draft_email()

Six sentences. One pain signal. One ask. Written from scratch every time.

Inputs and outputs

In. Brief plus confirmed recipient plus the chosen angle's tone profile.

Out. Subject line, body, suggested send time, and a list of the signals the email is grounded in.

Current version

v4.2.0 Forkable through the prompt library.

Model defaults

Anthropic Sonnet for the body. Haiku for subject-line variants. The body prompt has a hard rule: no sentence may appear in any other email produced this week against the same angle. We enforce that with a similarity check at the rejection gate. You can override per stage in your routing config.

How it fails

Drafts that read like templates. We measure templateness as cosine similarity to other drafts under the same angle in the last seven days. Anything above 0.78 gets rejected and re-drafted with an explicit penalty in the prompt.

Evals

Reply rate by angle, published quarterly. Last quarter ranged from 7.4% to 18.3% across active angles. Field Notes publishes the breakdown. The full eval set ships with the prompt and is editable. Eval format.