Diff

What it is

See exactly which files differ between two VMs, line by line.

flash diff compares two FlashVMs, or a snapshot and a VM. It lists every file added, deleted, renamed or modified, with line diffs and a ready-to-apply patch.

Why it matters

Before you keep an agent's work, you should see it. Diff shows the whole change, so nothing is taken on faith.

• Complete. Content, mode, type and link changes, all of it.
• Readable. Unified line diffs for every changed text file.
• Ready to ship. --patch prints a patch you can apply.

Runs on

• Linux x86_64
• Linux arm64
• macOS
• Windows x64
• Windows arm64

How it works

Name a before and an after.

CLI

flash diff agent-1 try-2
flash diff agent-1 try-2 --patch

MCP

flash_diff(a: "agent-1", b: "try-2")

API

flash diff agent-1 try-2 --json  →  {changes, line diffs, notes}

The result

The winning fork's whole change, file by file, before it is kept.

Review it, copy the fixed file out, and remove the rest.