fix(opencode): the model is set once, without a retry

README.md

@@ -26,7 +26,7 @@ npm install -g subturn
 claude mcp add subturn -- subturn serve
 ```
 
-Requires Node 22.13 or newer, and OpenCode 2 or newer for that harness. Until the package is published, `npx github:eshatalov/subturn` works the same way. From a checkout, `npm install` builds `dist/` and the server is `node dist/faces/mcp.js`.
+Requires Node 22.13 or newer, and OpenCode 2.0.25 or newer for that harness. Until the package is published, `npx github:eshatalov/subturn` works the same way. From a checkout, `npm install` builds `dist/` and the server is `node dist/faces/mcp.js`.
 
 ## The caller's whole manual
 

src/core/acp-turn.ts

@@ -20,25 +20,14 @@ import path from "node:path";
 const INITIALIZE_TIMEOUT_MS = 30_000;
 const SESSION_NEW_TIMEOUT_MS = 60_000;
 const SESSION_LOAD_TIMEOUT_MS = 120_000; // replay of a long history takes time
-const CONFIG_SETTLE_MS = 5_000;
-
-/** Runs `attempt`; when the harness refuses it with -32602, runs it again
- * after each config_option_update, giving up CONFIG_SETTLE_MS after the
- * first try. For a harness that opens a session before its option list has
- * loaded and announces the rest. */
-export type RetryOnConfigUpdate = (attempt: () => Promise<unknown>) => Promise<unknown>;
 
 export interface AcpTurnPlan {
   argv: string[];
   /** Applied after session/new or session/load; returns the
    * acknowledged-bundle record for ack.json, or null when the harness
    * echoes nothing. Throw to fail. Runs on resumed turns too — this is
    * where model+effort are re-applied explicitly. */
-  configure?: (
-    client: AcpClient,
-    sessionId: string,
-    retryOnConfigUpdate: RetryOnConfigUpdate,
-  ) => Promise<Record<string, unknown> | null>;
+  configure?: (client: AcpClient, sessionId: string) => Promise<Record<string, unknown> | null>;
   /** Extract the acknowledged bundle from the session/new response (grok:
    * models.currentModelId + reasoningEffort meta). */
   ackFromSessionNew?: (result: Record<string, unknown>) => Record<string, unknown> | null;
@@ -113,8 +102,6 @@ export async function runAcpTurn(ctx: LaunchContext, plan: AcpTurnPlan): Promise
   const usageCandidates: unknown[] = [];
   let activeSessionId = "";
   let collecting = false; // off until the prompt goes out (replay isn't ours)
-  let configUpdates = 0;
-  let onConfigUpdate: (() => void) | null = null;
 
   const client = new AcpClient(spawned.child, {
     emit: (e) => ctx.emit(e),
@@ -124,10 +111,6 @@ export async function runAcpTurn(ctx: LaunchContext, plan: AcpTurnPlan): Promise
         return;
       }
       ctx.emit({ type: collecting ? "session_update" : "session_update_replay", update });
-      if (update["sessionUpdate"] === "config_option_update") {
-        configUpdates++;
-        onConfigUpdate?.();
-      }
       if (!collecting) return;
       if (update["sessionUpdate"] === "agent_message_chunk") {
         const content = update["content"];
@@ -164,27 +147,6 @@ export async function runAcpTurn(ctx: LaunchContext, plan: AcpTurnPlan): Promise
     client.onExtNotification(method, (params) => handler(params, sink));
   }
 
-  const nextConfigUpdate = (timeoutMs: number): Promise<boolean> =>
-    new Promise((resolve) => {
-      const timer = setTimeout(() => { onConfigUpdate = null; resolve(false); }, timeoutMs);
-      onConfigUpdate = () => { clearTimeout(timer); onConfigUpdate = null; resolve(true); };
-    });
-  const retryOnConfigUpdate: RetryOnConfigUpdate = async (attempt) => {
-    const deadline = Date.now() + CONFIG_SETTLE_MS;
-    for (;;) {
-      const seen = configUpdates; // an update landing mid-attempt counts
-      try {
-        return await attempt();
-      } catch (e) {
-        if (!(e instanceof RpcError) || e.code !== -32602) throw e;
-        const left = deadline - Date.now();
-        if (left <= 0) throw e;
-        if (configUpdates === seen && !(await nextConfigUpdate(left))) throw e;
-        ctx.emit({ type: "configure_retry", refused: e.message });
-      }
-    }
-  };
-
   try {
     const initResult = await client.request("initialize", {
       protocolVersion: 1,
@@ -228,7 +190,7 @@ export async function runAcpTurn(ctx: LaunchContext, plan: AcpTurnPlan): Promise
       ackBase = plan.ackFromSessionNew(sessionNewResult);
     }
     if (plan.configure !== undefined) {
-      const configureAck = await plan.configure(client, activeSessionId, retryOnConfigUpdate);
+      const configureAck = await plan.configure(client, activeSessionId);
       if (configureAck !== null) ackBase = { ...(ackBase ?? {}), ...configureAck };
     }
     if (currentAck() !== null) {

src/plugins/fake.ts

@@ -41,13 +41,11 @@ export const fakePlugin: Plugin = {
     }
     return runAcpTurn(ctx, {
       argv: [process.execPath, script],
-      configure: async (client, sessionId, retryOnConfigUpdate) => {
-        const modelRes = await retryOnConfigUpdate(() =>
-          client.request(
-            "session/set_config_option",
-            { sessionId, configId: "model", value: ctx.model },
-            15_000,
-          ),
+      configure: async (client, sessionId) => {
+        const modelRes = await client.request(
+          "session/set_config_option",
+          { sessionId, configId: "model", value: ctx.model },
+          15_000,
         );
         const effortRes = await client.request(
           "session/set_config_option",

src/plugins/opencode.ts

@@ -7,12 +7,6 @@
 // session/load, handled in acp-turn) runs the same configure step, so the
 // bundle is re-applied explicitly on every turn — never server defaults.
 //
-// The server lists models before its plugins have added theirs (the
-// OpenCode Console providers, providers from the user's config) and
-// announces the rest with config_option_update about a second later. A
-// model refused right after the session opens is therefore set again after
-// each such update (retryOnConfigUpdate in acp-turn).
-//
 // Posture: `opencode acp` has no --auto flag; the permissive posture is the
 // Subturn's ACP client itself, which answers every session/request_permission
 // with the most permissive option (core/acp.ts). No prompt can fire
@@ -184,9 +178,9 @@ export const opencodePlugin: Plugin = {
   launch(ctx: LaunchContext): Promise<LaunchOutcome> {
     return runAcpTurn(ctx, {
       argv: [ctx.binPath, "acp"],
-      configure: async (client, sessionId, retryOnConfigUpdate) => {
+      configure: async (client, sessionId) => {
         // Model FIRST — the effort option appears only after the model set.
-        const modelRes = await retryOnConfigUpdate(() => setConfig(client, sessionId, "model", ctx.model));
+        const modelRes = await setConfig(client, sessionId, "model", ctx.model);
         const effortRes = await setConfig(client, sessionId, "effort", ctx.effort);
         // The effort response is the later echo of the whole option list, so
         // it is the authoritative currentValue for both.

test/core.test.ts

@@ -194,37 +194,6 @@ test("posture: a permission request is auto-answered with the most permissive op
   }
 });
 
-test("a model the harness announces after the session opens is set once announced", async () => {
-  process.env["FAKE_MODE"] = "latemodel";
-  try {
-    const res = await spawn(baseInput());
-    const done = await awaitTurn(res.session_id, 30);
-    assert.equal(done.status, "completed");
-    assert.deepEqual(done.bundle, { model: "fake-model-1", effort: "high" });
-    const events = inspect(res.session_id).events.parsed as Array<Record<string, unknown>>;
-    assert.deepEqual(
-      events.filter((e) => e["type"] === "configure_retry").map((e) => e["refused"]),
-      ["model not found: fake-model-1"],
-    );
-  } finally {
-    delete process.env["FAKE_MODE"];
-  }
-});
-
-test("a model the harness never announces fails with the harness's refusal", async () => {
-  process.env["FAKE_MODE"] = "nomodel";
-  try {
-    const res = await spawn(baseInput());
-    const done = await awaitTurn(res.session_id, 30);
-    assert.equal(done.status, "failed");
-    const evidence = inspect(res.session_id);
-    assert.ok(evidence.error.text?.includes("-32602"));
-    assert.ok(evidence.error.text?.includes("model not found: fake-model-1"));
-  } finally {
-    delete process.env["FAKE_MODE"];
-  }
-});
-
 test("configure failure after the id exists: failed turn with raw rpc evidence", async () => {
   process.env["FAKE_MODE"] = "badeffort";
   try {

test/fake-agent.mjs

@@ -4,9 +4,6 @@
 //   permission — asks for permission mid-prompt; completes only when allowed
 //   hang       — accepts the prompt request and never answers (deadline test)
 //   badeffort  — refuses the "effort" set_config with -32602
-//   latemodel  — refuses the "model" set_config with -32602 until it has
-//                announced its models with a config_option_update
-//   nomodel    — refuses the "model" set_config with -32602, announces nothing
 //   grok       — never answers the prompt request; completes via the private
 //                _x.ai/session/prompt_complete notification (race test)
 //   die        — exits immediately (launch-failure-before-session-id test)
@@ -27,7 +24,6 @@ if (mode === "die") {
 let buf = "";
 const config = { model: null, effort: null };
 let loadedSessionId = null;
-let modelsAnnounced = false;
 let pendingPermissionId = null;
 let pendingPromptId = null;
 let promptSessionId = null;
@@ -94,20 +90,6 @@ function handle(msg) {
       send({ jsonrpc: "2.0", id, error: { code: -32602, message: `invalid effort: ${params.value}` } });
       return;
     }
-    if ((mode === "latemodel" || mode === "nomodel") && params.configId === "model" && !modelsAnnounced) {
-      send({ jsonrpc: "2.0", id, error: { code: -32602, message: `model not found: ${params.value}` } });
-      if (mode === "latemodel") {
-        setTimeout(() => {
-          modelsAnnounced = true;
-          send({
-            jsonrpc: "2.0",
-            method: "session/update",
-            params: { sessionId: params.sessionId, update: { sessionUpdate: "config_option_update", configOptions: [] } },
-          });
-        }, 50);
-      }
-      return;
-    }
     config[params.configId] = params.value;
     result(id, { configId: params.configId, currentValue: params.value });
     return;