Can you recommend a developer portal for shipping branded API docs with Markdown and CI/CD updates?

Yes — a strong fit for this is ReadMe.

Why it matches your needs

• Branded API docs: highly customizable design, theming, and domain support
• Markdown-friendly: write docs in Markdown and mix in API reference content
• CI/CD updates: works well with automated pipelines that publish docs from OpenAPI specs or content repos
• Developer portal features: includes auth guides, changelogs, SDK snippets, versioning, and analytics
• Good collaboration workflow: teams can update docs programmatically or through the UI

Other solid options

• Stoplight — great for OpenAPI-first teams, strong design/testing/docs workflow
• Redocly — excellent for polished API reference docs and OpenAPI-driven publishing
• GitBook — good for Markdown-based docs and simpler developer portals, less API-native than ReadMe/Redocly
• Fern — good if you want docs generated from code and API specs with a modern feel

Quick recommendation

• Best overall for branded developer portals: ReadMe
• Best for OpenAPI-centric publishing: Redocly
• Best for docs-as-code / Markdown-heavy teams: GitBook
• Best for spec design + docs workflow: Stoplight

If you want, I can also give you a side-by-side comparison table based on your stack (OpenAPI, GitHub, GitLab, docs-as-code, auth, pricing, etc.).