stewards: write init's files on the thread's machine

plugins/stewards/server.test.ts

@@ -20,7 +20,8 @@ function world() {
   const repos = [{ dir: "web", url: "https://github.com/acme/web.git" }];
   const entities = new Map<string, EntitySnapshot>();
   const rpcCalls: Call[] = [];
-  const threads = new Map<string, { status: string; archivedAt: number | null; title?: string | null; parentThreadId?: string | null; sectionId?: string | null }>();
+  const threads = new Map<string, { status: string; archivedAt: number | null; title?: string | null; parentThreadId?: string | null; sectionId?: string | null; hostId?: string }>();
+  const writes: Array<{ path: string; hostId?: string }> = [];
   const sections: Array<{ id: string; name: string }> = [];
   /** Each thread's latest context window reading, as bb reports it. */
   const usage = new Map<string, number>();
@@ -66,6 +67,13 @@ function world() {
         ],
       }),
     },
+    files: {
+      mkdir: async () => ({}),
+      write: async (args: { path: string; hostId?: string }) => {
+        writes.push({ path: args.path, hostId: args.hostId });
+        return { outcome: "written" };
+      },
+    },
     hosts: { list: async () => [{ id: "host_off", status: "disconnected" }, { id: "host_on", status: "connected" }] },
     threadSections: {
       list: async () => sections.map((s) => ({ ...s })),
@@ -95,7 +103,10 @@ function world() {
       get: async ({ threadId }: { threadId: string }) => {
         const t = threads.get(threadId);
         if (t === undefined) throw Object.assign(new Error("not found"), { status: 404 });
-        return makeThreadResponse({ id: threadId, title: t.title ?? null, status: t.status as never, archivedAt: t.archivedAt, environmentId: "env1", providerId: "claude-code", parentThreadId: t.parentThreadId ?? null, sectionId: t.sectionId ?? null });
+        return {
+          ...makeThreadResponse({ id: threadId, title: t.title ?? null, status: t.status as never, archivedAt: t.archivedAt, environmentId: "env1", providerId: "claude-code", parentThreadId: t.parentThreadId ?? null, sectionId: t.sectionId ?? null }),
+          ...(t.hostId === undefined ? {} : { environment: { hostId: t.hostId } }),
+        };
       },
       list: async ({ sectionId, archived }: { sectionId?: string; archived?: boolean }) =>
         [...threads.entries()]
@@ -134,7 +145,7 @@ function world() {
     },
   };
   let now = Date.parse("2026-10-14T15:00:00Z");
-  return { files, repos, entities, rpcCalls, threads, sections, usage, metadata, spawns, sends, userTurns, sdk, now: () => now, advance: (ms: number) => (now += ms) };
+  return { files, writes, repos, entities, rpcCalls, threads, sections, usage, metadata, spawns, sends, userTurns, sdk, now: () => now, advance: (ms: number) => (now += ms) };
 }
 
 async function setup() {
@@ -1029,6 +1040,25 @@ describe("passes", () => {
   });
 });
 
+describe("bb stewards init", () => {
+  it("writes on the thread's own machine", async () => {
+    const t = await setup();
+    t.threads.set("thr_me", { status: "active", archivedAt: null, hostId: "host_me" });
+    const out = await t.harness.behavior.runCli(["init", "--teams", "eng"], { threadId: "thr_me", projectId: "p1", cwd: "/w" });
+    expect(out.exitCode).toBe(0);
+    expect(t.writes).toContainEqual({ path: `/w/.bb/${PROJECT_FILE}`, hostId: "host_me" });
+    expect(t.writes.every((w) => w.hostId === "host_me")).toBe(true);
+  });
+
+  it("writes on the project's machine when the thread names none, never on the server's own", async () => {
+    const t = await setup();
+    t.threads.set("thr_me", { status: "active", archivedAt: null });
+    await t.harness.behavior.runCli(["init", "--teams", "ENG"], { threadId: "thr_me", projectId: "p1", cwd: "/w" });
+    expect(t.writes.length).toBe(4);
+    expect(t.writes.every((w) => w.hostId === "host_on")).toBe(true);
+  });
+});
+
 describe("the settings page", () => {
   type Overview = { paused: boolean; projects: Array<{ name: string; configured: boolean; repos: string[]; playbooks: Array<{ kind: string; version: string | null }>; problems: string[]; projectStewardThreadId: string | null; stewards: Array<{ key: string; summary: string | null; actor: string | null; escalations: Array<{ route: string; question: string }> }> }> };
 

plugins/stewards/server.ts

@@ -454,15 +454,16 @@ export function createStewardsPlugin(deps: StewardsDeps): (bb: BbPluginApi) => P
 
     async function threadInfo(threadId: string): Promise<ThreadInfo | null> {
       try {
-        const t = (await bb.sdk.threads.get({ threadId })) as unknown as Partial<ThreadInfo>;
+        const t = (await bb.sdk.threads.get({ threadId })) as unknown as Partial<ThreadInfo> & { environment?: { hostId?: string | null } | null };
         return {
           id: threadId,
           title: t.title ?? null,
           status: String(t.status ?? "idle"),
           archivedAt: t.archivedAt ?? null,
           deletedAt: t.deletedAt ?? null,
           environmentId: t.environmentId ?? null,
-          environmentHostId: t.environmentHostId ?? null,
+          // The SDK's thread carries its machine on `environment`, not at the top level.
+          environmentHostId: t.environment?.hostId ?? t.environmentHostId ?? null,
           providerId: String(t.providerId ?? ""),
           parentThreadId: t.parentThreadId ?? null,
           sectionId: t.sectionId ?? null,
@@ -2032,7 +2033,12 @@ export function createStewardsPlugin(deps: StewardsDeps): (bb: BbPluginApi) => P
               }
               const dir = input.options.dir ?? (ctx.cwd === undefined ? undefined : `${ctx.cwd.replace(/\/$/u, "")}/.bb`);
               if (dir === undefined) throw new PluginCliError("No directory: run from a thread or pass --dir.", { code: "no_dir" });
-              const hostId = ctx.threadId === undefined ? undefined : ((await threadInfo(ctx.threadId))?.environmentHostId ?? undefined);
+              // Write on the thread's machine, else the project's: left to core, the
+              // write lands on the server's own daemon, which bb-gate's servers lack.
+              const hostId =
+                (ctx.threadId === undefined ? null : ((await threadInfo(ctx.threadId))?.environmentHostId ?? null)) ??
+                (ctx.projectId === undefined ? null : await projectHost(ctx.projectId)) ??
+                undefined;
               const files: Array<[string, string]> = [[PROJECT_FILE, projectFileTemplate(teams)], ...Object.entries(PLAYBOOK_TEMPLATES).map(([name, text]) => [playbookPath(name), text] as [string, string])];
               const lines: string[] = [];
               for (const [rel, content] of files) {