--system-prompt and --system-prompt-file can now be used together

--system-prompt and --system-prompt-file can now be used together

Passing both --system-prompt and --system-prompt-file no longer stops Claude Code from starting; the two are combined

Use it nowTier: how much it should matter to you

4Useful: my rating, 1 to 5

1Signal: worth watching, 1 to 5

CLIArea: what it touches

ImprovementsKind: in v2.1.283, 25 Sep 26

What probably matters to youSection of the release

What

The system prompt is the standing instructions Claude receives before your conversation. Claude Code has flags (options typed on the command line) that set it from text or from a file. Previously, giving both forms of the same flag stopped Claude Code with an error telling you to use only one. Now both are accepted and combined:

--system-prompt with --system-prompt-file: the file's contents are merged with the text you passed
--append-system-prompt with --append-system-prompt-file: the same, except in a Remote Control session

In a Remote Control session, giving both append flags is still refused, with a new message: "Error: --append-system-prompt cannot be given with --append-system-prompt-file in a Remote Control session. Remove --append-system-prompt."

Why

Scripts that pass both flags now start instead of failing. Because the two values are now combined, it is worth checking that the resulting prompt reads the way you expect.

How sure we are

Something disagreesSomething we can check disagrees with this entry, or the writer said they could not settle it.

The writer flagged doubtThe order in which the two values are combined, and what separates them, are not settled.

Anthropic's release notes agreeChanged --system-prompt and --append-system-prompt to accept their text and -file forms together; the file's text comes first

See this entry in the whole of v2.1.283 →

The build it came inv2.1.283

25 Sep 2026 · 386 entries, this one is #64.

Use it now39
You'll notice239
Nothing to try yet19
Under the hood89

Either side of it

v2.1.282Older

Open the release →

Names in this entry

cli--system-prompt
Replace the entire system prompt with custom text
cli--append-system-prompt
Append custom text to the end of the default system prompt

Anthropic's note

Upstream's own release notes for v2.1.283 name something this entry names, so the two are probably about the same change. Probably: the pairing is made on a shared name rather than on the words around it.

Changed --system-prompt and --append-system-prompt to accept their text and -file forms together; the file's text comes first

Is this right?