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BlocksArtifacts
Agent Mermaid Artifact
Agent Mermaid Artifact
Template-style Mermaid artifact with data-mermaidDelta streaming, diagram preview and source editor, SVG/PNG export, in-memory versions, and quick prompts — no database persistence.
Use this when users iterate on agent-drawn Mermaid diagrams in the browser, keeping versions in memory and exporting the result as SVG or PNG.
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Problems solved
Technical challenges this implementation handles out of the box.
- Stream Mermaid diagram JSON with data-mermaidDelta UI parts
- Edit diagram source alongside a live Mermaid preview
- Export diagrams as SVG or PNG
- Keep diagram versions in memory without database persistence
Use cases
Products and workflows this pattern is designed to support.
- Architecture explanation copilots
- Onboarding flow diagrams from chat
- Sequence and flowchart artifacts
- In-browser Mermaid editors for agents
Compare with
Similar patterns, and when each one is the better fit.
Agent Sheet ArtifactUse this when a chat agent should stream CSV table updates into a side artifact panel the user can edit as a grid, with versions kept in memory.
Agent Text ArtifactUse this when an agent should stream Markdown text into a document the user can edit in a rich editor next to the chat, with versions kept in memory.
Agent Slides ArtifactUse this when you are prototyping an agent that builds slide decks as a sortable, editable artifact streamed through data-slidesDelta parts.
Agent Code ArtifactUse this when users and agent tools both edit a runnable Python file beside the chat and you only need in-memory version history.
Setup
Requirements, wiring steps, and what this pattern adds to your project.
Getting started
Pick how you want to pull this pattern in. Then wire env vars and routes the same way.
- 1
Download → Next.js app
Use Download → Next.js app in the preview toolbar. You get a zip scaffold (Pro downloads rewrite preview `/view/.../api/*` paths to `/api/*` automatically).
- 2
Extract the zip and install dependencies
Unzip the archive, then run `pnpm install` (or npm / yarn) in the project folder.
- 3
Fill .env.local
The download includes .env.local placeholders when needed. Add real values for: AI_GATEWAY_API_KEY.
- 4
Customize the agent and tool files
Adapt prompts, tools, and stop conditions in the generated project for your product.
- 5
Run the app and open the pattern route
Run `pnpm dev`, open the setup/checklist page if present, then navigate to the generated pattern route and verify responses.
Environment variables
AI_GATEWAY_API_KEYGet key
Capabilities
AI SDK APIs
streamTextcreateUIMessageStreamgatewaytoolProviders
OpenAI
External services
Upstash
Files added
22 files
app/page.tsxapp/layout.tsxapp/api/agent-mermaid-artifact/route.tscomponents/agent-mermaid-demo.tsxcomponents/mermaid-artifact-tool.tsxcomponents/mermaid-artifact-panel.tsxcomponents/mermaid-diagram.tsxcomponents/data-stream-provider.tsxcomponents/data-stream-handler.tsxcomponents/empty-state.tsxhooks/use-artifact.tsxlib/types.tslib/create-artifact.tslib/mermaid-artifact.tsxlib/mermaid-document.tslib/mermaid-sanitize.tslib/mermaid-export.tslib/mermaid-theme.tslib/artifacts.tslib/rate-limit.tslib/request-utils.tsREADME.md
Dependencies
16 total
npm packages
10AISDKUpstashdate-fnslucide-reactmermaidNext.jsReactsonnerusehooks-tsZod
Registry components
buttondraweremptytabstextareatooltip
Critical files
2 files
lib/mermaid-artifact.tsxDefines mermaidArtifact with onStreamPart for data-mermaidDelta, Mermaid preview/source tabs, and export actions.
agent-mermaid-artifact/route.tscreateUIMessageStream merges streamText with updateMermaidDiagram tool; emits data-id, data-title, data-kind, data-mermaidDelta, data-finish.
Requirements
- Complexity
- Intermediate
- Setup time
- ~8 minutes
- Node
- 24+
- Memory
- 256MB
Upstash Redis
