Extends the declarative engine past cloud architecture. The tool routing was
divided by icon library — AWS through the engine, everything else hand-written
XML — which is the wrong axis. What matters is the LAYOUT SHAPE.
Measured first: a six-step approval flow declared in its natural order comes out
as one column, because the layout only arranges what nesting tells it to and
never looked at the arrows. That forces the arrow from the decision to its second
branch to jump over the first branch.
graph.ts computes what the layout should have looked at: layer assignment by
longest path, cycle breaking so a loop is drawn without setting the order, and
barycentre sweeping to cut edge crossings. It emits ordinary container
operations, so layout, routing and round-tripping are unchanged — reaching zero
arrows-through-boxes on a 14-node pipeline and zero crossings on a bipartite
graph whose declared order forces three.
Three new container kinds, each because one layout rule cannot serve them all:
pool — swimlanes. Lanes are real cells and each step is parented to its
band, so dragging a step to another role records the change.
sequence — participants across the top, one lifeline cell per participant so
head and line stay together on a drag. Messages bypass the router:
a message's height IS its order.
radial — mind maps and org charts. Children are a flat list and the
hierarchy comes from the links, because a branch is a box and a box
cannot hold children.
Flowchart box shapes (diamond, stadium, parallelogram, document) so a reader can
tell a branch from a step.
Two bugs the new tests caught: the duplicate-link guard blocked a sequence
diagram from having two messages between the same pair, and the fallback message
numbering was shared across containers, pushing a second diagram's messages off
its own lifelines.
523 unit tests and 17 diagram e2e tests pass. Every kind verified round-trip
stable to a fixed point, and rendered in a real browser — draw.io keeps the
lifeline shape and the lane markers.
Closes the loop: the model can now build and edit AWS architecture diagrams by
declaring structure, and never writes an mxCell again.
catalog.ts — 983 AWS icon and 19 group stencils as a name→style map, generated from
drawio-ai-kit's catalog (itself generated from jgraph's draw.io shape index). Styles
are verbatim, so the official category colours, connection points and aspect=fixed
come along for free and nothing is hand-assembled. An invented name is rejected with
suggestions instead of rendering as a blank square, which is what draw.io does with
an unknown resIcon today.
operations.ts — what the model actually sends: add_icon / add_container / move /
link / set_dir and so on, applied in order against the tree. Guards the things that
break a diagram quietly: duplicate ids (draw.io drops one of the two cells), edges
left pointing at a removed node, and moving a container inside itself.
index.ts — the entry point. current XML → parse → apply ops → check names → layout →
render → new XML. The tree is not stored between calls; it is re-derived from the
canvas every time, so a user's manual edits are input to the next layout rather than
state to reconcile.
Token cost, measured with Claude's tokenizer rather than estimated:
- build a VPC diagram: 515 tok as operations vs 3180 as XML (6.2x)
- add one icon: 27 tok as an operation vs 3823 re-emitting (142x)
- read current state: 216 tok as an outline vs 3180 as XML (14.7x)
The 142x is the one that matters day to day: "add a Redis" is one operation, not a
rewrite of the whole diagram.
Routing in the system prompt sends AWS architecture through this path and leaves
flowcharts, BPMN, sequence diagrams, mind maps and Azure/GCP on display_diagram —
the layout engine's primitives (nested rows, columns, grids) do not model a sequence
diagram's lifelines or a mind map's radial spread, and pretending otherwise would
make those worse rather than better.
Also: added a NOTICE recording the MIT port and the AWS Architecture Icons terms,
and a narrow .gitignore exception so the generated catalog is tracked while the
root data/ directory (admin settings, contains secrets) stays ignored.
403 unit tests + 3 new e2e. Verified in the real app: a structural tool call renders
with real stencils and container markers; a second call adds one node and keeps
everything from the first; an invented name is refused and nothing is drawn. The 13
existing diagram e2e tests still pass.
* feat: add Material Design Icons shape library (#685)
Add Google Material Design Icons as a new shape library using Google's
CDN. Includes top 300 most popular icons by usage, and updates system
prompts to guide the AI to call get_shape_library before using any icon
library.
* fix: align get_shape_library guidance for non-cloud icon libraries
* feat(prompt): add language-aware response rules with english fallback
Added language handling rules for user interactions.
* refactor(prompt): simplify language matching instruction
* fix(edit_diagram): implement cascade delete for children and edges
- Add automatic cascade deletion when deleting a cell
- Recursively delete all child cells (parent attribute references)
- Delete all edges referencing deleted cells (source/target)
- Skip silently if cell already deleted (handles AI redundant ops)
- Update prompts to inform AI about cascade behavior
Fixes#450
* fix: add root cell protection and sync MCP server cascade delete
- Add protection for root cells '0' and '1' to prevent full diagram wipe
- Sync MCP server with main app's cascade delete logic
- Both lib/utils.ts and packages/mcp-server now have identical delete behavior
* chore(mcp): bump version to 0.1.9
* fix(cascade-delete): recursively collect edge children (labels)
- Change from cellsToDelete.add(edgeId) to collectDescendants(edgeId)
- Fixes orphaned edge labels causing draw.io to crash/clear canvas
- Edge labels (parent=edgeId) are now deleted with their parent edge
Fixes#374 - Models were confused by the `type` field name and sent
`operation` instead. This change:
- Renames DiagramOperation.type to DiagramOperation.operation across
all files (MCP server, web app, hooks, components, system prompts)
- Adds JSON examples in tool descriptions to show correct format
- Updates all test data to use the new field name
Affected files:
- lib/utils.ts
- app/api/chat/route.ts
- hooks/use-diagram-tool-handlers.ts
- components/chat-message-display.tsx
- lib/system-prompts.ts
- packages/mcp-server/src/diagram-operations.ts
- packages/mcp-server/src/index.ts
- scripts/test-diagram-operations.mjs
MCP server version bumped to 0.1.6
* feat: add get_shape_library tool for AI icon discovery
- Add server-side tool that returns shape library documentation
- AI can fetch icon/shape names on-demand before generating diagrams
- Includes path traversal protection and input sanitization
- Library index embedded in tool description for discoverability
- Supports 33 libraries: AWS, Azure, GCP, Kubernetes, Cisco, etc.
* fix: improve get_shape_library error handling and imports
- Move fs/path imports to top of file (avoid dynamic imports per call)
- Distinguish file-not-found vs other errors in catch block
- Include invalid input in validation error message
- Log unexpected errors for debugging
* docs: add get_shape_library to system prompt tool list
- Add Tool4 (get_shape_library) to available tools section
- Add usage guidance in 'Choose the right tool' section
- Update AWS icons note to reference get_shape_library for icon discovery
* fix: display get_shape_library tool output in chat UI
* fix: correct state check for get_shape_library output display
* fix: make get_shape_library output respect fold state
* style: auto-format with Biome
---------
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
* refactor: replace text-based edit_diagram with ID-based operations
- Add applyDiagramOperations() function using DOMParser for ID lookup
- New schema: operations array with type (update/add/delete), cell_id, new_xml
- Update chat-panel.tsx handler for new operations format
- Update OperationsDisplay component to show operation type and cell_id
- Simplify system prompts with new ID-based examples
- Add ID validation for add operations
- Add warning for edges referencing deleted cells
* fix: add ID validation to update operation and remove dead code
- Add ID mismatch validation to update operation (consistency with add)
- Remove orphaned replaceXMLParts function (~300 lines of dead code)
- Update cell_id schema description for clarity
- Add unit tests for applyDiagramOperations (11 tests)
* feat: add minimal style mode toggle for faster diagram generation
- Add Minimal/Styled toggle switch in chat input UI
- When enabled, removes color/style instructions from system prompt
- Faster generation with plain black/white diagrams
- Improves XML auto-fix: handle foreign tags, extra closing tags, trailing garbage
- Fix isMxCellXmlComplete to strip Anthropic function-calling wrappers
- Add debug logging for truncation detection diagnosis
* fix: prevent false XML parse errors during streaming
- Escape unescaped & characters in convertToLegalXml() before DOMParser validation
- Only log console.error for final output, not during streaming updates
- Prevents Next.js dev mode error overlay from showing for expected streaming states
* refactor: simplify LLM XML format to output bare mxCells only
- Update wrapWithMxFile() to always add root cells (id=0, id=1) automatically
- LLM now generates only mxCell elements starting from id=2 (no wrapper tags)
- Update system prompts and tool descriptions with new format instructions
- Update cached responses to remove root cells and wrapper tags
- Update truncation detection to check for complete mxCell endings
- Update documentation in xml_guide.md
* fix: address PR review issues for XML format refactor
- Fix critical bug: inconsistent truncation check using old </root> pattern
- Fix stale error message referencing </root> tag
- Add isMxCellXmlComplete() helper for consistent truncation detection
- Improve regex patterns to handle any attribute order in root cells
- Update wrapWithMxFile JSDoc to document root cell removal behavior
* fix: handle non-self-closing root cells in wrapWithMxFile regex
* feat: add append_diagram tool for truncation continuation
When LLM output hits maxOutputTokens mid-generation, instead of
failing with an error loop, the system now:
1. Detects truncation (missing </root> in XML)
2. Stores partial XML and tells LLM to use new append_diagram tool
3. LLM continues generating from where it stopped
4. Fragments are accumulated until XML is complete
5. Server limits to 5 steps via stepCountIs(5)
Key changes:
- Add append_diagram tool definition in route.ts
- Add append_diagram handler in chat-panel.tsx
- Track continuation mode separately from error mode
- Continuation mode has unlimited retries (not counted against limit)
- Error mode still limited to MAX_AUTO_RETRY_COUNT (1)
- Update system prompts to document append_diagram tool
* fix: show friendly message and yellow badge for truncated output
- Add yellow 'Truncated' badge in UI instead of red 'Error' when XML is incomplete
- Show friendly error message for toolUse.input is invalid errors
- Built on top of append_diagram continuation feature
* refactor: remove debug logs and simplify truncation state
- Remove all debug console.log statements
- Remove isContinuationModeRef, derive from partialXmlRef.current.length > 0
* docs: fix append_diagram instructions for consistency
- Change 'Do NOT include' to 'Do NOT start with' (clearer intent)
- Add <mxCell id="0"> to prohibited start patterns
- Change 'closing tags </root></mxGraphModel>' to just '</root>' (wrapWithMxFile handles the rest)
- Add client-side PDF text extraction using unpdf library
- Support text files (.txt, .md, .json, .csv, .py, .js, .ts, etc.)
- Add file preview with character count for PDF/text files
- Add 150k character limit for extracted content
- Highlight Paper to Diagram example with NEW badge
- Fix React hydration error by adding explicit IDs to ResizablePanelGroup
- Remove code duplication by centralizing file utilities in pdf-utils.ts
- Add Biome as formatter and linter (replaces Prettier)
- Configure Husky + lint-staged for pre-commit hooks
- Add VS Code settings for format on save
- Ignore components/ui/ (shadcn generated code)
- Remove semicolons, use 4-space indent
- Reformat all files to new style
- Add App Context section describing the left/right panel layout
- Add App Features section with icon locations (history, theme, upload, export, clear)
- Dynamically inject model name into system prompt via {{MODEL_NAME}} placeholder
- Expand edit_diagram tool description with usage guidelines
- Extract system prompts to dedicated lib/system-prompts.ts module
- Add extended system prompt (~4000 tokens) for models with higher cache minimums (Opus 4.5, Haiku 4.5)
- Clean up debug logs while preserving informational and cache-related logs
- Improve code formatting and organization in chat route
