feat: add OpenCode Zen gateway support

.env.example

@@ -25,6 +25,13 @@ GOOGLE_GENERATIVE_AI_API_KEY=AIza...
 # Required only if ai.gateway is set to "openrouter" in configure()
 # OPENROUTER_API_KEY=sk-or-...
 
+# =============================================================================
+# Optional: OpenCode Zen
+# =============================================================================
+
+# Required only if ai.gateway is set to "opencodezen" in configure()
+# OPENCODEZEN_API_KEY=
+
 # =============================================================================
 # Optional: Cloudflare AI Gateway
 # =============================================================================

CHANGELOG.md

@@ -5,6 +5,12 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Added
+
+- **OpenCode Zen gateway support**: set `gateway: "opencodezen"` in `configure()` and provide `OPENCODEZEN_API_KEY` to route all model requests through [OpenCode Zen](https://opencode.ai/docs/ko/zen/) (`https://opencode.ai/zen/v1`), an OpenAI-compatible gateway with 30+ curated models including Claude, Gemini, GPT, Qwen, and more.
+
 ## [1.0.0] - 2026-03-27
 
 ### Added

README.md

@@ -31,9 +31,9 @@ ANTHROPIC_API_KEY=sk-ant-...
 GOOGLE_GENERATIVE_AI_API_KEY=AIza...
 ```
 
-Alternatively, you can use an AI gateway like Vercel AI Gateway or OpenRouter to route requests to multiple providers without managing individual API keys. If you choose this option, set `AI_GATEWAY_API_KEY` (for Vercel) or `OPENROUTER_API_KEY` (for OpenRouter) instead.
+Alternatively, you can use an AI gateway like Vercel AI Gateway, OpenRouter, or OpenCode Zen to route requests to multiple providers without managing individual API keys. If you choose this option, set `AI_GATEWAY_API_KEY` (for Vercel), `OPENROUTER_API_KEY` (for OpenRouter), or `OPENCODEZEN_API_KEY` (for OpenCode Zen) instead.
 
-You can also route requests through Cloudflare AI Gateway for observability, caching, and rate limiting. Unlike Vercel/OpenRouter, Cloudflare is a proxy (not a reseller), so you still need your own `ANTHROPIC_API_KEY` / `GOOGLE_GENERATIVE_AI_API_KEY` alongside `CLOUDFLARE_ACCOUNT_ID` and `CLOUDFLARE_AI_GATEWAY` (and `CLOUDFLARE_AI_GATEWAY_API_KEY` if the gateway has authentication enabled).
+You can also route requests through Cloudflare AI Gateway for observability, caching, and rate limiting. Unlike Vercel/OpenRouter/OpenCode Zen, Cloudflare is a proxy (not a reseller), so you still need your own `ANTHROPIC_API_KEY` / `GOOGLE_GENERATIVE_AI_API_KEY` alongside `CLOUDFLARE_ACCOUNT_ID` and `CLOUDFLARE_AI_GATEWAY` (and `CLOUDFLARE_AI_GATEWAY_API_KEY` if the gateway has authentication enabled).
 
 Set your Playwright project to read `.env` by adding the following to `playwright.config.ts`  (after `import { defineConfig, devices } from '@playwright/test';`):
 
@@ -82,8 +82,9 @@ import { runSteps, configure } from "passmark";
 
 configure({
   ai: {
-    gateway: "vercel" // or "openrouter" or "cloudflare"
-    // Set AI_GATEWAY_API_KEY (Vercel), OPENROUTER_API_KEY (OpenRouter), or
+    gateway: "vercel" // or "openrouter", "opencodezen", or "cloudflare"
+    // Set AI_GATEWAY_API_KEY (Vercel), OPENROUTER_API_KEY (OpenRouter),
+    // OPENCODEZEN_API_KEY (OpenCode Zen), or
     // CLOUDFLARE_ACCOUNT_ID + CLOUDFLARE_AI_GATEWAY (+ CLOUDFLARE_AI_GATEWAY_API_KEY
     // if the gateway is authenticated) in your .env file. Cloudflare also requires
     // the upstream provider keys (ANTHROPIC_API_KEY, GOOGLE_GENERATIVE_AI_API_KEY).
@@ -170,7 +171,7 @@ import { configure } from "passmark";
 
 configure({
   ai: {
-    gateway: "none", // "none" (default), "vercel", "openrouter", or "cloudflare"
+    gateway: "none", // "none" (default), "vercel", "openrouter", "opencodezen", or "cloudflare"
     models: {
       stepExecution: "google/gemini-3-flash",
       utility: "google/gemini-2.5-flash",
@@ -189,6 +190,7 @@ configure({
 | `GOOGLE_GENERATIVE_AI_API_KEY` | Yes | - | Google API key for Gemini models |
 | `AI_GATEWAY_API_KEY` | If gateway=vercel | - | Vercel AI Gateway API key |
 | `OPENROUTER_API_KEY` | If gateway=openrouter | - | OpenRouter API key |
+| `OPENCODEZEN_API_KEY` | If gateway=opencodezen | - | OpenCode Zen API key |
 | `CLOUDFLARE_ACCOUNT_ID` | If gateway=cloudflare | - | Cloudflare account ID that owns the AI Gateway |
 | `CLOUDFLARE_AI_GATEWAY` | If gateway=cloudflare | - | Cloudflare AI Gateway name (slug) |
 | `CLOUDFLARE_AI_GATEWAY_API_KEY` | If gateway=cloudflare and the gateway is authenticated | - | Cloudflare AI Gateway token (sent as `cf-aig-authorization`) |

src/__tests__/config.test.ts

@@ -29,6 +29,11 @@ describe("config", () => {
     expect(getConfig().ai?.gateway).toBe("openrouter");
   });
 
+  it("configure sets ai.gateway to opencodezen", () => {
+    configure({ ai: { gateway: "opencodezen" } });
+    expect(getConfig().ai?.gateway).toBe("opencodezen");
+  });
+
   it("configure merges without overwriting other keys", () => {
     configure({ uploadBasePath: "./uploads" });
     configure({ ai: { gateway: "none" } });

src/config.ts

@@ -9,7 +9,7 @@ export type EmailProvider = {
   extractContent: (params: { email: string; prompt: string }) => Promise<string>;
 };
 
-export type AIGateway = "vercel" | "openrouter" | "cloudflare" | "none";
+export type AIGateway = "vercel" | "openrouter" | "opencodezen" | "cloudflare" | "none";
 
 export type ModelConfig = {
   /** Model for executing individual steps. Default: google/gemini-3-flash */

src/models.ts

@@ -2,6 +2,7 @@ import { AIModelError, ConfigurationError } from "./errors";
 import { createAnthropic } from "@ai-sdk/anthropic";
 import { createGoogleGenerativeAI } from "@ai-sdk/google";
 import { createOpenRouter } from "@openrouter/ai-sdk-provider";
+import { createOpenAI } from "@ai-sdk/openai";
 import { gateway, type LanguageModel } from "ai";
 import { wrapAISDKModel } from "axiom/ai";
 import { getConfig } from "./config";
@@ -14,6 +15,7 @@ function wrapModel(model: LanguageModel): LanguageModel {
 let _google: ReturnType<typeof createGoogleGenerativeAI> | null = null;
 let _anthropic: ReturnType<typeof createAnthropic> | null = null;
 let _openrouter: ReturnType<typeof createOpenRouter> | null = null;
+let _opencodezen: ReturnType<typeof createOpenAI> | null = null;
 let _cloudflareGoogle: ReturnType<typeof createGoogleGenerativeAI> | null = null;
 let _cloudflareAnthropic: ReturnType<typeof createAnthropic> | null = null;
 
@@ -59,6 +61,21 @@ function getOpenRouterProvider() {
   return _openrouter;
 }
 
+function getOpenCodeZenProvider() {
+  if (!_opencodezen) {
+    if (!process.env.OPENCODEZEN_API_KEY) {
+      throw new ConfigurationError(
+        "OPENCODEZEN_API_KEY isn't set. Add it to your environment (for example: export OPENCODEZEN_API_KEY=your_key). See .env.example for reference.",
+      );
+    }
+    _opencodezen = createOpenAI({
+      baseURL: "https://opencode.ai/zen/v1",
+      apiKey: process.env.OPENCODEZEN_API_KEY,
+    });
+  }
+  return _opencodezen;
+}
+
 /**
  * Builds the per-provider Cloudflare AI Gateway base URL and (optional)
  * `cf-aig-authorization` header. We route through Cloudflare's native
@@ -148,6 +165,29 @@ function resolveOpenRouterModelId(modelId: string): string {
   return OPENROUTER_MODEL_ALIASES[modelId] ?? modelId;
 }
 
+/**
+ * Maps canonical model IDs (provider/model) to OpenCode Zen model IDs.
+ * Zen strips the provider prefix and uses its own naming for some models.
+ */
+const OPENCODEZEN_MODEL_ALIASES: Record<string, string> = {
+  "google/gemini-3.1-pro-preview": "gemini-3.1-pro",
+  "anthropic/claude-haiku-4.5": "claude-haiku-4-5",
+  "anthropic/claude-haiku-4-5": "claude-haiku-4-5",
+  "anthropic/claude-sonnet-4.6": "claude-sonnet-4-6",
+  "anthropic/claude-sonnet-4-6": "claude-sonnet-4-6",
+  "anthropic/claude-opus-4.7": "claude-opus-4-7",
+  "anthropic/claude-opus-4-7": "claude-opus-4-7",
+};
+
+function resolveOpenCodeZenModelId(modelId: string): string {
+  if (OPENCODEZEN_MODEL_ALIASES[modelId]) {
+    return OPENCODEZEN_MODEL_ALIASES[modelId];
+  }
+  // Strip provider prefix: "google/gemini-3-flash" → "gemini-3-flash"
+  const slashIndex = modelId.indexOf("/");
+  return slashIndex !== -1 ? modelId.slice(slashIndex + 1) : modelId;
+}
+
 /**
  * Resolves a canonical model ID to a LanguageModel instance wrapped with Axiom instrumentation.
  * Input format: "provider/model-name" (e.g. "google/gemini-3-flash")
@@ -180,6 +220,10 @@ export function resolveModel(modelId: string): LanguageModel {
     return wrapModel(getOpenRouterProvider()(resolveOpenRouterModelId(modelId)));
   }
 
+  if (gatewayConfig === "opencodezen") {
+    return wrapModel(getOpenCodeZenProvider()(resolveOpenCodeZenModelId(modelId)));
+  }
+
   const [provider, ...rest] = modelId.split("/");
   const modelName = rest.join("/");