## Overview
<!-- Brief description of what documentation is being added/updated -->
This patch adds docs how one would build custom HITL forms using
interrupts that describe UI forms.
## Type of change
**Type:** Update existing documentation
## Checklist
<!-- Put an 'x' in all boxes that apply -->
- [x] I have read the [contributing guidelines](README.md), including
the [language
policy](https://docs.langchain.com/oss/python/contributing/overview#language-policy)
- [x] I have tested my changes locally using `docs dev`
- [x] All code examples have been tested and work correctly
- [x] I have used **root relative** paths for internal links
- [x] I have updated navigation in `src/docs.json` if needed
(Internal team members only / optional): Create a preview deployment as
necessary using the [Create Preview Branch
workflow](https://github.com/langchain-ai/docs/actions/workflows/create-preview-branch.yml)
## Additional notes
<!-- Any other information that would be helpful for reviewers -->
---------
Co-authored-by: Naomi Pentrel <5212232+npentrel@users.noreply.github.com>
## Overview
Split the monolithic streaming/frontend documentation pages into
individual pattern-specific pages across LangChain, LangGraph, and
DeepAgents. Each page covers a single frontend pattern (tool calling,
human-in-the-loop, branching chat, etc.) with an interactive playground
embed powered by the `@langchain/docs-sandbox` npm package.
Also restructures the "Streaming" nav groups into a top-level
"Streaming" page and a new "Frontend" nav group for each product.
## Type of change
**Type:** New documentation page / Update existing documentation
## Related issues/PRs
- GitHub issue:
- Feature PR:
- Linear issue:
- Slack thread:
## Checklist
- [x] I have read the [contributing guidelines](README.md)
- [x] I have tested my changes locally using `docs dev`
- [ ] All code examples have been tested and work correctly
- [ ] I have used **root relative** paths for internal links
- [ ] I have updated navigation in `src/docs.json` if needed
(Internal team members only / optional): Create a preview deployment as
necessary using the [Create Preview Branch
workflow](https://github.com/langchain-ai/docs/actions/workflows/create-preview-branch.yml)
## Additional notes
### New frontend pattern pages
**LangChain** (10 pages):
`tool-calling`, `human-in-the-loop`, `branching-chat`,
`optimistic-updates`, `reasoning-tokens`, `structured-output`,
`async-iterator-tools`, `message-queues`, `join-rejoin`, `time-travel`
**DeepAgents** (2 pages):
`subagent-streaming`, `todo-list`
**LangGraph** (1 page):
`graph-execution`
Each page includes a `<PatternEmbed>` component that renders an
interactive playground preview from the `@langchain/docs-sandbox`
package.
### Playground embed build pipeline
The `PatternEmbed` component is now sourced from the
`@langchain/docs-sandbox` npm package rather than being manually
maintained in the source tree:
- Added `package.json` with `@langchain/docs-sandbox@0.0.3` dependency
- Added `.npmrc` with `legacy-peer-deps=true` (needed because the
package declares a peer dependency using pnpm's `workspace:*` protocol)
- Updated `pipeline/core/builder.py` to copy
`node_modules/@langchain/docs-sandbox/dist/PatternEmbed.jsx` →
`build/snippets/pattern-embed.jsx` during the build step
- CI pipelines need to run `npm install` before building docs
### Navigation changes (`src/docs.json`)
- Collapsed `Streaming` sub-group (overview + frontend) into a single
top-level `streaming` page under LangChain and DeepAgents
- Added new `Frontend` nav groups for LangChain (10 pages), DeepAgents
(3 pages including overview), and LangGraph (2 pages including overview)
---------
Co-authored-by: Naomi Pentrel <5212232+npentrel@users.noreply.github.com>
Christian Bromann