diff --git a/cmd/opencodereview/config_cmd.go b/cmd/opencodereview/config_cmd.go
index 78ed114..8065489 100644
--- a/cmd/opencodereview/config_cmd.go
+++ b/cmd/opencodereview/config_cmd.go
@@ -641,6 +641,11 @@ func setConfigValue(cfg *Config, key, value string) error {
 
 	switch key {
 	case "provider":
+		if value != "" {
+			if err := validateProviderName(value); err != nil {
+				return err
+			}
+		}
 		if cfg.Provider != value {
 			cfg.Model = ""
 		}
@@ -995,33 +1000,35 @@ func ensureModelInList(models []string, model string) []string {
 }
 
 func setProviderValue(cfg *Config, key, value string) error {
-	parts := strings.SplitN(key, ".", 3)
-	if len(parts) != 3 || parts[1] == "" || parts[2] == "" {
+	dot := strings.LastIndex(key, ".")
+	if dot <= len("providers.") || dot == len(key)-1 {
 		return fmt.Errorf("invalid provider key %q: expected providers.<name>.<field>", key)
 	}
-	if _, isPreset := llm.LookupProvider(parts[1]); !isPreset {
-		return setCustomProviderField(cfg, parts[1], parts[2], key, value)
+	name, field := key[len("providers."):dot], key[dot+1:]
+	if _, isPreset := llm.LookupProvider(name); !isPreset {
+		return setCustomProviderField(cfg, name, field, key, value)
+	}
+	entry := cfg.Providers[name]
+	if err := applyProviderField(name, &entry, field, key, value); err != nil {
+		return err
 	}
 	if cfg.Providers == nil {
 		cfg.Providers = make(map[string]ProviderEntry)
 	}
-	entry := cfg.Providers[parts[1]]
-	if err := applyProviderField(parts[1], &entry, parts[2], key, value); err != nil {
-		return err
-	}
-	cfg.Providers[parts[1]] = entry
+	cfg.Providers[name] = entry
 	return nil
 }
 
 func setCustomProviderValue(cfg *Config, key, value string) error {
-	parts := strings.SplitN(key, ".", 3)
-	if len(parts) != 3 || parts[1] == "" || parts[2] == "" {
+	dot := strings.LastIndex(key, ".")
+	if dot <= len("custom_providers.") || dot == len(key)-1 {
 		return fmt.Errorf("invalid custom provider key %q: expected custom_providers.<name>.<field>", key)
 	}
-	if preset, isPreset := llm.LookupProvider(parts[1]); isPreset {
-		return fmt.Errorf("custom provider name %q conflicts with a preset provider; use providers.%s.%s to configure the preset or choose a different custom provider name", parts[1], preset.Name, parts[2])
+	name, field := key[len("custom_providers."):dot], key[dot+1:]
+	if preset, isPreset := llm.LookupProvider(name); isPreset {
+		return fmt.Errorf("custom provider name %q conflicts with a preset provider; use providers.%s.%s to configure the preset or choose a different custom provider name", name, preset.Name, field)
 	}
-	return setCustomProviderField(cfg, parts[1], parts[2], key, value)
+	return setCustomProviderField(cfg, name, field, key, value)
 }
 
 func isAuxiliaryProviderField(field string) bool {
@@ -1033,18 +1040,33 @@ func isAuxiliaryProviderField(field string) bool {
 	}
 }
 
+func validateProviderName(name string) error {
+	for _, segment := range strings.Split(name, ".") {
+		if strings.TrimSpace(segment) == "" {
+			return fmt.Errorf("invalid provider name %q: dot-separated segments must not be empty or whitespace", name)
+		}
+	}
+	return nil
+}
+
 func setCustomProviderField(cfg *Config, name, field, key, value string) error {
+	if err := validateProviderName(name); err != nil {
+		return fmt.Errorf("%s: %w", key, err)
+	}
+	if _, exists := cfg.CustomProviders[name]; strings.Contains(name, ".") && !exists {
+		return fmt.Errorf("provider %q is not configured for key %q; create or select it first:\n  ocr config set provider %s", name, key, name)
+	}
 	if _, exists := cfg.CustomProviders[name]; isAuxiliaryProviderField(field) && !exists {
 		providerKey := strings.TrimSuffix(key, "."+field)
 		return fmt.Errorf("provider %q is not configured; set a core field first (protocol is required for every custom provider):\n  ocr config set %s.protocol <protocol>", name, providerKey)
 	}
-	if cfg.CustomProviders == nil {
-		cfg.CustomProviders = make(map[string]ProviderEntry)
-	}
 	entry := cfg.CustomProviders[name]
 	if err := applyProviderField(name, &entry, field, key, value); err != nil {
 		return err
 	}
+	if cfg.CustomProviders == nil {
+		cfg.CustomProviders = make(map[string]ProviderEntry)
+	}
 	cfg.CustomProviders[name] = entry
 	return nil
 }
diff --git a/cmd/opencodereview/config_cmd_test.go b/cmd/opencodereview/config_cmd_test.go
index 4ebb675..618d5ac 100644
--- a/cmd/opencodereview/config_cmd_test.go
+++ b/cmd/opencodereview/config_cmd_test.go
@@ -220,6 +220,118 @@ func TestSetConfigValueProviderEntryNonPresetWritesCustomProvider(t *testing.T)
 	}
 }
 
+func TestSetConfigValueDottedProviderName(t *testing.T) {
+	fields := []struct {
+		field string
+		value string
+	}{
+		{"url", "https://example.invalid/v1"},
+		{"protocol", llm.ProtocolAnthropicBedrock},
+		{"model", "some-model"},
+		{"api_key", "test-key"},
+		{"api_key_cmd", "secret-tool lookup service x"},
+		{"models", `["some-model","other-model"]`},
+		{"auth_header", "authorization"},
+		{"timeout_sec", "120"},
+		{"extra_body", `{"temperature":0.2}`},
+		{"extra_headers", "X-Gateway=test"},
+		{"retry_codes", "400,403"},
+		{"aws_region", "us-west-2"},
+		{"aws_profile", "test-profile"},
+	}
+	want := ProviderEntry{
+		URL:          "https://example.invalid/v1",
+		Protocol:     llm.ProtocolAnthropicBedrock,
+		Model:        "some-model",
+		APIKey:       "test-key",
+		APIKeyCmd:    "secret-tool lookup service x",
+		Models:       []string{"some-model", "other-model"},
+		AuthHeader:   "authorization",
+		TimeoutSec:   120,
+		ExtraBody:    map[string]any{"temperature": 0.2},
+		ExtraHeaders: map[string]string{"X-Gateway": "test"},
+		RetryCodes:   []int{400, 403},
+		AWSRegion:    "us-west-2",
+		AWSProfile:   "test-profile",
+	}
+	for _, prefix := range []string{"providers", "custom_providers"} {
+		for _, name := range []string{"mimo-v2.6-flash", "openai.gateway.v2", "foo.api_key"} {
+			t.Run(prefix+"."+name, func(t *testing.T) {
+				cfg := &Config{}
+				if err := setConfigValue(cfg, "provider", name); err != nil {
+					t.Fatal(err)
+				}
+				for _, tt := range fields {
+					key := prefix + "." + name + "." + tt.field
+					if err := setConfigValue(cfg, key, tt.value); err != nil {
+						t.Fatalf("setConfigValue(%q): %v", key, err)
+					}
+				}
+				if !reflect.DeepEqual(cfg.CustomProviders, map[string]ProviderEntry{name: want}) {
+					t.Errorf("CustomProviders = %#v, want only %q with %#v", cfg.CustomProviders, name, want)
+				}
+				if len(cfg.Providers) != 0 || cfg.Provider != name {
+					t.Errorf("Providers = %#v, Provider = %q", cfg.Providers, cfg.Provider)
+				}
+			})
+		}
+	}
+}
+
+func TestSetConfigValueRejectsInvalidProviderNames(t *testing.T) {
+	for _, name := range []string{" ", ".a", "a.", "a..b", "a. .b", "anthropic."} {
+		for _, key := range []string{"provider", "providers." + name + ".url", "custom_providers." + name + ".url"} {
+			t.Run(key+"/"+name, func(t *testing.T) {
+				cfg := &Config{Provider: "openai", Model: "saved-model", CustomProviders: map[string]ProviderEntry{name: {}}}
+				before, err := json.Marshal(cfg)
+				if err != nil {
+					t.Fatal(err)
+				}
+				value := "https://example.invalid/v1"
+				if key == "provider" {
+					value = name
+				}
+				if err := setConfigValue(cfg, key, value); err == nil || !strings.Contains(err.Error(), "invalid provider name") {
+					t.Fatalf("setConfigValue(%q, %q) = %v, want invalid provider name", key, value, err)
+				}
+				after, err := json.Marshal(cfg)
+				if err != nil {
+					t.Fatal(err)
+				}
+				if string(after) != string(before) {
+					t.Fatalf("configuration changed after rejected write: %s", after)
+				}
+			})
+		}
+	}
+}
+
+func TestSetConfigValueDottedProviderRequiresExistingEntry(t *testing.T) {
+	for _, prefix := range []string{"providers", "custom_providers"} {
+		for _, name := range []string{"mimo-v2.6-flash", "foo.api_key", "openai.extra_body"} {
+			key := prefix + "." + name + ".model"
+			t.Run(key, func(t *testing.T) {
+				cfg := &Config{Provider: "openai", Model: "saved-model"}
+				want := *cfg
+				err := setConfigValue(cfg, key, "some-model")
+				if err == nil || !strings.Contains(err.Error(), key) || !strings.Contains(err.Error(), "ocr config set provider "+name) {
+					t.Fatalf("setConfigValue(%q) = %v, want explicit creation guidance", key, err)
+				}
+				if !reflect.DeepEqual(*cfg, want) {
+					t.Fatalf("configuration changed after rejected write: %#v", cfg)
+				}
+				cfg.CustomProviders = map[string]ProviderEntry{name: {}}
+				if err := setConfigValue(cfg, key, "some-model"); err != nil {
+					t.Fatal(err)
+				}
+				if cfg.Provider != "openai" || cfg.CustomProviders[name].Model != "some-model" {
+					t.Fatalf("unexpected configuration: %#v", cfg)
+				}
+			})
+		}
+	}
+}
+
 func TestSetConfigValueProviderEntryModelsJSON(t *testing.T) {
 	cfg := &Config{}
 
@@ -364,10 +476,15 @@ func TestSetConfigValueProviderEntryInvalidKey(t *testing.T) {
 }
 
 func TestSetConfigValueProviderEntryInvalidPath(t *testing.T) {
-	cfg := &Config{}
-
-	if err := setConfigValue(cfg, "providers.anthropic", "value"); err == nil {
-		t.Fatal("expected error for incomplete provider path")
+	for _, prefix := range []string{"providers", "custom_providers"} {
+		for _, suffix := range []string{"", "anthropic", ".url", "anthropic.", "mimo-v2.6-flash."} {
+			key := prefix + "." + suffix
+			t.Run(key, func(t *testing.T) {
+				if err := setConfigValue(&Config{}, key, "value"); err == nil || !strings.Contains(err.Error(), "invalid") {
+					t.Fatalf("setConfigValue(%q) = %v, want invalid path error", key, err)
+				}
+			})
+		}
 	}
 }
 
diff --git a/cmd/opencodereview/main_test.go b/cmd/opencodereview/main_test.go
index b7a16cf..c89da5d 100644
--- a/cmd/opencodereview/main_test.go
+++ b/cmd/opencodereview/main_test.go
@@ -4,12 +4,79 @@
 package main
 
 import (
+	"bytes"
 	"os"
 	"os/exec"
 	"strings"
 	"testing"
 )
 
+func TestRunConfigSetProviderNames(t *testing.T) {
+	if os.Getenv("OCR_TEST_CONFIG_SET") == "1" {
+		rootCmd.SetArgs(os.Args[3:])
+		os.Exit(run())
+	}
+	setTestHome(t, t.TempDir())
+	configPath, err := defaultConfigPath()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := saveConfig(configPath, &Config{Provider: "openai", Model: "saved-model"}); err != nil {
+		t.Fatal(err)
+	}
+	tests := []struct {
+		key   string
+		value string
+		code  int
+	}{
+		{"providers.openai.extra_body.model", "some-model", 1},
+		{"custom_providers.openai.extra_body.model", "some-model", 1},
+		{"providers.openai..url", "https://example.invalid/v1", 1},
+		{"providers..a.url", "https://example.invalid/v1", 1},
+		{"providers. .url", "https://example.invalid/v1", 1},
+		{"custom_providers.anthropic..url", "https://example.invalid/v1", 1},
+		{"provider", ".gateway", 1},
+		{"provider", "gateway.", 1},
+		{"provider", "gateway..v2", 1},
+		{"provider", " ", 1},
+		{"provider", "mimo-v2.6-flash", 0},
+		{"providers.mimo-v2.6-flash.url", "https://example.invalid/v1", 0},
+		{"custom_providers.mimo-v2.6-flash.protocol", "openai", 0},
+		{"provider", "foo.api_key", 0},
+		{"custom_providers.foo.api_key.model", "some-model", 0},
+	}
+	for _, tt := range tests {
+		t.Run(tt.key+"/"+tt.value, func(t *testing.T) {
+			before, err := os.ReadFile(configPath)
+			if err != nil {
+				t.Fatal(err)
+			}
+			cmd := exec.Command(os.Args[0], "-test.run=^TestRunConfigSetProviderNames$", "--", "config", "set", tt.key, tt.value)
+			cmd.Env = append(os.Environ(), "OCR_TEST_CONFIG_SET=1", "OCR_NO_UPDATE=1", "OCR_ENABLE_TELEMETRY=0")
+			output, err := cmd.CombinedOutput()
+			if cmd.ProcessState == nil || cmd.ProcessState.ExitCode() != tt.code {
+				t.Fatalf("exit error = %v, want code %d; output:\n%s", err, tt.code, output)
+			}
+			after, err := os.ReadFile(configPath)
+			if err != nil {
+				t.Fatal(err)
+			}
+			if tt.code != 0 && !bytes.Equal(before, after) {
+				t.Fatalf("configuration changed after rejected write: %s", after)
+			}
+		})
+	}
+	cfg, err := loadOrCreateConfig(configPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cfg.CustomProviders["mimo-v2.6-flash"].URL != "https://example.invalid/v1" ||
+		cfg.CustomProviders["mimo-v2.6-flash"].Protocol != "openai" ||
+		cfg.CustomProviders["foo.api_key"].Model != "some-model" {
+		t.Fatalf("dotted provider fields were not persisted: %#v", cfg.CustomProviders)
+	}
+}
+
 func TestRunFlushesTelemetryOnError(t *testing.T) {
 	if os.Getenv("OCR_TEST_RUN_ERROR") == "1" {
 		rootCmd.SetArgs([]string{"--invalid-flag"})
diff --git a/cmd/opencodereview/provider_cmd.go b/cmd/opencodereview/provider_cmd.go
index 75ad999..59f4670 100644
--- a/cmd/opencodereview/provider_cmd.go
+++ b/cmd/opencodereview/provider_cmd.go
@@ -158,6 +158,9 @@ func applyCustomProviderConfig(configPath string, cfg *Config, result providerTU
 	if result.provider == "" {
 		return fmt.Errorf("provider name is required")
 	}
+	if err := validateProviderName(result.provider); err != nil {
+		return err
+	}
 	model := result.resolvedModel()
 	if model == "" {
 		return fmt.Errorf("model is required")
diff --git a/cmd/opencodereview/provider_cmd_test.go b/cmd/opencodereview/provider_cmd_test.go
index 70b0599..e861aa8 100644
--- a/cmd/opencodereview/provider_cmd_test.go
+++ b/cmd/opencodereview/provider_cmd_test.go
@@ -289,6 +289,21 @@ func TestApplyCustomProviderConfig_MissingProvider(t *testing.T) {
 	}
 }
 
+func TestApplyCustomProviderConfigInvalidName(t *testing.T) {
+	for _, name := range []string{" ", ".gateway", "gateway.", "gateway..v2"} {
+		t.Run(name, func(t *testing.T) {
+			cfg := &Config{Provider: "openai", Model: "saved-model"}
+			err := applyCustomProviderConfig(filepath.Join(t.TempDir(), "config.json"), cfg, providerTUIResult{provider: name, model: "some-model"})
+			if err == nil {
+				t.Fatal("expected invalid provider name error")
+			}
+			if cfg.Provider != "openai" || cfg.Model != "saved-model" || cfg.CustomProviders != nil {
+				t.Fatalf("configuration changed after rejected write: %#v", cfg)
+			}
+		})
+	}
+}
+
 func TestApplyCustomProviderConfig_MissingModel(t *testing.T) {
 	err := applyCustomProviderConfig("", &Config{}, providerTUIResult{provider: "p", model: ""})
 	if err == nil {
diff --git a/cmd/opencodereview/provider_tui.go b/cmd/opencodereview/provider_tui.go
index a7a1a5c..02c0b05 100644
--- a/cmd/opencodereview/provider_tui.go
+++ b/cmd/opencodereview/provider_tui.go
@@ -1246,6 +1246,11 @@ func (m providerTUIModel) applyCreateCustomProvider() (tea.Model, tea.Cmd) {
 		m.cpStep = cpStepName
 		return m, m.cpNameInput.Focus()
 	}
+	if err := validateProviderName(r.provider); err != nil {
+		m.formError = err.Error()
+		m.cpStep = cpStepName
+		return m, m.cpNameInput.Focus()
+	}
 	if m.customProviderNameTaken(r.provider) {
 		m.formError = fmt.Sprintf(`Provider "%s" already exists`, r.provider)
 		m.cpStep = cpStepName
diff --git a/cmd/opencodereview/provider_tui_persist_test.go b/cmd/opencodereview/provider_tui_persist_test.go
index 8174309..b9b38d1 100644
--- a/cmd/opencodereview/provider_tui_persist_test.go
+++ b/cmd/opencodereview/provider_tui_persist_test.go
@@ -184,6 +184,22 @@ func TestApplyCreateCustomProvider(t *testing.T) {
 		return m
 	}
 
+	for _, name := range []string{".gateway", "gateway.", "gateway..v2"} {
+		t.Run("invalid name "+name, func(t *testing.T) {
+			cfg := &Config{Provider: "openai", Model: "saved-model"}
+			m := setup(t, cfg, filepath.Join(t.TempDir(), "config.json"))
+			m.cpNameInput.SetValue(name)
+			out, _ := m.applyCreateCustomProvider()
+			got := out.(providerTUIModel)
+			if got.formError == "" || got.savedInSession || got.cpStep != cpStepName {
+				t.Fatalf("invalid name was not rejected: formError=%q, saved=%v, step=%v", got.formError, got.savedInSession, got.cpStep)
+			}
+			if cfg.Provider != "openai" || cfg.Model != "saved-model" || cfg.CustomProviders != nil {
+				t.Fatalf("configuration changed after rejected write: %#v", cfg)
+			}
+		})
+	}
+
 	t.Run("nil config guard", func(t *testing.T) {
 		m := setup(t, &Config{}, filepath.Join(t.TempDir(), "c.json"))
 		m.existingCfg = nil
diff --git a/extensions/frontend/src/shared/__tests__/providers.test.ts b/extensions/frontend/src/shared/__tests__/providers.test.ts
index 5546d4b..4a74bcb 100644
--- a/extensions/frontend/src/shared/__tests__/providers.test.ts
+++ b/extensions/frontend/src/shared/__tests__/providers.test.ts
@@ -3,10 +3,18 @@
 
 import { PROVIDER_PRESETS as generatedPresets } from '../providers.generated';
 import { isPresetProvider, lookupPreset, mergeModelLists, PROVIDER_PRESETS, usesAmbientAuth } from '../providers';
-import { buildOfficialSaveEntries, detectInitialTab, isConfigReady } from '../configUtils';
+import { buildOfficialSaveEntries, detectInitialTab, isConfigReady, isValidProviderName } from '../configUtils';
 import { OcrConfig } from '../types';
 
 describe('generated provider presets', () => {
+  it.each(['my-gateway', 'mimo-v2.6-flash', 'foo.api_key'])('accepts provider name %s', (name) => {
+    expect(isValidProviderName(name)).toBe(true);
+  });
+
+  it.each(['', ' ', '.a', 'a.', 'a..b', 'a. .b'])('rejects provider name %s', (name) => {
+    expect(isValidProviderName(name)).toBe(false);
+  });
+
   it('keeps providers sorted by name with the existing initial provider', () => {
     const names = PROVIDER_PRESETS.map((preset) => preset.name);
     expect(names).toEqual([...names].sort());
diff --git a/extensions/frontend/src/shared/configUtils.ts b/extensions/frontend/src/shared/configUtils.ts
index d3e9266..d438a3c 100644
--- a/extensions/frontend/src/shared/configUtils.ts
+++ b/extensions/frontend/src/shared/configUtils.ts
@@ -18,6 +18,10 @@ export interface ConfigEntry {
   value: string;
 }
 
+export function isValidProviderName(name: string): boolean {
+  return name.split('.').every((segment) => segment.trim() !== '');
+}
+
 export function detectInitialTab(config: OcrConfig | null): ProviderTab {
   if (!config) return 'official';
   if (config.provider) {
@@ -120,15 +124,15 @@ export function buildCustomCreateSaveEntries(params: {
   authHeader: string;
 }): ConfigEntry[] {
   const entries: ConfigEntry[] = [
+    { key: 'provider', value: params.name.trim() },
     { key: `custom_providers.${params.name}.protocol`, value: params.protocol },
     { key: `custom_providers.${params.name}.url`, value: params.url.trim() },
     { key: `custom_providers.${params.name}.model`, value: params.model.trim() },
     { key: `custom_providers.${params.name}.api_key`, value: params.apiKey.trim() },
-    { key: 'provider', value: params.name.trim() },
   ];
   const models = params.models.trim();
   if (models) {
-    entries.splice(3, 0, { key: `custom_providers.${params.name}.models`, value: models });
+    entries.splice(4, 0, { key: `custom_providers.${params.name}.models`, value: models });
   }
   if (params.authHeader.trim()) {
     entries.push({ key: `custom_providers.${params.name}.auth_header`, value: params.authHeader.trim() });
diff --git a/extensions/frontend/src/webview/views/ConfigView.tsx b/extensions/frontend/src/webview/views/ConfigView.tsx
index 8d2a85a..c86860c 100644
--- a/extensions/frontend/src/webview/views/ConfigView.tsx
+++ b/extensions/frontend/src/webview/views/ConfigView.tsx
@@ -3,7 +3,7 @@
 
 import { useEffect, useMemo, useState } from 'preact/hooks';
 import type { ComponentChildren } from 'preact';
-import { ConfigEntry, ConfigPanelFocus, ProviderTab, buildCustomCreateSaveEntries, buildCustomUpdateSaveEntries, buildOfficialSaveEntries, describeActiveProvider, detectInitialTab, isConfigReady, listCustomProviderNames } from '../../shared/configUtils';
+import { ConfigEntry, ConfigPanelFocus, ProviderTab, buildCustomCreateSaveEntries, buildCustomUpdateSaveEntries, buildOfficialSaveEntries, describeActiveProvider, detectInitialTab, isConfigReady, isValidProviderName, listCustomProviderNames } from '../../shared/configUtils';
 import { mergeModelLists, PROVIDER_PRESETS, usesAmbientAuth } from '../../shared/providers';
 import { EnvCheckResult, LogLine, OcrConfig } from '../../shared/types';
 import { CliStatus, ConnTest } from '../configStore';
@@ -450,8 +450,8 @@ function CustomForm({
   const [apiKeyTouched, setApiKeyTouched] = useState(false);
   const [authHeader, setAuthHeader] = useState(entry?.authHeader ?? '');
 
-  const canSaveCreate = name.trim() !== '' && url.trim() !== '' && model.trim() !== '' && apiKey.trim() !== '';
-  const canSaveEdit = !isCreate && name.trim() !== '' && url.trim() !== '' && model.trim() !== ''
+  const canSaveCreate = isValidProviderName(name) && url.trim() !== '' && model.trim() !== '' && apiKey.trim() !== '';
+  const canSaveEdit = !isCreate && isValidProviderName(name) && url.trim() !== '' && model.trim() !== ''
     && Boolean(entry?.apiKey || apiKey.trim());
   const canSave = isCreate ? canSaveCreate : canSaveEdit;
 
diff --git a/extensions/idea/src/main/kotlin/com/alibaba/opencodereview/idea/services/ConfigDraft.kt b/extensions/idea/src/main/kotlin/com/alibaba/opencodereview/idea/services/ConfigDraft.kt
index 322059c..a62cc73 100644
--- a/extensions/idea/src/main/kotlin/com/alibaba/opencodereview/idea/services/ConfigDraft.kt
+++ b/extensions/idea/src/main/kotlin/com/alibaba/opencodereview/idea/services/ConfigDraft.kt
@@ -113,16 +113,22 @@ private fun RawConfig.setProviderEntryField(
     }
 }
 
-private fun RawConfig.setCustomProviderField(name: String, field: String, value: String) =
+private fun isValidProviderName(name: String): Boolean = name.split('.').all { it.isNotBlank() }
+
+private fun RawConfig.setCustomProviderField(name: String, field: String, value: String) {
+    if (!isValidProviderName(name)) return
+    if ('.' in name && (this["custom_providers"] as? JsonObject)?.containsKey(name) != true) return
     setProviderEntryField("custom_providers", name, field, value)
+}
 
 /** `providers.<name>.<field>`: if name is a built-in provider, write to providers; otherwise write to custom_providers. */
 private fun RawConfig.setProviderValue(key: String, value: String) {
-    val parts = key.split('.')
-    if (parts.size != 3) return
-    val name = parts[1]
-    val field = parts[2]
-    if (isPresetProvider(name)) {
+    val prefix = if (key.startsWith("providers.")) "providers." else "custom_providers."
+    val dot = key.lastIndexOf('.')
+    if (dot <= prefix.length || dot == key.length - 1) return
+    val name = key.substring(prefix.length, dot)
+    val field = key.substring(dot + 1)
+    if (prefix == "providers." && isPresetProvider(name)) {
         // Consistent with isPresetProvider / ConfigUtils: preset keys are stored canonically lowercased, so "OpenAI"
         // is not judged preset yet written under a capitalized key that later lookups would miss.
         setProviderEntryField("providers", name.trim().lowercase(Locale.ROOT), field, value)
@@ -145,18 +151,14 @@ private fun RawConfig.setLlmField(field: String, element: JsonElement) {
 }
 
 private fun RawConfig.setConfigValue(key: String, value: String) {
-    if (key.startsWith("providers.")) {
+    if (key.startsWith("providers.") || key.startsWith("custom_providers.")) {
         setProviderValue(key, value)
         return
     }
-    if (key.startsWith("custom_providers.")) {
-        val parts = key.split('.')
-        if (parts.size == 3) setCustomProviderField(parts[1], parts[2], value)
-        return
-    }
 
     when (key) {
         "provider" -> {
+            if (value.isNotEmpty() && !isValidProviderName(value)) return
             // Preset providers are stored canonically lowercased, matching the providers bucket keys; custom providers keep the user's original name.
             val providerName = if (isPresetProvider(value)) value.trim().lowercase(Locale.ROOT) else value
             // Clear the top-level model when the provider changes: the old model usually does not belong to the new provider
diff --git a/extensions/idea/src/test/kotlin/com/alibaba/opencodereview/idea/services/ConfigDraftTest.kt b/extensions/idea/src/test/kotlin/com/alibaba/opencodereview/idea/services/ConfigDraftTest.kt
index a3249df..880865e 100644
--- a/extensions/idea/src/test/kotlin/com/alibaba/opencodereview/idea/services/ConfigDraftTest.kt
+++ b/extensions/idea/src/test/kotlin/com/alibaba/opencodereview/idea/services/ConfigDraftTest.kt
@@ -14,6 +14,58 @@ import kotlin.test.assertTrue
 
 class ConfigDraftTest {
 
+    @Test
+    fun `explicitly created dotted providers retain all draft fields`() {
+        for (prefix in listOf("providers", "custom_providers")) {
+            for (name in listOf("mimo-v2.6-flash", "foo.api_key", "openai.extra_body")) {
+                val d = draft(
+                    "{}",
+                    "provider" to name,
+                    "$prefix.$name.protocol" to "openai",
+                    "$prefix.$name.url" to "https://example.invalid/v1",
+                    "$prefix.$name.model" to "some-model",
+                    "$prefix.$name.api_key" to "test-key",
+                    "$prefix.$name.models" to "some-model,other-model",
+                    "$prefix.$name.auth_header" to "authorization",
+                )
+                assertEquals(name, d.str("provider"))
+                val expected = parseRawConfig(
+                    """{"protocol":"openai","url":"https://example.invalid/v1","model":"some-model","api_key":"test-key","models":["some-model","other-model"],"auth_header":"authorization"}""",
+                )
+                assertEquals(JsonObject(expected), d.obj("custom_providers", name))
+                assertNull(d.obj("providers"))
+            }
+        }
+    }
+
+    @Test
+    fun `dotted field writes require an existing provider without changing the active provider`() {
+        for (prefix in listOf("providers", "custom_providers")) {
+            for (name in listOf("mimo-v2.6-flash", "foo.api_key", "openai.extra_body")) {
+                val base = parseRawConfig("""{"provider":"openai","model":"saved-model"}""")
+                val entries = listOf(ConfigEntry("$prefix.$name.model", "some-model"))
+                assertEquals(base, applyConfigEntries(base, entries))
+                val existing = parseRawConfig("""{"provider":"openai","custom_providers":{"$name":{}}}""")
+                val d = applyConfigEntries(existing, entries)
+                assertEquals("openai", d.str("provider"))
+                assertEquals("some-model", d.str("custom_providers", name, "model"))
+                assertEquals(JsonObject(emptyMap()), existing.obj("custom_providers", name))
+            }
+        }
+    }
+
+    @Test
+    fun `invalid provider names leave the draft unchanged`() {
+        for (name in listOf(" ", ".a", "a.", "a..b", "a. .b", "anthropic.")) {
+            val base = parseRawConfig("""{"provider":"openai","model":"saved-model","custom_providers":{"$name":{}}}""")
+            assertEquals(base, applyConfigEntries(base, listOf(ConfigEntry("provider", name))))
+            for (prefix in listOf("providers", "custom_providers")) {
+                val entries = listOf(ConfigEntry("$prefix.$name.url", "https://example.invalid/v1"))
+                assertEquals(base, applyConfigEntries(base, entries))
+            }
+        }
+    }
+
     private fun draft(base: String, vararg entries: Pair<String, String>): RawConfig =
         applyConfigEntries(parseRawConfig(base), entries.map { ConfigEntry(it.first, it.second) })
 
diff --git a/extensions/vscode/src/extension/services/__tests__/configDraft.test.ts b/extensions/vscode/src/extension/services/__tests__/configDraft.test.ts
index 898a0a3..e0274ca 100644
--- a/extensions/vscode/src/extension/services/__tests__/configDraft.test.ts
+++ b/extensions/vscode/src/extension/services/__tests__/configDraft.test.ts
@@ -2,8 +2,48 @@
 // Copyright 2026 alibaba/open-code-review Contributors
 
 import { applyConfigEntries } from '../configDraft';
+import { buildCustomCreateSaveEntries } from '@shared/configUtils';
 
 describe('applyConfigEntries', () => {
+  it.each(['mimo-v2.6-flash', 'foo.api_key', 'openai.extra_body'])('creates %s before applying form fields', (name) => {
+    const entries = buildCustomCreateSaveEntries({
+      name, protocol: 'openai', url: 'https://example.invalid/v1', model: 'some-model',
+      models: 'some-model,other-model', apiKey: 'test-key', authHeader: 'authorization',
+    });
+    expect(entries[0]).toEqual({ key: 'provider', value: name });
+    const base = { provider: 'openai', model: 'saved-model' };
+    const draft = applyConfigEntries(base, entries);
+    expect(draft.provider).toBe(name);
+    expect(draft.custom_providers).toEqual({
+      [name]: {
+        protocol: 'openai', url: 'https://example.invalid/v1', model: 'some-model',
+        models: ['some-model', 'other-model'], api_key: 'test-key', auth_header: 'authorization',
+      },
+    });
+    expect(base).toEqual({ provider: 'openai', model: 'saved-model' });
+  });
+
+  it.each(['providers', 'custom_providers'])('requires existing dotted names for %s', (prefix) => {
+    const base = { provider: 'openai', model: 'saved-model' };
+    for (const name of ['mimo-v2.6-flash', 'foo.api_key', 'openai.extra_body']) {
+      const entry = { key: `${prefix}.${name}.model`, value: 'some-model' };
+      expect(applyConfigEntries(base, [entry])).toEqual(base);
+      const existing = { ...base, custom_providers: { [name]: {} } };
+      const draft = applyConfigEntries(existing, [entry]);
+      expect(draft.provider).toBe('openai');
+      expect(draft.custom_providers).toEqual({ [name]: { model: 'some-model' } });
+      expect(existing.custom_providers[name]).toEqual({});
+    }
+  });
+
+  it.each([' ', '.a', 'a.', 'a..b', 'a. .b', 'anthropic.'])('rejects invalid name %s', (name) => {
+    const base = { provider: 'openai', model: 'saved-model', custom_providers: { [name]: {} } };
+    expect(applyConfigEntries(base, [{ key: 'provider', value: name }])).toEqual(base);
+    for (const prefix of ['providers', 'custom_providers']) {
+      expect(applyConfigEntries(base, [{ key: `${prefix}.${name}.url`, value: 'https://example.invalid/v1' }])).toEqual(base);
+    }
+  });
+
   it('merges built-in provider entries', () => {
     const draft = applyConfigEntries({}, [
       { key: 'provider', value: 'anthropic' },
diff --git a/extensions/vscode/src/extension/services/configDraft.ts b/extensions/vscode/src/extension/services/configDraft.ts
index e3e593d..4c31b8a 100644
--- a/extensions/vscode/src/extension/services/configDraft.ts
+++ b/extensions/vscode/src/extension/services/configDraft.ts
@@ -1,7 +1,7 @@
 // SPDX-License-Identifier: Apache-2.0
 // Copyright 2026 alibaba/open-code-review Contributors
 
-import { ConfigEntry } from '@shared/configUtils';
+import { ConfigEntry, isValidProviderName } from '@shared/configUtils';
 import { isPresetProvider } from '@shared/providers';
 
 type RawProviderEntry = Record<string, unknown>;
@@ -57,6 +57,8 @@ function applyProviderField(entry: RawProviderEntry, field: string, value: strin
 }
 
 function setCustomProviderField(cfg: RawConfig, name: string, field: string, value: string): void {
+  if (!isValidProviderName(name)) return;
+  if (name.includes('.') && !Object.prototype.hasOwnProperty.call(cfg.custom_providers ?? {}, name)) return;
   if (!cfg.custom_providers) cfg.custom_providers = {};
   const entry = { ...(cfg.custom_providers[name] ?? {}) };
   applyProviderField(entry, field, value);
@@ -64,11 +66,12 @@ function setCustomProviderField(cfg: RawConfig, name: string, field: string, val
 }
 
 function setProviderValue(cfg: RawConfig, key: string, value: string): void {
-  const parts = key.split('.');
-  if (parts.length !== 3) return;
-  const name = parts[1];
-  const field = parts[2];
-  if (isPresetProvider(name)) {
+  const prefix = key.startsWith('providers.') ? 'providers.' : 'custom_providers.';
+  const dot = key.lastIndexOf('.');
+  if (dot <= prefix.length || dot === key.length - 1) return;
+  const name = key.slice(prefix.length, dot);
+  const field = key.slice(dot + 1);
+  if (prefix === 'providers.' && isPresetProvider(name)) {
     if (!cfg.providers) cfg.providers = {};
     const entry = { ...(cfg.providers[name] ?? {}) };
     applyProviderField(entry, field, value);
@@ -79,18 +82,14 @@ function setProviderValue(cfg: RawConfig, key: string, value: string): void {
 }
 
 function setConfigValue(cfg: RawConfig, key: string, value: string): void {
-  if (key.startsWith('providers.')) {
+  if (key.startsWith('providers.') || key.startsWith('custom_providers.')) {
     setProviderValue(cfg, key, value);
     return;
   }
-  if (key.startsWith('custom_providers.')) {
-    const parts = key.split('.');
-    if (parts.length === 3) setCustomProviderField(cfg, parts[1], parts[2], value);
-    return;
-  }
 
   switch (key) {
     case 'provider':
+      if (value && !isValidProviderName(value)) return;
       if (cfg.provider !== value) cfg.model = '';
       cfg.provider = value;
       if (isPresetProvider(value)) {
diff --git a/pages/src/content/docs/en/configuration.md b/pages/src/content/docs/en/configuration.md
index 4d5dbf6..6115ac6 100644
--- a/pages/src/content/docs/en/configuration.md
+++ b/pages/src/content/docs/en/configuration.md
@@ -163,6 +163,14 @@ rather than accepted and ignored.
 
 ### Custom providers
 
+Names such as `mimo-v2.6-flash` and `foo.api_key` are supported. Before
+setting fields on a new name containing dots, create and select it with
+`ocr config set provider <name>`; this changes the active provider. Existing
+dotted entries can be edited without selecting them, through either
+`providers.<name>.<field>` or `custom_providers.<name>.<field>`. Names must
+not start or end with a dot, contain consecutive dots, or have empty or
+whitespace-only segments. Dot-free names still support implicit creation.
+
 Any provider name not in the table above is treated as custom and must
 supply at least `url` and `protocol` (`protocol` is `anthropic`,
 `openai`, `openai-responses`, or `anthropic-bedrock`):
diff --git a/pages/src/content/docs/ja/configuration.md b/pages/src/content/docs/ja/configuration.md
index 5943ba2..2ae44c0 100644
--- a/pages/src/content/docs/ja/configuration.md
+++ b/pages/src/content/docs/ja/configuration.md
@@ -160,6 +160,13 @@ Model:  claude-sonnet-5
 
 ### カスタム provider
 
+`mimo-v2.6-flash` や `foo.api_key` のような名前を使用できます。ドットを含む新しい
+名前のフィールドを設定する前に、`ocr config set provider <name>` で作成して選択してください。
+この操作は現在の provider を変更します。既存のエントリは選択せずに
+`providers.<name>.<field>` または `custom_providers.<name>.<field>` で編集できます。
+名前の先頭・末尾のドット、連続したドット、空または空白のみの区切り部分は使用できません。
+ドットを含まない名前は引き続きフィールドの設定時に自動作成されます。
+
 上記の表にない provider 名はすべてカスタムとみなされ、少なくとも `url` と
 `protocol` を指定する必要があります（`protocol` は `anthropic`、`openai`、
 `openai-responses`、または `anthropic-bedrock`）。
diff --git a/pages/src/content/docs/ko/configuration.md b/pages/src/content/docs/ko/configuration.md
index a3905eb..2aac659 100644
--- a/pages/src/content/docs/ko/configuration.md
+++ b/pages/src/content/docs/ko/configuration.md
@@ -139,6 +139,8 @@ Bedrock은 `llm.protocol`이나 `OCR_LLM_PROTOCOL`로는 사용할 수 **없습
 
 ### 커스텀 프로바이더 {#custom-providers}
 
+`mimo-v2.6-flash`, `foo.api_key`처럼 점이 포함된 이름을 사용할 수 있습니다. 새로운 이름에 점이 있다면 필드를 설정하기 전에 `ocr config set provider <name>`으로 생성하고 선택하세요. 이 명령은 현재 프로바이더를 변경합니다. 기존 항목은 선택하지 않고도 `providers.<name>.<field>` 또는 `custom_providers.<name>.<field>`로 수정할 수 있습니다. 이름의 처음이나 끝에 점이 있거나, 점이 연속되거나, 구분된 부분이 비어 있거나 공백으로만 구성된 이름은 허용되지 않습니다. 점이 없는 이름은 필드 설정 시 계속 자동으로 생성됩니다.
+
 위 표에 없는 프로바이더 이름은 커스텀으로 취급하며 최소한 `url`과 `protocol`을 지정해야 합니다(`protocol`은 `anthropic`, `openai`, `openai-responses`, `anthropic-bedrock` 중 하나):
 
 ```bash
diff --git a/pages/src/content/docs/ru/configuration.md b/pages/src/content/docs/ru/configuration.md
index e35b1de..a9f05dd 100644
--- a/pages/src/content/docs/ru/configuration.md
+++ b/pages/src/content/docs/ru/configuration.md
@@ -169,6 +169,15 @@ Model:  claude-sonnet-5
 
 ### Пользовательские провайдеры
 
+Поддерживаются имена вида `mimo-v2.6-flash` и `foo.api_key`. Прежде чем
+задавать поля нового имени с точками, создайте и выберите его командой
+`ocr config set provider <name>`; она меняет активного провайдера.
+Существующие записи можно редактировать без выбора через
+`providers.<name>.<field>` или `custom_providers.<name>.<field>`.
+Имя не должно начинаться или заканчиваться точкой, содержать несколько
+точек подряд, пустые части или части только из пробелов. Имена без точек
+по-прежнему создаются неявно при настройке полей.
+
 Любое имя провайдера, которого нет в таблице выше, считается
 пользовательским. Для него необходимо задать как минимум `url` и `protocol`
 (`protocol` может принимать значения `anthropic`, `openai`,
diff --git a/pages/src/content/docs/zh/configuration.md b/pages/src/content/docs/zh/configuration.md
index 5acc38d..230f088 100644
--- a/pages/src/content/docs/zh/configuration.md
+++ b/pages/src/content/docs/zh/configuration.md
@@ -153,6 +153,12 @@ URL 加一个 token，没有地方放区域或 profile，而 bedrock 这两个
 
 ### 自定义 provider
 
+支持 `mimo-v2.6-flash` 和 `foo.api_key` 这样的名称。为新的含点名称设置字段前，
+请先运行 `ocr config set provider <name>` 创建并选中它；这会更改当前 provider。
+已有的含点条目无需选中即可通过 `providers.<name>.<field>` 或
+`custom_providers.<name>.<field>` 编辑。名称不能以点开头或结尾、包含连续的点，
+也不能包含空白或仅由空白字符组成的分段。不含点的名称仍支持隐式创建。
+
 任何不在上表中的 provider 名都视为自定义，至少要提供 `url` 和 `protocol`
 （`protocol` 取 `anthropic`、`openai`、`openai-responses` 或
 `anthropic-bedrock`）：