Transcript writes and head/tail reads can go through the v5 storage backend / Claude Code v2.1.222

Under the hood

Useful1 Signal2

Internals

Transcript writing can be redirected to a different storage layer, but nothing turns that on here.

Transcript append and truncate can target a v5 storage backend; the write path is new and inert without a handle.

What

Transcript append, truncate and read helpers can now be pointed at a v5 storage backend instead of the filesystem, but only when a backend handle is passed in.

Details

The helpers take an optional backend handle; when present they call backend.append, backend.delete, backend.readText and backend.stat with a key rather than touching files.
Failures throw Error("transcript stream append failed") or Error("transcript stream delete failed").
The exporter class gained a storageV5 field.
storageV5 existed in the previous build but only on the read path; the write path is new here and inert without a handle.

Evidence

transcript stream append failed

Strings lifted out of the shipped bundle, so the claim above can be checked against them.