CLAUDE_CODE_ATTRIBUTION_HEADER
Updated by Alex Sorokoletov
CLAUDE_CODE_ATTRIBUTION_HEADER is a Claude Code environment variable: API billing header in system prompt. Present since v2.1.69 or earlier and still present in v2.1.310. It is listed in the official reference.
| Status | Present in v2.1.310 |
|---|---|
| Added | Present since v2.1.69 or earlier |
| Category | Other |
| Official docs | Listed |
How to set it
For one session, export it in the shell that starts Claude Code:
export CLAUDE_CODE_ATTRIBUTION_HEADER=<value>
claudeTo apply it to every session, add it to the env object of a settings file:
// ~/.claude/settings.json
{
"env": {
"CLAUDE_CODE_ATTRIBUTION_HEADER": "<value>"
}
}Release notes that mention it
- Claude Code "self signed certificate in certificate chain": NODE_EXTRA_CA_CERTS, CLAUDE_CODE_CERT_STORE and the emSign Block
- Claude Code --client-data-url: Signed Model Configuration and --allow-other-models
- CLAUDE_CODE_ATTRIBUTION_HEADER: Fix Bedrock 400 Errors & Prompt Caching Issues
- 83 Undocumented Claude Code Environment Variables (v2.1.19)
Related variables
CLAUDE_CODE_ATTRIBUTION_ANNOUNCEMENTCLAUDE_CODE_ATTRIBUTION_PROJECTANTHROPIC_BETAS: Comma-separated beta feature headers.ANTHROPIC_CUSTOM_HEADERS: Custom HTTP headers (newline-separated Key: Value).ANTHROPIC_FEDERATION_RULE_IDANTHROPIC_ORGANIZATION_IDANTHROPIC_WORKSPACE_IDBETA_TRACING_ENDPOINT: Custom endpoint for beta tracing.
Frequently asked questions
What does CLAUDE_CODE_ATTRIBUTION_HEADER do?
API billing header in system prompt
Which Claude Code version has CLAUDE_CODE_ATTRIBUTION_HEADER?
Present since v2.1.69 or earlier and still present in v2.1.310.
How do I set CLAUDE_CODE_ATTRIBUTION_HEADER?
Export it before starting Claude Code (export CLAUDE_CODE_ATTRIBUTION_HEADER=value), or add it to the "env" object in ~/.claude/settings.json to apply it to every session.
All variables, searchable: Claude Code environment variables.