{"version":"1.0.128","anchor":"adaptive-system-prompt-identity","canonical_anchor":"adaptive-system-prompt-identity","heading":"Adaptive System Prompt Identity","tier":null,"area":null,"scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/1.0.128\/e\/adaptive-system-prompt-identity","release_url":"https:\/\/changelogs.core-directive.com\/v\/1.0.128","markdown":"### Adaptive System Prompt Identity\n\n**What:** Claude Code now uses different identity strings based on operational context (interactive CLI vs non-interactive SDK usage).\n\n**Details:**\n\n- **Interactive CLI mode:** \"You are Claude Code, Anthropic's official CLI for Claude.\"\n- **SDK with custom system prompt:** \"You are Claude Code, Anthropic's official CLI for Claude, running within the Claude Agent SDK.\"\n- **SDK without custom prompt:** \"You are a Claude agent, built on Anthropic's Claude Agent SDK.\"\n- Vertex AI provider always uses the standard CLI identity\n- Enables context-aware behavior based on how Claude Code is being used\n- **Evidence**: Identity selection function `A$1()` at line 366028, identity strings at lines 366024-366027"}