diff --git a/dev/openapi-ts.config.ts b/dev/openapi-ts.config.ts
index 2bd71dca0..e391a6546 100644
--- a/dev/openapi-ts.config.ts
+++ b/dev/openapi-ts.config.ts
@@ -47,8 +47,8 @@ export default defineConfig(() => {
             // 'full.yaml',
             // 'sdk-method-class-conflict.yaml',
             // 'object-property-names.yaml',
-            // 'openai.yaml',
-            'opencode.yaml',
+            'openai.yaml',
+            // 'opencode.yaml',
             // 'pagination-ref.yaml',
             // 'sdk-instance.yaml',
             // 'sdk-nested-classes.yaml',
@@ -106,6 +106,10 @@ export default defineConfig(() => {
           // importFileExtension: '.js',
           // indexFile: false,
           // lint: 'eslint',
+          nameConflictResolver({ attempt, baseName }) {
+            console.log('resolving conflict for:', { attempt, baseName });
+            return attempt === 0 ? baseName : `${baseName}_N${attempt + 1}`;
+          },
           path: path.resolve(__dirname, '.gen'),
           preferExportAll: true,
           resolveModuleName: (moduleName) => {
diff --git a/packages/codegen-core/src/__tests__/exports.test.ts b/packages/codegen-core/src/__tests__/exports.test.ts
index b8f54bbfc..94aa02c71 100644
--- a/packages/codegen-core/src/__tests__/exports.test.ts
+++ b/packages/codegen-core/src/__tests__/exports.test.ts
@@ -39,6 +39,7 @@ export type _TypeExports = [
   index.ImportMember,
   index.ImportModule,
   index.Language,
+  index.NameConflictResolver,
   index.NameConflictResolvers,
   index.Node,
   index.Output,
diff --git a/packages/codegen-core/src/index.ts b/packages/codegen-core/src/index.ts
index f4a235156..307b70a74 100644
--- a/packages/codegen-core/src/index.ts
+++ b/packages/codegen-core/src/index.ts
@@ -26,7 +26,10 @@ export {
   simpleNameConflictResolver,
   underscoreNameConflictResolver,
 } from './planner/resolvers';
-export type { IAnalysisContext as AnalysisContext } from './planner/types';
+export type {
+  IAnalysisContext as AnalysisContext,
+  NameConflictResolver,
+} from './planner/types';
 export { Project } from './project/project';
 export type { IProject } from './project/types';
 export { fromRef, fromRefs, isRef, ref, refs } from './refs/refs';
diff --git a/packages/openapi-ts/src/ir/context.ts b/packages/openapi-ts/src/ir/context.ts
index adcb261a6..416a10b93 100644
--- a/packages/openapi-ts/src/ir/context.ts
+++ b/packages/openapi-ts/src/ir/context.ts
@@ -1,4 +1,4 @@
-import { Project, simpleNameConflictResolver } from '@hey-api/codegen-core';
+import { Project } from '@hey-api/codegen-core';
 
 import type { Package } from '~/config/utils/package';
 import { packageFactory } from '~/config/utils/package';
@@ -68,11 +68,9 @@ export class Context<Spec extends Record<string, any> = any> {
     spec: Spec;
   }) {
     this.config = config;
+    // TODO: allow overriding via config
     this.gen = new Project({
       defaultFileName: 'index',
-      defaultNameConflictResolver(args) {
-        return simpleNameConflictResolver(args);
-      },
       fileName: (base) => {
         const name = buildName({
           config: config.output.fileName,
@@ -86,10 +84,11 @@ export class Context<Spec extends Record<string, any> = any> {
           ? name
           : `${name}${suffix}`;
       },
-      nameConflictResolvers: {
-        // TODO: allow overriding via config
-      },
-      // TODO: allow overriding via config
+      nameConflictResolvers: config.output.nameConflictResolver
+        ? {
+            typescript: config.output.nameConflictResolver,
+          }
+        : undefined,
       renderers: [
         new TypeScriptRenderer({
           preferExportAll: config.output.preferExportAll,
diff --git a/packages/openapi-ts/src/types/output.d.ts b/packages/openapi-ts/src/types/output.d.ts
index ee03a8f9d..471bda9ef 100644
--- a/packages/openapi-ts/src/types/output.d.ts
+++ b/packages/openapi-ts/src/types/output.d.ts
@@ -1,3 +1,4 @@
+import type { NameConflictResolver } from '@hey-api/codegen-core';
 import type ts from 'typescript';
 
 import type { StringCase, StringName } from './case';
@@ -89,6 +90,11 @@ export type UserOutput = {
    * @default null
    */
   lint?: Linters | null;
+  /**
+   * Optional name conflict resolver to customize how naming conflicts
+   * are handled.
+   */
+  nameConflictResolver?: NameConflictResolver;
   /**
    * The absolute path to the output folder.
    */
@@ -178,6 +184,11 @@ export type Output = {
    * Which linter to use to process output folder?
    */
   lint: Linters | null;
+  /**
+   * Optional name conflict resolver to customize how naming conflicts
+   * are handled.
+   */
+  nameConflictResolver: NameConflictResolver | undefined;
   /**
    * The absolute path to the output folder.
    */