feat(cloud): custom sandbox base images

packages/agent/src/adapters/claude/session/options.ts

@@ -183,7 +183,9 @@ function buildEnvironment(gateway?: GatewayEnv): Record<string, string> {
     }),
     ...(gateway?.openaiBaseUrl && { OPENAI_BASE_URL: gateway.openaiBaseUrl }),
     ...(gateway?.openaiApiKey && { OPENAI_API_KEY: gateway.openaiApiKey }),
-    ELECTRON_RUN_AS_NODE: "1",
+    ...((process.versions.electron || process.env.ELECTRON_RUN_AS_NODE) && {
+      ELECTRON_RUN_AS_NODE: "1",
+    }),
     CLAUDE_CODE_ENABLE_ASK_USER_QUESTION_TOOL: "true",
     // Offload all MCP tools by default
     ENABLE_TOOL_SEARCH: "auto:0",

packages/api-client/src/posthog-client.ts

@@ -52,6 +52,7 @@ import type {
   PriorityJudgmentArtefact,
   RepoSelectionArtefact,
   SafetyJudgmentArtefact,
+  SandboxCustomImage,
   SandboxEnvironment,
   SandboxEnvironmentInput,
   Signal,
@@ -119,6 +120,13 @@ export class SeatPaymentFailedError extends Error {
   }
 }
 
+export class SandboxCustomImagesDisabledError extends Error {
+  constructor(message?: string) {
+    super(message ?? "Custom sandbox images are not enabled");
+    this.name = "SandboxCustomImagesDisabledError";
+  }
+}
+
 export type UsageLimitType = "burst" | "sustained" | null;
 
 // Stable message so callers recognize this after a saga reduces the error to a string.
@@ -477,6 +485,7 @@ interface CloudRunOptions {
   model?: string;
   reasoningLevel?: string;
   sandboxEnvironmentId?: string;
+  customImageId?: string;
   prAuthorshipMode?: PrAuthorshipMode;
   runSource?: CloudRunSource;
   signalReportId?: string;
@@ -548,6 +557,9 @@ function buildCloudRunRequestBody(
   if (options?.sandboxEnvironmentId) {
     body.sandbox_environment_id = options.sandboxEnvironmentId;
   }
+  if (options?.customImageId) {
+    body.custom_image_id = options.customImageId;
+  }
   if (options?.prAuthorshipMode) {
     body.pr_authorship_mode = options.prAuthorshipMode;
   }
@@ -4404,6 +4416,155 @@ export class PostHogAPIClient {
     }
   }
 
+  async listSandboxCustomImages(): Promise<SandboxCustomImage[]> {
+    const teamId = await this.getTeamId();
+    const url = new URL(
+      `${this.api.baseUrl}/api/projects/${teamId}/sandbox_custom_images/`,
+    );
+    const response = await this.api.fetcher.fetch({
+      method: "get",
+      url,
+      path: `/api/projects/${teamId}/sandbox_custom_images/`,
+    });
+    if (!response.ok) {
+      if (response.status === 403) {
+        const errorData = (await response.json().catch(() => ({}))) as {
+          detail?: string;
+        };
+        throw new SandboxCustomImagesDisabledError(errorData.detail);
+      }
+      throw new Error(
+        `Failed to fetch sandbox custom images: ${response.statusText}`,
+      );
+    }
+    const data = (await response.json()) as {
+      results?: SandboxCustomImage[];
+    };
+    return data.results ?? [];
+  }
+
+  async createSandboxCustomImage(input: {
+    name: string;
+    description?: string;
+    repository?: string | null;
+    private?: boolean;
+  }): Promise<SandboxCustomImage> {
+    const teamId = await this.getTeamId();
+    const url = new URL(
+      `${this.api.baseUrl}/api/projects/${teamId}/sandbox_custom_images/`,
+    );
+    const response = await this.api.fetcher.fetch({
+      method: "post",
+      url,
+      path: `/api/projects/${teamId}/sandbox_custom_images/`,
+      overrides: {
+        body: JSON.stringify(input),
+      },
+    });
+    if (!response.ok) {
+      const errorData = (await response.json().catch(() => ({}))) as {
+        detail?: string;
+      };
+      throw new Error(
+        errorData.detail ??
+          `Failed to create sandbox custom image: ${response.statusText}`,
+      );
+    }
+    return (await response.json()) as SandboxCustomImage;
+  }
+
+  async getSandboxCustomImage(id: string): Promise<SandboxCustomImage> {
+    const teamId = await this.getTeamId();
+    const url = new URL(
+      `${this.api.baseUrl}/api/projects/${teamId}/sandbox_custom_images/${id}/`,
+    );
+    const response = await this.api.fetcher.fetch({
+      method: "get",
+      url,
+      path: `/api/projects/${teamId}/sandbox_custom_images/${id}/`,
+    });
+    if (!response.ok) {
+      throw new Error(
+        `Failed to fetch sandbox custom image: ${response.statusText}`,
+      );
+    }
+    return (await response.json()) as SandboxCustomImage;
+  }
+
+  async ensureSandboxCustomImageBuilderTask(
+    id: string,
+  ): Promise<SandboxCustomImage> {
+    const teamId = await this.getTeamId();
+    const url = new URL(
+      `${this.api.baseUrl}/api/projects/${teamId}/sandbox_custom_images/${id}/builder_task/`,
+    );
+    const response = await this.api.fetcher.fetch({
+      method: "post",
+      url,
+      path: `/api/projects/${teamId}/sandbox_custom_images/${id}/builder_task/`,
+      overrides: {
+        body: JSON.stringify({}),
+      },
+    });
+    if (!response.ok) {
+      const errorData = (await response.json().catch(() => ({}))) as {
+        detail?: string;
+      };
+      throw new Error(
+        errorData.detail ??
+          `Failed to open image builder session: ${response.statusText}`,
+      );
+    }
+    return (await response.json()) as SandboxCustomImage;
+  }
+
+  async buildSandboxCustomImage(
+    id: string,
+    specYaml?: string | null,
+  ): Promise<SandboxCustomImage> {
+    const teamId = await this.getTeamId();
+    const url = new URL(
+      `${this.api.baseUrl}/api/projects/${teamId}/sandbox_custom_images/${id}/build/`,
+    );
+    const response = await this.api.fetcher.fetch({
+      method: "post",
+      url,
+      path: `/api/projects/${teamId}/sandbox_custom_images/${id}/build/`,
+      overrides: {
+        body: JSON.stringify(
+          specYaml === undefined ? {} : { spec_yaml: specYaml },
+        ),
+      },
+    });
+    if (!response.ok) {
+      const errorData = (await response.json().catch(() => ({}))) as {
+        detail?: string;
+      };
+      throw new Error(
+        errorData.detail ??
+          `Failed to build sandbox custom image: ${response.statusText}`,
+      );
+    }
+    return (await response.json()) as SandboxCustomImage;
+  }
+
+  async deleteSandboxCustomImage(id: string): Promise<void> {
+    const teamId = await this.getTeamId();
+    const url = new URL(
+      `${this.api.baseUrl}/api/projects/${teamId}/sandbox_custom_images/${id}/`,
+    );
+    const response = await this.api.fetcher.fetch({
+      method: "delete",
+      url,
+      path: `/api/projects/${teamId}/sandbox_custom_images/${id}/`,
+    });
+    if (!response.ok) {
+      throw new Error(
+        `Failed to delete sandbox custom image: ${response.statusText}`,
+      );
+    }
+  }
+
   /** Find an exported asset by session recording ID. */
   async findExportBySessionRecordingId(
     projectId: number,

packages/core/src/settings/sandboxEnvironmentForm.ts

@@ -15,6 +15,7 @@ export interface SandboxEnvironmentFormState {
   include_default_domains: boolean;
   environment_variables_text: string;
   private: boolean;
+  custom_image_id: string | null;
 }
 
 export function isValidDomain(domain: string): boolean {
@@ -71,6 +72,7 @@ export function emptyForm(): SandboxEnvironmentFormState {
     include_default_domains: true,
     environment_variables_text: "",
     private: true,
+    custom_image_id: null,
   };
 }
 
@@ -84,6 +86,7 @@ export function formFromEnv(
     include_default_domains: env.include_default_domains,
     environment_variables_text: "",
     private: env.private,
+    custom_image_id: env.custom_image_id ?? null,
   };
 }
 
@@ -100,6 +103,7 @@ export function buildSandboxEnvironmentInput(
     include_default_domains: isCustom ? form.include_default_domains : false,
     private: form.private,
     repositories: [],
+    custom_image_id: form.custom_image_id,
     ...(form.environment_variables_text.trim()
       ? { environment_variables: envVars }
       : {}),

packages/core/src/sidebar/groupTasks.test.ts

@@ -220,6 +220,37 @@ describe("groupByRepository", () => {
     expect(groups[0]?.name).toBe("Other");
   });
 
+  it("routes image-builder tasks to a pinned 'Custom images' group above 'Other'", () => {
+    const tasks: TestTask[] = [
+      { id: "t1", repository: null, originProduct: "image_builder" },
+      {
+        id: "t2",
+        repository: {
+          fullPath: "posthog/code",
+          name: "code",
+          organization: "PostHog",
+        },
+        originProduct: "image_builder",
+      },
+      task("t3"),
+      task("t4", {
+        fullPath: "posthog/posthog",
+        name: "posthog",
+        organization: "PostHog",
+      }),
+    ];
+
+    const groups = groupByRepository(tasks, []);
+
+    expect(groups.map((g) => g.id)).toEqual([
+      "posthog/posthog",
+      "custom-images",
+      "other",
+    ]);
+    expect(groups[1]?.name).toBe("Custom images");
+    expect(groups[1]?.tasks.map((t) => t.id)).toEqual(["t1", "t2"]);
+  });
+
   it("keeps the bare name for a group without an organization when others collide", () => {
     const tasks: TestTask[] = [
       task("t1", {

packages/core/src/sidebar/groupTasks.ts

@@ -13,8 +13,11 @@ export interface TaskRepositoryInfo {
 
 export interface GroupableTask {
   repository: TaskRepositoryInfo | null;
+  originProduct?: string;
 }
 
+export const CUSTOM_IMAGES_GROUP_ID = "custom-images";
+
 export interface TaskGroup<T extends GroupableTask> {
   id: string;
   name: string;
@@ -69,8 +72,13 @@ export function groupByRepository<T extends GroupableTask>(
 
   for (const task of tasks) {
     const repository = task.repository;
-    const groupId = repository?.fullPath ?? "other";
-    const groupName = repository?.name ?? "Other";
+    const isImageBuilder = task.originProduct === "image_builder";
+    const groupId = isImageBuilder
+      ? CUSTOM_IMAGES_GROUP_ID
+      : (repository?.fullPath ?? "other");
+    const groupName = isImageBuilder
+      ? "Custom images"
+      : (repository?.name ?? "Other");
 
     let group = groupMap.get(groupId);
     if (!group) {
@@ -106,25 +114,27 @@ export function groupByRepository<T extends GroupableTask>(
     }
   }
 
-  // The "other" group (tasks without a resolvable repository) always sorts to
-  // the bottom, regardless of the alphabetical or persisted folder order.
-  const pinOtherLast = (a: TaskGroup<T>, b: TaskGroup<T>): number | null => {
-    const aOther = a.id === "other";
-    const bOther = b.id === "other";
-    if (aOther && bOther) return 0;
-    if (aOther) return 1;
-    if (bOther) return -1;
-    return null;
+  // Custom-images and "other" always sort last, in that order.
+  const pinnedRank = (group: TaskGroup<T>): number => {
+    if (group.id === CUSTOM_IMAGES_GROUP_ID) return 1;
+    if (group.id === "other") return 2;
+    return 0;
+  };
+  const pinSpecialLast = (a: TaskGroup<T>, b: TaskGroup<T>): number | null => {
+    const aRank = pinnedRank(a);
+    const bRank = pinnedRank(b);
+    if (aRank === 0 && bRank === 0) return null;
+    return aRank - bRank;
   };
 
   if (folderOrder.length === 0) {
     return groups.sort(
-      (a, b) => pinOtherLast(a, b) ?? a.name.localeCompare(b.name),
+      (a, b) => pinSpecialLast(a, b) ?? a.name.localeCompare(b.name),
     );
   }
 
   return groups.sort((a, b) => {
-    const pinned = pinOtherLast(a, b);
+    const pinned = pinSpecialLast(a, b);
     if (pinned !== null) return pinned;
     const aIndex = folderOrder.indexOf(a.id);
     const bIndex = folderOrder.indexOf(b.id);

packages/core/src/task-detail/taskCreationApiClient.ts

@@ -9,6 +9,7 @@ export interface CreateTaskRunClientOptions {
   model?: string;
   reasoningLevel?: string;
   sandboxEnvironmentId?: string;
+  customImageId?: string;
   prAuthorshipMode?: PrAuthorshipMode;
   runSource?: CloudRunSource;
   signalReportId?: string;

packages/core/src/task-detail/taskCreationSaga.ts

@@ -400,6 +400,7 @@ export class TaskCreationSaga extends Saga<
             model: input.model,
             reasoningLevel: input.reasoningLevel,
             sandboxEnvironmentId: input.sandboxEnvironmentId,
+            customImageId: input.customImageId,
             prAuthorshipMode,
             runSource: input.cloudRunSource ?? "manual",
             signalReportId: input.signalReportId,

packages/core/src/task-detail/taskInput.ts

@@ -17,6 +17,7 @@ export interface PrepareTaskInputOptions {
   reasoningLevel?: string;
   environmentId?: string | null;
   sandboxEnvironmentId?: string;
+  customImageId?: string;
   signalReportId?: string;
   additionalDirectories?: string[];
   channelContext?: string;
@@ -52,6 +53,7 @@ export function prepareTaskInput(
     reasoningLevel: options.reasoningLevel,
     environmentId: options.environmentId ?? undefined,
     sandboxEnvironmentId: options.sandboxEnvironmentId,
+    customImageId: options.customImageId,
     cloudPrAuthorshipMode:
       options.signalReportId && isCloud ? "user" : undefined,
     cloudRunSource: