> ## Documentation Index
> Fetch the complete documentation index at: https://docs.corti.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Recipe 3 — Reference Corti Standards + per-call end-user overrides

> Apply per-call overrides on top of a Corti Standard template so end users can tweak titles, writing styles, or schemas for a single generation.

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← Back to [Customization Cookbook](/textgen/customization-cookbook)

**Scenario:** You want clinicians (or your product UI) to tweak how a Standard renders for a single document — switch a section title, change the writing style, swap the output schema. The tweak does **not** persist; the next call uses the Standard as-is again.

**Your product can decide between two patterns** for collecting the tweak from end-users:

* **Presets.** You pre-build a small set of inheriting variant sections/templates ([Recipe 2](/textgen/customization-cookbook/recipe-2-inherit-corti-standard)) and your UI picks one. The end user clicks "Telegraphic style"; you route the request to the corresponding pre-built section ID. No prompt engineering for the user; deterministic.
* **Free-prompt.** Your UI exposes a text field ("How would you like the writing style?"). You drop the user's prompt straight into `writingStylePrompt` on a runtime override. Maximum flexibility, less deterministic.
* **Hybrid.** Presets for the common cases + a free-prompt field for last-mile tweaks.

**What you do:**

Use Path 2 (`templateRef` + `overrides`) at `POST /documents`. The base template is untouched; a drift-proof auto-generated template aggregate is persisted for traceability — but **retained for 30 days only** (see [Guided Synthesis](/textgen/documents-guided-synthesis#auto-generated-template-aggregates-30-day-retention)). If you want the customized variant to persist long-term, convert the aggregate into a permanent project-owned template before the retention window expires.

```json title="POST /documents — Path 2 (templateRef + overrides)" expandable theme={null}
{
  "outputLanguage": "en-US",
  "interactionId": "<your-interaction-id>",
  "templateRef": {
    "templateId": "<your-template-id>",
    "overrides": {
      "instructions": {
        "prompt": "Produce a focused note for a follow-up encounter."
      },
      "sections": [
        {
          "sectionId": "<your-section-id>",
          "generation": {
            "heading": "Anamnesis",
            "instructions": {
              "writingStylePrompt": "Telegraphic — values and facts only, no narrative."
            }
          }
        }
      ]
    }
  }
}
```

**Why this lever:** Zero authoring overhead — no new resources to manage, no inheriting resource to keep in sync. The base Standard always stays current. Each call records the tweak via the auto-generated aggregate in the response (`templateId`, `templateVersionId`), so you can audit what produced any given document.

**Caveat:** Each section override must reference a section that is **already linked** to the base template version. You can't add new sections via overrides — use Path 3 (assembly) for that.

***

Previous: [Recipe 2 — Inherit from a Corti Standard via `inheritFromId`](/textgen/customization-cookbook/recipe-2-inherit-corti-standard) · Next: [Recipe 4 — Author your own sections & templates](/textgen/customization-cookbook/recipe-4-author-your-own)