CLAUDE_CODE_OTEL_CONTENT_MAX_LENGTH

Updated October 13, 2026 by Alex Sorokoletov

CLAUDE_CODE_OTEL_CONTENT_MAX_LENGTH is a Claude Code environment variable: Caps the length of content attributes on OpenTelemetry spans and logs; the truncation function takes the minimum of this value (default 60 KB) and the standard OTEL attribute-length limits, appending a "[TRUNCATED — Content exceeds NKB limit]" marker. Added between v2.1.212 and v2.1.215 and still present in v2.1.294. It is listed in the official reference.

How to set it

For one session, export it in the shell that starts Claude Code:

export CLAUDE_CODE_OTEL_CONTENT_MAX_LENGTH=<value>
claude

To apply it to every session, add it to the env object of a settings file:

// ~/.claude/settings.json
{
  "env": {
    "CLAUDE_CODE_OTEL_CONTENT_MAX_LENGTH": "<value>"
  }
}

Release notes that mention it

• Claude Code Version Tracker: Undocumented Env Vars, Feature Gates & Models
• claude-code-env-vars-v2-1-215

Related variables

• OTEL_ATTRIBUTE_VALUE_LENGTH_LIMIT
• OTEL_LOG_TOOL_CONTENT: Include tool input/output in telemetry.
• CLAUDE_CODE_ENABLE_FEEDBACK_SURVEY_FOR_OTEL: Re-enables the session quality survey for enterprise deployments with OTEL enabled.
• CLAUDE_CODE_OTEL_DIAG_STDERR
• CLAUDE_CODE_OTEL_FLUSH_TIMEOUT_MS: OpenTelemetry flush timeout; default 5000ms.
• CLAUDE_CODE_OTEL_HEADERS_HELPER_DEBOUNCE_MS: Debounce for OTEL headers helper.
• CLAUDE_CODE_OTEL_SHUTDOWN_TIMEOUT_MS: OpenTelemetry shutdown timeout; default 2000ms.
• OTEL_LOG_ASSISTANT_RESPONSES

Frequently asked questions

All variables, searchable: Claude Code environment variables.