a lowercase tool that we forward-rename.
+// Before the fix, triggering ANY forward rename caused the reverse pass to
+// lowercase every TitleCase tool in the response using a global reverse map,
+// corrupting tool names the client originally sent in TitleCase (notably Amp
+// CLI's `Bash`, which its registry lookup cannot find as `bash`).
+func TestRemapOAuthToolNames_MixedCase_OnlyRenamedToolsReversed(t *testing.T) {
+	body := []byte(`{"tools":[` +
+		`{"name":"Bash","input_schema":{"type":"object","properties":{"cmd":{"type":"string"}}}},` +
+		`{"name":"glob","input_schema":{"type":"object","properties":{"filePattern":{"type":"string"}}}}` +
+		`]}`)
+
+	out, reverseMap := remapOAuthToolNames(body)
+
+	// Forward: TitleCase `Bash` is not a forward-map key, must pass through.
+	if got := gjson.GetBytes(out, "tools.0.name").String(); got != "Bash" {
+		t.Fatalf("tools.0.name = %q, want %q (TitleCase tool must not be renamed)", got, "Bash")
+	}
+	// Forward: `glob` is a forward-map key, upstream sees `Glob`.
+	if got := gjson.GetBytes(out, "tools.1.name").String(); got != "Glob" {
+		t.Fatalf("tools.1.name = %q, want %q", got, "Glob")
+	}
+
+	// Reverse map records ONLY the rename that happened.
+	if len(reverseMap) != 1 || reverseMap["Glob"] != "glob" {
+		t.Fatalf("reverseMap = %v, want {Glob:glob}", reverseMap)
+	}
+
+	// Upstream responds with a `Bash` tool_use. Since we never renamed `Bash`,
+	// reverseRemap MUST leave it alone.
+	bashResp := []byte(`{"content":[{"type":"tool_use","id":"toolu_01","name":"Bash","input":{"cmd":"ls"}}]}`)
+	reversed := reverseRemapOAuthToolNames(bashResp, reverseMap)
+	if got := gjson.GetBytes(reversed, "content.0.name").String(); got != "Bash" {
+		t.Fatalf("content.0.name = %q, want %q (Bash must be preserved; was never forward-renamed)", got, "Bash")
+	}
+
+	// Upstream responds with a `Glob` tool_use. Since we renamed `glob`→`Glob`,
+	// reverseRemap MUST restore the original `glob`.
+	globResp := []byte(`{"content":[{"type":"tool_use","id":"toolu_02","name":"Glob","input":{"filePattern":"**/*.go"}}]}`)
+	reversed = reverseRemapOAuthToolNames(globResp, reverseMap)
+	if got := gjson.GetBytes(reversed, "content.0.name").String(); got != "glob" {
+		t.Fatalf("content.0.name = %q, want %q (Glob must be restored to client's original `glob`)", got, "glob")
+	}
+}
+
+// TestReverseRemapOAuthToolNamesFromStreamLine_HonorsPerRequestMap guards the
+// SSE streaming code path against the same mixed-case bug.
+func TestReverseRemapOAuthToolNamesFromStreamLine_HonorsPerRequestMap(t *testing.T) {
+	reverseMap := map[string]string{"Glob": "glob"}
+
+	// Bash block was never renamed, must pass through as-is.
+	bashLine := []byte(`data: {"type":"content_block_start","index":0,"content_block":{"type":"tool_use","id":"toolu_01","name":"Bash","input":{}}}`)
+	out := reverseRemapOAuthToolNamesFromStreamLine(bashLine, reverseMap)
+	if !bytes.Contains(out, []byte(`"name":"Bash"`)) {
+		t.Fatalf("Bash should be preserved, got: %s", string(out))
+	}
+	if bytes.Contains(out, []byte(`"name":"bash"`)) {
+		t.Fatalf("Bash must not be lowercased, got: %s", string(out))
+	}
+
+	// Glob block IS in the reverseMap, must be restored to `glob`.
+	globLine := []byte(`data: {"type":"content_block_start","index":0,"content_block":{"type":"tool_use","id":"toolu_02","name":"Glob","input":{}}}`)
+	out = reverseRemapOAuthToolNamesFromStreamLine(globLine, reverseMap)
+	if !bytes.Contains(out, []byte(`"name":"glob"`)) {
+		t.Fatalf("Glob should be restored to glob, got: %s", string(out))
+	}
+}
+
+func TestPrepareClaudeOAuthToolNamesForUpstream_MixedCaseWithPrefix(t *testing.T) {
+	body := []byte(`{"tools":[` +
+		`{"name":"Bash","input_schema":{"type":"object","properties":{"cmd":{"type":"string"}}}},` +
+		`{"name":"glob","input_schema":{"type":"object","properties":{"filePattern":{"type":"string"}}}}` +
+		`],"messages":[{"role":"assistant","content":[` +
+		`{"type":"tool_use","id":"toolu_01","name":"Bash","input":{}},` +
+		`{"type":"tool_use","id":"toolu_02","name":"glob","input":{}}` +
+		`]}]}`)
+
+	out, reverseMap := prepareClaudeOAuthToolNamesForUpstream(body, "proxy_", false)
+
+	if got := gjson.GetBytes(out, "tools.0.name").String(); got != "proxy_Bash" {
+		t.Fatalf("tools.0.name = %q, want %q", got, "proxy_Bash")
+	}
+	if got := gjson.GetBytes(out, "tools.1.name").String(); got != "proxy_Glob" {
+		t.Fatalf("tools.1.name = %q, want %q", got, "proxy_Glob")
+	}
+	if got := gjson.GetBytes(out, "messages.0.content.0.name").String(); got != "proxy_Bash" {
+		t.Fatalf("messages.0.content.0.name = %q, want %q", got, "proxy_Bash")
+	}
+	if got := gjson.GetBytes(out, "messages.0.content.1.name").String(); got != "proxy_Glob" {
+		t.Fatalf("messages.0.content.1.name = %q, want %q", got, "proxy_Glob")
+	}
+	if len(reverseMap) != 1 || reverseMap["Glob"] != "glob" {
+		t.Fatalf("reverseMap = %v, want {Glob:glob}", reverseMap)
+	}
+}
+
+func TestRestoreClaudeOAuthToolNamesFromResponse_MixedCaseWithPrefix(t *testing.T) {
+	reverseMap := map[string]string{"Glob": "glob"}
+	resp := []byte(`{"content":[` +
+		`{"type":"tool_use","id":"toolu_01","name":"proxy_Bash","input":{}},` +
+		`{"type":"tool_use","id":"toolu_02","name":"proxy_Glob","input":{}}` +
+		`]}`)
+
+	out := restoreClaudeOAuthToolNamesFromResponse(resp, "proxy_", false, reverseMap)
+
+	if got := gjson.GetBytes(out, "content.0.name").String(); got != "Bash" {
+		t.Fatalf("content.0.name = %q, want %q", got, "Bash")
+	}
+	if got := gjson.GetBytes(out, "content.1.name").String(); got != "glob" {
+		t.Fatalf("content.1.name = %q, want %q", got, "glob")
+	}
+}
+
+func TestRestoreClaudeOAuthToolNamesFromStreamLine_MixedCaseWithPrefix(t *testing.T) {
+	reverseMap := map[string]string{"Glob": "glob"}
+
+	bashLine := []byte(`data: {"type":"content_block_start","index":0,"content_block":{"type":"tool_use","id":"toolu_01","name":"proxy_Bash","input":{}}}`)
+	out := restoreClaudeOAuthToolNamesFromStreamLine(bashLine, "proxy_", false, reverseMap)
+	if !bytes.Contains(out, []byte(`"name":"Bash"`)) {
+		t.Fatalf("Bash should be preserved, got: %s", string(out))
+	}
+	if bytes.Contains(out, []byte(`"name":"bash"`)) {
+		t.Fatalf("Bash must not be lowercased, got: %s", string(out))
+	}
+
+	globLine := []byte(`data: {"type":"content_block_start","index":0,"content_block":{"type":"tool_use","id":"toolu_02","name":"proxy_Glob","input":{}}}`)
+	out = restoreClaudeOAuthToolNamesFromStreamLine(globLine, "proxy_", false, reverseMap)
+	if !bytes.Contains(out, []byte(`"name":"glob"`)) {
+		t.Fatalf("Glob should be restored to glob, got: %s", string(out))
+	}
+}