feat: support changing agent per prompt

packages/control-plane/src/db/automation-store.ts

@@ -21,6 +21,7 @@ export interface AutomationRow {
   schedule_cron: string | null;
   schedule_tz: string;
   model: string;
+  agent: string | null;
   reasoning_effort: string | null;
   enabled: number; // SQLite integer boolean
   next_run_at: number | null;
@@ -69,6 +70,7 @@ export function toAutomation(row: AutomationRow): Automation {
     scheduleCron: row.schedule_cron,
     scheduleTz: row.schedule_tz,
     model: row.model,
+    agent: row.agent,
     reasoningEffort: row.reasoning_effort,
     enabled: row.enabled === 1,
     nextRunAt: row.next_run_at,
@@ -113,10 +115,10 @@ export class AutomationStore {
       .prepare(
         `INSERT INTO automations
          (id, name, repo_owner, repo_name, base_branch, repo_id, instructions,
-          trigger_type, schedule_cron, schedule_tz, model, reasoning_effort, enabled, next_run_at,
+          trigger_type, schedule_cron, schedule_tz, model, agent, reasoning_effort, enabled, next_run_at,
           consecutive_failures, created_by, created_at, updated_at, deleted_at,
           event_type, trigger_config, trigger_auth_data)
-         VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`
+         VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)`
       )
       .bind(
         row.id,
@@ -130,6 +132,7 @@ export class AutomationStore {
         row.schedule_cron,
         row.schedule_tz,
         row.model,
+        row.agent,
         row.reasoning_effort,
         row.enabled,
         row.next_run_at,
@@ -188,6 +191,7 @@ export class AutomationStore {
       "schedule_cron",
       "schedule_tz",
       "model",
+      "agent",
       "reasoning_effort",
       "base_branch",
       "next_run_at",

packages/control-plane/src/db/repo-agent-cache.ts

@@ -0,0 +1,63 @@
+import type { AvailableAgent } from "@open-inspect/shared";
+
+interface RepoAgentCacheRow {
+  repo_owner: string;
+  repo_name: string;
+  branch: string;
+  agents_json: string;
+  created_at: number;
+  updated_at: number;
+}
+
+function normalize(value: string): string {
+  return value.trim().toLowerCase();
+}
+
+function parseAgents(value: string): AvailableAgent[] {
+  try {
+    const parsed = JSON.parse(value);
+    if (!Array.isArray(parsed)) return [];
+    return parsed.filter(
+      (agent): agent is AvailableAgent =>
+        typeof agent === "object" &&
+        agent !== null &&
+        typeof (agent as AvailableAgent).name === "string"
+    );
+  } catch {
+    return [];
+  }
+}
+
+export class RepoAgentCacheStore {
+  constructor(private readonly db: D1Database) {}
+
+  async get(owner: string, name: string, branch: string): Promise<AvailableAgent[] | null> {
+    const row = await this.db
+      .prepare(
+        "SELECT agents_json FROM repo_agent_cache WHERE repo_owner = ? AND repo_name = ? AND branch = ?"
+      )
+      .bind(normalize(owner), normalize(name), branch)
+      .first<Pick<RepoAgentCacheRow, "agents_json">>();
+
+    return row ? parseAgents(row.agents_json) : null;
+  }
+
+  async upsert(
+    owner: string,
+    name: string,
+    branch: string,
+    agents: AvailableAgent[]
+  ): Promise<void> {
+    const now = Date.now();
+    await this.db
+      .prepare(
+        `INSERT INTO repo_agent_cache (repo_owner, repo_name, branch, agents_json, created_at, updated_at)
+         VALUES (?, ?, ?, ?, ?, ?)
+         ON CONFLICT(repo_owner, repo_name, branch) DO UPDATE SET
+           agents_json = excluded.agents_json,
+           updated_at = excluded.updated_at`
+      )
+      .bind(normalize(owner), normalize(name), branch, JSON.stringify(agents), now, now)
+      .run();
+  }
+}

packages/control-plane/src/router.ts

@@ -461,6 +461,11 @@ const routes: Route[] = [
     pattern: parsePattern("/sessions/:id/messages"),
     handler: handleSessionMessages,
   },
+  {
+    method: "GET",
+    pattern: parsePattern("/sessions/:id/agents"),
+    handler: handleSessionAgents,
+  },
   {
     method: "POST",
     pattern: parsePattern("/sessions/:id/pr"),
@@ -932,6 +937,7 @@ async function handleSessionPrompt(
     authorId?: string;
     source?: string;
     model?: string;
+    agent?: string;
     reasoningEffort?: string;
     attachments?: Array<{ type: string; name: string; url?: string }>;
     callbackContext?: CallbackContext;
@@ -955,6 +961,7 @@ async function handleSessionPrompt(
           authorId: body.authorId || "anonymous",
           source: body.source || "web",
           model: body.model,
+          agent: body.agent,
           reasoningEffort: body.reasoningEffort,
           attachments: body.attachments,
           callbackContext: body.callbackContext,
@@ -1027,6 +1034,20 @@ async function handleSessionArtifacts(
   );
 }
 
+async function handleSessionAgents(
+  _request: Request,
+  env: Env,
+  match: RegExpMatchArray,
+  ctx: RequestContext
+): Promise<Response> {
+  const stub = getSessionStub(env, match);
+  if (!stub) return error("Session ID required");
+
+  return stub.fetch(
+    internalRequest(buildSessionInternalUrl(SessionInternalPaths.agents), undefined, ctx)
+  );
+}
+
 function getRequiredFormString(value: MultipartFieldValue | null, name: string): string | Response {
   if (typeof value !== "string" || value.trim().length === 0) {
     return error(`${name} is required`, 400);

packages/control-plane/src/routes/automations.ts

@@ -175,6 +175,7 @@ async function handleCreateAutomation(
 
   // Validate model
   const model = getValidModelOrDefault(body.model);
+  const agent = body.agent?.trim() ? body.agent.trim() : null;
   const reasoningEffort = resolveReasoningEffort(model, body.reasoningEffort);
   if (body.reasoningEffort !== undefined && body.reasoningEffort !== null && !reasoningEffort) {
     return error("Invalid reasoning effort for selected model", 400);
@@ -228,6 +229,7 @@ async function handleCreateAutomation(
     schedule_cron: body.scheduleCron ?? null,
     schedule_tz: body.scheduleTz ?? "UTC",
     model,
+    agent,
     reasoning_effort: reasoningEffort,
     enabled: 1,
     next_run_at: nextRunAt,
@@ -347,6 +349,8 @@ async function handleUpdateAutomation(
   }
 
   const nextModel = body.model !== undefined ? getValidModelOrDefault(body.model) : existing.model;
+  const nextAgent =
+    body.agent !== undefined ? (body.agent?.trim() ? body.agent.trim() : null) : existing.agent;
   const requestedReasoningEffort = body.reasoningEffort;
   const resolvedReasoningEffort =
     requestedReasoningEffort !== undefined
@@ -370,6 +374,7 @@ async function handleUpdateAutomation(
   if (body.scheduleCron !== undefined) updateFields.schedule_cron = body.scheduleCron;
   if (body.scheduleTz !== undefined) updateFields.schedule_tz = body.scheduleTz;
   if (body.model !== undefined) updateFields.model = nextModel;
+  if (body.agent !== undefined) updateFields.agent = nextAgent;
   if (body.reasoningEffort !== undefined || body.model !== undefined) {
     updateFields.reasoning_effort = resolvedReasoningEffort;
   }

packages/control-plane/src/routes/repos.ts

@@ -3,6 +3,7 @@
  */
 
 import { RepoMetadataStore } from "../db/repo-metadata";
+import { RepoAgentCacheStore } from "../db/repo-agent-cache";
 import type { Env } from "../types";
 import type {
   EnrichedRepository,
@@ -323,6 +324,25 @@ async function handleListBranches(
   }
 }
 
+async function handleGetRepoAgents(
+  request: Request,
+  env: Env,
+  match: RegExpMatchArray,
+  _ctx: RequestContext
+): Promise<Response> {
+  const params = extractRepoParams(match);
+  if (params instanceof Response) return params;
+  const { owner, name } = params;
+  const branch = new URL(request.url).searchParams.get("branch")?.trim();
+  if (!branch) {
+    return error("branch is required", 400);
+  }
+
+  const store = new RepoAgentCacheStore(env.DB);
+  const agents = await store.get(owner, name, branch);
+  return json({ agents: agents ?? [] });
+}
+
 export const reposRoutes: Route[] = [
   {
     method: "GET",
@@ -344,4 +364,9 @@ export const reposRoutes: Route[] = [
     pattern: parsePattern("/repos/:owner/:name/branches"),
     handler: handleListBranches,
   },
+  {
+    method: "GET",
+    pattern: parsePattern("/repos/:owner/:name/agents"),
+    handler: handleGetRepoAgents,
+  },
 ];

packages/control-plane/src/scheduler/durable-object.ts

@@ -612,6 +612,7 @@ export class SchedulerDO extends DurableObject<Env> {
         content: instructionsOverride ?? automation.instructions,
         authorId: automation.created_by,
         source: "automation",
+        agent: automation.agent,
         callbackContext,
       }),
     });

packages/control-plane/src/session/contracts.ts

@@ -14,6 +14,7 @@ export const SessionInternalPaths = {
   events: "/internal/events",
   artifacts: "/internal/artifacts",
   messages: "/internal/messages",
+  agents: "/internal/agents",
   createPr: "/internal/create-pr",
   wsToken: "/internal/ws-token",
   archive: "/internal/archive",