diff --git a/src/__tests__/config.test.ts b/src/__tests__/config.test.ts
index 5534c97..b1f54cc 100644
--- a/src/__tests__/config.test.ts
+++ b/src/__tests__/config.test.ts
@@ -34,6 +34,7 @@ import {
   updateWorktreeSession,
   getLanguage,
   loadProjectConfig,
+  saveProjectConfig,
   isVerboseMode,
   resolveConfigValue,
   invalidateGlobalConfigCache,
@@ -501,60 +502,6 @@ describe('analytics config resolution', () => {
   });
 });
 
-describe('model config resolution', () => {
-  let testDir: string;
-  let originalTaktConfigDir: string | undefined;
-
-  beforeEach(() => {
-    testDir = join(tmpdir(), `takt-test-${randomUUID()}`);
-    mkdirSync(testDir, { recursive: true });
-    originalTaktConfigDir = process.env.TAKT_CONFIG_DIR;
-    process.env.TAKT_CONFIG_DIR = join(testDir, 'global-takt');
-    invalidateGlobalConfigCache();
-  });
-
-  afterEach(() => {
-    if (originalTaktConfigDir === undefined) {
-      delete process.env.TAKT_CONFIG_DIR;
-    } else {
-      process.env.TAKT_CONFIG_DIR = originalTaktConfigDir;
-    }
-    invalidateGlobalConfigCache();
-
-    if (existsSync(testDir)) {
-      rmSync(testDir, { recursive: true, force: true });
-    }
-  });
-
-  it('should resolve project model over global model', () => {
-    const projectConfigDir = getProjectConfigDir(testDir);
-    mkdirSync(projectConfigDir, { recursive: true });
-    writeFileSync(join(projectConfigDir, 'config.yaml'), 'piece: default\nmodel: project-model\n');
-
-    const globalConfigDir = process.env.TAKT_CONFIG_DIR!;
-    mkdirSync(globalConfigDir, { recursive: true });
-    writeFileSync(join(globalConfigDir, 'config.yaml'), 'model: global-model\n');
-
-    expect(resolveConfigValue(testDir, 'model')).toBe('project-model');
-  });
-
-  it('should fallback to global model when project model is not set', () => {
-    const projectConfigDir = getProjectConfigDir(testDir);
-    mkdirSync(projectConfigDir, { recursive: true });
-    writeFileSync(join(projectConfigDir, 'config.yaml'), 'piece: default\n');
-
-    const globalConfigDir = process.env.TAKT_CONFIG_DIR!;
-    mkdirSync(globalConfigDir, { recursive: true });
-    writeFileSync(join(globalConfigDir, 'config.yaml'), 'model: global-model\n');
-
-    expect(resolveConfigValue(testDir, 'model')).toBe('global-model');
-  });
-
-  it('should return undefined when neither project nor global model is set', () => {
-    expect(resolveConfigValue(testDir, 'model')).toBeUndefined();
-  });
-});
-
 describe('isVerboseMode', () => {
   let testDir: string;
   let originalTaktConfigDir: string | undefined;
@@ -1209,3 +1156,157 @@ describe('provider-based session management', () => {
     });
   });
 });
+
+describe('loadProjectConfig snake_case normalization', () => {
+  let testDir: string;
+
+  beforeEach(() => {
+    testDir = join(tmpdir(), `takt-test-${randomUUID()}`);
+    mkdirSync(testDir, { recursive: true });
+  });
+
+  afterEach(() => {
+    if (existsSync(testDir)) {
+      rmSync(testDir, { recursive: true, force: true });
+    }
+  });
+
+  it('should normalize auto_pr → autoPr and remove snake_case key', () => {
+    const projectConfigDir = getProjectConfigDir(testDir);
+    mkdirSync(projectConfigDir, { recursive: true });
+    writeFileSync(join(projectConfigDir, 'config.yaml'), 'auto_pr: true\n');
+
+    const config = loadProjectConfig(testDir);
+
+    expect(config.autoPr).toBe(true);
+    expect((config as Record<string, unknown>).auto_pr).toBeUndefined();
+  });
+
+  it('should normalize draft_pr → draftPr and remove snake_case key', () => {
+    const projectConfigDir = getProjectConfigDir(testDir);
+    mkdirSync(projectConfigDir, { recursive: true });
+    writeFileSync(join(projectConfigDir, 'config.yaml'), 'draft_pr: true\n');
+
+    const config = loadProjectConfig(testDir);
+
+    expect(config.draftPr).toBe(true);
+    expect((config as Record<string, unknown>).draft_pr).toBeUndefined();
+  });
+
+  it('should normalize base_branch → baseBranch and remove snake_case key', () => {
+    const projectConfigDir = getProjectConfigDir(testDir);
+    mkdirSync(projectConfigDir, { recursive: true });
+    writeFileSync(join(projectConfigDir, 'config.yaml'), 'base_branch: main\n');
+
+    const config = loadProjectConfig(testDir);
+
+    expect(config.baseBranch).toBe('main');
+    expect((config as Record<string, unknown>).base_branch).toBeUndefined();
+  });
+});
+
+describe('saveProjectConfig snake_case denormalization', () => {
+  let testDir: string;
+
+  beforeEach(() => {
+    testDir = join(tmpdir(), `takt-test-${randomUUID()}`);
+    mkdirSync(testDir, { recursive: true });
+  });
+
+  afterEach(() => {
+    if (existsSync(testDir)) {
+      rmSync(testDir, { recursive: true, force: true });
+    }
+  });
+
+  it('should persist autoPr as auto_pr and reload correctly', () => {
+    saveProjectConfig(testDir, { piece: 'default', autoPr: true });
+
+    const saved = loadProjectConfig(testDir);
+
+    expect(saved.autoPr).toBe(true);
+    expect((saved as Record<string, unknown>).auto_pr).toBeUndefined();
+  });
+
+  it('should persist draftPr as draft_pr and reload correctly', () => {
+    saveProjectConfig(testDir, { piece: 'default', draftPr: true });
+
+    const saved = loadProjectConfig(testDir);
+
+    expect(saved.draftPr).toBe(true);
+    expect((saved as Record<string, unknown>).draft_pr).toBeUndefined();
+  });
+
+  it('should persist baseBranch as base_branch and reload correctly', () => {
+    saveProjectConfig(testDir, { piece: 'default', baseBranch: 'main' });
+
+    const saved = loadProjectConfig(testDir);
+
+    expect(saved.baseBranch).toBe('main');
+    expect((saved as Record<string, unknown>).base_branch).toBeUndefined();
+  });
+
+  it('should not write camelCase keys to YAML file', () => {
+    saveProjectConfig(testDir, { piece: 'default', autoPr: true, draftPr: false, baseBranch: 'develop' });
+
+    const projectConfigDir = getProjectConfigDir(testDir);
+    const content = readFileSync(join(projectConfigDir, 'config.yaml'), 'utf-8');
+
+    expect(content).toContain('auto_pr:');
+    expect(content).toContain('draft_pr:');
+    expect(content).toContain('base_branch:');
+    expect(content).not.toContain('autoPr:');
+    expect(content).not.toContain('draftPr:');
+    expect(content).not.toContain('baseBranch:');
+  });
+});
+
+describe('resolveConfigValue autoPr/draftPr/baseBranch from project config', () => {
+  let testDir: string;
+  let originalTaktConfigDir: string | undefined;
+
+  beforeEach(() => {
+    testDir = join(tmpdir(), `takt-test-${randomUUID()}`);
+    mkdirSync(testDir, { recursive: true });
+    originalTaktConfigDir = process.env.TAKT_CONFIG_DIR;
+    process.env.TAKT_CONFIG_DIR = join(testDir, 'global-takt');
+    invalidateGlobalConfigCache();
+  });
+
+  afterEach(() => {
+    if (originalTaktConfigDir === undefined) {
+      delete process.env.TAKT_CONFIG_DIR;
+    } else {
+      process.env.TAKT_CONFIG_DIR = originalTaktConfigDir;
+    }
+    invalidateGlobalConfigCache();
+
+    if (existsSync(testDir)) {
+      rmSync(testDir, { recursive: true, force: true });
+    }
+  });
+
+  it('should resolve autoPr from project config written in snake_case YAML', () => {
+    const projectConfigDir = getProjectConfigDir(testDir);
+    mkdirSync(projectConfigDir, { recursive: true });
+    writeFileSync(join(projectConfigDir, 'config.yaml'), 'auto_pr: true\n');
+
+    expect(resolveConfigValue(testDir, 'autoPr')).toBe(true);
+  });
+
+  it('should resolve draftPr from project config written in snake_case YAML', () => {
+    const projectConfigDir = getProjectConfigDir(testDir);
+    mkdirSync(projectConfigDir, { recursive: true });
+    writeFileSync(join(projectConfigDir, 'config.yaml'), 'draft_pr: true\n');
+
+    expect(resolveConfigValue(testDir, 'draftPr')).toBe(true);
+  });
+
+  it('should resolve baseBranch from project config written in snake_case YAML', () => {
+    const projectConfigDir = getProjectConfigDir(testDir);
+    mkdirSync(projectConfigDir, { recursive: true });
+    writeFileSync(join(projectConfigDir, 'config.yaml'), 'base_branch: main\n');
+
+    expect(resolveConfigValue(testDir, 'baseBranch')).toBe('main');
+  });
+});
diff --git a/src/infra/config/project/projectConfig.ts b/src/infra/config/project/projectConfig.ts
index a1fe8bf..bbdd97d 100644
--- a/src/infra/config/project/projectConfig.ts
+++ b/src/infra/config/project/projectConfig.ts
@@ -104,11 +104,24 @@ export function loadProjectConfig(projectDir: string): ProjectLocalConfig {
 
   applyProjectConfigEnvOverrides(parsedConfig);
 
+  const {
+    auto_pr,
+    draft_pr,
+    base_branch,
+    provider_options,
+    provider_profiles,
+    analytics,
+    ...rest
+  } = parsedConfig;
+
   return {
     ...DEFAULT_PROJECT_CONFIG,
-    ...(parsedConfig as ProjectLocalConfig),
-    analytics: normalizeAnalytics(parsedConfig.analytics as Record<string, unknown> | undefined),
-    providerOptions: normalizeProviderOptions(parsedConfig.provider_options as {
+    ...(rest as ProjectLocalConfig),
+    autoPr: auto_pr as boolean | undefined,
+    draftPr: draft_pr as boolean | undefined,
+    baseBranch: base_branch as string | undefined,
+    analytics: normalizeAnalytics(analytics as Record<string, unknown> | undefined),
+    providerOptions: normalizeProviderOptions(provider_options as {
       codex?: { network_access?: boolean };
       opencode?: { network_access?: boolean };
       claude?: {
@@ -118,7 +131,7 @@ export function loadProjectConfig(projectDir: string): ProjectLocalConfig {
         };
       };
     } | undefined),
-    providerProfiles: normalizeProviderProfiles(parsedConfig.provider_profiles as Record<string, { default_permission_mode: unknown; movement_permission_overrides?: Record<string, unknown> }> | undefined),
+    providerProfiles: normalizeProviderProfiles(provider_profiles as Record<string, { default_permission_mode: unknown; movement_permission_overrides?: Record<string, unknown> }> | undefined),
   };
 }
 
@@ -129,21 +142,21 @@ export function saveProjectConfig(projectDir: string, config: ProjectLocalConfig
   const configDir = getConfigDir(projectDir);
   const configPath = getConfigPath(projectDir);
 
-  // Ensure directory exists
   if (!existsSync(configDir)) {
     mkdirSync(configDir, { recursive: true });
   }
 
-  // Copy project resources (only copies files that don't exist)
   copyProjectResourcesToDir(configDir);
 
   const savePayload: Record<string, unknown> = { ...config };
+
   const rawAnalytics = denormalizeAnalytics(config.analytics);
   if (rawAnalytics) {
     savePayload.analytics = rawAnalytics;
   } else {
     delete savePayload.analytics;
   }
+
   const rawProfiles = denormalizeProviderProfiles(config.providerProfiles);
   if (rawProfiles && Object.keys(rawProfiles).length > 0) {
     savePayload.provider_profiles = rawProfiles;
@@ -153,6 +166,13 @@ export function saveProjectConfig(projectDir: string, config: ProjectLocalConfig
   delete savePayload.providerProfiles;
   delete savePayload.providerOptions;
 
+  if (config.autoPr !== undefined) savePayload.auto_pr = config.autoPr;
+  if (config.draftPr !== undefined) savePayload.draft_pr = config.draftPr;
+  if (config.baseBranch !== undefined) savePayload.base_branch = config.baseBranch;
+  delete savePayload.autoPr;
+  delete savePayload.draftPr;
+  delete savePayload.baseBranch;
+
   const content = stringify(savePayload, { indent: 2 });
   writeFileSync(configPath, content, 'utf-8');
   invalidateResolvedConfigCache(projectDir);
diff --git a/src/infra/config/resolveConfigValue.ts b/src/infra/config/resolveConfigValue.ts
index 86fc104..5125e5c 100644
--- a/src/infra/config/resolveConfigValue.ts
+++ b/src/infra/config/resolveConfigValue.ts
@@ -113,30 +113,7 @@ function getLocalLayerValue<K extends ConfigParameterKey>(
   project: ReturnType<typeof loadProjectConfigCached>,
   key: K,
 ): LoadedConfig[K] | undefined {
-  switch (key) {
-    case 'piece':
-      return project.piece as LoadedConfig[K] | undefined;
-    case 'provider':
-      return project.provider as LoadedConfig[K] | undefined;
-    case 'model':
-      return project.model as LoadedConfig[K] | undefined;
-    case 'autoPr':
-      return project.auto_pr as LoadedConfig[K] | undefined;
-    case 'draftPr':
-      return project.draft_pr as LoadedConfig[K] | undefined;
-    case 'verbose':
-      return project.verbose as LoadedConfig[K] | undefined;
-    case 'analytics':
-      return project.analytics as LoadedConfig[K] | undefined;
-    case 'providerOptions':
-      return project.providerOptions as LoadedConfig[K] | undefined;
-    case 'providerProfiles':
-      return project.providerProfiles as LoadedConfig[K] | undefined;
-    case 'baseBranch':
-      return project.base_branch as LoadedConfig[K] | undefined;
-    default:
-      return undefined;
-  }
+  return project[key as keyof typeof project] as LoadedConfig[K] | undefined;
 }
 
 function getGlobalLayerValue<K extends ConfigParameterKey>(
diff --git a/src/infra/config/types.ts b/src/infra/config/types.ts
index 44dc5a4..7dbd7f6 100644
--- a/src/infra/config/types.ts
+++ b/src/infra/config/types.ts
@@ -12,26 +12,20 @@ export interface ProjectLocalConfig {
   piece?: string;
   /** Provider selection for agent runtime */
   provider?: 'claude' | 'codex' | 'opencode' | 'mock';
-  /** Model selection for agent runtime */
-  model?: string;
   /** Auto-create PR after worktree execution */
-  auto_pr?: boolean;
+  autoPr?: boolean;
   /** Create PR as draft */
-  draft_pr?: boolean;
+  draftPr?: boolean;
+  /** Base branch to clone from (overrides global baseBranch) */
+  baseBranch?: string;
   /** Verbose output mode */
   verbose?: boolean;
   /** Project-level analytics overrides */
   analytics?: AnalyticsConfig;
   /** Provider-specific options (overrides global, overridden by piece/movement) */
-  provider_options?: MovementProviderOptions;
-  /** Provider-specific options (camelCase alias) */
   providerOptions?: MovementProviderOptions;
   /** Provider-specific permission profiles (project-level override) */
-  provider_profiles?: ProviderPermissionProfiles;
-  /** Provider-specific permission profiles (camelCase alias) */
   providerProfiles?: ProviderPermissionProfiles;
-  /** Custom settings */
-  [key: string]: unknown;
 }
 
 /** Persona session data for persistence */