diff --git a/plugins/backstage-plugin-coder/src/api/CoderClient.test.ts b/plugins/backstage-plugin-coder/src/api/CoderClient.test.ts
index 9addcd1a..2bfa6b24 100644
--- a/plugins/backstage-plugin-coder/src/api/CoderClient.test.ts
+++ b/plugins/backstage-plugin-coder/src/api/CoderClient.test.ts
@@ -1,8 +1,4 @@
-import {
-  CODER_AUTH_HEADER_KEY,
-  CoderClient,
-  disabledClientError,
-} from './CoderClient';
+import { CODER_AUTH_HEADER_KEY, CoderClient } from './CoderClient';
 import type { IdentityApi } from '@backstage/core-plugin-api';
 import { UrlSync } from './UrlSync';
 import { rest } from 'msw';
@@ -12,8 +8,8 @@ import { delay } from '../utils/time';
 import {
   mockWorkspacesList,
   mockWorkspacesListForRepoSearch,
-} from '../testHelpers/mockCoderAppData';
-import type { Workspace, WorkspacesResponse } from '../typesConstants';
+} from '../testHelpers/mockCoderPluginData';
+import type { Workspace, WorkspacesResponse } from './vendoredSdk';
 import {
   getMockConfigApi,
   getMockDiscoveryApi,
@@ -100,50 +96,6 @@ describe(`${CoderClient.name}`, () => {
     });
   });
 
-  describe('cleanupClient functionality', () => {
-    it('Will prevent any new SDK requests from going through', async () => {
-      const client = new CoderClient({ apis: getConstructorApis() });
-      client.cleanupClient();
-
-      // Request should fail, even though token is valid
-      await expect(() => {
-        return client.syncToken(mockCoderAuthToken);
-      }).rejects.toThrow(disabledClientError);
-
-      await expect(() => {
-        return client.sdk.getWorkspaces({
-          q: 'owner:me',
-          limit: 0,
-        });
-      }).rejects.toThrow(disabledClientError);
-    });
-
-    it('Will abort any pending requests', async () => {
-      const client = new CoderClient({
-        initialToken: mockCoderAuthToken,
-        apis: getConstructorApis(),
-      });
-
-      // Sanity check to ensure that request can still go through normally
-      const workspacesPromise1 = client.sdk.getWorkspaces({
-        q: 'owner:me',
-        limit: 0,
-      });
-
-      await expect(workspacesPromise1).resolves.toEqual<WorkspacesResponse>({
-        workspaces: mockWorkspacesList,
-        count: mockWorkspacesList.length,
-      });
-
-      const workspacesPromise2 = client.sdk.getWorkspaces({
-        q: 'owner:me',
-        limit: 0,
-      });
-      client.cleanupClient();
-      await expect(() => workspacesPromise2).rejects.toThrow();
-    });
-  });
-
   // Eventually the Coder SDK is going to get too big to test every single
   // function. Focus tests on the functionality specifically being patched in
   // for Backstage
@@ -180,10 +132,10 @@ describe(`${CoderClient.name}`, () => {
       });
 
       const { urlSync } = apis;
-      const apiEndpoint = await urlSync.getApiEndpoint();
+      const assetsEndpoint = await urlSync.getAssetsEndpoint();
 
-      const allWorkspacesAreRemapped = !workspaces.some(ws =>
-        ws.template_icon.startsWith(apiEndpoint),
+      const allWorkspacesAreRemapped = workspaces.every(ws =>
+        ws.template_icon.startsWith(assetsEndpoint),
       );
 
       expect(allWorkspacesAreRemapped).toBe(true);
diff --git a/plugins/backstage-plugin-coder/src/api/CoderClient.ts b/plugins/backstage-plugin-coder/src/api/CoderClient.ts
index 7c09f72c..4c5333dd 100644
--- a/plugins/backstage-plugin-coder/src/api/CoderClient.ts
+++ b/plugins/backstage-plugin-coder/src/api/CoderClient.ts
@@ -1,19 +1,19 @@
-import globalAxios, {
+import {
   AxiosError,
-  type AxiosInstance,
   type InternalAxiosRequestConfig as RequestConfig,
 } from 'axios';
 import { type IdentityApi, createApiRef } from '@backstage/core-plugin-api';
-import {
-  type Workspace,
-  CODER_API_REF_ID_PREFIX,
-  WorkspacesRequest,
-  WorkspacesResponse,
-  User,
-} from '../typesConstants';
+import { CODER_API_REF_ID_PREFIX } from '../typesConstants';
 import type { UrlSync } from './UrlSync';
 import type { CoderWorkspacesConfig } from '../hooks/useCoderWorkspacesConfig';
-import { CoderSdk } from './MockCoderSdk';
+import {
+  type CoderSdk,
+  type User,
+  type Workspace,
+  type WorkspacesRequest,
+  type WorkspacesResponse,
+  makeCoderSdk,
+} from './vendoredSdk';
 
 export const CODER_AUTH_HEADER_KEY = 'Coder-Session-Token';
 const DEFAULT_REQUEST_TIMEOUT_MS = 20_000;
@@ -39,11 +39,6 @@ type CoderClientApi = Readonly<{
    * Return value indicates whether the token is valid.
    */
   syncToken: (newToken: string) => Promise<boolean>;
-
-  /**
-   * Cleans up a client instance, removing its links to all external systems.
-   */
-  cleanupClient: () => void;
 }>;
 
 const sharedCleanupAbortReason = new DOMException(
@@ -59,19 +54,30 @@ export const disabledClientError = new Error(
 );
 
 type ConstructorInputs = Readonly<{
+  /**
+   * initialToken is strictly for testing, and is basically limited to making it
+   * easier to test API logic.
+   *
+   * If trying to test UI logic that depends on CoderClient, it's probably
+   * better to interact with CoderClient indirectly through the auth components,
+   * so that React state is aware of everything.
+   */
   initialToken?: string;
-  requestTimeoutMs?: number;
 
+  requestTimeoutMs?: number;
   apis: Readonly<{
     urlSync: UrlSync;
     identityApi: IdentityApi;
   }>;
 }>;
 
+type RequestInterceptor = (
+  config: RequestConfig,
+) => RequestConfig | Promise<RequestConfig>;
+
 export class CoderClient implements CoderClientApi {
   private readonly urlSync: UrlSync;
   private readonly identityApi: IdentityApi;
-  private readonly axios: AxiosInstance;
 
   private readonly requestTimeoutMs: number;
   private readonly cleanupController: AbortController;
@@ -82,33 +88,28 @@ export class CoderClient implements CoderClientApi {
 
   constructor(inputs: ConstructorInputs) {
     const {
-      apis,
       initialToken,
+      apis: { urlSync, identityApi },
       requestTimeoutMs = DEFAULT_REQUEST_TIMEOUT_MS,
     } = inputs;
-    const { urlSync, identityApi } = apis;
 
     this.urlSync = urlSync;
     this.identityApi = identityApi;
-    this.axios = globalAxios.create();
-
     this.loadedSessionToken = initialToken;
     this.requestTimeoutMs = requestTimeoutMs;
-
     this.cleanupController = new AbortController();
     this.trackedEjectionIds = new Set();
 
-    this.sdk = this.getBackstageCoderSdk(this.axios);
+    this.sdk = this.createBackstageCoderSdk();
     this.addBaseRequestInterceptors();
   }
 
   private addRequestInterceptor(
-    requestInterceptor: (
-      config: RequestConfig,
-    ) => RequestConfig | Promise<RequestConfig>,
+    requestInterceptor: RequestInterceptor,
     errorInterceptor?: (error: unknown) => unknown,
   ): number {
-    const ejectionId = this.axios.interceptors.request.use(
+    const axios = this.sdk.getAxiosInstance();
+    const ejectionId = axios.interceptors.request.use(
       requestInterceptor,
       errorInterceptor,
     );
@@ -120,7 +121,8 @@ export class CoderClient implements CoderClientApi {
   private removeRequestInterceptorById(ejectionId: number): boolean {
     // Even if we somehow pass in an ID that hasn't been associated with the
     // Axios instance, that's a noop. No harm in calling method no matter what
-    this.axios.interceptors.request.eject(ejectionId);
+    const axios = this.sdk.getAxiosInstance();
+    axios.interceptors.request.eject(ejectionId);
 
     if (!this.trackedEjectionIds.has(ejectionId)) {
       return false;
@@ -179,10 +181,8 @@ export class CoderClient implements CoderClientApi {
     this.addRequestInterceptor(baseRequestInterceptor, baseErrorInterceptor);
   }
 
-  private getBackstageCoderSdk(
-    axiosInstance: AxiosInstance,
-  ): BackstageCoderSdk {
-    const baseSdk = new CoderSdk(axiosInstance);
+  private createBackstageCoderSdk(): BackstageCoderSdk {
+    const baseSdk = makeCoderSdk();
 
     const getWorkspaces: (typeof baseSdk)['getWorkspaces'] = async request => {
       const workspacesRes = await baseSdk.getWorkspaces(request);
@@ -335,23 +335,6 @@ export class CoderClient implements CoderClientApi {
       this.removeRequestInterceptorById(validationId);
     }
   };
-
-  cleanupClient = (): void => {
-    this.trackedEjectionIds.forEach(id => {
-      this.axios.interceptors.request.eject(id);
-    });
-
-    this.trackedEjectionIds.clear();
-    this.cleanupController.abort(sharedCleanupAbortReason);
-    this.loadedSessionToken = undefined;
-
-    // Not using this.addRequestInterceptor, because we don't want to track this
-    // interceptor at all. It should never be ejected once the client has been
-    // disabled
-    this.axios.interceptors.request.use(() => {
-      throw disabledClientError;
-    });
-  };
 }
 
 function appendParamToQuery(
diff --git a/plugins/backstage-plugin-coder/src/api/MockCoderSdk.ts b/plugins/backstage-plugin-coder/src/api/MockCoderSdk.ts
deleted file mode 100644
index 3100242b..00000000
--- a/plugins/backstage-plugin-coder/src/api/MockCoderSdk.ts
+++ /dev/null
@@ -1,48 +0,0 @@
-/**
- * @file This is a temporary (and significantly limited) implementation of the
- * "Coder SDK" that will eventually be imported from Coder core
- *
- * @todo Replace this with a full, proper implementation, and then expose it to
- * plugin users.
- */
-import globalAxios, { type AxiosInstance } from 'axios';
-import {
-  type User,
-  type WorkspacesRequest,
-  type WorkspacesResponse,
-} from '../typesConstants';
-
-type CoderSdkApi = {
-  getAuthenticatedUser: () => Promise<User>;
-  getWorkspaces: (request: WorkspacesRequest) => Promise<WorkspacesResponse>;
-};
-
-export class CoderSdk implements CoderSdkApi {
-  private readonly axios: AxiosInstance;
-
-  constructor(axiosInstance?: AxiosInstance) {
-    this.axios = axiosInstance ?? globalAxios.create();
-  }
-
-  getWorkspaces = async (
-    request: WorkspacesRequest,
-  ): Promise<WorkspacesResponse> => {
-    const urlParams = new URLSearchParams({
-      q: request.q ?? '',
-      limit: String(request.limit || 0),
-      after_id: request.after_id ?? '',
-      offset: String(request.offset || 0),
-    });
-
-    const response = await this.axios.get<WorkspacesResponse>(
-      `/workspaces?${urlParams.toString()}`,
-    );
-
-    return response.data;
-  };
-
-  getAuthenticatedUser = async (): Promise<User> => {
-    const response = await this.axios.get<User>('/users/me');
-    return response.data;
-  };
-}
diff --git a/plugins/backstage-plugin-coder/src/api/UrlSync.test.ts b/plugins/backstage-plugin-coder/src/api/UrlSync.test.ts
index 4932edea..62001e4e 100644
--- a/plugins/backstage-plugin-coder/src/api/UrlSync.test.ts
+++ b/plugins/backstage-plugin-coder/src/api/UrlSync.test.ts
@@ -4,8 +4,8 @@ import {
   getMockConfigApi,
   getMockDiscoveryApi,
   mockBackstageAssetsEndpoint,
-  mockBackstageApiEndpoint,
   mockBackstageUrlRoot,
+  mockBackstageApiEndpointWithoutSdkPath,
 } from '../testHelpers/mockBackstageData';
 
 // Tests have to assume that DiscoveryApi and ConfigApi will always be in sync,
@@ -23,7 +23,7 @@ describe(`${UrlSync.name}`, () => {
     const cachedUrls = urlSync.getCachedUrls();
     expect(cachedUrls).toEqual<UrlSyncSnapshot>({
       baseUrl: mockBackstageUrlRoot,
-      apiRoute: mockBackstageApiEndpoint,
+      apiRoute: mockBackstageApiEndpointWithoutSdkPath,
       assetsRoute: mockBackstageAssetsEndpoint,
     });
   });
@@ -50,7 +50,7 @@ describe(`${UrlSync.name}`, () => {
 
     expect(newSnapshot).toEqual<UrlSyncSnapshot>({
       baseUrl: 'blah',
-      apiRoute: 'blah/coder/api/v2',
+      apiRoute: 'blah/coder',
       assetsRoute: 'blah/coder',
     });
   });
@@ -76,7 +76,7 @@ describe(`${UrlSync.name}`, () => {
 
     expect(onChange).toHaveBeenCalledWith({
       baseUrl: 'blah',
-      apiRoute: 'blah/coder/api/v2',
+      apiRoute: 'blah/coder',
       assetsRoute: 'blah/coder',
     } satisfies UrlSyncSnapshot);
 
diff --git a/plugins/backstage-plugin-coder/src/api/UrlSync.ts b/plugins/backstage-plugin-coder/src/api/UrlSync.ts
index ae05294b..8b3548d6 100644
--- a/plugins/backstage-plugin-coder/src/api/UrlSync.ts
+++ b/plugins/backstage-plugin-coder/src/api/UrlSync.ts
@@ -42,14 +42,10 @@ const PROXY_URL_KEY_FOR_DISCOVERY_API = 'proxy';
 
 type UrlPrefixes = Readonly<{
   proxyPrefix: string;
-  apiRoutePrefix: string;
-  assetsRoutePrefix: string;
 }>;
 
 export const defaultUrlPrefixes = {
   proxyPrefix: `/api/proxy`,
-  apiRoutePrefix: '/api/v2',
-  assetsRoutePrefix: '', // Deliberately left as empty string
 } as const satisfies UrlPrefixes;
 
 export type UrlSyncSnapshot = Readonly<{
@@ -104,12 +100,10 @@ export class UrlSync implements UrlSyncApi {
   }
 
   private prepareNewSnapshot(newProxyUrl: string): UrlSyncSnapshot {
-    const { assetsRoutePrefix, apiRoutePrefix } = this.urlPrefixes;
-
     return {
       baseUrl: newProxyUrl.replace(proxyRouteReplacer, ''),
-      assetsRoute: `${newProxyUrl}${CODER_PROXY_PREFIX}${assetsRoutePrefix}`,
-      apiRoute: `${newProxyUrl}${CODER_PROXY_PREFIX}${apiRoutePrefix}`,
+      assetsRoute: `${newProxyUrl}${CODER_PROXY_PREFIX}`,
+      apiRoute: `${newProxyUrl}${CODER_PROXY_PREFIX}`,
     };
   }
 
diff --git a/plugins/backstage-plugin-coder/src/api/queryOptions.ts b/plugins/backstage-plugin-coder/src/api/queryOptions.ts
index b10ecfe2..4e55861d 100644
--- a/plugins/backstage-plugin-coder/src/api/queryOptions.ts
+++ b/plugins/backstage-plugin-coder/src/api/queryOptions.ts
@@ -1,5 +1,5 @@
 import type { UseQueryOptions } from '@tanstack/react-query';
-import type { Workspace, WorkspacesRequest } from '../typesConstants';
+import type { Workspace, WorkspacesRequest } from './vendoredSdk';
 import type { CoderWorkspacesConfig } from '../hooks/useCoderWorkspacesConfig';
 import type { BackstageCoderSdk } from './CoderClient';
 import type { CoderAuth } from '../components/CoderProvider';
@@ -44,13 +44,13 @@ function getSharedWorkspacesQueryKey(coderQuery: string) {
 
 type WorkspacesFetchInputs = Readonly<{
   auth: CoderAuth;
-  coderSdk: BackstageCoderSdk;
+  sdk: BackstageCoderSdk;
   coderQuery: string;
 }>;
 
 export function workspaces({
   auth,
-  coderSdk,
+  sdk,
   coderQuery,
 }: WorkspacesFetchInputs): UseQueryOptions<readonly Workspace[]> {
   const enabled = auth.isAuthenticated;
@@ -61,7 +61,7 @@ export function workspaces({
     keepPreviousData: enabled && coderQuery !== '',
     refetchInterval: getCoderWorkspacesRefetchInterval,
     queryFn: async () => {
-      const res = await coderSdk.getWorkspaces({
+      const res = await sdk.getWorkspaces({
         q: coderQuery,
         limit: 0,
       });
@@ -79,7 +79,7 @@ type WorkspacesByRepoFetchInputs = Readonly<
 
 export function workspacesByRepo({
   coderQuery,
-  coderSdk,
+  sdk,
   auth,
   workspacesConfig,
 }: WorkspacesByRepoFetchInputs): UseQueryOptions<readonly Workspace[]> {
@@ -95,7 +95,7 @@ export function workspacesByRepo({
     refetchInterval: getCoderWorkspacesRefetchInterval,
     queryFn: async () => {
       const request: WorkspacesRequest = { q: coderQuery, limit: 0 };
-      const res = await coderSdk.getWorkspacesByRepo(request, workspacesConfig);
+      const res = await sdk.getWorkspacesByRepo(request, workspacesConfig);
       return res.workspaces;
     },
   };
diff --git a/plugins/backstage-plugin-coder/src/components/CoderErrorBoundary/CoderErrorBoundary.tsx b/plugins/backstage-plugin-coder/src/components/CoderErrorBoundary/CoderErrorBoundary.tsx
index c1f2bc61..5843a180 100644
--- a/plugins/backstage-plugin-coder/src/components/CoderErrorBoundary/CoderErrorBoundary.tsx
+++ b/plugins/backstage-plugin-coder/src/components/CoderErrorBoundary/CoderErrorBoundary.tsx
@@ -39,7 +39,7 @@ class ErrorBoundaryCore extends Component<
 
   render() {
     const { children, fallbackUi } = this.props;
-    return this.state.hasError ? fallbackUi : children;
+    return <>{this.state.hasError ? fallbackUi : children}</>;
   }
 }
 
diff --git a/plugins/backstage-plugin-coder/src/components/CoderProvider/CoderAuthProvider.tsx b/plugins/backstage-plugin-coder/src/components/CoderProvider/CoderAuthProvider.tsx
index c9b6fbb1..664bb311 100644
--- a/plugins/backstage-plugin-coder/src/components/CoderProvider/CoderAuthProvider.tsx
+++ b/plugins/backstage-plugin-coder/src/components/CoderProvider/CoderAuthProvider.tsx
@@ -165,19 +165,23 @@ function useAuthState(): CoderAuth {
     return unsubscribe;
   }, [queryClient]);
 
+  const registerNewToken = useCallback((newToken: string) => {
+    if (newToken !== '') {
+      setAuthToken(newToken);
+    }
+  }, []);
+
+  const ejectToken = useCallback(() => {
+    setAuthToken('');
+    window.localStorage.removeItem(TOKEN_STORAGE_KEY);
+    queryClient.removeQueries({ queryKey: [CODER_QUERY_KEY_PREFIX] });
+  }, [queryClient]);
+
   return {
     ...authState,
     isAuthenticated: validAuthStatuses.includes(authState.status),
-    registerNewToken: newToken => {
-      if (newToken !== '') {
-        setAuthToken(newToken);
-      }
-    },
-    ejectToken: () => {
-      setAuthToken('');
-      window.localStorage.removeItem(TOKEN_STORAGE_KEY);
-      queryClient.removeQueries({ queryKey: [CODER_QUERY_KEY_PREFIX] });
-    },
+    registerNewToken,
+    ejectToken,
   };
 }
 
diff --git a/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/CoderWorkspacesCard.test.tsx b/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/CoderWorkspacesCard.test.tsx
index a8cbef6c..8acc04a1 100644
--- a/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/CoderWorkspacesCard.test.tsx
+++ b/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/CoderWorkspacesCard.test.tsx
@@ -10,7 +10,7 @@ import {
   mockWorkspaceNoParameters,
   mockWorkspaceWithMatch2,
   mockWorkspacesList,
-} from '../../testHelpers/mockCoderAppData';
+} from '../../testHelpers/mockCoderPluginData';
 import { type CoderAuthStatus } from '../CoderProvider';
 import { CoderWorkspacesCard } from './CoderWorkspacesCard';
 import userEvent from '@testing-library/user-event';
diff --git a/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/ReminderAccordion.test.tsx b/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/ReminderAccordion.test.tsx
index 0ae1d918..5be7284b 100644
--- a/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/ReminderAccordion.test.tsx
+++ b/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/ReminderAccordion.test.tsx
@@ -2,7 +2,7 @@ import React from 'react';
 import { screen } from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import { renderInCoderEnvironment } from '../../testHelpers/setup';
-import type { Workspace } from '../../typesConstants';
+import type { Workspace } from '../../api/vendoredSdk';
 import { mockCoderWorkspacesConfig } from '../../testHelpers/mockBackstageData';
 import {
   type WorkspacesCardContext,
diff --git a/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/Root.tsx b/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/Root.tsx
index 0866d95a..452f0a9c 100644
--- a/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/Root.tsx
+++ b/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/Root.tsx
@@ -15,7 +15,7 @@ import {
   useCoderWorkspacesConfig,
   type CoderWorkspacesConfig,
 } from '../../hooks/useCoderWorkspacesConfig';
-import type { Workspace } from '../../typesConstants';
+import type { Workspace } from '../../api/vendoredSdk';
 import { useCoderWorkspacesQuery } from '../../hooks/useCoderWorkspacesQuery';
 import { CoderAuthFormCardWrapper } from '../CoderAuthFormCardWrapper';
 
diff --git a/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesList.test.tsx b/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesList.test.tsx
index 50bc1de1..bc7e0273 100644
--- a/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesList.test.tsx
+++ b/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesList.test.tsx
@@ -3,8 +3,8 @@ import { type WorkspacesListProps, WorkspacesList } from './WorkspacesList';
 import { renderInCoderEnvironment } from '../../testHelpers/setup';
 import { CardContext, WorkspacesCardContext, WorkspacesQuery } from './Root';
 import { mockCoderWorkspacesConfig } from '../../testHelpers/mockBackstageData';
-import { mockWorkspaceWithMatch } from '../../testHelpers/mockCoderAppData';
-import { Workspace } from '../../typesConstants';
+import { mockWorkspaceWithMatch } from '../../testHelpers/mockCoderPluginData';
+import type { Workspace } from '../../api/vendoredSdk';
 import { screen } from '@testing-library/react';
 
 type RenderInputs = Readonly<{
diff --git a/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesList.tsx b/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesList.tsx
index 1e47b08a..9301d6a4 100644
--- a/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesList.tsx
+++ b/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesList.tsx
@@ -1,7 +1,7 @@
 import React, { type HTMLAttributes, type ReactNode, Fragment } from 'react';
 
 import { type Theme, makeStyles } from '@material-ui/core';
-import type { Workspace } from '../../typesConstants';
+import type { Workspace } from '../../api/vendoredSdk';
 import { useWorkspacesCardContext } from './Root';
 import { WorkspacesListItem } from './WorkspacesListItem';
 import { Placeholder } from './Placeholder';
diff --git a/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesListItem.test.tsx b/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesListItem.test.tsx
index 03ff2623..471d3356 100644
--- a/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesListItem.test.tsx
+++ b/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesListItem.test.tsx
@@ -1,9 +1,13 @@
 import React from 'react';
 import { screen } from '@testing-library/react';
 import { renderInCoderEnvironment } from '../../testHelpers/setup';
-import { mockWorkspaceWithMatch } from '../../testHelpers/mockCoderAppData';
-import type { Workspace } from '../../typesConstants';
+import { mockWorkspaceWithMatch } from '../../testHelpers/mockCoderPluginData';
+import type { Workspace } from '../../api/vendoredSdk';
 import { WorkspacesListItem } from './WorkspacesListItem';
+import {
+  MockWorkspaceAgent,
+  MockWorkspaceResource,
+} from '../../testHelpers/coderEntities';
 
 type RenderInput = Readonly<{
   isOnline?: boolean;
@@ -19,9 +23,11 @@ async function renderListItem(inputs?: RenderInput) {
       status: isOnline ? 'running' : 'stopped',
       resources: [
         {
+          ...MockWorkspaceResource,
           id: '1',
           agents: [
             {
+              ...MockWorkspaceAgent,
               id: '2',
               status: isOnline ? 'connected' : 'disconnected',
             },
diff --git a/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesListItem.tsx b/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesListItem.tsx
index f7292e51..a5a588ae 100644
--- a/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesListItem.tsx
+++ b/plugins/backstage-plugin-coder/src/components/CoderWorkspacesCard/WorkspacesListItem.tsx
@@ -11,7 +11,8 @@ import { useId } from '../../hooks/hookPolyfills';
 import { useCoderAppConfig } from '../CoderProvider';
 import { getWorkspaceAgentStatuses } from '../../utils/workspaces';
 
-import type { Workspace, WorkspaceStatus } from '../../typesConstants';
+import type { WorkspaceStatus } from '../../api/vendoredSdk';
+import type { Workspace } from '../../api/vendoredSdk';
 import { WorkspacesListIcon } from './WorkspacesListIcon';
 import { VisuallyHidden } from '../VisuallyHidden';
 
diff --git a/plugins/backstage-plugin-coder/src/hooks/hookPolyfills.ts b/plugins/backstage-plugin-coder/src/hooks/hookPolyfills.ts
index 3b777c5e..ce15f948 100644
--- a/plugins/backstage-plugin-coder/src/hooks/hookPolyfills.ts
+++ b/plugins/backstage-plugin-coder/src/hooks/hookPolyfills.ts
@@ -25,5 +25,11 @@ function useIdPolyfill(): string {
   return readonlyId;
 }
 
+const ReactWithNewerHooks = React as typeof React & {
+  useId?: () => string;
+};
+
 export const useId =
-  typeof React.useId === 'undefined' ? useIdPolyfill : React.useId;
+  typeof ReactWithNewerHooks.useId === 'undefined'
+    ? useIdPolyfill
+    : ReactWithNewerHooks.useId;
diff --git a/plugins/backstage-plugin-coder/src/hooks/useCoderSdk.ts b/plugins/backstage-plugin-coder/src/hooks/useCoderSdk.ts
index 8fbec12c..7b7017a1 100644
--- a/plugins/backstage-plugin-coder/src/hooks/useCoderSdk.ts
+++ b/plugins/backstage-plugin-coder/src/hooks/useCoderSdk.ts
@@ -1,7 +1,13 @@
+/**
+ * @file This defines the general helper for accessing the Coder SDK from
+ * Backstage in a type-safe way.
+ *
+ * This hook is meant to be used both internally AND externally.
+ */
 import { useApi } from '@backstage/core-plugin-api';
 import { coderClientApiRef, type BackstageCoderSdk } from '../api/CoderClient';
 
 export function useCoderSdk(): BackstageCoderSdk {
-  const coderClient = useApi(coderClientApiRef);
-  return coderClient.sdk;
+  const { sdk } = useApi(coderClientApiRef);
+  return sdk;
 }
diff --git a/plugins/backstage-plugin-coder/src/hooks/useCoderWorkspacesQuery.test.ts b/plugins/backstage-plugin-coder/src/hooks/useCoderWorkspacesQuery.test.ts
index d29e64a5..49535619 100644
--- a/plugins/backstage-plugin-coder/src/hooks/useCoderWorkspacesQuery.test.ts
+++ b/plugins/backstage-plugin-coder/src/hooks/useCoderWorkspacesQuery.test.ts
@@ -6,7 +6,7 @@ import { mockCoderWorkspacesConfig } from '../testHelpers/mockBackstageData';
 import {
   mockWorkspaceNoParameters,
   mockWorkspacesList,
-} from '../testHelpers/mockCoderAppData';
+} from '../testHelpers/mockCoderPluginData';
 
 beforeAll(() => {
   jest.useFakeTimers();
diff --git a/plugins/backstage-plugin-coder/src/hooks/useCoderWorkspacesQuery.ts b/plugins/backstage-plugin-coder/src/hooks/useCoderWorkspacesQuery.ts
index 4e41ef86..63b4f2f7 100644
--- a/plugins/backstage-plugin-coder/src/hooks/useCoderWorkspacesQuery.ts
+++ b/plugins/backstage-plugin-coder/src/hooks/useCoderWorkspacesQuery.ts
@@ -13,13 +13,13 @@ export function useCoderWorkspacesQuery({
   coderQuery,
   workspacesConfig,
 }: QueryInput) {
+  const sdk = useCoderSdk();
   const auth = useInternalCoderAuth();
-  const coderSdk = useCoderSdk();
   const hasRepoData = workspacesConfig && workspacesConfig.repoUrl;
 
   const queryOptions = hasRepoData
-    ? workspacesByRepo({ auth, coderSdk, coderQuery, workspacesConfig })
-    : workspaces({ auth, coderSdk, coderQuery });
+    ? workspacesByRepo({ auth, sdk, coderQuery, workspacesConfig })
+    : workspaces({ auth, sdk, coderQuery });
 
   return useQuery(queryOptions);
 }
diff --git a/plugins/backstage-plugin-coder/src/hooks/useUrlSync.test.tsx b/plugins/backstage-plugin-coder/src/hooks/useUrlSync.test.tsx
index 164242f7..90cac33d 100644
--- a/plugins/backstage-plugin-coder/src/hooks/useUrlSync.test.tsx
+++ b/plugins/backstage-plugin-coder/src/hooks/useUrlSync.test.tsx
@@ -6,13 +6,13 @@ import { type UseUrlSyncResult, useUrlSync } from './useUrlSync';
 import type { DiscoveryApi } from '@backstage/core-plugin-api';
 import {
   mockBackstageAssetsEndpoint,
-  mockBackstageApiEndpoint,
   mockBackstageUrlRoot,
   getMockConfigApi,
+  mockBackstageApiEndpointWithoutSdkPath,
 } from '../testHelpers/mockBackstageData';
 
 function renderUseUrlSync() {
-  let proxyEndpoint: string = mockBackstageApiEndpoint;
+  let proxyEndpoint: string = mockBackstageApiEndpointWithoutSdkPath;
   const mockDiscoveryApi: DiscoveryApi = {
     getBaseUrl: async () => proxyEndpoint,
   };
@@ -53,7 +53,7 @@ describe(`${useUrlSync.name}`, () => {
           state: {
             baseUrl: mockBackstageUrlRoot,
             assetsRoute: mockBackstageAssetsEndpoint,
-            apiRoute: mockBackstageApiEndpoint,
+            apiRoute: mockBackstageApiEndpointWithoutSdkPath,
           },
         }),
       );
diff --git a/plugins/backstage-plugin-coder/src/testHelpers/coderEntities.ts b/plugins/backstage-plugin-coder/src/testHelpers/coderEntities.ts
new file mode 100644
index 00000000..b5cf5abf
--- /dev/null
+++ b/plugins/backstage-plugin-coder/src/testHelpers/coderEntities.ts
@@ -0,0 +1,305 @@
+/**
+ * @file This is a subset of the mock data from the Coder OSS repo. No values
+ * are modified; if any values should be patched for Backstage testing, those
+ * should be updated in the mockCoderPluginData.ts file.
+ *
+ * @see {@link https://github.com/coder/coder/blob/main/site/src/testHelpers/entities.ts}
+ */
+import type * as TypesGen from '../api/vendoredSdk';
+
+const MockOrganization: TypesGen.Organization = {
+  id: 'fc0774ce-cc9e-48d4-80ae-88f7a4d4a8b0',
+  name: 'Test Organization',
+  created_at: '',
+  updated_at: '',
+  is_default: true,
+};
+
+const MockOwnerRole: TypesGen.Role = {
+  name: 'owner',
+  display_name: 'Owner',
+  site_permissions: [],
+  organization_permissions: {},
+  user_permissions: [],
+  organization_id: '',
+};
+
+export const MockUser: TypesGen.User = {
+  id: 'test-user',
+  username: 'TestUser',
+  email: 'test@coder.com',
+  created_at: '',
+  status: 'active',
+  organization_ids: [MockOrganization.id],
+  roles: [MockOwnerRole],
+  avatar_url: 'https://avatars.githubusercontent.com/u/95932066?s=200&v=4',
+  last_seen_at: '',
+  login_type: 'password',
+  theme_preference: '',
+  name: '',
+};
+
+const MockProvisionerJob: TypesGen.ProvisionerJob = {
+  created_at: '',
+  id: 'test-provisioner-job',
+  status: 'succeeded',
+  file_id: MockOrganization.id,
+  completed_at: '2022-05-17T17:39:01.382927298Z',
+  tags: {
+    scope: 'organization',
+    owner: '',
+    wowzers: 'whatatag',
+    isCapable: 'false',
+    department: 'engineering',
+    dreaming: 'true',
+  },
+  queue_position: 0,
+  queue_size: 0,
+};
+
+const MockProvisioner: TypesGen.ProvisionerDaemon = {
+  created_at: '2022-05-17T17:39:01.382927298Z',
+  id: 'test-provisioner',
+  name: 'Test Provisioner',
+  provisioners: ['echo'],
+  tags: { scope: 'organization' },
+  version: 'v2.34.5',
+  api_version: '1.0',
+};
+
+const MockTemplateVersion: TypesGen.TemplateVersion = {
+  id: 'test-template-version',
+  created_at: '2022-05-17T17:39:01.382927298Z',
+  updated_at: '2022-05-17T17:39:01.382927298Z',
+  template_id: 'test-template',
+  job: MockProvisionerJob,
+  name: 'test-version',
+  message: 'first version',
+  readme: `---
+name:Template test
+---
+## Instructions
+You can add instructions here
+
+[Some link info](https://coder.com)`,
+  created_by: MockUser,
+  archived: false,
+};
+
+const MockWorkspaceAgentLogSource: TypesGen.WorkspaceAgentLogSource = {
+  created_at: '2023-05-04T11:30:41.402072Z',
+  id: 'dc790496-eaec-4f88-a53f-8ce1f61a1fff',
+  display_name: 'Startup Script',
+  icon: '',
+  workspace_agent_id: '',
+};
+
+const MockBuildInfo: TypesGen.BuildInfoResponse = {
+  agent_api_version: '1.0',
+  external_url: 'file:///mock-url',
+  version: 'v99.999.9999+c9cdf14',
+  dashboard_url: 'https:///mock-url',
+  workspace_proxy: false,
+  upgrade_message: 'My custom upgrade message',
+  deployment_id: '510d407f-e521-4180-b559-eab4a6d802b8',
+};
+
+const MockWorkspaceApp: TypesGen.WorkspaceApp = {
+  id: 'test-app',
+  slug: 'test-app',
+  display_name: 'Test App',
+  icon: '',
+  subdomain: false,
+  health: 'disabled',
+  external: false,
+  url: '',
+  sharing_level: 'owner',
+  healthcheck: {
+    url: '',
+    interval: 0,
+    threshold: 0,
+  },
+};
+
+const MockWorkspaceAgentScript: TypesGen.WorkspaceAgentScript = {
+  log_source_id: MockWorkspaceAgentLogSource.id,
+  cron: '',
+  log_path: '',
+  run_on_start: true,
+  run_on_stop: false,
+  script: "echo 'hello world'",
+  start_blocks_login: false,
+  timeout: 0,
+};
+
+export const MockWorkspaceAgent: TypesGen.WorkspaceAgent = {
+  apps: [MockWorkspaceApp],
+  architecture: 'amd64',
+  created_at: '',
+  environment_variables: {},
+  id: 'test-workspace-agent',
+  name: 'a-workspace-agent',
+  operating_system: 'linux',
+  resource_id: '',
+  status: 'connected',
+  updated_at: '',
+  version: MockBuildInfo.version,
+  api_version: '1.0',
+  latency: {
+    'Coder Embedded DERP': {
+      latency_ms: 32.55,
+      preferred: true,
+    },
+  },
+  connection_timeout_seconds: 120,
+  troubleshooting_url: 'https://coder.com/troubleshoot',
+  lifecycle_state: 'starting',
+  logs_length: 0,
+  logs_overflowed: false,
+  log_sources: [MockWorkspaceAgentLogSource],
+  scripts: [MockWorkspaceAgentScript],
+  startup_script_behavior: 'non-blocking',
+  subsystems: ['envbox', 'exectrace'],
+  health: {
+    healthy: true,
+  },
+  display_apps: [
+    'ssh_helper',
+    'port_forwarding_helper',
+    'vscode',
+    'vscode_insiders',
+    'web_terminal',
+  ],
+};
+
+export const MockWorkspaceResource: TypesGen.WorkspaceResource = {
+  id: 'test-workspace-resource',
+  name: 'a-workspace-resource',
+  agents: [MockWorkspaceAgent],
+  created_at: '',
+  job_id: '',
+  type: 'google_compute_disk',
+  workspace_transition: 'start',
+  hide: false,
+  icon: '',
+  metadata: [{ key: 'size', value: '32GB', sensitive: false }],
+  daily_cost: 10,
+};
+
+const MockWorkspaceBuild: TypesGen.WorkspaceBuild = {
+  build_number: 1,
+  created_at: '2022-05-17T17:39:01.382927298Z',
+  id: '1',
+  initiator_id: MockUser.id,
+  initiator_name: MockUser.username,
+  job: MockProvisionerJob,
+  template_version_id: MockTemplateVersion.id,
+  template_version_name: MockTemplateVersion.name,
+  transition: 'start',
+  updated_at: '2022-05-17T17:39:01.382927298Z',
+  workspace_name: 'test-workspace',
+  workspace_owner_id: MockUser.id,
+  workspace_owner_name: MockUser.username,
+  workspace_owner_avatar_url: MockUser.avatar_url,
+  workspace_id: '759f1d46-3174-453d-aa60-980a9c1442f3',
+  deadline: '2022-05-17T23:39:00.00Z',
+  reason: 'initiator',
+  resources: [MockWorkspaceResource],
+  status: 'running',
+  daily_cost: 20,
+};
+
+const MockTemplate: TypesGen.Template = {
+  id: 'test-template',
+  created_at: '2022-05-17T17:39:01.382927298Z',
+  updated_at: '2022-05-18T17:39:01.382927298Z',
+  organization_id: MockOrganization.id,
+  name: 'test-template',
+  display_name: 'Test Template',
+  provisioner: MockProvisioner.provisioners[0],
+  active_version_id: MockTemplateVersion.id,
+  active_user_count: 1,
+  build_time_stats: {
+    start: {
+      P50: 1000,
+      P95: 1500,
+    },
+    stop: {
+      P50: 1000,
+      P95: 1500,
+    },
+    delete: {
+      P50: 1000,
+      P95: 1500,
+    },
+  },
+  description: 'This is a test description.',
+  default_ttl_ms: 24 * 60 * 60 * 1000,
+  activity_bump_ms: 1 * 60 * 60 * 1000,
+  autostop_requirement: {
+    days_of_week: ['sunday'],
+    weeks: 1,
+  },
+  autostart_requirement: {
+    days_of_week: [
+      'monday',
+      'tuesday',
+      'wednesday',
+      'thursday',
+      'friday',
+      'saturday',
+      'sunday',
+    ],
+  },
+  created_by_id: 'test-creator-id',
+  created_by_name: 'test_creator',
+  icon: '/icon/code.svg',
+  allow_user_cancel_workspace_jobs: true,
+  failure_ttl_ms: 0,
+  time_til_dormant_ms: 0,
+  time_til_dormant_autodelete_ms: 0,
+  allow_user_autostart: true,
+  allow_user_autostop: true,
+  require_active_version: false,
+  deprecated: false,
+  deprecation_message: '',
+  max_port_share_level: 'public',
+};
+
+const MockWorkspaceAutostartEnabled: TypesGen.UpdateWorkspaceAutostartRequest =
+  {
+    // Runs at 9:30am Monday through Friday using Canada/Eastern
+    // (America/Toronto) time
+    schedule: 'CRON_TZ=Canada/Eastern 30 9 * * 1-5',
+  };
+
+export const MockWorkspace: TypesGen.Workspace = {
+  id: 'test-workspace',
+  name: 'Test-Workspace',
+  created_at: '',
+  updated_at: '',
+  template_id: MockTemplate.id,
+  template_name: MockTemplate.name,
+  template_icon: MockTemplate.icon,
+  template_display_name: MockTemplate.display_name,
+  template_allow_user_cancel_workspace_jobs:
+    MockTemplate.allow_user_cancel_workspace_jobs,
+  template_active_version_id: MockTemplate.active_version_id,
+  template_require_active_version: MockTemplate.require_active_version,
+  outdated: false,
+  owner_id: MockUser.id,
+  organization_id: MockOrganization.id,
+  owner_name: MockUser.username,
+  owner_avatar_url: 'https://avatars.githubusercontent.com/u/7122116?v=4',
+  autostart_schedule: MockWorkspaceAutostartEnabled.schedule,
+  ttl_ms: 2 * 60 * 60 * 1000,
+  latest_build: MockWorkspaceBuild,
+  last_used_at: '2022-05-16T15:29:10.302441433Z',
+  health: {
+    healthy: true,
+    failing_agents: [],
+  },
+  automatic_updates: 'never',
+  allow_renames: true,
+  favorite: false,
+};
diff --git a/plugins/backstage-plugin-coder/src/testHelpers/mockBackstageData.ts b/plugins/backstage-plugin-coder/src/testHelpers/mockBackstageData.ts
index 34f11218..8c96f8d2 100644
--- a/plugins/backstage-plugin-coder/src/testHelpers/mockBackstageData.ts
+++ b/plugins/backstage-plugin-coder/src/testHelpers/mockBackstageData.ts
@@ -67,13 +67,25 @@ export const rawRepoUrl = `${cleanedRepoUrl}/tree/main/`;
 export const mockBackstageUrlRoot = 'http://localhost:7007';
 
 /**
- * The API endpoint to use with the mock server during testing.
+ * A version of the mock API endpoint that doesn't have the Coder API versioning
+ * prefix. Mainly used for tests that need to assert that the core API URL is
+ * formatted correctly, before the CoderSdk adds anything else to the end
+ *
+ * The string literal expression is complicated, but hover over it to see what
+ * the final result is.
+ */
+export const mockBackstageApiEndpointWithoutSdkPath =
+  `${mockBackstageUrlRoot}${defaultUrlPrefixes.proxyPrefix}${CODER_PROXY_PREFIX}` as const;
+
+/**
+ * The API endpoint to use with the mock server during testing. Adds additional
+ * path information that will normally be added via the Coder SDK.
  *
  * The string literal expression is complicated, but hover over it to see what
  * the final result is.
  */
 export const mockBackstageApiEndpoint =
-  `${mockBackstageUrlRoot}${defaultUrlPrefixes.proxyPrefix}${CODER_PROXY_PREFIX}${defaultUrlPrefixes.apiRoutePrefix}` as const;
+  `${mockBackstageApiEndpointWithoutSdkPath}/api/v2` as const;
 
 /**
  * The assets endpoint to use during testing.
@@ -82,7 +94,7 @@ export const mockBackstageApiEndpoint =
  * the final result is.
  */
 export const mockBackstageAssetsEndpoint =
-  `${mockBackstageUrlRoot}${defaultUrlPrefixes.proxyPrefix}${CODER_PROXY_PREFIX}${defaultUrlPrefixes.assetsRoutePrefix}` as const;
+  `${mockBackstageUrlRoot}${defaultUrlPrefixes.proxyPrefix}${CODER_PROXY_PREFIX}` as const;
 
 export const mockBearerToken = 'This-is-an-opaque-value-by-design';
 export const mockCoderAuthToken = 'ZG0HRy2gGN-mXljc1s5FqtE8WUJ4sUc5X';
diff --git a/plugins/backstage-plugin-coder/src/testHelpers/mockCoderAppData.ts b/plugins/backstage-plugin-coder/src/testHelpers/mockCoderPluginData.ts
similarity index 61%
rename from plugins/backstage-plugin-coder/src/testHelpers/mockCoderAppData.ts
rename to plugins/backstage-plugin-coder/src/testHelpers/mockCoderPluginData.ts
index 412e0e05..a3bfb10d 100644
--- a/plugins/backstage-plugin-coder/src/testHelpers/mockCoderAppData.ts
+++ b/plugins/backstage-plugin-coder/src/testHelpers/mockCoderPluginData.ts
@@ -1,21 +1,45 @@
-import type { Workspace } from '../typesConstants';
-import { mockBackstageApiEndpoint } from './mockBackstageData';
+import type { User, Workspace } from '../api/vendoredSdk';
+import {
+  MockUser,
+  MockWorkspace,
+  MockWorkspaceAgent,
+  MockWorkspaceResource,
+} from './coderEntities';
+import {
+  mockBackstageApiEndpoint,
+  mockBackstageAssetsEndpoint,
+} from './mockBackstageData';
+
+export const mockUserWithProxyUrls: User = {
+  ...MockUser,
+  avatar_url: `${mockBackstageAssetsEndpoint}/blueberry.png`,
+};
 
 /**
  * The main mock for a workspace whose repo URL matches cleanedRepoUrl
  */
 export const mockWorkspaceWithMatch: Workspace = {
+  ...MockWorkspace,
   id: 'workspace-with-match',
   name: 'Test-Workspace',
   template_icon: `${mockBackstageApiEndpoint}/emojis/dog.svg`,
   owner_name: 'lil brudder',
+
   latest_build: {
+    ...MockWorkspace.latest_build,
     id: 'workspace-with-match-build',
     status: 'running',
     resources: [
       {
+        ...MockWorkspaceResource,
         id: 'workspace-with-match-resource',
-        agents: [{ id: 'test-workspace-agent', status: 'connected' }],
+        agents: [
+          {
+            ...MockWorkspaceAgent,
+            id: 'test-workspace-agent',
+            status: 'connected',
+          },
+        ],
       },
     ],
   },
@@ -28,17 +52,27 @@ export const mockWorkspaceWithMatch: Workspace = {
  * return multiple values back
  */
 export const mockWorkspaceWithMatch2: Workspace = {
+  ...MockWorkspace,
   id: 'workspace-with-match-2',
   name: 'Another-Test',
   template_icon: `${mockBackstageApiEndpoint}/emojis/z.svg`,
   owner_name: 'Coach Z',
+
   latest_build: {
+    ...MockWorkspace.latest_build,
     id: 'workspace-with-match-2-build',
     status: 'running',
     resources: [
       {
+        ...MockWorkspaceResource,
         id: 'workspace-with-match-2-resource',
-        agents: [{ id: 'test-workspace-agent', status: 'connected' }],
+        agents: [
+          {
+            ...MockWorkspaceAgent,
+            id: 'test-workspace-agent',
+            status: 'connected',
+          },
+        ],
       },
     ],
   },
@@ -49,19 +83,31 @@ export const mockWorkspaceWithMatch2: Workspace = {
  * cleanedRepoUrl
  */
 export const mockWorkspaceNoMatch: Workspace = {
+  ...MockWorkspace,
   id: 'workspace-no-match',
   name: 'No-match',
   template_icon: `${mockBackstageApiEndpoint}/emojis/star.svg`,
   owner_name: 'homestar runner',
+
   latest_build: {
+    ...MockWorkspace.latest_build,
     id: 'workspace-no-match-build',
     status: 'stopped',
     resources: [
       {
+        ...MockWorkspaceResource,
         id: 'workspace-no-match-resource',
         agents: [
-          { id: 'test-workspace-agent-a', status: 'disconnected' },
-          { id: 'test-workspace-agent-b', status: 'timeout' },
+          {
+            ...MockWorkspaceAgent,
+            id: 'test-workspace-agent-a',
+            status: 'disconnected',
+          },
+          {
+            ...MockWorkspaceAgent,
+            id: 'test-workspace-agent-b',
+            status: 'timeout',
+          },
         ],
       },
     ],
@@ -72,17 +118,22 @@ export const mockWorkspaceNoMatch: Workspace = {
  * A workspace with no build parameters whatsoever
  */
 export const mockWorkspaceNoParameters: Workspace = {
+  ...MockWorkspace,
   id: 'workspace-no-parameters',
   name: 'No-parameters',
   template_icon: `${mockBackstageApiEndpoint}/emojis/cheese.png`,
   owner_name: 'The Cheat',
   latest_build: {
+    ...MockWorkspace.latest_build,
     id: 'workspace-no-parameters-build',
     status: 'running',
     resources: [
       {
+        ...MockWorkspaceResource,
         id: 'workspace-no-parameters-resource',
-        agents: [{ id: 'test-workspace-c', status: 'timeout' }],
+        agents: [
+          { ...MockWorkspaceAgent, id: 'test-workspace-c', status: 'timeout' },
+        ],
       },
     ],
   },
diff --git a/plugins/backstage-plugin-coder/src/testHelpers/server.ts b/plugins/backstage-plugin-coder/src/testHelpers/server.ts
index 69fe816a..bacd3f43 100644
--- a/plugins/backstage-plugin-coder/src/testHelpers/server.ts
+++ b/plugins/backstage-plugin-coder/src/testHelpers/server.ts
@@ -11,19 +11,18 @@ import { setupServer } from 'msw/node';
 /* eslint-enable @backstage/no-undeclared-imports */
 
 import {
+  mockUserWithProxyUrls,
   mockWorkspacesList,
   mockWorkspacesListForRepoSearch,
-} from './mockCoderAppData';
+} from './mockCoderPluginData';
 import {
-  mockBackstageAssetsEndpoint,
   mockBearerToken,
   mockCoderAuthToken,
   mockCoderWorkspacesConfig,
   mockBackstageApiEndpoint as root,
 } from './mockBackstageData';
-import type { WorkspacesResponse } from '../typesConstants';
 import { CODER_AUTH_HEADER_KEY } from '../api/CoderClient';
-import { User } from '../typesConstants';
+import type { User, WorkspacesResponse } from '../api/vendoredSdk';
 
 type RestResolver<TBody extends DefaultBodyType = any> = ResponseResolver<
   RestRequest<TBody>,
@@ -83,7 +82,6 @@ export function wrappedGet<TBody extends DefaultBodyType = any>(
 export const mockServerEndpoints = {
   workspaces: `${root}/workspaces`,
   authenticatedUser: `${root}/users/me`,
-  workspaceBuildParameters: `${root}/workspacebuilds/:workspaceBuildId/parameters`,
 } as const satisfies Record<string, string>;
 
 const mainTestHandlers: readonly RestHandler[] = [
@@ -93,7 +91,7 @@ const mainTestHandlers: readonly RestHandler[] = [
       `param:"\\w+?=${repoUrl.replace('/', '\\/')}"`,
     );
 
-    const queryText = String(req.url.searchParams.get('q'));
+    const queryText = String(req.url.searchParams.get('q') ?? '');
     const requestContainsRepoInfo = paramMatcherRe.test(queryText);
 
     const baseWorkspaces = requestContainsRepoInfo
@@ -129,14 +127,7 @@ const mainTestHandlers: readonly RestHandler[] = [
 
   // This is the dummy request used to verify a user's auth status
   wrappedGet(mockServerEndpoints.authenticatedUser, (_, res, ctx) => {
-    return res(
-      ctx.status(200),
-      ctx.json<User>({
-        id: '1',
-        avatar_url: `${mockBackstageAssetsEndpoint}/blueberry.png`,
-        username: 'blueberry',
-      }),
-    );
+    return res(ctx.status(200), ctx.json<User>(mockUserWithProxyUrls));
   }),
 ];
 
diff --git a/plugins/backstage-plugin-coder/src/typesConstants.ts b/plugins/backstage-plugin-coder/src/typesConstants.ts
index 76551f89..986696bd 100644
--- a/plugins/backstage-plugin-coder/src/typesConstants.ts
+++ b/plugins/backstage-plugin-coder/src/typesConstants.ts
@@ -1,14 +1,3 @@
-import {
-  type Output,
-  array,
-  number,
-  object,
-  string,
-  union,
-  literal,
-  optional,
-} from 'valibot';
-
 export type ReadonlyJsonValue =
   | string
   | number
@@ -30,80 +19,6 @@ export const CODER_API_REF_ID_PREFIX = 'backstage-plugin-coder';
 
 export const DEFAULT_CODER_DOCS_LINK = 'https://coder.com/docs/v2/latest';
 
-export const workspaceAgentStatusSchema = union([
-  literal('connected'),
-  literal('connecting'),
-  literal('disconnected'),
-  literal('timeout'),
-]);
-
-export const workspaceAgentSchema = object({
-  id: string(),
-  status: workspaceAgentStatusSchema,
-});
-
-export const workspaceResourceSchema = object({
-  id: string(),
-  agents: optional(array(workspaceAgentSchema)),
-});
-
-export const workspaceStatusSchema = union([
-  literal('canceled'),
-  literal('canceling'),
-  literal('deleted'),
-  literal('deleting'),
-  literal('failed'),
-  literal('pending'),
-  literal('running'),
-  literal('starting'),
-  literal('stopped'),
-  literal('stopping'),
-]);
-
-export const workspaceBuildSchema = object({
-  id: string(),
-  resources: array(workspaceResourceSchema),
-  status: workspaceStatusSchema,
-});
-
-export const workspaceSchema = object({
-  id: string(),
-  name: string(),
-  template_icon: string(),
-  owner_name: string(),
-  latest_build: workspaceBuildSchema,
-});
-
-export const workspacesResponseSchema = object({
-  count: number(),
-  workspaces: array(workspaceSchema),
-});
-
-export type WorkspaceAgentStatus = Output<typeof workspaceAgentStatusSchema>;
-export type WorkspaceAgent = Output<typeof workspaceAgentSchema>;
-export type WorkspaceResource = Output<typeof workspaceResourceSchema>;
-export type WorkspaceStatus = Output<typeof workspaceStatusSchema>;
-export type WorkspaceBuild = Output<typeof workspaceBuildSchema>;
-export type Workspace = Output<typeof workspaceSchema>;
-export type WorkspacesResponse = Output<typeof workspacesResponseSchema>;
-
-export type WorkspacesRequest = Readonly<{
-  after_id?: string;
-  limit?: number;
-  offset?: number;
-  q?: string;
-}>;
-
-// This is actually the MinimalUser type from Coder core (User extends from
-// ReducedUser, which extends from MinimalUser). Don't need all the properties
-// until we roll out full SDK support, so going with the least privileged
-// type definition for now
-export type User = Readonly<{
-  id: string;
-  username: string;
-  avatar_url: string;
-}>;
-
 /**
  * 2024-05-22 - While this isn't documented anywhere, TanStack Query defaults to
  * retrying a failed API request 3 times before exposing an error to the UI
diff --git a/plugins/backstage-plugin-coder/src/utils/workspaces.ts b/plugins/backstage-plugin-coder/src/utils/workspaces.ts
index c36b6d4b..f9317a97 100644
--- a/plugins/backstage-plugin-coder/src/utils/workspaces.ts
+++ b/plugins/backstage-plugin-coder/src/utils/workspaces.ts
@@ -1,4 +1,4 @@
-import type { Workspace, WorkspaceAgentStatus } from '../typesConstants';
+import { Workspace, WorkspaceAgentStatus } from '../api/vendoredSdk';
 
 export function getWorkspaceAgentStatuses(
   workspace: Workspace,