Two tools that come up constantly when working with credentials, tokens, and configuration: uuidgen for generating unique identifiers and base64 for encoding binary or sensitive data as ASCII text.

Generate a UUID

uuidgen

Produces something like:

40CB8E14-B8E7-4C7F-849E-76E1ACC23101

Encode with base64

echo -n "my super secret" | base64

bXkgc3VwZXIgc2VjcmV0

The -n flag suppresses the trailing newline that echo appends by default. This matters: without it, the newline becomes part of the input and changes the encoded output.

Decode with base64

echo bXkgc3VwZXIgc2VjcmV0 | base64 -d

my super secret%

The % at the end indicates there is no trailing newline in the decoded output — the shell prompt is appending it for display. This is normal.

The -n flag matters

If you omit -n during encoding:

bXkgc3VwZXIgc2VjcmV0Cg==

That is a different value. The input was my super secret\n, not my super secret. Decoding it will produce output without the trailing %:

my super secret

Which means the decoded value contains \n at the end — something that can cause subtle failures when the value is used as a key or token.

Copy directly to clipboard on macOS

echo -n "my super secret" | base64 | pbcopy

The encoded value bXkgc3VwZXIgc2VjcmV0 lands in the clipboard, ready to paste.