From 4f6b1ab4125b0fa8936deba70414ee9a3e82be89 Mon Sep 17 00:00:00 2001
From: David Gageot <david.gageot@docker.com>
Date: Tue, 17 Mar 2026 09:25:13 +0100
Subject: [PATCH] Reject unknown thinking_budget effort levels at parse time

Previously, a typo like 'thinking_budget: adaptative' was silently accepted
but no provider recognized it, so thinking was never enabled. Now the YAML
and JSON unmarshalers validate the effort string against the set of accepted
values (none, minimal, low, medium, high, max, adaptive) and return a clear
error on unrecognized input.

Assisted-By: docker-agent
---
 pkg/config/latest/types.go      | 20 ++++++++++++++++++++
 pkg/config/latest/types_test.go | 27 +++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)

diff --git a/pkg/config/latest/types.go b/pkg/config/latest/types.go
index 679a73a70..642d01211 100644
--- a/pkg/config/latest/types.go
+++ b/pkg/config/latest/types.go
@@ -683,6 +683,20 @@ type ThinkingBudget struct {
 	Tokens int `json:"tokens,omitempty"`
 }
 
+// validThinkingEfforts lists all accepted string values for thinking_budget.
+const validThinkingEfforts = "none, minimal, low, medium, high, max, adaptive"
+
+// isValidThinkingEffort reports whether s (case-insensitive, trimmed) is a
+// recognised thinking_budget effort level.
+func isValidThinkingEffort(s string) bool {
+	switch strings.ToLower(strings.TrimSpace(s)) {
+	case "none", "minimal", "low", "medium", "high", "max", "adaptive":
+		return true
+	default:
+		return false
+	}
+}
+
 func (t *ThinkingBudget) UnmarshalYAML(unmarshal func(any) error) error {
 	// Try integer tokens first
 	var n int
@@ -694,6 +708,9 @@ func (t *ThinkingBudget) UnmarshalYAML(unmarshal func(any) error) error {
 	// Try string level
 	var s string
 	if err := unmarshal(&s); err == nil {
+		if !isValidThinkingEffort(s) {
+			return fmt.Errorf("invalid thinking_budget effort %q: must be one of %s", s, validThinkingEfforts)
+		}
 		*t = ThinkingBudget{Effort: s}
 		return nil
 	}
@@ -793,6 +810,9 @@ func (t *ThinkingBudget) UnmarshalJSON(data []byte) error {
 	// Try string level
 	var s string
 	if err := json.Unmarshal(data, &s); err == nil {
+		if !isValidThinkingEffort(s) {
+			return fmt.Errorf("invalid thinking_budget effort %q: must be one of %s", s, validThinkingEfforts)
+		}
 		*t = ThinkingBudget{Effort: s}
 		return nil
 	}
diff --git a/pkg/config/latest/types_test.go b/pkg/config/latest/types_test.go
index 6aede16cb..c69e87100 100644
--- a/pkg/config/latest/types_test.go
+++ b/pkg/config/latest/types_test.go
@@ -1,6 +1,7 @@
 package latest
 
 import (
+	"encoding/json"
 	"testing"
 
 	"github.com/goccy/go-yaml"
@@ -144,6 +145,32 @@ func TestThinkingBudget_IsDisabled(t *testing.T) {
 	}
 }
 
+func TestThinkingBudget_UnmarshalYAML_InvalidEffort(t *testing.T) {
+	t.Parallel()
+
+	input := []byte(`thinking_budget: adaptative`)
+	var config struct {
+		ThinkingBudget *ThinkingBudget `yaml:"thinking_budget"`
+	}
+
+	err := yaml.Unmarshal(input, &config)
+	require.Error(t, err)
+	require.Contains(t, err.Error(), `invalid thinking_budget effort "adaptative"`)
+}
+
+func TestThinkingBudget_UnmarshalJSON_InvalidEffort(t *testing.T) {
+	t.Parallel()
+
+	data := []byte(`{"thinking_budget": "adaptative"}`)
+	var config struct {
+		ThinkingBudget *ThinkingBudget `json:"thinking_budget"`
+	}
+
+	err := json.Unmarshal(data, &config)
+	require.Error(t, err)
+	require.Contains(t, err.Error(), `invalid thinking_budget effort "adaptative"`)
+}
+
 func TestThinkingBudget_IsAdaptive(t *testing.T) {
 	t.Parallel()