API Deprecation Notice from a Changelog (No Invented Sunset Dates)

Prompt

Act as an API program manager writing a customer deprecation notice from a changelog. You only announce endpoints, dates, and replacements that appear in Inputs. You do not invent a sunset date, a migration window, a traffic percentage, or a successor API. This is not a git changelog and not a Keep a Changelog dump.
You work only from Inputs. Do not invent stats, citations, quotes, URLs, names, IDs, or records that are not in Inputs.

Inputs:
- Product and API surface: [Product]
- Pasted changelog excerpt (include version and date if present): [Changelog]
- Endpoints or fields being removed (quote from Changelog): [Removed]
- Replacement I can prove (or NONE): [Replacement]
- Sunset or last-call date that is already committed in Changelog or policy: [Sunset or NONE]
- Support channel and SLA I may cite: [Support]
- Who must act (role, not named people unless pasted): [Audience]
- Migration steps I can prove: [Steps]
- Words I must not use: [Banned]
- Word budget: [Budget or 350]

Generate:
1. Honesty ledger: every version, date, endpoint, field, and replacement that appears in Changelog, Removed, Replacement, Sunset. Forbidden: any date or successor not on that list.
2. Subject line (70 chars max) using Product and Removed only. Print the count. No sunset date unless Sunset is not NONE.
3. Notice body: what is going away, what stays, who must act. Quote Removed. If Sunset is NONE, write sunset date not specified and do not pick one.
4. Replacement paragraph: only Replacement. If NONE, write no successor named in the brief.
5. Migration: numbered steps from Steps only. Missing auth, SDK, or URL writes NOT IN INPUTS.
6. Support footer: only Support. Do not invent a status page URL.
7. FAQ (4): only questions answerable from Inputs. If a question needs a date you do not have, write not specified.
8. Compliance pass: quote Banned words, invented sunset dates, invented traffic share. Cut them. Print word count vs Budget.

Constraints:
- Customer deprecation notice, not a git changelog and not Keep a Changelog.
- Never invent a sunset date, last-call date, or replacement path.
- Do not claim usage percentages, request volume, or breaking-change class unless Changelog states them.
- Stay under Budget words.
- No emojis.

Instructions

Replace every [bracket] with your details before running. Works on ChatGPT, Claude, and Gemini.

Examples

Example Input

Product: Northwind Billing API v3
Changelog: 2026-08-12 v3.9.0 notes: GET /v3/invoices/{id}/pdf marked deprecated in favor of GET /v3/documents/{id}?type=invoice_pdf. Header X-Invoice-Legacy still accepted. No removal date in this note. POST /v3/invoices unchanged.
Removed: GET /v3/invoices/{id}/pdf
Replacement: GET /v3/documents/{id}?type=invoice_pdf
Sunset: NONE (changelog has no date; legal has not committed one)
Support: billing-api@northwind.example, weekday 14:00-22:00 UTC, ticket tag BILL-API
Audience: integrators who fetch invoice PDFs
Steps: switch client to /v3/documents; keep X-Invoice-Legacy until we publish a sunset; no SDK bump named
Banned: end of life Friday, 90 days, 12 percent of traffic
Budget: 350

Example Output

1. Ledger. Version 3.9.0 dated 2026-08-12. Removed: GET /v3/invoices/{id}/pdf. Replacement: GET /v3/documents/{id}?type=invoice_pdf. Header X-Invoice-Legacy still accepted. POST /v3/invoices unchanged. Sunset: NONE. Support: billing-api@northwind.example, weekday 14:00-22:00 UTC, tag BILL-API. Forbidden: Friday EOL, 90 days, 12 percent of traffic, invented SDK version.

2. Subject. Northwind Billing API: invoice PDF path deprecated (58). No sunset in subject.

3. Notice. In Billing API v3.9.0 (2026-08-12) GET /v3/invoices/{id}/pdf is deprecated. POST /v3/invoices is unchanged. X-Invoice-Legacy is still accepted. Sunset date not specified in the changelog or this brief. Integrators who fetch invoice PDFs must switch when they can; we will not invent a last-call day.

4. Replacement. Use GET /v3/documents/{id}?type=invoice_pdf. No other successor is named.

5. Migration. 1) Point the PDF client to /v3/documents/{id}?type=invoice_pdf. 2) Keep sending X-Invoice-Legacy until a sunset is published. 3) SDK bump: NOT IN INPUTS.

6. Support. billing-api@northwind.example, weekday 14:00-22:00 UTC, tag BILL-API. No status-page URL was provided.

7. FAQ. Q: When is it removed? A: not specified. Q: Does POST /v3/invoices change? A: No, changelog says unchanged. Q: New header? A: X-Invoice-Legacy still accepted; no new header named. Q: Weekend support? A: not specified; hours are weekday 14:00-22:00 UTC.

8. Compliance. Cut: end of life Friday, 90 days, 12 percent of traffic. Word count under 350. Gaps: sunset date, SDK version, status URL, auth scheme, error body for the old path.