Restructure API Reference docs: consolidate config, errors, and server URLs

[devin-ai-integration]

Restructure API Reference documentation

Summary

Consolidates and reorganizes the API Reference documentation section:

1. Moved configuration options from generate-api-ref.mdx into customize-api-ref.mdx as a "Configuration options" section using ParamField components with Badge tags indicating supported reference types (OpenAPI, Fern Definition, GraphQL, OpenRPC, Webhook, WebSocket, AsyncAPI). The old markdown table was removed and replaced with a link to the customize page.

2. Merged endpoint errors page into customize-api-ref.mdx as a "Displaying endpoint errors" subsection. Deleted the standalone endpoint-errors.mdx and removed it from navigation.

3. Merged server URLs page into api-explorer.mdx under the existing "Multiple environments" section. Deleted the standalone server-urls.mdx and removed it from navigation.

4. Added reference type badges to ### subsection headings throughout the customize page, cross-referenced against the ApiReferenceConfiguration schema and individual reference type pages.

5. Added WebSocket tab examples to the three sections with WebSocket/AsyncAPI badges (Ordering section contents, Styling endpoints, Hiding endpoints), showing WSS /path/name syntax.

6. Cleaned up reference generation pages: simplified descriptions and introductory text for generate-api-ref.mdx, generate-webhook-ref.mdx, generate-websocket-ref.mdx, and generate-openrpc-ref.mdx. Restructured generate-api-ref.mdx with a Steps component and added a tip about other supported reference types.

7. Updated navigation titles to use consistent sentence case with "Reference" capitalized (e.g., "Generate REST API Reference", "Customize API Reference layout").

8. Added redirects for old URLs: endpoint-errors, server-urls, and the generate-api-ref#api-reference-configuration-options anchor.

9. Updated internal links (changelog entry) and added WSS to Vale style exceptions.

Review & Testing Checklist for Human

• Verify the preview deployment renders correctly: badges under each ### heading, ParamField components in config section, WebSocket tabs, and endpoint errors section.
• Verify AsyncAPI badge color — uses <Badge color="teal">AsyncAPI</Badge>. Confirm "teal" is a supported Badge color and renders properly in light/dark mode.
• Test redirects — Verify the three new redirects resolve correctly, especially the fragment-based redirect (generate-api-ref#api-reference-configuration-options → customize-api-reference-layout#configuration-options), which may not be supported by Fern's redirect system.
• Verify server-urls consolidation — The content from the deleted server-urls.mdx was moved into api-explorer.mdx's "Multiple environments" section. Confirm no content was lost and the environment persistence Loom embed still works.
• Check WebSocket tab examples — The three new WebSocket tabs use plant-themed endpoints (/plants/live-updates, /plants/growth-monitor). Verify YAML syntax is valid and examples are consistent with doc conventions.

Notes

• Link to Devin run
• Requested by @devalog

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[github-actions]

🚫 [vale] _{reported by reviewdog 🐶}
[FernStyles.Reject] Use 'API Reference' instead of 'API reference'.

[github-actions]

🌿 Preview your docs: https://fern-preview-7eafe0ee-0585-44a9-9460-ed34f44a0e1f.docs.buildwithfern.com/learn

Here are the markdown pages you've updated:

• learn/docs/api-references/api-explorer/overview
• learn/docs/api-references/customize-api-reference-layout
• learn/docs/api-references/generate-api-ref
• learn/docs/api-references/generate-openrpc-ref
• learn/docs/api-references/generate-webhook-reference
• learn/docs/api-references/generate-websocket-ref
• learn/docs/changelog/2025/11/25

[github-actions]

🚫 [vale] _{reported by reviewdog 🐶}
[Microsoft.Contractions] Use 'don't' instead of 'Do not'.

[github-actions]

🚫 [vale] _{reported by reviewdog 🐶}
[Microsoft.Contractions] Use 'don't' instead of 'Do not'.