feat(chat): expose model options config

src/routes/chat.ts

@@ -1,6 +1,13 @@
 import { Router } from "express";
 import { z } from "zod";
 
+import {
+  agentModelOptions,
+  isSupportedModel,
+  resolveDefaultModel,
+  type SupportedModel,
+} from "../chat/models.js";
+import { config } from "../config.js";
 import { type LearningOrchestrator } from "../learning/orchestrator.js";
 import { type SessionTranscriptStore } from "../sessions/transcriptStore.js";
 import { logger } from "../logger.js";
@@ -28,8 +35,6 @@ import {
   type PermissionRequestPayload,
   type QuestionRequestPayload,
   streamPromptResponse,
-  supportedModels,
-  type SupportedModel,
   type TodoUpdatePayload,
 } from "./chatStream.js";
 import {
@@ -54,7 +59,9 @@ import {
 const payloadSchema = z.object({
   message: z.string().min(1).max(10000),
   session_id: z.string().max(128).optional(),
-  model: z.enum(supportedModels).optional(),
+  model: z.string().refine(isSupportedModel, {
+    message: "unsupported model",
+  }).optional(),
   approval_mode: z.enum(["request", "always"]).optional().default("request"),
 });
 
@@ -115,6 +122,13 @@ export const buildChatRouter = (
 ) => {
   const chatRouter = Router();
 
+  chatRouter.get("/models", (_req, res) => {
+    res.json({
+      default_model: resolveDefaultModel(config.OPENCODE_MODEL),
+      models: agentModelOptions,
+    });
+  });
+
   chatRouter.post("/session", async (req, res) => {
     const parsed = createSessionPayloadSchema.safeParse(req.body ?? {});
     if (!parsed.success) {

src/routes/chatStream.ts

@@ -1,6 +1,7 @@
 import type { Event as OpencodeEvent, Part } from "@opencode-ai/sdk/v2";
 
 import { writeLlmRequestAuditLog } from "../audit/llmRequestAudit.js";
+import { type SupportedModel } from "../chat/models.js";
 import { logger } from "../logger.js";
 import {
   type PermissionReply,
@@ -54,12 +55,6 @@ export {
   type TodoUpdatePayload,
 } from "./chatStreamEvents.js";
 
-export const supportedModels = [
-  "deepseek/deepseek-v4-flash",
-  "deepseek/deepseek-v4-pro",
-] as const;
-
-export type SupportedModel = (typeof supportedModels)[number];
 export type ApprovalMode = "request" | "always";
 
 type StreamPromptOptions = {