diff --git a/internal/translator/antigravity/claude/antigravity_claude_request.go b/internal/translator/antigravity/claude/antigravity_claude_request.go
index a3f9fa48..c4e07b6a 100644
--- a/internal/translator/antigravity/claude/antigravity_claude_request.go
+++ b/internal/translator/antigravity/claude/antigravity_claude_request.go
@@ -440,14 +440,8 @@ func ConvertClaudeRequestToAntigravity(modelName string, inputRawJSON []byte, _
 				out, _ = sjson.Set(out, "request.generationConfig.thinkingConfig.thinkingBudget", budget)
 				out, _ = sjson.Set(out, "request.generationConfig.thinkingConfig.includeThoughts", true)
 			}
-		case "auto":
-			// Amp sends thinking.type="auto" — use max budget from model config
-			// Antigravity API for Claude models requires a concrete positive budget,
-			// not -1. Use a high default that ApplyThinking will cap to model max.
-			out, _ = sjson.Set(out, "request.generationConfig.thinkingConfig.thinkingBudget", 64000)
-			out, _ = sjson.Set(out, "request.generationConfig.thinkingConfig.includeThoughts", true)
-		case "adaptive":
-			// Keep adaptive as a high level sentinel; ApplyThinking resolves it
+		case "adaptive", "auto":
+			// Keep adaptive/auto as a high level sentinel; ApplyThinking resolves it
 			// to model-specific max capability.
 			out, _ = sjson.Set(out, "request.generationConfig.thinkingConfig.thinkingLevel", "high")
 			out, _ = sjson.Set(out, "request.generationConfig.thinkingConfig.includeThoughts", true)
diff --git a/internal/translator/codex/claude/codex_claude_request.go b/internal/translator/codex/claude/codex_claude_request.go
index 64e41fb5..739b39e9 100644
--- a/internal/translator/codex/claude/codex_claude_request.go
+++ b/internal/translator/codex/claude/codex_claude_request.go
@@ -230,8 +230,8 @@ func ConvertClaudeRequestToCodex(modelName string, inputRawJSON []byte, _ bool)
 					reasoningEffort = effort
 				}
 			}
-		case "adaptive":
-			// Claude adaptive means "enable with max capacity"; keep it as highest level
+		case "adaptive", "auto":
+			// Claude adaptive/auto means "enable with max capacity"; keep it as highest level
 			// and let ApplyThinking normalize per target model capability.
 			reasoningEffort = string(thinking.LevelXHigh)
 		case "disabled":
diff --git a/internal/translator/gemini-cli/claude/gemini-cli_claude_request.go b/internal/translator/gemini-cli/claude/gemini-cli_claude_request.go
index ee661381..653bbeb2 100644
--- a/internal/translator/gemini-cli/claude/gemini-cli_claude_request.go
+++ b/internal/translator/gemini-cli/claude/gemini-cli_claude_request.go
@@ -180,8 +180,8 @@ func ConvertClaudeRequestToCLI(modelName string, inputRawJSON []byte, _ bool) []
 				out, _ = sjson.Set(out, "request.generationConfig.thinkingConfig.thinkingBudget", budget)
 				out, _ = sjson.Set(out, "request.generationConfig.thinkingConfig.includeThoughts", true)
 			}
-		case "adaptive":
-			// Keep adaptive as a high level sentinel; ApplyThinking resolves it
+		case "adaptive", "auto":
+			// Keep adaptive/auto as a high level sentinel; ApplyThinking resolves it
 			// to model-specific max capability.
 			out, _ = sjson.Set(out, "request.generationConfig.thinkingConfig.thinkingLevel", "high")
 			out, _ = sjson.Set(out, "request.generationConfig.thinkingConfig.includeThoughts", true)
diff --git a/internal/translator/gemini/claude/gemini_claude_request.go b/internal/translator/gemini/claude/gemini_claude_request.go
index e882f769..b5756d20 100644
--- a/internal/translator/gemini/claude/gemini_claude_request.go
+++ b/internal/translator/gemini/claude/gemini_claude_request.go
@@ -161,8 +161,8 @@ func ConvertClaudeRequestToGemini(modelName string, inputRawJSON []byte, _ bool)
 				out, _ = sjson.Set(out, "generationConfig.thinkingConfig.thinkingBudget", budget)
 				out, _ = sjson.Set(out, "generationConfig.thinkingConfig.includeThoughts", true)
 			}
-		case "adaptive":
-			// Keep adaptive as a high level sentinel; ApplyThinking resolves it
+		case "adaptive", "auto":
+			// Keep adaptive/auto as a high level sentinel; ApplyThinking resolves it
 			// to model-specific max capability.
 			out, _ = sjson.Set(out, "generationConfig.thinkingConfig.thinkingLevel", "high")
 			out, _ = sjson.Set(out, "generationConfig.thinkingConfig.includeThoughts", true)
diff --git a/internal/translator/openai/claude/openai_claude_request.go b/internal/translator/openai/claude/openai_claude_request.go
index acb79a13..e3efb83c 100644
--- a/internal/translator/openai/claude/openai_claude_request.go
+++ b/internal/translator/openai/claude/openai_claude_request.go
@@ -75,8 +75,8 @@ func ConvertClaudeRequestToOpenAI(modelName string, inputRawJSON []byte, stream
 						out, _ = sjson.Set(out, "reasoning_effort", effort)
 					}
 				}
-			case "adaptive":
-				// Claude adaptive means "enable with max capacity"; keep it as highest level
+			case "adaptive", "auto":
+				// Claude adaptive/auto means "enable with max capacity"; keep it as highest level
 				// and let ApplyThinking normalize per target model capability.
 				out, _ = sjson.Set(out, "reasoning_effort", string(thinking.LevelXHigh))
 			case "disabled":