CLAUDE_CODE_EXTRA_BODY
A Claude Code environment variable, read out of the shipped bundle. It has been in the build since v2.1.138, including the newest one read.
What it is
JSON object to merge into the top level of every API request body. Useful for passing provider-specific parameters that Claude Code doesn't expose directly. A value exported in your shell also applies to the [background sessions](/docs/en/agent-view) you dispatch with claude agents or --bg. Before v2.1.206, background sessions ignored a shell-exported value and used whatever copy the background supervisor process inherited
Anthropic's own wording. Read off Environment variables, captured 2026-08-28.
Presence across releases
| Releases | Reading | Declared type | Default |
|---|---|---|---|
| 2.1.245 – 2.1.250 5 releases | never mined | — | — |
| 2.1.242 – 2.1.243 2 releases | in the build | — | — |
| 2.1.160 – 2.1.241 73 releases | in the build | str | — |
| 2.1.138 – 2.1.159 20 releases | in the build | — | — |
A row reading never mined is a release with no archived bundle behind it. Nothing was read out of it, so nothing here says whether the name was in it. A declared type or a default is only ever what that release's own bundle stated.
Changelog entries naming it
-
v2.1.232Per-turn attribution key sent as
tk, andtkis now a reserved metadata nametkis now a reserved metadata name and stripped from your extra metadata or body.named in this entry
Documentation pages
- Environment variables reference table Claude Code CLI
- Manage multiple agents with agent view mentions it Claude Code CLI
- Claude Code changelog mentions it Claude Code CLI
A reference table page is one whose own table defines this name, and it is where the description above came from. A page that mentions it carries the name somewhere in its text and may say nothing about it at all. Every page carrying it.
Names beside it
Every environment variable in the inventory starting claude_code_extra, up to twelve of them.
Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the environment variable does. All environment variables.