diff --git a/.github/workflows/external-integration.yml b/.github/workflows/external-integration.yml
index f81be6e4f4..4d2571a206 100644
--- a/.github/workflows/external-integration.yml
+++ b/.github/workflows/external-integration.yml
@@ -42,7 +42,7 @@ jobs:
           echo "Created tgz packages:"
           ls -la ./tgz-packages/
 
-          cd packages/integration-tester
+          cd core/packages/tsp-integration
           npm link
 
       - name: Checkout
diff --git a/packages/integration-tester/config/integration-test-config.yaml b/.typespec-integration/config.yaml
similarity index 87%
rename from packages/integration-tester/config/integration-test-config.yaml
rename to .typespec-integration/config.yaml
index 90b51cec92..3749a462e3 100644
--- a/packages/integration-tester/config/integration-test-config.yaml
+++ b/.typespec-integration/config.yaml
@@ -5,7 +5,7 @@ suites:
     pattern: "specification/**/tspconfig.yaml"
     entrypoints:
       - name: "client.tsp"
-        options: ["--dry-run"]
+        options: ["--no-emit"]
       - name: "main.tsp"
   azure-specs-pr:
     repo: https://github.com/Azure/azure-rest-api-specs-pr
@@ -13,5 +13,5 @@ suites:
     pattern: "specification/**/tspconfig.yaml"
     entrypoints:
       - name: "client.tsp"
-        options: ["--dry-run"]
+        options: ["--no-emit"]
       - name: "main.tsp"
diff --git a/core b/core
index 4d31f6e11a..e00bbe26b6 160000
--- a/core
+++ b/core
@@ -1 +1 @@
-Subproject commit 4d31f6e11a0320676d7e654d338ca5e5a9cd4103
+Subproject commit e00bbe26b64afb94ece8f056943f007d90da3e2a
diff --git a/packages/integration-tester/cmd/tsp-integration.js b/packages/integration-tester/cmd/tsp-integration.js
deleted file mode 100755
index 8fb1272183..0000000000
--- a/packages/integration-tester/cmd/tsp-integration.js
+++ /dev/null
@@ -1,2 +0,0 @@
-#!/usr/bin/env node
-import "../dist/cli.js";
diff --git a/packages/integration-tester/package.json b/packages/integration-tester/package.json
deleted file mode 100644
index ca9948d0c3..0000000000
--- a/packages/integration-tester/package.json
+++ /dev/null
@@ -1,44 +0,0 @@
-{
-  "name": "@azure-tools/integration-tester",
-  "private": true,
-  "version": "0.1.0",
-  "type": "module",
-  "description": "CLI tool for testing typespec package changes against external repos",
-  "homepage": "https://github.com/microsoft/typespec",
-  "license": "MIT",
-  "author": "Microsoft",
-  "files": [
-    "dist"
-  ],
-  "bin": {
-    "tsp-integration": "./cmd/tsp-integration.js"
-  },
-  "repository": "https://github.com/microsoft/typespec.git",
-  "engines": {
-    "node": ">=20.0.0"
-  },
-  "scripts": {
-    "watch": "tsc -p ./tsconfig.build.json --watch",
-    "build": "tsc -p ./tsconfig.build.json",
-    "clean": "rimraf dist/ temp/",
-    "test": "vitest run",
-    "test:watch": "vitest -w"
-  },
-  "dependencies": {
-    "@pnpm/workspace.find-packages": "^1000.0.24",
-    "execa": "^9.6.1",
-    "globby": "~16.1.0",
-    "log-symbols": "^7.0.1",
-    "ora": "^9.0.0",
-    "pathe": "^2.0.3",
-    "picocolors": "~1.1.1",
-    "simple-git": "^3.28.0",
-    "tar": "^7.5.2",
-    "yaml": "~2.8.2"
-  },
-  "devDependencies": {
-    "typescript": "~5.9.2",
-    "vitest": "^4.0.15"
-  },
-  "bugs": "https://github.com/microsoft/typespec/issues"
-}
diff --git a/packages/integration-tester/src/cli.ts b/packages/integration-tester/src/cli.ts
deleted file mode 100644
index 7c33b408f0..0000000000
--- a/packages/integration-tester/src/cli.ts
+++ /dev/null
@@ -1,72 +0,0 @@
-import { readFile } from "node:fs/promises";
-import { parseArgs } from "node:util";
-import { join, resolve } from "pathe";
-import { parse } from "yaml";
-import { runIntegrationTestSuite, Stages, type Stage } from "./run.js";
-import { projectRoot, ValidationFailedError } from "./utils.js";
-
-process.on("SIGINT", () => process.exit(0));
-
-const args = parseArgs({
-  args: process.argv.slice(2),
-  allowPositionals: true,
-  options: {
-    clean: {
-      type: "boolean",
-      default: false,
-    },
-    stage: {
-      type: "string",
-      multiple: true,
-    },
-    "tgz-dir": {
-      type: "string",
-    },
-    repo: {
-      type: "string",
-      description: "The path to the repository to test. Defaults temp/{suiteName}.",
-    },
-    interactive: {
-      type: "boolean",
-      default: false,
-      short: "i",
-      description: "Enable interactive mode for validation.",
-    },
-  },
-});
-
-const suiteName = args.positionals[0];
-const config = parse(
-  await readFile(join(projectRoot, "config/integration-test-config.yaml"), "utf8"),
-);
-const suite = config.suites[suiteName];
-if (suite === undefined) {
-  throw new Error(`Integration test suite "${suiteName}" not found in config.`);
-}
-
-let stages: Stage[] | undefined = undefined;
-if (args.values.stage) {
-  stages = args.values.stage as Stage[];
-  for (const stage of stages) {
-    if (!Stages.includes(stage)) {
-      throw new Error(
-        `Invalid stage "${stage}" specified. Valid stages are: ${Stages.join(", ")}.`,
-      );
-    }
-  }
-}
-
-const wd = args.values.repo ?? join(projectRoot, "temp", suiteName);
-try {
-  await runIntegrationTestSuite(wd, suiteName, suite, {
-    clean: args.values.clean,
-    stages,
-    tgzDir: args.values["tgz-dir"] && resolve(process.cwd(), args.values["tgz-dir"]),
-    interactive: args.values.interactive,
-  });
-} catch (error) {
-  if (error instanceof ValidationFailedError) {
-    process.exit(1);
-  }
-  throw error;
-}
diff --git a/packages/integration-tester/src/config/types.ts b/packages/integration-tester/src/config/types.ts
deleted file mode 100644
index bf56d8fedc..0000000000
--- a/packages/integration-tester/src/config/types.ts
+++ /dev/null
@@ -1,15 +0,0 @@
-export interface IntegrationTestsConfig {
-  suites: Record<string, IntegrationTestSuite>;
-}
-
-export interface IntegrationTestSuite {
-  repo: string;
-  branch: string;
-  pattern?: string;
-  entrypoints?: Entrypoint[];
-}
-
-export interface Entrypoint {
-  name: string;
-  options?: string[];
-}
diff --git a/packages/integration-tester/src/find-packages.ts b/packages/integration-tester/src/find-packages.ts
deleted file mode 100644
index e51a2369c0..0000000000
--- a/packages/integration-tester/src/find-packages.ts
+++ /dev/null
@@ -1,157 +0,0 @@
-import { findWorkspacePackagesNoCheck } from "@pnpm/workspace.find-packages";
-import { readdir } from "node:fs/promises";
-import { relative, resolve } from "pathe";
-import pc from "picocolors";
-import * as tar from "tar";
-import { log } from "./utils.js";
-
-/**
- * Collection of packages indexed by package name.
- */
-export interface Packages {
-  [key: string]: {
-    /** The package name (e.g., "@typespec/compiler") */
-    name: string;
-    /** Absolute path to the package directory or .tgz file */
-    path: string;
-  };
-}
-
-/**
- * Options for {@link findPackages}
- */
-export interface FindPackageOptions {
-  /** Directory containing PNPM workspace to scan for packages */
-  wsDir?: string;
-  /** Directory containing .tgz artifact files */
-  tgzDir?: string;
-}
-
-/**
- * Finds packages from either a workspace directory or tgz artifact directory.
- *
- * @param options - Configuration specifying the source to find packages from
- * @returns Promise resolving to a collection of discovered packages
- * @throws Error if neither wsDir nor tgzDir is provided
- */
-export function findPackages(options: FindPackageOptions): Promise<Packages> {
-  if (options.tgzDir) {
-    return findPackagesFromTgzArtifactDir(options.tgzDir);
-  }
-  if (options.wsDir) {
-    return findPackagesFromWorkspace(options.wsDir);
-  } else {
-    throw new Error("Either wsDir or tgzDir must be provided to findPackages");
-  }
-}
-
-/**
- * Prints a formatted list of discovered packages to the console.
- *
- * @param packages - Collection of packages to display
- */
-export function printPackages(packages: Packages): void {
-  log("Found packages:");
-  for (const [name, pkg] of Object.entries(packages)) {
-    log(`  ${pc.green(name)}: ${pc.cyan(relative(process.cwd(), pkg.path))}`);
-  }
-}
-
-/**
- * Discovers packages from a directory containing .tgz artifact files.
- *
- * This function scans a directory for .tgz files and extracts package information
- * by reading the package.json from within each tar file.
- *
- * @param tgzDir - Directory containing .tgz artifact files
- * @returns Promise resolving to discovered packages with paths pointing to .tgz files
- */
-export async function findPackagesFromTgzArtifactDir(tgzDir: string): Promise<Packages> {
-  const packages: Packages = {};
-
-  const items = await readdir(tgzDir, { withFileTypes: true });
-  const tgzFiles = items
-    .filter((item) => item.isFile() && item.name.endsWith(".tgz"))
-    .map((item) => item.name);
-
-  // Process tar files in parallel
-  await Promise.all(
-    tgzFiles.map(async (tgzFile) => {
-      const fullPath = resolve(tgzDir, tgzFile);
-      const packageName = await extractPackageNameFromTgzFile(fullPath);
-
-      if (packageName) {
-        packages[packageName] = {
-          name: packageName,
-          path: fullPath,
-        };
-      }
-    }),
-  );
-
-  return packages;
-}
-
-/**
- * Extracts the package name by reading package.json from a .tgz file.
- *
- * This function reads the package.json file from the root of the tar archive
- * to get the accurate package name, which is more reliable than parsing filenames.
- *
- * @param tgzFilePath - Path to the .tgz file
- * @returns Promise resolving to the package name, or null if not found
- */
-async function extractPackageNameFromTgzFile(tgzFilePath: string): Promise<string | null> {
-  try {
-    let packageJsonContent: string | null = null;
-
-    await tar.t({
-      file: tgzFilePath,
-      // cspell:ignore onentry
-      onentry: (entry) => {
-        if (entry.path === "package/package.json") {
-          entry.on("data", (chunk) => {
-            if (packageJsonContent === null) {
-              packageJsonContent = "";
-            }
-            packageJsonContent += chunk.toString();
-          });
-        }
-      },
-    });
-
-    if (packageJsonContent) {
-      const packageJson = JSON.parse(packageJsonContent);
-      return packageJson.name || null;
-    }
-
-    return null;
-  } catch (error) {
-    throw new Error(`Failed to read package.json from ${tgzFilePath}: ${error}`);
-  }
-}
-
-/**
- * Discovers packages from a PNPM workspace configuration.
- *
- * This function uses PNPM's workspace discovery to find all packages in a monorepo.
- * It filters out private packages and packages without names.
- *
- * @param root - Root directory of the PNPM workspace
- * @returns Promise resolving to discovered packages with paths pointing to package directories
- */
-export async function findPackagesFromWorkspace(root: string): Promise<Packages> {
-  const pnpmPackages = await findWorkspacePackagesNoCheck(root);
-  const packages: Packages = {};
-
-  for (const pkg of pnpmPackages) {
-    if (!pkg.manifest.name || pkg.manifest.private) continue;
-
-    packages[pkg.manifest.name] = {
-      name: pkg.manifest.name,
-      path: pkg.rootDirRealPath,
-    };
-  }
-
-  return packages;
-}
diff --git a/packages/integration-tester/src/git.ts b/packages/integration-tester/src/git.ts
deleted file mode 100644
index 7da4d45d32..0000000000
--- a/packages/integration-tester/src/git.ts
+++ /dev/null
@@ -1,123 +0,0 @@
-import { execa } from "execa";
-import { mkdir, rm } from "fs/promises";
-import type { Ora } from "ora";
-import { relative } from "pathe";
-import pc from "picocolors";
-import { ResetMode, simpleGit } from "simple-git";
-import type { IntegrationTestSuite } from "./config/types.js";
-import { action, log, ValidationFailedError } from "./utils.js";
-/**
- * Options for ensuring repository state.
- */
-export interface EnsureRepoStateOptions {
-  /** If true, forces a clean clone instead of updating existing repository */
-  clean?: boolean;
-}
-/**
- * Ensures the repository is in the correct state by either cloning or updating it.
- *
- * @param suite - Integration test suite configuration containing repo and branch info
- * @param dir - Target directory for the repository
- * @param options - Options controlling the operation behavior
- */
-export async function ensureRepoState(
-  { repo, branch }: IntegrationTestSuite,
-  dir: string,
-  options: EnsureRepoStateOptions = {},
-): Promise<void> {
-  await action(`Checkout repo ${pc.cyan(repo)} at branch ${pc.cyan(branch)}`, async (spinner) => {
-    const shouldUpdate = options.clean ? false : await repoExists(dir);
-    if (shouldUpdate) {
-      await updateExistingRepo(spinner, { branch }, dir);
-    } else {
-      await cloneRepo(spinner, repo, branch, dir);
-    }
-  });
-}
-
-/**
- * Checks if a Git repository exists in the specified directory.
- *
- * @param dir - Directory to check for Git repository
- * @returns true if a Git repository exists, false otherwise
- */
-async function repoExists(dir: string): Promise<boolean> {
-  try {
-    await execa("git", ["-C", dir, "rev-parse", "--git-dir"]);
-    return true;
-  } catch {
-    return false;
-  }
-}
-
-/**
- * Clones a Git repository from the specified URL to the target directory.
- * Performs a shallow clone with depth 1 to minimize download time and disk usage.
- *
- * @param spinner - Ora spinner for progress indication
- * @param repo - Repository URL to clone from
- * @param branch - Branch to clone
- * @param dir - Target directory for the cloned repository
- */
-async function cloneRepo(spinner: Ora, repo: string, branch: string, dir: string): Promise<void> {
-  const relativeDir = relative(process.cwd(), dir);
-
-  spinner.text = `Cleaning directory ${pc.cyan(relativeDir)}`;
-  await rm(dir, { recursive: true, force: true });
-  await mkdir(dir, { recursive: true });
-
-  spinner.text = `Cloning repo ${pc.cyan(repo)} at branch ${pc.cyan(branch)} into ${pc.cyan(relativeDir)}`;
-  await simpleGit().clone(repo, dir, { "--branch": branch, "--depth": 1 });
-}
-
-/**
- * Updates an existing Git repository to the latest state of the specified branch.
- * Performs a complete reset of local changes and pulls the latest commits.
- *
- * @param spinner - Ora spinner for progress indication
- * @param suite - Object containing the branch to checkout
- * @param dir - Directory containing the Git repository to update
- */
-export async function updateExistingRepo(
-  spinner: Ora,
-  { branch }: Pick<IntegrationTestSuite, "branch">,
-  dir: string,
-): Promise<void> {
-  const git = simpleGit(dir);
-  const baseText = spinner.text;
-
-  spinner.text = `${baseText} - Resetting local changes`;
-  await git.reset(ResetMode.HARD, ["HEAD"]);
-  await git.clean("fd");
-
-  spinner.text = `${baseText} - Fetching latest changes`;
-  await git.fetch("origin");
-
-  spinner.text = `${baseText} - Checking out branch ${pc.cyan(branch)}`;
-  await git.checkout(branch);
-
-  spinner.text = `${baseText} - Pulling latest changes`;
-  await git.pull("origin", branch);
-}
-
-/**
- * Validates that the Git repository has no uncommitted changes.
- * Logs the status and diff if changes are detected.
- *
- * @param dir - Directory containing the Git repository to validate
- */
-export async function validateGitClean(dir: string): Promise<void> {
-  const git = simpleGit(dir);
-  const result = await git.status();
-
-  if (result.isClean()) {
-    log(`${pc.green("✔")} No git changes detected`);
-  } else {
-    log(`${pc.red("x")} Git changes detected after validation:`);
-    log(result);
-
-    const diffResult = await execa("git", ["diff", "--color=always"], { cwd: dir });
-    log(diffResult.stdout);
-    throw new ValidationFailedError();
-  }
-}
diff --git a/packages/integration-tester/src/keyboard-api.test.ts b/packages/integration-tester/src/keyboard-api.test.ts
deleted file mode 100644
index ae7fef17cd..0000000000
--- a/packages/integration-tester/src/keyboard-api.test.ts
+++ /dev/null
@@ -1,68 +0,0 @@
-import { Readable, Writable } from "stream";
-import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
-import { registerConsoleShortcuts } from "./keyboard-api.js";
-import type { TspRunner } from "./validate.js";
-
-let runner: TspRunner;
-let stdin: NodeJS.ReadStream;
-let stdout: Writable;
-let cleanup: () => void;
-
-beforeEach(() => {
-  runner = {
-    rerunAll: vi.fn(),
-    rerunFailed: vi.fn(),
-    cancelCurrentRun: vi.fn(),
-    exit: vi.fn(),
-    isCancelling: false,
-  } as any;
-  stdout = new Writable({
-    write(chunk, __, callback) {
-      callback();
-    },
-  });
-
-  stdin = new Readable({ read: () => "" }) as NodeJS.ReadStream;
-  stdin.isTTY = true;
-  stdin.setRawMode = () => stdin;
-  cleanup = registerConsoleShortcuts(runner, stdin, stdout);
-});
-
-afterEach(() => {
-  cleanup?.();
-});
-
-describe("when no test is running", () => {
-  it("calls exit when q is pressed", () => {
-    stdin.emit("data", "q");
-    expect(runner.exit).toHaveBeenCalled();
-  });
-
-  it("calls rerunAll when a is pressed", () => {
-    stdin.emit("data", "a");
-    expect(runner.rerunAll).toHaveBeenCalled();
-  });
-
-  it("calls rerunFailed when f is pressed", () => {
-    stdin.emit("data", "f");
-    expect(runner.rerunFailed).toHaveBeenCalled();
-  });
-});
-
-describe("when tests are running", () => {
-  beforeEach(() => {
-    runner.runningPromise = Promise.resolve() as any;
-  });
-  describe("calls cancelCurrentRun when cancel keys are pressed", () => {
-    it.each(["q", "c", "a", "f", "space", "\x03"])(`%s`, (key) => {
-      stdin.emit("data", key);
-      expect(runner.cancelCurrentRun).toHaveBeenCalled();
-    });
-  });
-
-  it("does NOT call cancelCurrentRun when other keys are pressed", () => {
-    stdin.emit("data", "b");
-    stdin.emit("data", "d");
-    expect(runner.cancelCurrentRun).not.toHaveBeenCalled();
-  });
-});
diff --git a/packages/integration-tester/src/keyboard-api.ts b/packages/integration-tester/src/keyboard-api.ts
deleted file mode 100644
index cc5ae4103b..0000000000
--- a/packages/integration-tester/src/keyboard-api.ts
+++ /dev/null
@@ -1,80 +0,0 @@
-import pc from "picocolors";
-import readline from "readline";
-import type { Writable } from "stream";
-import type { TspRunner } from "./validate.js";
-
-const keys = [
-  [["a", "return"], "rerun all tests"],
-  ["f", "rerun only failed tests"],
-  ["q", "quit"],
-];
-const cancelKeys = ["space", "c", ...keys.map((key) => key[0]).flat()];
-
-export function registerConsoleShortcuts(
-  ctx: TspRunner,
-  stdin: NodeJS.ReadStream | undefined = process.stdin,
-  stdout: NodeJS.WriteStream | Writable = process.stdout,
-): () => void {
-  let rl: readline.Interface | undefined;
-
-  async function keypressHandler(str: string, key: readline.Key) {
-    // Cancel run and exit when ctrl-c or esc is pressed.
-    // If cancelling takes long and key is pressed multiple times, exit forcefully.
-    if (str === "\x03" || str === "\x1B" || (key && key.ctrl && key.name === "c")) {
-      if (!ctx.isCancelling) {
-        stdout.write(pc.red("Cancelling test run. Press CTRL+c again to exit forcefully.\n"));
-        process.exitCode = 130;
-
-        await ctx.cancelCurrentRun();
-      }
-      return ctx.exit();
-    }
-
-    const name = key?.name;
-
-    if (ctx.runningPromise) {
-      if (name && cancelKeys.includes(name)) {
-        stdout.write(pc.yellow("Cancelling current test run...\n"));
-        await ctx.cancelCurrentRun();
-      }
-      return;
-    }
-
-    // quit
-    if (name === "q") {
-      return ctx.exit();
-    }
-    // rerun all tests
-    if (name === "a" || name === "return") {
-      return ctx.rerunAll();
-    }
-    // rerun only failed tests
-    if (name === "f") {
-      return ctx.rerunFailed();
-    }
-  }
-
-  function on() {
-    off();
-    rl = readline.createInterface({ input: stdin, escapeCodeTimeout: 50 });
-    readline.emitKeypressEvents(stdin, rl);
-    if (stdin.isTTY) {
-      stdin.setRawMode(true);
-    }
-    stdin.on("keypress", keypressHandler);
-  }
-
-  function off() {
-    rl?.close();
-    rl = undefined;
-    stdin.removeListener("keypress", keypressHandler);
-    if (stdin.isTTY) {
-      stdin.setRawMode(false);
-    }
-  }
-
-  on();
-  return function cleanup(): void {
-    off();
-  };
-}
diff --git a/packages/integration-tester/src/patch-package-json.ts b/packages/integration-tester/src/patch-package-json.ts
deleted file mode 100644
index 74b8f47619..0000000000
--- a/packages/integration-tester/src/patch-package-json.ts
+++ /dev/null
@@ -1,50 +0,0 @@
-import { readFileSync } from "fs";
-import { writeFile } from "fs/promises";
-import { join } from "path";
-import { relative } from "pathe";
-import pc from "picocolors";
-import type { Packages } from "./find-packages.js";
-import { log } from "./utils.js";
-
-interface PackageJson {
-  name?: string;
-  version?: string;
-  dependencies?: Record<string, string>;
-  devDependencies?: Record<string, string>;
-  peerDependencies?: Record<string, string>;
-  overrides?: Record<string, string>;
-  [key: string]: any;
-}
-
-export async function patchPackageJson(dir: string, packages: Packages) {
-  const packageJsonPath = join(dir, "package.json");
-
-  // Read existing package.json
-  const packageJson: PackageJson = JSON.parse(readFileSync(packageJsonPath, "utf8"));
-
-  // Ensure dependency objects exist
-  packageJson.dependencies = packageJson.dependencies ?? {};
-  packageJson.devDependencies = packageJson.devDependencies ?? {};
-  packageJson.peerDependencies = packageJson.peerDependencies ?? {};
-  packageJson.overrides = packageJson.overrides ?? {};
-
-  // Update dependencies to point to tgz files
-  for (const pkg of Object.values(packages)) {
-    const packageName = pkg.name;
-    const relativePath = relative(dir, pkg.path);
-    const filePath = `file:${relativePath}`;
-
-    for (const depType of ["dependencies", "devDependencies", "peerDependencies"]) {
-      if (packageJson[depType]?.[packageName]) {
-        packageJson[depType][packageName] = filePath;
-        log(`Updated ${pc.magenta(depType)}: ${pc.green(packageName)} -> ${pc.cyan(filePath)}`);
-      }
-    }
-
-    // Also set in overrides to ensure all nested dependencies use our version
-    packageJson.overrides[packageName] = filePath;
-  }
-
-  // Write updated package.json
-  await writeFile(packageJsonPath, JSON.stringify(packageJson, null, 2));
-}
diff --git a/packages/integration-tester/src/run.ts b/packages/integration-tester/src/run.ts
deleted file mode 100644
index cc6174983d..0000000000
--- a/packages/integration-tester/src/run.ts
+++ /dev/null
@@ -1,75 +0,0 @@
-import pc from "picocolors";
-import type { IntegrationTestSuite } from "./config/types.js";
-import { findPackages, printPackages } from "./find-packages.js";
-import { ensureRepoState, validateGitClean } from "./git.js";
-import { patchPackageJson } from "./patch-package-json.js";
-import { TaskRunner } from "./runner.js";
-import { action, execWithSpinner, log, repoRoot } from "./utils.js";
-import { validateSpecs } from "./validate.js";
-
-export interface RunIntegrationTestSuiteOptions {
-  /** Only run specific stages. */
-  stages?: Stage[];
-  /** Clean the temp directory. By default tries to reuse the repo by reseting and pulling latest changes. */
-  clean?: boolean;
-  /** Directory for .tgz files. If not provided it will get the packages from the repo. */
-  tgzDir?: string;
-  /** Enable interactive mode for validation. */
-  interactive?: boolean;
-}
-
-export const Stages = ["checkout", "patch", "install", "validate", "validate:clean"] as const;
-export type Stage = (typeof Stages)[number];
-
-export async function runIntegrationTestSuite(
-  wd: string,
-  suiteName: string,
-  config: IntegrationTestSuite,
-  options: RunIntegrationTestSuiteOptions = {},
-): Promise<void> {
-  const runner = new TaskRunner<Stage>({ verbose: options.clean, stages: options.stages });
-  log(
-    `Running ${options.stages ? options.stages.map(pc.yellow).join(", ") : "all"} stage${options.stages?.length !== 1 ? "s" : ""}`,
-    pc.cyan(suiteName),
-    config,
-  );
-
-  await runner.stage("checkout", async () => {
-    await ensureRepoState(config, wd, {
-      clean: options.clean,
-    });
-  });
-
-  await runner.stage("patch", async () => {
-    const packages = await action("Resolving local package versions", async () => {
-      const packages = await findPackages(
-        options.tgzDir ? { tgzDir: options.tgzDir } : { wsDir: repoRoot },
-      );
-      printPackages(packages);
-      return packages;
-    });
-
-    await action("Patching package.json", async () => {
-      await patchPackageJson(wd, packages);
-    });
-  });
-
-  await runner.stage("install", async () => {
-    await action("Installing dependencies", async (spinner) => {
-      await execWithSpinner(spinner, "npm", ["install", "--no-package-lock"], {
-        cwd: wd,
-      });
-      await execWithSpinner(spinner, "git", ["checkout", "--", "package.json"], {
-        cwd: wd,
-      });
-    });
-  });
-
-  await runner.stage("validate", async () => {
-    await validateSpecs(runner, wd, config, { interactive: options.interactive });
-  });
-
-  await runner.stage("validate:clean", async () => {
-    await validateGitClean(wd);
-  });
-}
diff --git a/packages/integration-tester/src/runner.ts b/packages/integration-tester/src/runner.ts
deleted file mode 100644
index 7d3111e0d8..0000000000
--- a/packages/integration-tester/src/runner.ts
+++ /dev/null
@@ -1,47 +0,0 @@
-/* eslint-disable no-console */
-import pc from "picocolors";
-
-export interface TaskRunnerOptions<Stages extends string> {
-  readonly verbose?: boolean;
-  readonly stages?: Stages[];
-}
-
-export class TaskRunner<Stages extends string = string> {
-  #verbose: boolean;
-  #stages: Stages[] | undefined;
-
-  constructor(options: TaskRunnerOptions<Stages> = {}) {
-    this.#stages = options.stages;
-    this.#verbose = options.verbose === undefined ? Boolean(process.env.CI) : options.verbose;
-  }
-
-  async stage(name: Stages, fn: () => Promise<unknown>): Promise<void> {
-    if (this.#stages && !this.#stages.includes(name)) {
-      return;
-    }
-    await fn();
-  }
-
-  reportTaskWithDetails(status: "pass" | "fail" | "skip", name: string, details: string) {
-    const statusStr =
-      status === "pass" ? pc.green("pass") : status === "fail" ? pc.red("fail") : pc.gray("skip");
-    const message = `${statusStr} ${name}`;
-    if (this.#verbose || status === "fail") {
-      this.group(message, details);
-    } else {
-      console.log(message);
-    }
-  }
-
-  group(name: string, content: string) {
-    if (process.env.GITHUB_ACTIONS) {
-      console.log(`::group::${name}`);
-      console.log(content);
-      console.log("::endgroup::");
-    } else {
-      console.group(name);
-      console.log(content);
-      console.groupEnd();
-    }
-  }
-}
diff --git a/packages/integration-tester/src/utils.ts b/packages/integration-tester/src/utils.ts
deleted file mode 100644
index 46ba385d55..0000000000
--- a/packages/integration-tester/src/utils.ts
+++ /dev/null
@@ -1,168 +0,0 @@
-/* eslint-disable no-console */
-import { spawn, type SpawnOptions } from "child_process";
-import logSymbols from "log-symbols";
-import ora, { type Ora } from "ora";
-import { resolve } from "pathe";
-import pc from "picocolors";
-
-export class ValidationFailedError extends Error {}
-
-export const projectRoot = resolve(import.meta.dirname, "..");
-export const repoRoot = resolve(projectRoot, "../..");
-
-export async function execWithSpinner(
-  spinner: Ora,
-  command: string,
-  args: string[],
-  options: SpawnOptions = {},
-): Promise<void> {
-  return new Promise((resolve, reject) => {
-    const subprocess = spawn(command, args, {
-      stdio: "pipe",
-      ...options,
-    });
-
-    // Handle stdout
-    subprocess.stdout!.on("data", (data) => {
-      spinner.clear();
-      console.log(data.toString());
-      spinner.render();
-    });
-
-    // Handle stderr
-    subprocess.stderr!.on("data", (data) => {
-      spinner.clear();
-      // Ora seems to swallow the stderr output?
-      console.error(data.toString());
-      spinner.render();
-    });
-
-    subprocess.on("close", (code) => {
-      if (code !== 0) {
-        reject(new Error(`Command failed with exit code ${code}`));
-      } else {
-        resolve();
-      }
-    });
-  });
-}
-
-export async function action<T>(message: string, fn: (spinner: Ora) => Promise<T>): Promise<T> {
-  if (process.stderr.isTTY) {
-    return dynamicAction(message, fn);
-  } else {
-    return staticAction(message, fn);
-  }
-}
-
-export async function dynamicAction<T>(
-  message: string,
-  fn: (spinner: Ora) => Promise<T>,
-): Promise<T> {
-  const oldLog = console.log;
-
-  console.log = (...args: any[]) => {
-    spinner.clear();
-    oldLog(...args);
-    spinner.render();
-  };
-  const spinner = ora(message).start();
-  try {
-    const result = await fn(spinner);
-    spinner.succeed(message);
-    return result;
-  } catch (error) {
-    spinner.fail(message);
-    throw error;
-  } finally {
-    console.log = oldLog;
-  }
-}
-
-export async function staticAction<T>(
-  message: string,
-  fn: (spinner: Ora) => Promise<T>,
-): Promise<T> {
-  const spinner = ora(message).start();
-  console.log(`- ${message}`);
-  try {
-    const result = await fn(spinner);
-    console.log(`${pc.red(logSymbols.success)} ${message}`);
-
-    return result;
-  } catch (error) {
-    console.log(`${pc.red(logSymbols.error)} ${message}`);
-    throw error;
-  }
-}
-
-export function log(...args: any[]) {
-  console.log(...args);
-}
-
-/** Run tasks with limited concurrency */
-export async function runWithConcurrency<T, R>(
-  items: T[],
-  concurrency: number,
-  processor: (item: T) => Promise<R>,
-): Promise<R[]> {
-  if (items.length === 0) {
-    return [];
-  }
-
-  const toRun = [...items];
-  const results: R[] = [];
-  let completed = 0;
-  let running = 0;
-
-  return new Promise((resolve, reject) => {
-    function runNext() {
-      if (toRun.length === 0 || running >= concurrency) {
-        return;
-      }
-
-      const item = toRun.shift();
-      if (!item) {
-        return;
-      }
-
-      running++;
-      processor(item)
-        .then((result) => {
-          results.push(result);
-          completed++;
-          running--;
-
-          if (completed === items.length) {
-            resolve(results);
-            return;
-          }
-
-          runNext();
-        })
-        .catch((error) => {
-          reject(error);
-        });
-    }
-
-    // Start initial batch of tasks up to concurrency limit
-    for (let i = 0; i < Math.min(concurrency, toRun.length); i++) {
-      runNext();
-    }
-  });
-}
-
-export async function waitForUserInput(): Promise<string> {
-  const readline = await import("readline");
-  const rl = readline.createInterface({
-    input: process.stdin,
-    output: process.stdout,
-  });
-
-  return new Promise((resolve) => {
-    rl.question("", (answer) => {
-      rl.close();
-      resolve(answer.trim());
-    });
-  });
-}
diff --git a/packages/integration-tester/src/validate.ts b/packages/integration-tester/src/validate.ts
deleted file mode 100644
index e83b5a5485..0000000000
--- a/packages/integration-tester/src/validate.ts
+++ /dev/null
@@ -1,276 +0,0 @@
-import { execa } from "execa";
-import { readdir } from "fs/promises";
-import { globby } from "globby";
-import { cpus } from "os";
-import { dirname, join, relative } from "pathe";
-import pc from "picocolors";
-import type { Entrypoint, IntegrationTestSuite } from "./config/types.js";
-import { registerConsoleShortcuts } from "./keyboard-api.js";
-import type { TaskRunner } from "./runner.js";
-import { log, runWithConcurrency, ValidationFailedError } from "./utils.js";
-
-// Number of parallel TypeSpec compilations to run
-const COMPILATION_CONCURRENCY = cpus().length;
-
-export interface ValidateSpecsOptions {
-  interactive?: boolean;
-}
-
-export async function validateSpecs(
-  runner: TaskRunner,
-  dir: string,
-  suite: IntegrationTestSuite,
-  options: ValidateSpecsOptions = {},
-): Promise<void> {
-  const tspConfigDirs = await findTspProjects(dir, suite.pattern ?? "**/tspconfig.yaml");
-
-  if (tspConfigDirs.length === 0) {
-    log("No tspconfig.yaml files found in specification directory");
-    return;
-  }
-
-  runner.group(
-    `Found ${pc.yellow(tspConfigDirs.length)} TypeSpec projects`,
-    tspConfigDirs.map((projectDir) => pc.bold(relative(dir, projectDir))).join("\n"),
-  );
-
-  const tspRunner = new TspRunner(runner, dir, suite, tspConfigDirs, options);
-  await tspRunner.run();
-}
-
-/** Run  */
-export class TspRunner {
-  /** If the runner is currently cancelling */
-  isCancelling = false;
-  runningPromise: Promise<BatchRunResult> | null = null;
-
-  /** Workspace directory */
-  dir: string;
-
-  /** Test suit used for this runner */
-  suite: IntegrationTestSuite;
-
-  /** Last set of failing projects */
-  #failedProjects: string[] = [];
-
-  #runner: TaskRunner;
-  #projectDirs: string[];
-  #options: ValidateSpecsOptions;
-
-  constructor(
-    runner: TaskRunner,
-    dir: string,
-    suite: IntegrationTestSuite,
-    tspConfigDirs: string[],
-    options: ValidateSpecsOptions = {},
-  ) {
-    this.#runner = runner;
-    this.dir = dir;
-    this.suite = suite;
-    this.#options = options;
-    this.#projectDirs = tspConfigDirs;
-  }
-
-  async run(): Promise<void> {
-    if (!this.#options.interactive) {
-      const result = await this.#exec(this.#projectDirs);
-      if (result.failureCount > 0) {
-        throw new ValidationFailedError();
-      }
-      return;
-    }
-    registerConsoleShortcuts(this);
-    await this.rerunAll();
-  }
-
-  async #exec(projectsToRun: string[]): Promise<BatchRunResult> {
-    this.runningPromise = this.#execWorker(projectsToRun);
-    return await this.runningPromise;
-  }
-  async #execWorker(projectsToRun: string[]): Promise<BatchRunResult> {
-    this.isCancelling = false;
-    const result = await runValidation(this.#runner, this, projectsToRun);
-    if (this.#options.interactive) {
-      log(
-        `\nPress ${pc.yellow("a")} to rerun all tests, ${pc.yellow("f")} to rerun failed tests, or ${pc.yellow("q")} to quit.`,
-      );
-    }
-    this.#failedProjects = result.failedProjects;
-    this.runningPromise = null;
-    return result;
-  }
-
-  async cancelCurrentRun(): Promise<void> {
-    if (this.runningPromise) {
-      this.isCancelling = true;
-      await this.runningPromise;
-      this.isCancelling = false;
-    }
-  }
-
-  async rerunFailed(): Promise<void> {
-    process.stdin.write("\x1Bc"); // Clear console
-    if (this.#failedProjects.length === 0) {
-      log(pc.green("No failed projects to rerun."));
-      return;
-    }
-    log(pc.green(`Rerunning ${pc.yellow(this.#failedProjects.length)} failed project(s)...`));
-    await this.#exec(this.#failedProjects);
-  }
-
-  async rerunAll(): Promise<void> {
-    process.stdin.write("\x1Bc"); // Clear console
-    log(pc.green(`Running all ${this.#projectDirs.length} projects...`));
-    await this.#exec(this.#projectDirs);
-  }
-
-  exit(): void {
-    process.exit(this.#failedProjects.length > 0 ? 1 : 0);
-  }
-}
-
-export interface BatchRunResult {
-  readonly successCount: number;
-  readonly failureCount: number;
-  readonly skippedCount: number;
-  readonly failedProjects: string[];
-}
-async function runValidation(
-  runner: TaskRunner,
-  tspRunner: TspRunner,
-  projectsToRun: string[],
-): Promise<BatchRunResult> {
-  let successCount = 0;
-  let failureCount = 0;
-  let skippedCount = 0;
-  const failedProjects: string[] = [];
-
-  // Create a processor function that handles the compilation and logging
-  const processProject = async (projectDir: string) => {
-    if (tspRunner.isCancelling) {
-      runner.reportTaskWithDetails("skip", relative(tspRunner.dir, projectDir), "Cancelled");
-      return { dir: projectDir, result: { status: "skip", output: "Cancelled" } };
-    }
-    const result = await verifyProject(runner, tspRunner.dir, projectDir, tspRunner.suite);
-    runner.reportTaskWithDetails(result.status, relative(tspRunner.dir, projectDir), result.output);
-    return { dir: projectDir, result };
-  };
-
-  // Run compilations in parallel with limited concurrency
-  const results = await runWithConcurrency(projectsToRun, COMPILATION_CONCURRENCY, processProject);
-
-  // Count successes and failures
-  for (const { dir, result } of results) {
-    switch (result.status) {
-      case "skip":
-        skippedCount++;
-        break;
-      case "pass":
-        successCount++;
-        break;
-      case "fail":
-        failureCount++;
-        failedProjects.push(dir);
-        break;
-    }
-  }
-
-  log(`\n=== Summary ===`);
-  const passed = pc.bold(pc.green(`${successCount} passed`));
-  const failed = failureCount > 0 ? pc.bold(pc.red(`${failureCount} failed`)) : undefined;
-  const skipped = skippedCount > 0 ? pc.bold(pc.gray(`${skippedCount} skipped`)) : undefined;
-  log(
-    [passed, failed, skipped].filter(Boolean).join(pc.gray(" | ")),
-    pc.gray(`(${projectsToRun.length})`),
-  );
-
-  if (failureCount > 0) {
-    log("\nFailed folders:");
-    failedProjects.forEach((x) => log(`  - ${relative(tspRunner.dir, x)}`));
-  }
-
-  return { successCount, failureCount, skippedCount, failedProjects };
-}
-
-async function findTspProjects(wd: string, pattern: string): Promise<string[]> {
-  const result = await globby(pattern, {
-    cwd: wd,
-    absolute: true,
-  });
-  return result.map((x) => dirname(x));
-}
-
-/** Find which entrypoints are available */
-async function findTspEntrypoints(
-  directory: string,
-  suite: IntegrationTestSuite,
-): Promise<Entrypoint[]> {
-  try {
-    const entries = await readdir(directory);
-    return (suite.entrypoints ?? [{ name: "main.tsp" }]).filter((entrypoint) =>
-      entries.includes(entrypoint.name),
-    );
-  } catch (error) {
-    return [];
-  }
-}
-
-interface ProjectTestResult {
-  status: "pass" | "fail" | "skip";
-  output: string;
-}
-async function verifyProject(
-  runner: TaskRunner,
-  workspaceDir: string,
-  dir: string,
-  suite: IntegrationTestSuite,
-): Promise<ProjectTestResult> {
-  const entrypoints = await findTspEntrypoints(dir, suite);
-
-  if (entrypoints.length === 0) {
-    const result: ProjectTestResult = {
-      status: "fail",
-      output: `Project '${dir}' has no valid entrypoints to compile. Checked for: ${suite.entrypoints?.map((e) => e.name).join(", ") ?? "main.tsp"}`,
-    };
-    runner.reportTaskWithDetails("fail", dir, result.output);
-    return result;
-  }
-
-  let output = "";
-  for (const entrypoint of entrypoints) {
-    const result = await execTspCompile(
-      workspaceDir,
-      join(dir, entrypoint.name),
-      entrypoint.options,
-    );
-    if (!result.success) {
-      return { status: "fail", output: result.output };
-    } else {
-      output += result.output;
-      output += `Entrypoint '${entrypoint.name}' compiled successfully.\n`;
-    }
-  }
-  return { status: "pass", output };
-}
-
-async function execTspCompile(
-  directory: string,
-  file: string,
-  args: string[] = [],
-): Promise<{ success: boolean; output: string }> {
-  const { failed, all } = await execa(
-    "npm",
-    ["exec", "--no", "--", "tsp", "compile", file, "--warn-as-error", ...args],
-    {
-      cwd: directory,
-      stdio: "pipe",
-      all: true,
-      reject: false,
-      env: { FORCE_COLOR: pc.isColorSupported ? "1" : undefined }, // Force color output
-    },
-  );
-  return {
-    success: !failed,
-    output: all,
-  };
-}
diff --git a/packages/integration-tester/tsconfig.build.json b/packages/integration-tester/tsconfig.build.json
deleted file mode 100644
index ab4fd1577a..0000000000
--- a/packages/integration-tester/tsconfig.build.json
+++ /dev/null
@@ -1,6 +0,0 @@
-{
-  "extends": "./tsconfig.json",
-  "references": [],
-  "include": ["src"],
-  "exclude": ["**/*.test.*", "test/**/*"]
-}
diff --git a/packages/integration-tester/tsconfig.json b/packages/integration-tester/tsconfig.json
deleted file mode 100644
index 4400ae4a4e..0000000000
--- a/packages/integration-tester/tsconfig.json
+++ /dev/null
@@ -1,9 +0,0 @@
-{
-  "extends": "../../core/tsconfig.base.json",
-  "compilerOptions": {
-    "declaration": true,
-    "verbatimModuleSyntax": true,
-    "rootDir": "src",
-    "outDir": "dist"
-  }
-}
diff --git a/packages/integration-tester/vitest.config.ts b/packages/integration-tester/vitest.config.ts
deleted file mode 100644
index e236e91da2..0000000000
--- a/packages/integration-tester/vitest.config.ts
+++ /dev/null
@@ -1,4 +0,0 @@
-import { defineConfig, mergeConfig } from "vitest/config";
-import { defaultTypeSpecVitestConfig } from "../../core/vitest.config.js";
-
-export default mergeConfig(defaultTypeSpecVitestConfig, defineConfig({}));
diff --git a/pnpm-lock.yaml b/pnpm-lock.yaml
index 8d39cf1e0f..7073aea7ec 100644
--- a/pnpm-lock.yaml
+++ b/pnpm-lock.yaml
@@ -2337,6 +2337,46 @@ importers:
         specifier: ~5.9.2
         version: 5.9.3
 
+  core/packages/tsp-integration:
+    dependencies:
+      '@pnpm/workspace.find-packages':
+        specifier: ^1000.0.24
+        version: 1000.0.55(@pnpm/logger@1001.0.1)(@pnpm/worker@1000.6.2(@pnpm/logger@1001.0.1)(@types/node@25.0.9))(typanion@3.14.0)
+      execa:
+        specifier: ^9.6.1
+        version: 9.6.1
+      globby:
+        specifier: ~16.1.0
+        version: 16.1.0
+      log-symbols:
+        specifier: ^7.0.1
+        version: 7.0.1
+      ora:
+        specifier: ^9.0.0
+        version: 9.0.0
+      pathe:
+        specifier: ^2.0.3
+        version: 2.0.3
+      picocolors:
+        specifier: ~1.1.1
+        version: 1.1.1
+      simple-git:
+        specifier: ^3.28.0
+        version: 3.30.0
+      tar:
+        specifier: ^7.5.2
+        version: 7.5.4
+      yaml:
+        specifier: ~2.8.2
+        version: 2.8.2
+    devDependencies:
+      typescript:
+        specifier: ~5.9.2
+        version: 5.9.3
+      vitest:
+        specifier: ^4.0.15
+        version: 4.0.17(@types/node@25.0.9)(@vitest/ui@4.0.17)(happy-dom@20.3.4)(jsdom@25.0.1)(tsx@4.21.0)(yaml@2.8.2)
+
   core/packages/tspd:
     dependencies:
       '@alloy-js/core':
@@ -2660,46 +2700,6 @@ importers:
         specifier: ~5.9.2
         version: 5.9.3
 
-  packages/integration-tester:
-    dependencies:
-      '@pnpm/workspace.find-packages':
-        specifier: ^1000.0.24
-        version: 1000.0.55(@pnpm/logger@1001.0.1)(@pnpm/worker@1000.6.2(@pnpm/logger@1001.0.1)(@types/node@25.0.9))(typanion@3.14.0)
-      execa:
-        specifier: ^9.6.1
-        version: 9.6.1
-      globby:
-        specifier: ~16.1.0
-        version: 16.1.0
-      log-symbols:
-        specifier: ^7.0.1
-        version: 7.0.1
-      ora:
-        specifier: ^9.0.0
-        version: 9.0.0
-      pathe:
-        specifier: ^2.0.3
-        version: 2.0.3
-      picocolors:
-        specifier: ~1.1.1
-        version: 1.1.1
-      simple-git:
-        specifier: ^3.28.0
-        version: 3.30.0
-      tar:
-        specifier: ^7.5.2
-        version: 7.5.4
-      yaml:
-        specifier: ~2.8.2
-        version: 2.8.2
-    devDependencies:
-      typescript:
-        specifier: ~5.9.2
-        version: 5.9.3
-      vitest:
-        specifier: ^4.0.15
-        version: 4.0.17(@types/node@25.0.9)(@vitest/ui@4.0.17)(happy-dom@20.3.4)(jsdom@25.0.1)(tsx@4.21.0)(yaml@2.8.2)
-
   packages/samples:
     dependencies:
       '@azure-tools/typespec-autorest':