https://spencer.wtf/2026/02/20/cleaning-up-merged-git-branches-a-one-liner-from-the-cias-leaked-dev-docs.html

Spencer Dixon
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Cleaning up merged git branches: a one-liner from the CIA's leaked
dev docs

20 Feb 2026

In 2017, WikiLeaks published Vault7 - a large cache of CIA hacking
tools and internal documents. Buried among the exploits and
surveillance tools was something far more mundane: a page of internal
developer documentation with git tips and tricks.

Most of it is fairly standard stuff, amending commits, stashing
changes, using bisect. But one tip has lived in my ~/.zshrc ever
since.

The Problem

Over time, a local git repo accumulates stale branches. Every feature
branch, hotfix, and experiment you've ever merged sits there doing
nothing. git branch starts to look like a graveyard.

You can list merged branches with:

git branch --merged

But deleting them one by one is tedious. The CIA's dev team has a
cleaner solution:

The original command

git branch --merged | grep -v "\*\|master" | xargs -n 1 git branch -d

How it works:

  * git branch --merged -- lists all local branches that have already
    been merged into the current branch
  * grep -v "\*\|master" -- filters out the current branch (*) and
    master so you don't delete either
  * xargs -n 1 git branch -d -- deletes each remaining branch one at a
    time, safely (lowercase -d won't touch unmerged branches)

The updated command

Since most projects now use main instead of master, you can update
the command and exclude any other branches you frequently use:

git branch --merged origin/main | grep -vE "^\s*(\*|main|develop)" | xargs -n 1 git branch -d

Run this from main after a deployment and your branch list goes from
40 entries back down to a handful.

I keep this as a git alias so I don't have to remember the syntax:

alias ciaclean='git branch --merged origin/main | grep -vE "^\s*(\*|main|develop)" | xargs -n 1 git branch -d'

Then in your repo just run:

ciaclean

Small thing, but one of those commands that quietly saves a few
minutes every week and keeps me organised.

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