refactor(host): make every remaining consumer use HostResolution

e2e-harness/__tests__/e2e-flow-snapshot.test.ts

@@ -17,6 +17,7 @@ import { WizardStore } from '@ui/tui/store';
 import { InkUI } from '@ui/tui/ink-ui';
 import { setUI } from '@ui/index';
 import { buildSession, RunPhase } from '@lib/wizard-session';
+import { HostResolution } from '@lib/host-resolution';
 import { Integration } from '@lib/constants';
 import { FRAMEWORK_REGISTRY } from '@lib/registry';
 import { WizardReadiness } from '@lib/health-checks/readiness';
@@ -66,7 +67,7 @@ function traceFlow(
       store.setCredentials({
         accessToken: 'phx_x',
         projectApiKey: 'phc_x',
-        host: 'https://us.posthog.com',
+        host: HostResolution.fromApiHost('https://us.posthog.com'),
         projectId: 1,
       });
     } else if (screen === ScreenId.Run) {

e2e-harness/__tests__/wizard-ci-driver.test.ts

@@ -13,6 +13,7 @@ import { WizardStore } from '@ui/tui/store';
 import { InkUI } from '@ui/tui/ink-ui';
 import { setUI } from '@ui/index';
 import { buildSession, RunPhase, McpOutcome } from '@lib/wizard-session';
+import { HostResolution } from '@lib/host-resolution';
 import { Integration } from '@lib/constants';
 import { FRAMEWORK_REGISTRY } from '@lib/registry';
 import { WizardReadiness } from '@lib/health-checks/readiness';
@@ -72,7 +73,7 @@ describe('WizardCiDriver — full integration flow', () => {
     store.setCredentials({
       accessToken: 'phx_secret_should_not_leak',
       projectApiKey: 'phc_public',
-      host: 'https://us.posthog.com',
+      host: HostResolution.fromApiHost('https://us.posthog.com'),
       projectId: 42,
     });
 
@@ -112,7 +113,7 @@ describe('WizardCiDriver — full integration flow', () => {
     store.setCredentials({
       accessToken: 'phx_secret_should_not_leak',
       projectApiKey: 'phc_public',
-      host: 'https://us.posthog.com',
+      host: HostResolution.fromApiHost('https://us.posthog.com'),
       projectId: 7,
     });
     const state = driver.readState();

src/commands/doctor.ts

@@ -58,7 +58,11 @@ async function runDoctorCI(options: Record<string, unknown>): Promise<void> {
       baseUrl: options.baseUrl as string | undefined,
     });
 
-    const issues = await fetchHealthIssues(accessToken, host, projectId);
+    const issues = await fetchHealthIssues(
+      accessToken,
+      host.apiHost,
+      projectId,
+    );
     if (issues.length === 0) {
       getUI().log.success('No active issues — your project looks healthy.');
       process.exit(0);

src/lib/agent/__tests__/agent-prompt-loader.test.ts

@@ -13,6 +13,7 @@ import {
   type OrchestratorPromptContext,
 } from '../agent-prompt-loader';
 import { QueueStore } from '@lib/agent/runner/sequence/orchestrator/queue';
+import { HostResolution } from '@lib/host-resolution';
 
 function tmpDir(): string {
   return fs.mkdtempSync(path.join(os.tmpdir(), 'agent-loader-test-'));
@@ -280,7 +281,7 @@ describe('assembleTaskPrompt', () => {
   const ctx: OrchestratorPromptContext = {
     projectId: 1,
     projectApiKey: 'phc_x',
-    host: 'https://us.posthog.com',
+    host: HostResolution.fromApiHost('https://us.posthog.com'),
   };
 
   it('points the agent at its installed task instructions', () => {

src/lib/agent/__tests__/agent-prompt.test.ts

@@ -1,5 +1,6 @@
 import { assemblePrompt, type PromptContext } from '@lib/agent/agent-prompt';
 import type { ProgramRun } from '@lib/agent/agent-runner';
+import { HostResolution } from '@lib/host-resolution';
 
 function makeRunDef(overrides: Partial<ProgramRun> = {}): ProgramRun {
   return {
@@ -16,7 +17,7 @@ function makeRunDef(overrides: Partial<ProgramRun> = {}): ProgramRun {
 const baseCtx: PromptContext = {
   projectId: 42,
   projectApiKey: 'phc_test123',
-  host: 'https://app.posthog.com',
+  host: HostResolution.fromApiHost('https://app.posthog.com'),
 };
 
 describe('assemblePrompt', () => {

src/lib/agent/agent-interface.ts

@@ -25,7 +25,7 @@ import {
 } from '@lib/wizard-session';
 import { wizardAbort, WizardError } from '@utils/wizard-abort';
 import { createCustomHeaders } from '@utils/custom-headers';
-import { HostResolution } from '@lib/host-resolution';
+import type { HostResolution } from '@lib/host-resolution';
 import { LINTING_TOOLS } from '@lib/safe-tools';
 import { createWizardToolsServer, WIZARD_TOOL_NAMES } from '@lib/wizard-tools';
 import {
@@ -176,7 +176,7 @@ export type AgentConfig = {
   workingDirectory: string;
   posthogMcpUrl: string;
   posthogApiKey: string;
-  posthogApiHost: string;
+  host: HostResolution;
   additionalMcpServers?: Record<string, { url: string }>;
   detectPackageManager: PackageManagerDetector;
   /** Base URL for the skills server (context-mill dev or GitHub releases) */
@@ -620,16 +620,12 @@ export async function initializeAgent(
   logToFile('Install directory:', options.installDir);
 
   try {
-    // TODO: clean up in #755
-    const gatewayUrl = HostResolution.fromApiHost(
-      config.posthogApiHost,
-    ).gatewayUrl;
-
     // Configure model routing (inherited by the SDK subprocess). All model
     // calls route through the PostHog LLM gateway, authed with the user's
     // OAuth token.
     // Disable experimental betas (like input_examples) the gateway doesn't support.
     process.env.CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS = 'true';
+    const gatewayUrl = config.host.gatewayUrl;
     process.env.ANTHROPIC_BASE_URL = gatewayUrl;
     process.env.ANTHROPIC_AUTH_TOKEN = config.posthogApiKey;
 

src/lib/agent/agent-prompt-loader.ts

@@ -20,6 +20,7 @@ import type {
   QueuedTask,
 } from './runner/sequence/orchestrator/queue';
 import type { ResolvedTask } from './runner/sequence/orchestrator/executor';
+import type { HostResolution } from '@lib/host-resolution';
 import { DEFAULT_AGENT_MODEL } from '@lib/constants';
 
 /**
@@ -31,7 +32,7 @@ import { DEFAULT_AGENT_MODEL } from '@lib/constants';
 export interface OrchestratorPromptContext {
   projectId: number;
   projectApiKey: string;
-  host: string;
+  host: HostResolution;
   /** Path to the framework's reference implementation (EXAMPLE.md), if available. */
   examplePath?: string;
   /** Path to the framework's rules (COMMANDMENTS.md), if available. */
@@ -44,7 +45,7 @@ function projectContext(ctx: OrchestratorPromptContext): string {
 Project context:
 - PostHog Project ID: ${ctx.projectId}
 - PostHog public token: ${ctx.projectApiKey}
-- PostHog Host: ${ctx.host}`;
+- PostHog Host: ${ctx.host.apiHost}`;
 }
 
 /** Points the agent at the framework's reference integration to learn patterns from. */

src/lib/agent/agent-prompt.ts

@@ -8,14 +8,15 @@
  */
 
 import type { ProgramRun } from './agent-runner.js';
+import type { HostResolution } from '@lib/host-resolution';
 
 /**
  * Values available to prompt builders after OAuth completes.
  */
 export interface PromptContext {
   projectId: number;
   projectApiKey: string;
-  host: string;
+  host: HostResolution;
   /** Set when skillId was provided and the skill was installed successfully. */
   skillPath?: string;
   /**
@@ -44,7 +45,7 @@ function defaultProjectPrompt(ctx: PromptContext): string {
 Project context:
 - PostHog Project ID: ${ctx.projectId}
 - PostHog public token: ${ctx.projectApiKey}
-- PostHog Host: ${ctx.host}`;
+- PostHog Host: ${ctx.host.apiHost}`;
 }
 
 function skillPrompt(skillPath: string, reportFile: string): string {

src/lib/agent/mcp-prompt-streaming.ts

@@ -15,7 +15,6 @@
 import type { AgentChunk } from '@ui/tui/services/mcp-suggested-prompts-services';
 import type { Credentials } from '@lib/wizard-session';
 import { DEFAULT_AGENT_MODEL, WIZARD_USER_AGENT } from '@lib/constants';
-import { HostResolution, mcpUrlFor } from '@lib/host-resolution';
 import { logToFile } from '@utils/debug';
 import { buildAgentEnv } from '@lib/agent/agent-interface';
 import { sanitizeAgentSubprocessEnv } from '@lib/agent/agent-env-isolation';
@@ -42,13 +41,6 @@ const MODEL = DEFAULT_AGENT_MODEL;
 // telemetry on average turn counts per prompt.
 const MAX_TURNS = 30;
 
-// One MCP url for every region: the server resolves the user's region from
-// the bearer token, so the EU subdomain (a Claude Code OAuth workaround) is
-// not needed here.
-function resolveMcpUrl(): string {
-  return mcpUrlFor(false);
-}
-
 /**
  * Extract a short, single-line summary from an arbitrary value. Used
  * for tool-call args and tool-result bodies so the screen has something
@@ -201,8 +193,7 @@ export async function* runMcpPromptViaSdk(args: {
   process.env.CLAUDE_CODE_DISABLE_EXPERIMENTAL_BETAS = 'true';
 
   // Route through the PostHog LLM gateway, authed with the user's OAuth token.
-  // TODO: clean up in #755
-  const gatewayUrl = HostResolution.fromApiHost(credentials.host).gatewayUrl;
+  const gatewayUrl = credentials.host.gatewayUrl;
   process.env.ANTHROPIC_BASE_URL = gatewayUrl;
   process.env.ANTHROPIC_AUTH_TOKEN = credentials.accessToken;
   process.env.CLAUDE_CODE_OAUTH_TOKEN = credentials.accessToken;
@@ -226,7 +217,7 @@ export async function* runMcpPromptViaSdk(args: {
       once: true,
     });
 
-  const mcpUrl = resolveMcpUrl();
+  const mcpUrl = credentials.host.mcpUrl;
   logToFile(
     `[runMcpPromptViaSdk] mcpUrl=${mcpUrl} model=${MODEL} resume=${
       resumeSessionId ?? '(none)'

src/lib/agent/runner/harness/anthropic/index.ts

@@ -43,22 +43,16 @@ export const anthropicBackend: AgentHarness = {
       middleware,
       model,
     } = inputs;
-    const {
-      skillsBaseUrl,
-      accessToken,
-      host,
-      mcpUrl,
-      wizardFlags,
-      wizardMetadata,
-    } = boot;
+    const { skillsBaseUrl, credentials, wizardFlags, wizardMetadata } = boot;
+    const { accessToken, host } = credentials;
 
     getUI().log.step('Initializing Claude agent...');
     const agent = await initializeAgent(
       {
         workingDirectory: session.installDir,
-        posthogMcpUrl: mcpUrl,
+        posthogMcpUrl: host.mcpUrl,
         posthogApiKey: accessToken,
-        posthogApiHost: host,
+        host,
         additionalMcpServers: config.additionalMcpServers,
         detectPackageManager:
           config.detectPackageManager ?? detectNodePackageManagers,
@@ -124,9 +118,9 @@ export const anthropicBackend: AgentHarness = {
     const agent = await initializeAgent(
       {
         workingDirectory: session.installDir,
-        posthogMcpUrl: boot.mcpUrl,
-        posthogApiKey: boot.accessToken,
-        posthogApiHost: boot.host,
+        posthogMcpUrl: boot.credentials.host.mcpUrl,
+        posthogApiKey: boot.credentials.accessToken,
+        host: boot.credentials.host,
         detectPackageManager: detectNodePackageManagers,
         skillsBaseUrl: boot.skillsBaseUrl,
         wizardFlags: boot.wizardFlags,

src/lib/agent/runner/harness/pi/index.ts

@@ -16,7 +16,6 @@ import fs from 'fs';
 import path from 'path';
 import { getUI } from '@ui';
 import { getLogFilePath, logToFile } from '@utils/debug';
-import { getLlmGatewayUrl } from '@utils/urls';
 import {
   Harness,
   POSTHOG_FLAG_HEADER_PREFIX,
@@ -95,16 +94,16 @@ function piMcpContext(boot: BootstrapResult, instructions?: string): string {
     return ['', '## PostHog MCP server', instructions].join('\n');
   }
   const project = boot.project?.name
-    ? `${boot.project.name} (id ${boot.projectId})`
-    : `id ${boot.projectId}`;
+    ? `${boot.project.name} (id ${boot.credentials.projectId})`
+    : `id ${boot.credentials.projectId}`;
   // Fallback: a `## PostHog project` block with name/id, host, region.
   return [
     '',
     '## PostHog project',
     'Your `posthog_exec` calls run against this project:',
     `- Project: ${project}`,
-    `- Host: ${boot.host}`,
-    `- Region: ${boot.cloudRegion}`,
+    `- Host: ${boot.credentials.host.apiHost}`,
+    `- Region: ${boot.credentials.host.region}`,
   ].join('\n');
 }
 
@@ -314,14 +313,14 @@ export const piBackend: AgentHarness = {
       // `/v1` the Anthropic SDK strips.
       const api = gatewayApiFor(modelId);
       const caps = modelCapabilities(modelId, boot.wizardFlags);
-      const gatewayUrl = getLlmGatewayUrl(boot.host);
+      const gatewayUrl = boot.credentials.host.gatewayUrl;
       const baseUrl =
         api === 'openai-completions' ? `${gatewayUrl}/v1` : gatewayUrl;
       const registry = ModelRegistry.inMemory(AuthStorage.create());
       registry.registerProvider(GATEWAY_PROVIDER, {
         name: 'PostHog Gateway',
         baseUrl,
-        apiKey: boot.accessToken,
+        apiKey: boot.credentials.accessToken,
         authHeader: true,
         api,
         headers: buildGatewayHeaders(boot.wizardMetadata, boot.wizardFlags),
@@ -368,7 +367,10 @@ export const piBackend: AgentHarness = {
         // so it gets the bare gateway URL regardless of which API shape the
         // agent's model uses. Without this, pi has no ANTHROPIC_* env (it
         // auths programmatically) and triage would silently no-op.
-        triageAuth: { baseURL: gatewayUrl, authToken: boot.accessToken },
+        triageAuth: {
+          baseURL: gatewayUrl,
+          authToken: boot.credentials.accessToken,
+        },
         // Where pi's bash runs; the rm allowance is confined to this tree.
         workingDirectory: session.installDir,
       });
@@ -392,8 +394,8 @@ export const piBackend: AgentHarness = {
         const { setupPostHogMcp } = await import('./mcp');
         const mcp = await setupPostHogMcp({
           agentDir: getAgentDir(),
-          mcpUrl: boot.mcpUrl,
-          accessToken: boot.accessToken,
+          mcpUrl: boot.credentials.host.mcpUrl,
+          accessToken: boot.credentials.accessToken,
           userAgent: WIZARD_USER_AGENT,
         });
         extensionFactories.push(mcp.extensionFactory);

src/lib/agent/runner/sequence/linear.ts

@@ -10,7 +10,6 @@ import { OutroKind } from '../../../wizard-session';
 import { getUI } from '../../../../ui';
 import { AgentErrorType, AgentSignals } from '../../agent-interface';
 import { restoreClaudeSettings } from '../../claude-settings';
-import { HostResolution } from '@lib/host-resolution';
 import { logToFile } from '../../../../utils/debug';
 import { createBenchmarkPipeline } from '../../../middleware/benchmark';
 import {
@@ -40,16 +39,8 @@ export async function runLinearProgram(
   boot: BootstrapResult,
   composed = false,
 ): Promise<void> {
-  const {
-    skillsBaseUrl,
-    projectApiKey,
-    host,
-    accessToken,
-    projectId,
-    cloudRegion,
-    wizardFlags,
-    project,
-  } = boot;
+  const { skillsBaseUrl, credentials, wizardFlags, project } = boot;
+  const { projectApiKey, host, projectId } = credentials;
 
   // 5. Skill install (if skillId provided)
   let skillPath: string | undefined;
@@ -270,12 +261,7 @@ export async function runLinearProgram(
 
   // 10. Post-run hooks
   if (config.postRun) {
-    await config.postRun(session, {
-      accessToken,
-      projectApiKey,
-      host,
-      projectId,
-    });
+    await config.postRun(session, credentials);
   }
 
   // A composed sub-run (integration inside self-driving) skips the terminal
@@ -291,23 +277,14 @@ export async function runLinearProgram(
   // that the screen never reads. UI.setOutroData() goes through the store
   // and also merges in any post-snapshot URLs from the live session.
   const outroData = config.buildOutroData
-    ? config.buildOutroData(
-        session,
-        { accessToken, projectApiKey, host, projectId },
-        cloudRegion,
-      )
+    ? config.buildOutroData(session, credentials)
     : {
         kind: OutroKind.Success,
         message: config.successMessage,
         reportFile: config.reportFile,
         docsUrl: config.docsUrl,
-        // TODO: clean up in #755
         continueUrl: session.signup
-          ? `${
-              HostResolution.fromRegion(cloudRegion, {
-                baseUrl: session.baseUrl,
-              }).appHost
-            }/products?source=wizard`
+          ? `${host.appHost}/products?source=wizard`
           : undefined,
       };
   if (outroData) {