Add experimental drive-backed workflow memory

.github/aw/actions-lock.json

@@ -53,6 +53,16 @@
       "version": "v8.0.1",
       "sha": "3e5f45b2cfb9172054b4087a40e8e0b5a5461e7c"
     },
+    "actions/gh-drives-preview/checkout@main": {
+      "repo": "actions/gh-drives-preview/checkout",
+      "version": "main",
+      "sha": "c9163b96f9720dc55e0de19b37028ae22dcfa42a"
+    },
+    "actions/gh-drives-preview/commit@main": {
+      "repo": "actions/gh-drives-preview/commit",
+      "version": "main",
+      "sha": "c9163b96f9720dc55e0de19b37028ae22dcfa42a"
+    },
     "actions/github-script@v9.0.0": {
       "repo": "actions/github-script",
       "version": "v9.0.0",

actions/setup/js/validate_memory_step.cjs

@@ -6,7 +6,7 @@ const { validateMemoryFiles } = require("./validate_memory_files.cjs");
 /**
  * @param {{ error: (message: string) => void, info: (message: string) => void, setFailed: (message: string) => void }} core
  * @param {{
- *   kind: "repo" | "cache",
+ *   kind: "repo" | "cache" | "drive",
  *   formatJSON?: boolean,
  *   requireValidationScript?: boolean,
  *   writeMarker?: boolean,

docs/src/content/docs/reference/drive-memory.md

@@ -0,0 +1,73 @@
+---
+title: Drive Memory
+description: Experimental persistent workflow memory backed by GitHub Drives.
+sidebar:
+  order: 1510
+---
+
+Drive memory provides persistent file storage across workflow runs using the experimental [GitHub Drives preview](https://github.com/actions/gh-drives-preview). The repository must be enrolled in the preview, and the workflow must run on a Linux runner with FUSE support.
+
+> [!CAUTION]
+> Drive memory and the underlying GitHub Drives service are experimental. The configuration and storage behavior may change without notice.
+
+## Enable drive memory
+
+```aw wrap
+---
+tools:
+  drive-memory: true
+---
+```
+
+The compiler mounts the `default` drive and exposes it to the agent at `/tmp/gh-aw/drive-memory/`. It automatically grants the generated job `contents: read`, `id-token: write`, and the required `drives` permission.
+
+## Configure a drive
+
+```aw wrap
+---
+tools:
+  drive-memory:
+    drive-name: agent-memory
+    disk-size: 20G
+    prefetch: true
+    description: Long-lived notes and state
+    allowed-extensions: [".json", ".jsonl", ".txt", ".md"]
+---
+```
+
+- `drive-name` selects the persistent drive. It defaults to `default`.
+- `disk-size` sets the size when the drive is first created and defaults to `10G`.
+- `prefetch` eagerly downloads existing content after mounting.
+- `restore-only` mounts with `drives: read` and never commits local changes.
+- `description`, `allowed-extensions`, and `validation` behave like their [cache-memory](/gh-aw/reference/cache-memory/) equivalents.
+
+## Multiple drives
+
+```aw wrap
+---
+tools:
+  drive-memory:
+    - id: notes
+      drive-name: agent-notes
+    - id: reference
+      drive-name: shared-reference
+      restore-only: true
+      prefetch: true
+---
+```
+
+The `default` entry is exposed at `/tmp/gh-aw/drive-memory/`; named entries use `/tmp/gh-aw/drive-memory-{id}/`.
+
+## Persistence and threat detection
+
+Without threat detection, the compiler checks out each drive before the agent and commits validated changes afterward. With threat detection enabled, the agent receives a non-publishing checkout and the compiler stages drive contents as an artifact. A separate `update_drive_memory` job publishes the artifact only after detection succeeds. Before replacing the drive, that job verifies it has not changed since the agent checked it out; concurrent updates cause the publish to fail instead of being overwritten.
+
+Drive names are repository-wide and branch-aware according to the preview service. GitHub Drives allows one active writer for a drive, so overlapping runs that write the same drive can contend for the writer lease.
+
+## Limitations
+
+- GitHub-hosted `ubuntu-latest` is the supported preview runner.
+- Repositories must be enrolled in the GitHub Drives preview.
+- Drive mounts are not supported inside job containers.
+- The upstream actions currently have no versioned release, so gh-aw pins the preview `main` commit.
+- Do not store secrets in drive memory.