fix(configure): stop pinning a default model for OpenCode and CoDev Code

src/ModelApp.tsx

@@ -347,13 +347,29 @@ export function ModelApp() {
 							</Box>
 						)}
 						{phase === "done" && chosenModel && (
-							<Text>
-								{"Default model updated to "}
-								<Text color="cyan">{chosenModel}</Text>
-								{" for "}
-								{formatToolList(tools.map((t) => TOOL_LABEL[t]))}
-								{"."}
-							</Text>
+							<Box flexDirection="column">
+								<Text>
+									{"Default model updated to "}
+									<Text color="cyan">{chosenModel}</Text>
+									{" for "}
+									{formatToolList(tools.map((t) => TOOL_LABEL[t]))}
+									{"."}
+								</Text>
+								{/* Their configs carry no model pin (see configureOpenCodeKind),
+								    so a model already selected in-CLI keeps winning there —
+								    say so rather than let the line above imply otherwise. */}
+								{tools.some((t) => t === "opencode" || t === "codev-code") && (
+									<Text dimColor>
+										{"In "}
+										{formatToolList(
+											tools
+												.filter((t) => t === "opencode" || t === "codev-code")
+												.map((t) => TOOL_LABEL[t]),
+										)}
+										{", switch models anytime with /models."}
+									</Text>
+								)}
+							</Box>
 						)}
 					</Step>
 				)}

src/lib/configure.ts

@@ -924,9 +924,16 @@ function configureOpenCodeKind(
 	const provider = resolveProvider(creds);
 	// Fall back to [defaultModel] when `models` is unset so callers that don't
 	// know about the list (e.g. older fixtures, the fallback path with no
-	// fetched list) still produce a valid one-entry map.
-	const allModels =
-		creds.models && creds.models.length > 0 ? creds.models : [defaultModel];
+	// fetched list) still produce a valid one-entry map. The chosen model leads
+	// the map: with no top-level pin (see below) a first launch with no saved
+	// selection falls through to the provider's first model, so ordering is
+	// what carries the choice.
+	const allModels = [
+		...new Set([
+			defaultModel,
+			...(creds.models && creds.models.length > 0 ? creds.models : []),
+		]),
+	];
 
 	// A custom-provider model with no `limit` defaults to context 0, which both
 	// mis-sizes the window and disables OpenCode's auto-compaction entirely.
@@ -959,9 +966,15 @@ function configureOpenCodeKind(
 	writeJson(sourcePath, {
 		[OPENCODE_K.schema]: OPENCODE_SCHEMA_URL,
 		...(mcp !== undefined ? { [OPENCODE_K.mcp]: mcp } : {}),
-		// Top-level `model` pins the initial active model OpenCode uses on
-		// launch. Format is `<provider>/<modelId>` per OpenCode's schema.
-		[OPENCODE_K.model]: `${provider.id}/${defaultModel}`,
+		// No top-level `model`. The install-time model choice exists for Claude
+		// Code and Codex, which can only run one model at a time; OpenCode and
+		// CoDev Code switch freely in-CLI (docs/hub/installation). A pin there
+		// outranks their saved selection on every launch — it beats the recent
+		// models in their state dir — so each in-CLI switch reverted on restart
+		// and only hand-editing the config undid it. The chosen model leads the
+		// models map instead, which decides the first launch and yields to any
+		// later selection. This is why `codevhub model` steers only Claude Code
+		// and Codex.
 		// OpenCode has no percentage trigger; it compacts at `context − reserved`.
 		// Reserve the headroom that lands the trigger at ~85% of the window, to
 		// match Claude Code and Codex.

tests/ModelApp.test.tsx

@@ -126,6 +126,11 @@ describe("ModelApp", () => {
 		expect(history).toContain(
 			"Default model updated to new-alpha for Claude Code and OpenCode.",
 		);
+		// OpenCode's config carries no model pin (it switches in-CLI), so the
+		// line above must not read as authoritative for it.
+		expect(history).toContain(
+			"In OpenCode, switch models anytime with /models.",
+		);
 		expect(configureClaude).toHaveBeenCalledWith({
 			apiKey: "sk-existing",
 			baseUrl: undefined,

tests/lib/configure.test.ts

@@ -398,8 +398,9 @@ describe("configureOpenCode", () => {
 		expect(config.provider.netgate.models["chosen-model"].name).toBe(
 			"chosen-model",
 		);
-		// Top-level `model` pins the active default in <provider>/<modelId> form.
-		expect(config.model).toBe("netgate/chosen-model");
+		// No top-level `model`: OpenCode and CoDev Code switch models in-CLI, and
+		// a pin would outrank that selection on every launch.
+		expect(config.model).toBeUndefined();
 		// Declares the gateway window so OpenCode sizes context correctly and its
 		// auto-compaction fires (a model with no `limit` defaults to context 0,
 		// which disables compaction). `output` is required alongside `context`.
@@ -443,8 +444,10 @@ describe("configureOpenCode", () => {
 				output: ["text"],
 			});
 		}
-		// Top-level default still points at the chosen one.
-		expect(config.model).toBe("netgate/model-a");
+		// With no pin, the map order carries the choice: a launch with nothing
+		// selected yet takes the provider's first model.
+		expect(config.model).toBeUndefined();
+		expect(Object.keys(map)[0]).toBe("model-a");
 	});
 
 	test("falls back to [model] when `models` is absent (older call sites)", async () => {
@@ -596,8 +599,9 @@ describe("configureCodevCode", () => {
 		expect(config.provider.netgate.models["chosen-model"].name).toBe(
 			"chosen-model",
 		);
-		// Top-level `model` pins the active default in <provider>/<modelId> form.
-		expect(config.model).toBe("netgate/chosen-model");
+		// No top-level `model`: OpenCode and CoDev Code switch models in-CLI, and
+		// a pin would outrank that selection on every launch.
+		expect(config.model).toBeUndefined();
 		// The fork shares OpenCode's window/compaction handling, so the same
 		// limit + compaction blocks must land in its config.
 		expect(config.provider.netgate.models["chosen-model"].limit).toEqual({
@@ -1652,7 +1656,7 @@ describe("custom provider identity", () => {
 		expect(config.model_providers.netgate).toBeUndefined();
 	});
 
-	test("opencode writes the custom id in both the provider map and `model`", async () => {
+	test("opencode writes the custom id in the provider map", async () => {
 		const { configureOpenCode } = await import("@/lib/configure.js");
 		configureOpenCode(custom);
 
@@ -1662,7 +1666,7 @@ describe("custom provider identity", () => {
 				"utf-8",
 			),
 		);
-		expect(config.model).toBe("acme-ai/m");
+		expect(config.provider["acme-ai"].models.m).toBeDefined();
 		expect(config.provider["acme-ai"].name).toBe("Acme AI");
 		expect(config.provider["acme-ai"].options.apiKey).toBe("sk-user");
 		expect(config.provider.netgate).toBeUndefined();
@@ -1675,7 +1679,7 @@ describe("custom provider identity", () => {
 		const config = JSON.parse(
 			readFileSync(join(tempDir, ".config", "codev", "codev.json"), "utf-8"),
 		);
-		expect(config.model).toBe("acme-ai/m");
+		expect(config.provider["acme-ai"].models.m).toBeDefined();
 		expect(config.provider["acme-ai"].name).toBe("Acme AI");
 	});