diff --git a/package.json b/package.json
index 24841e9..99ba551 100644
--- a/package.json
+++ b/package.json
@@ -42,16 +42,13 @@
     "@agent-ix/ts-plugin-kit": ">=0.1.3",
     "@clack/prompts": ">=1.5.1",
     "@napi-rs/keyring": ">=1.3.0",
+    "@oclif/core": ">=4.11.4",
     "age-encryption": ">=0.3.0",
     "react": ">=19.2.7",
     "yaml": ">=2.9.0",
     "zod": ">=4.4.3"
   },
-  "peerDependencies": {
-    "@oclif/core": ">=4.11.4"
-  },
   "devDependencies": {
-    "@oclif/core": ">=4.11.4",
     "@types/node": ">=25.9.2",
     "@types/react": ">=19.2.17",
     "@typescript-eslint/eslint-plugin": ">=8.60.1",
diff --git a/src/commands/base-command.ts b/src/commands/base-command.ts
index 0ed56fa..e037e2f 100644
--- a/src/commands/base-command.ts
+++ b/src/commands/base-command.ts
@@ -61,6 +61,11 @@ export abstract class BaseCommand extends Command {
       projectConfigRoot: noProject ? undefined : join(process.cwd(), ".ix"),
       projectConfigEnabled: noProject !== true,
     });
+    // Enforce declared capability requirements as part of the oclif lifecycle
+    // so the runner (FR-015) short-circuits commands whose required
+    // capabilities are unavailable before `run()` executes. `prerun()` is a
+    // no-op for commands that declare no capabilities.
+    await this.prerun();
   }
 
   public async prerun(): Promise<void> {
diff --git a/src/index.ts b/src/index.ts
index 2b5cf8f..0a1fb51 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -62,6 +62,19 @@ export {
 export { BaseCommand } from "./commands/base-command.js";
 export type { CommandCapabilities } from "./runtime/capability-spec.js";
 
+// ── oclif runner + core-plugin host (FR-015) ───────────────────────────
+// Lets a consuming CLI (quoin) run BaseCommand subclasses and commands
+// contributed by packages declared as oclif core plugins via a single
+// `import { run } from "@agent-ix/ix-cli-core"; run()` entry point.
+export {
+  run,
+  execute,
+  loadConfig,
+  listCorePlugins,
+  type RunnerLoadOptions,
+  type CorePluginInfo,
+} from "./runtime/runner.js";
+
 // ── Marketplace adapter over @agent-ix/ts-plugin-kit (FR-019) ──────────
 // Thin wiring: ix-cli-core adapts the external marketplace library (cache
 // layout + oclif command-plugin bridge); it does NOT implement an installer.
diff --git a/src/runtime/runner.ts b/src/runtime/runner.ts
new file mode 100644
index 0000000..77383c3
--- /dev/null
+++ b/src/runtime/runner.ts
@@ -0,0 +1,115 @@
+import {
+  Config,
+  execute as oclifExecute,
+  run as oclifRun,
+  type Interfaces,
+} from "@oclif/core";
+
+/**
+ * oclif runner + core-plugin host for IX CLIs (FR-015).
+ *
+ * A consuming binary (e.g. quoin) ships a thin `bin` script that simply
+ * delegates to this runner:
+ *
+ * ```js
+ * #!/usr/bin/env node
+ * import { run } from "@agent-ix/ix-cli-core";
+ * await run(undefined, import.meta.url);
+ * ```
+ *
+ * The runner is a wafer-thin wrapper over `@oclif/core`. Command discovery
+ * (the consumer's own `oclif.commands` dir) and **core-plugin** discovery
+ * (packages listed in the consumer's `package.json` `oclif.plugins` array
+ * that are also declared as `dependencies`) are performed by `@oclif/core`'s
+ * own `Config` loader. ix-cli-core never imports `@oclif/plugin-plugins`:
+ * runtime, user-installed plugins are out of scope — only **bundled** core
+ * plugins shipped as dependencies of the host CLI are loaded.
+ *
+ * `BaseCommand` subclasses contributed by either the host or a core plugin
+ * run unchanged: their base flags (`--config-root`, `--no-project-config`)
+ * and capability hooks are wired through `init()`/`prerun()` exactly as they
+ * are when run directly.
+ */
+
+/**
+ * Options accepted by {@link run}: a pre-loaded {@link Config}, a directory /
+ * file-URL string (e.g. `import.meta.url`), an oclif `Options` object, or
+ * `undefined` to fall back to the caller's module location.
+ */
+export type RunnerLoadOptions = Interfaces.LoadOptions;
+
+/**
+ * Run an IX CLI from `argv`.
+ *
+ * Loads the consuming CLI's oclif {@link Config} from `options` (resolving its
+ * `commands` dir and core `plugins`), then dispatches the requested command.
+ * Returns the command's result; throws on error (it does **not** call
+ * `process.exit`, so it is safe to use in tests). Use {@link execute} for a
+ * top-level bin that should handle errors and set the process exit code.
+ *
+ * @param argv argument vector (defaults to `process.argv.slice(2)`)
+ * @param options config source — defaults to oclif's own resolution
+ */
+export async function run(
+  argv?: string[],
+  options?: RunnerLoadOptions,
+): Promise<unknown> {
+  return oclifRun(argv ?? process.argv.slice(2), options);
+}
+
+/**
+ * Load-and-run entry point for a top-level bin script.
+ *
+ * Thin pass-through to `@oclif/core`'s `execute`, which loads the config from
+ * `dir` (typically `import.meta.url`), runs the command, flushes output, and
+ * handles errors / process exit codes. Prefer {@link run} in tests.
+ */
+export async function execute(options: {
+  args?: string[];
+  development?: boolean;
+  dir?: string;
+  loadOptions?: RunnerLoadOptions;
+}): Promise<unknown> {
+  return oclifExecute(options);
+}
+
+/**
+ * Load the consuming CLI's oclif {@link Config} without running a command.
+ *
+ * Exposes the host's resolved plugin/command graph so a CLI (or a test) can
+ * introspect what was discovered — including core plugins — before dispatch.
+ * The returned config can be passed straight back into {@link run} as
+ * `options` to avoid re-resolving.
+ */
+export async function loadConfig(options?: RunnerLoadOptions): Promise<Config> {
+  return Config.load(options);
+}
+
+/** A core plugin discovered and loaded by the host. */
+export interface CorePluginInfo {
+  /** Package name of the plugin. */
+  name: string;
+  /** Absolute path to the plugin package root. */
+  root: string;
+  /** oclif plugin type — `core` for bundled host plugins. */
+  type: string;
+  /** Command ids contributed by this plugin. */
+  commandIDs: string[];
+}
+
+/**
+ * List the **core plugins** loaded into a {@link Config} (excludes the root/host
+ * plugin itself). These are the packages from the host's `oclif.plugins` that
+ * `@oclif/core` resolved from its dependencies. Useful for `doctor`/diagnostic
+ * output and for asserting plugin-host wiring in tests.
+ */
+export function listCorePlugins(config: Config): CorePluginInfo[] {
+  return [...config.plugins.values()]
+    .filter((p) => !p.isRoot && p.type === "core")
+    .map((p) => ({
+      name: p.name,
+      root: p.root,
+      type: p.type,
+      commandIDs: [...p.commandIDs],
+    }));
+}
diff --git a/tests/runner.test.ts b/tests/runner.test.ts
new file mode 100644
index 0000000..88f4ddc
--- /dev/null
+++ b/tests/runner.test.ts
@@ -0,0 +1,198 @@
+import { execSync } from "node:child_process";
+import {
+  existsSync,
+  mkdirSync,
+  mkdtempSync,
+  readFileSync,
+  rmSync,
+  symlinkSync,
+  writeFileSync,
+} from "node:fs";
+import { tmpdir } from "node:os";
+import { dirname, join } from "node:path";
+import { fileURLToPath } from "node:url";
+import { afterAll, beforeAll, describe, expect, it } from "vitest";
+
+import { listCorePlugins, loadConfig, run } from "../src/index.js";
+
+/**
+ * FR-015 / TC-015 — oclif runner + core-plugin host.
+ *
+ * Builds a throwaway "consumer CLI" on disk (a host package with its own
+ * `oclif.commands` dir plus a bundled core plugin declared in `oclif.plugins`)
+ * and drives it through the exported {@link run} runner. The fixture command
+ * modules are loaded natively by `@oclif/core`, so they import `BaseCommand`
+ * from the built package via a symlink into the fixture's `node_modules` —
+ * exactly how a real consumer (quoin) imports it.
+ */
+
+const repoRoot = join(dirname(fileURLToPath(import.meta.url)), "..");
+const distEntry = join(repoRoot, "dist", "index.js");
+
+let tmp: string;
+
+const consumerPkg = {
+  name: "@ixcc-fixture/consumer",
+  version: "0.0.0",
+  type: "module",
+  bin: { ixfix: "./bin/run.js" },
+  oclif: {
+    bin: "ixfix",
+    commands: "./commands",
+    // Declare the bundled package as an oclif *core plugin*. oclif matches
+    // this against `dependencies` and loads it from node_modules.
+    plugins: ["@ixcc-fixture/hello-plugin"],
+  },
+  dependencies: { "@ixcc-fixture/hello-plugin": "*" },
+};
+
+const pluginPkg = {
+  name: "@ixcc-fixture/hello-plugin",
+  version: "0.0.0",
+  type: "module",
+  oclif: { commands: "./commands" },
+};
+
+// Host command: a BaseCommand subclass. Writes its parsed base flags to a file
+// so the test can assert end-to-end dispatch AND base-flag plumbing.
+const greetCmd = `
+import { BaseCommand } from "@agent-ix/ix-cli-core";
+import { Flags } from "@oclif/core";
+import { writeFileSync } from "node:fs";
+
+export default class Greet extends BaseCommand {
+  static description = "greet (host BaseCommand subclass)";
+  static flags = { out: Flags.string({ required: true }) };
+  async run() {
+    const { flags } = await this.parse(Greet);
+    writeFileSync(
+      flags.out,
+      "greet|config-root=" +
+        (flags["config-root"] ?? "") +
+        "|no-project=" +
+        flags["no-project-config"],
+    );
+    this.log("greet ran");
+  }
+}
+`;
+
+// Core-plugin command: also a BaseCommand subclass, contributed by the plugin.
+const helloCmd = `
+import { BaseCommand } from "@agent-ix/ix-cli-core";
+import { Flags } from "@oclif/core";
+import { writeFileSync } from "node:fs";
+
+export default class Hello extends BaseCommand {
+  static description = "hello (contributed by a core plugin)";
+  static flags = { out: Flags.string({ required: true }) };
+  async run() {
+    const { flags } = await this.parse(Hello);
+    writeFileSync(flags.out, "hello-plugin ran");
+  }
+}
+`;
+
+// Host command declaring an unsatisfiable required capability. Used to prove
+// the capability hook (prerun) fires through the runner's lifecycle.
+const guardedCmd = `
+import { BaseCommand } from "@agent-ix/ix-cli-core";
+
+export default class Guarded extends BaseCommand {
+  static description = "requires the github capability";
+  static capabilities = { required: ["github"] };
+  async run() {
+    this.log("should never run");
+  }
+}
+`;
+
+function writeJson(path: string, value: unknown): void {
+  writeFileSync(path, JSON.stringify(value, null, 2));
+}
+
+beforeAll(() => {
+  // The fixture command modules import the *built* package, mirroring a real
+  // consumer. Ensure dist exists (CI builds before test; build on demand for a
+  // clean local checkout).
+  if (!existsSync(distEntry)) {
+    execSync("pnpm run build", { cwd: repoRoot, stdio: "inherit" });
+  }
+
+  tmp = mkdtempSync(join(tmpdir(), "ixcc-runner-"));
+
+  // ── host package ──────────────────────────────────────────────────────
+  writeJson(join(tmp, "package.json"), consumerPkg);
+  mkdirSync(join(tmp, "commands"), { recursive: true });
+  writeFileSync(join(tmp, "commands", "greet.js"), greetCmd);
+  writeFileSync(join(tmp, "commands", "guarded.js"), guardedCmd);
+
+  // ── node_modules: symlink the package under test + @oclif/core ─────────
+  mkdirSync(join(tmp, "node_modules", "@agent-ix"), { recursive: true });
+  mkdirSync(join(tmp, "node_modules", "@oclif"), { recursive: true });
+  mkdirSync(join(tmp, "node_modules", "@ixcc-fixture"), { recursive: true });
+  symlinkSync(
+    repoRoot,
+    join(tmp, "node_modules", "@agent-ix", "ix-cli-core"),
+    "dir",
+  );
+  symlinkSync(
+    join(repoRoot, "node_modules", "@oclif", "core"),
+    join(tmp, "node_modules", "@oclif", "core"),
+    "dir",
+  );
+
+  // ── core plugin (bundled dependency) ───────────────────────────────────
+  const pluginRoot = join(tmp, "node_modules", "@ixcc-fixture", "hello-plugin");
+  mkdirSync(join(pluginRoot, "commands"), { recursive: true });
+  writeJson(join(pluginRoot, "package.json"), pluginPkg);
+  writeFileSync(join(pluginRoot, "commands", "hello.js"), helloCmd);
+});
+
+afterAll(() => {
+  if (tmp) rmSync(tmp, { recursive: true, force: true });
+});
+
+describe("oclif runner + core-plugin host (FR-015 / TC-015)", () => {
+  it("discovers the host commands AND the core-plugin's commands", async () => {
+    const config = await loadConfig({ root: tmp });
+
+    const ids = config.commandIDs;
+    expect(ids).toContain("greet"); // host command
+    expect(ids).toContain("hello"); // contributed by the core plugin
+
+    const core = listCorePlugins(config);
+    const plugin = core.find((p) => p.name === "@ixcc-fixture/hello-plugin");
+    expect(plugin).toBeDefined();
+    expect(plugin?.type).toBe("core");
+    expect(plugin?.commandIDs).toContain("hello");
+  });
+
+  it("runs a host BaseCommand subclass end-to-end, with base flags parsed", async () => {
+    const config = await loadConfig({ root: tmp });
+    const out = join(tmp, "greet.out");
+
+    await run(["greet", "--out", out, "--config-root", "/custom/root"], config);
+
+    expect(readFileSync(out, "utf8")).toBe(
+      "greet|config-root=/custom/root|no-project=false",
+    );
+  });
+
+  it("runs a command contributed by the core plugin via the runner", async () => {
+    const config = await loadConfig({ root: tmp });
+    const out = join(tmp, "hello.out");
+
+    await run(["hello", "--out", out], config);
+
+    expect(readFileSync(out, "utf8")).toBe("hello-plugin ran");
+  });
+
+  it("short-circuits a command whose required capability is unavailable", async () => {
+    const config = await loadConfig({ root: tmp });
+    // The capability hook (prerun) runs in BaseCommand.init via the runner;
+    // with no provider registered, `github` is unavailable and the command
+    // must error before its run() body executes.
+    await expect(run(["guarded"], config)).rejects.toThrow();
+  });
+});