chore(billing): delete the dead seat-based billing feature

The usage-based billing cutover shipped (#3485, #3487, #3488) and the
seat model is dead code: nothing rendered useSeat, the seat store was
only fed by auth/onboarding sync calls, and the /api/seats/* client
methods have no remaining product surface.

Removed: shared seat types/plan keys, core SeatService/seatView/
seatErrors + tokens, the UI seat store/client/hook, api-client seat
methods and seat error classes, the SUBSCRIPTION_STARTED/CANCELLED
analytics events, the orphaned "upgrade_dialog" surface literal, and
the gateway invalidate-plan-cache chain (router procedure, service
method, endpoint, URL helper) whose only caller was the seat upgrade
flow.

Auth identity sync keeps the usage-snapshot cache clear (still
load-bearing for usage billing); the llmGateway query invalidation it
carried was a no-op (no queries live under that key) and is dropped.

Generated-By: PostHog Code
Task-Id: 1039ea23-9930-44e2-9888-b05cf8b129ec

Author: adboio

apps/code/src/main/di/container.ts

@@ -4,7 +4,6 @@ import { readFile as fsReadFile, stat as fsStat } from "node:fs/promises";
 import { TypedContainer } from "@inversifyjs/strongly-typed";
 import { DEFAULT_GATEWAY_MODEL } from "@posthog/agent/gateway-models";
 import {
-  getGatewayInvalidatePlanCacheUrl,
   getGatewayUsageUrl,
   getLlmGatewayUrl,
 } from "@posthog/agent/posthog-api";
@@ -491,8 +490,6 @@ container.bind(LLM_GATEWAY_HOST).toDynamicValue((ctx) => {
     messagesUrl: (apiHost: string) =>
       `${getLlmGatewayUrl(apiHost)}/v1/messages`,
     usageUrl: (apiHost: string) => getGatewayUsageUrl(apiHost),
-    invalidatePlanCacheUrl: (apiHost: string) =>
-      getGatewayInvalidatePlanCacheUrl(apiHost),
     defaultModel: DEFAULT_GATEWAY_MODEL,
   };
 });

apps/code/src/renderer/desktop-contributions.ts

@@ -1,6 +1,5 @@
 import { agentChatCoreModule } from "@posthog/core/agent-chat/agentChat.module";
 import { autoresearchCoreModule } from "@posthog/core/autoresearch/autoresearch.module";
-import { billingCoreModule } from "@posthog/core/billing/billing.module";
 import { taskThreadCoreModule } from "@posthog/core/canvas/taskThread.module";
 import { inboxCoreModule } from "@posthog/core/inbox/inbox.module";
 import { githubConnectModule } from "@posthog/core/integrations/githubConnect.module";
@@ -37,7 +36,6 @@ export function registerDesktopContributions(): void {
     authUiModule,
     autoresearchCoreModule,
     billingUiModule,
-    billingCoreModule,
     taskThreadCoreModule,
     browserTabsUiModule,
     cloneUiModule,

packages/agent/src/posthog-api.ts

@@ -7,17 +7,9 @@ import type {
   TaskRun,
   TaskRunArtifact,
 } from "./types";
-import {
-  getGatewayInvalidatePlanCacheUrl,
-  getGatewayUsageUrl,
-  getLlmGatewayUrl,
-} from "./utils/gateway";
-
-export {
-  getGatewayInvalidatePlanCacheUrl,
-  getGatewayUsageUrl,
-  getLlmGatewayUrl,
-};
+import { getGatewayUsageUrl, getLlmGatewayUrl } from "./utils/gateway";
+
+export { getGatewayUsageUrl, getLlmGatewayUrl };
 
 const DEFAULT_USER_AGENT = `posthog/agent.hog.dev; version: ${packageJson.version}`;
 

packages/agent/src/utils/gateway.ts

@@ -92,10 +92,3 @@ export function getGatewayUsageUrl(
 ): string {
   return `${getGatewayBaseUrl(posthogHost)}/v1/usage/${product}`;
 }
-
-export function getGatewayInvalidatePlanCacheUrl(
-  posthogHost: string,
-  product: GatewayProduct = "posthog_code",
-): string {
-  return `${getGatewayBaseUrl(posthogHost)}/v1/usage/${product}/invalidate-plan-cache`;
-}

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

@@ -7,15 +7,13 @@ import type {
   CloudRunSource,
   ExecutionMode,
   PrAuthorshipMode,
-  SeatData,
   StoredLogEntry,
   TaskRunArtifactMetadata,
 } from "@posthog/shared";
 import {
   DISMISSAL_REASON_OPTIONS,
   type DismissalReasonOptionValue,
   resolveCloudInitialPermissionMode,
-  SEAT_PRODUCT_KEY,
 } from "@posthog/shared";
 import type {
   AgentAnalyticsData,
@@ -119,22 +117,6 @@ export function setPosthogApiClientAppVersion(version: string): void {
   clientAppVersion = version;
 }
 
-export class SeatSubscriptionRequiredError extends Error {
-  redirectUrl: string;
-  constructor(redirectUrl: string) {
-    super("Billing subscription required");
-    this.name = "SeatSubscriptionRequiredError";
-    this.redirectUrl = redirectUrl;
-  }
-}
-
-export class SeatPaymentFailedError extends Error {
-  constructor(message?: string) {
-    super(message ?? "Payment failed");
-    this.name = "SeatPaymentFailedError";
-  }
-}
-
 export class SandboxCustomImagesDisabledError extends Error {
   constructor(message?: string) {
     super(message ?? "Custom sandbox images are not enabled");
@@ -4452,113 +4434,6 @@ export class PostHogAPIClient {
     return data.results ?? [];
   }
 
-  async getMySeat(
-    options: { best?: boolean } = { best: true },
-  ): Promise<SeatData | null> {
-    try {
-      const url = new URL(`${this.api.baseUrl}/api/seats/me/`);
-      url.searchParams.set("product_key", SEAT_PRODUCT_KEY);
-      if (options.best) {
-        url.searchParams.set("best", "true");
-      }
-      const response = await this.api.fetcher.fetch({
-        method: "get",
-        url,
-        path: "/api/seats/me/",
-      });
-      return (await response.json()) as SeatData;
-    } catch (error) {
-      if (this.isFetcherStatusError(error, 404)) {
-        return null;
-      }
-      throw error;
-    }
-  }
-
-  async createSeat(planKey: string): Promise<SeatData> {
-    try {
-      const user = await this.getCurrentUser();
-      const distinctId = user.distinct_id;
-      if (!distinctId) {
-        throw new Error("Cannot create seat: user has no distinct_id");
-      }
-      const url = new URL(`${this.api.baseUrl}/api/seats/`);
-      const response = await this.api.fetcher.fetch({
-        method: "post",
-        url,
-        path: "/api/seats/",
-        overrides: {
-          body: JSON.stringify({
-            product_key: SEAT_PRODUCT_KEY,
-            plan_key: planKey,
-            user_distinct_id: distinctId,
-          }),
-        },
-      });
-      return (await response.json()) as SeatData;
-    } catch (error) {
-      this.throwSeatError(error);
-    }
-  }
-
-  async upgradeSeat(planKey: string): Promise<SeatData> {
-    try {
-      const url = new URL(`${this.api.baseUrl}/api/seats/me/`);
-      const response = await this.api.fetcher.fetch({
-        method: "patch",
-        url,
-        path: "/api/seats/me/",
-        overrides: {
-          body: JSON.stringify({
-            product_key: SEAT_PRODUCT_KEY,
-            plan_key: planKey,
-          }),
-        },
-      });
-      return (await response.json()) as SeatData;
-    } catch (error) {
-      this.throwSeatError(error);
-    }
-  }
-
-  async cancelSeat(): Promise<void> {
-    try {
-      const url = new URL(`${this.api.baseUrl}/api/seats/me/`);
-      url.searchParams.set("product_key", SEAT_PRODUCT_KEY);
-      await this.api.fetcher.fetch({
-        method: "delete",
-        url,
-        path: "/api/seats/me/",
-      });
-    } catch (error) {
-      if (this.isFetcherStatusError(error, 204)) {
-        return;
-      }
-      this.throwSeatError(error);
-    }
-  }
-
-  async reactivateSeat(): Promise<SeatData> {
-    try {
-      const url = new URL(`${this.api.baseUrl}/api/seats/me/reactivate/`);
-      const response = await this.api.fetcher.fetch({
-        method: "post",
-        url,
-        path: "/api/seats/me/reactivate/",
-        overrides: {
-          body: JSON.stringify({ product_key: SEAT_PRODUCT_KEY }),
-        },
-      });
-      return (await response.json()) as SeatData;
-    } catch (error) {
-      this.throwSeatError(error);
-    }
-  }
-
-  private isFetcherStatusError(error: unknown, status: number): boolean {
-    return error instanceof Error && error.message.includes(`[${status}]`);
-  }
-
   private parseFetcherError(error: unknown): {
     status: number;
     body: Record<string, unknown>;
@@ -4607,26 +4482,6 @@ export class PostHogAPIClient {
     }
   }
 
-  private throwSeatError(error: unknown): never {
-    const parsed = this.parseFetcherError(error);
-
-    if (parsed) {
-      if (
-        parsed.status === 400 &&
-        typeof parsed.body.redirect_url === "string"
-      ) {
-        throw new SeatSubscriptionRequiredError(parsed.body.redirect_url);
-      }
-      if (parsed.status === 402) {
-        const message =
-          typeof parsed.body.error === "string" ? parsed.body.error : undefined;
-        throw new SeatPaymentFailedError(message);
-      }
-    }
-
-    throw error;
-  }
-
   /**
    * Check if a feature flag is enabled for the current project.
    * Returns true if the flag exists and is active, false otherwise.