File Storage

Objective: write sessions, transcripts, events, snapshots, and cursors to disk.

import { FileSessionStorage } from "@harness-kernel/storage-file";

const store = await createHarnessSessionStore({
  agent: { definition: agent },
  providers: [new OpenAIProvider()],
  defaultModel: "openai/gpt-5.1",
  storage: new FileSessionStorage(),
});

const result = await store.send("file-storage", "Create a short status report.");
console.log(result.outputDir);

The output directory belongs to the host. It is safe to change per environment:

new FileSessionStorage({
  rootDir: process.env.HARNESS_KERNEL_DIR ?? ".harness-kernel",
});

Boundary note: storage is runtime infrastructure. Agent packages should not depend on FileSessionStorage.

API: Storage and Storage File.