{"version":"2.1.248","anchor":"switching-model-over-the-sdk-can-also-swap-the-system-prompt","canonical_anchor":"switching-model-over-the-sdk-can-also-swap-the-system-prompt","heading":"Switching model over the SDK can also swap the system prompt","tier":"use","area":"SDK","scope":null,"heads_up":null,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.248\/e\/switching-model-over-the-sdk-can-also-swap-the-system-prompt","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.248","markdown":"### Switching model over the SDK can also swap the system prompt\n\nOver the SDK, set_model can also swap your custom system prompt from the next turn.\n\n**What**\n\nThe `set_model` control request accepts an internal `system_prompt` field that replaces the custom system prompt (the same slot as `--system-prompt`) starting from the next turn. It applies only if the model change itself is accepted and the value is non-empty; older transports report success without applying it.\n\n**Evidence**\n\n`@internal Replaces the custom system prompt (the --system-prompt \/ initialize systemPrompt slot) from the next turn on.`\n\n- Area: SDK\n- Names: `set_model`, `system_prompt`, `--system-prompt`\n- Tier: Use it now\n- Useful: 4\/5\n- Signal: 4\/5"}