add-family

name	add-family
description	Add a new drmTMB distribution family with likelihood, simulation, tests, and documentation.

Add a Distribution Family

Use this skill when adding a new response family to drmTMB.

Required Outputs

• R family constructor.
• TMB density implementation or template integration.
• Simulation function.
• Parameter-recovery tests.
• Documentation and examples.
• Update to docs/design/02-family-registry.md.
• Update to docs/design/03-likelihoods.md.
• Update to docs/design/19-family-link-contract.md when the family adds a new link, fitted-response rule, variance rule, or parameter meaning.

Checklist

1. Define response dimension: univariate or bivariate.
2. Define distributional parameters.
3. Define links and inverse links.
4. Define native parameter meanings.
5. Define what predict(type = "response"), fitted(), and sigma() return.
6. Define the variance rule or explain why no finite variance is available.
7. Define valid parameter bounds.
8. Write likelihood on numerically stable scales.
9. Add starting-value strategy.
10. Add simulation tests for typical and boundary cases.
11. Add tests for link-scale predictions, response-scale predictions, and fitted response summaries.
12. Add user-facing documentation.

Do not add families just because they are available elsewhere. Families should serve a clear distributional-regression use case.