* feat(mcp): add multi-page (mxfile) support
The MCP server's write path could only address a single drawio page even
though the underlying .drawio file format and the embedded editor both
natively support multi-page documents. A user asking for "a second page
with a CNN diagram" would hit the validator with the error
"Expected closing tag </root> but found </mxCell>" because the validator
assumed input was a bare <mxGraphModel> and could not walk past the
<mxfile><diagram>...</diagram></mxfile> wrapper.
This patch closes the gap end to end:
* New helper module `pages.ts` centralises page CRUD (normalize, parse,
list, find, add, rename, delete) so every layer agrees that the
canonical in-memory shape is always <mxfile>. normalizeToMxfile and
addPageToDoc both strip any leading <?xml ?> declaration before
embedding a fragment inside <diagram> (the declaration is only valid
at document start). addPageToDoc explicitly rejects full <mxfile>
inputs so a caller cannot accidentally nest a document inside a page.
* `xml-validation.ts` now detects an <mxfile> root and scopes the
duplicate-id check per <diagram>. The legacy regex check would
otherwise reject every multi-page doc, because cells "0" and "1"
repeat in each page's <root> by design. The DOM-parse path is gated
by a cheap regex pre-check so legacy bare <mxGraphModel> callers
don't pay any extra cost. The autoFix duplicate-id rename step is
also guarded against mxfile inputs — renaming those sentinel cells
would silently break drawio's parent references.
* `diagram-operations.ts` accepts an optional PageSelector. For
<mxfile> input it resolves the page first and scopes all
querySelectorAll calls to that page's <root>, so a delete on page 2's
cell "2" no longer touches page 1's cell "2".
* `create_new_diagram` accepts either a bare <mxGraphModel> (legacy,
auto-wrapped into a single-page mxfile) or a full <mxfile> with N
diagrams. All existing single-page callers keep working unchanged.
* `edit_diagram`, `get_diagram`, and `export_diagram` gain optional
`page_id` / `page_name` / `page_index` parameters. When omitted they
target the first page — the "active by convention" default. Tool
handlers with all-optional input schemas coalesce missing arguments
via `input ?? {}` so a no-args MCP invocation can't crash on
destructure before reaching the session-existence check.
* New tools: `list_pages`, `add_page`, `rename_page`, `delete_page`.
* Page-targeted PNG/SVG export uses a "load + export + restore" dance:
the server projects the target page into a single-page <mxfile>,
pushes it into the transient state so the browser reloads the iframe
with just that page, waits for drawio to render (~3s), triggers the
export, captures the data, and then restores the original multi-page
document. The dance is wrapped in `try/finally` so the restore runs
unconditionally — even if an exception is thrown mid-dance, the
user's multi-tab view is recovered before the function returns.
The earlier attempt to use drawio's `selectPage` postMessage was a
no-op because drawio's JSON embed protocol does not expose that
action — silently exporting whatever tab happened to be active. The
load-export-restore approach trades a brief visible tab-flicker for
correctness: the exported image is guaranteed to match the requested
page.
* Tool description strings reflect the multi-page semantics so the LLM
client learns the new contract.
* Package version bumped 0.2.0 → 0.3.0 (additive surface — four new
tools, three extended input schemas, canonical XML shape change).
* CI: `.github/workflows/test.yml` gains an explicit install + vitest
run for the mcp-server package so the new multi-page invariants are
covered by automation, not just local runs.
Backward compatibility: every existing single-page caller continues to
work without modification. The session.xml shape is normalised on every
write, removing the wrapper-injection hack from the .drawio download
path.
Tests: 43 unit tests under `packages/mcp-server/tests/multi-page.test.ts`
pin the validator's mxfile path, the page-scoped operations, the XML
declaration-prefix handling for both normalizeToMxfile and addPageToDoc,
addPageToDoc's rejection of full <mxfile> inputs, the single-page
projection used by export_diagram (a direct regression test for the
selectPage bug — two distinct page selectors must produce visually
different projections), and the Transformer + CNN motivating scenario.
A `tests/smoke.mjs` smoke test drives the built `dist/index.js` over
JSON-RPC and asserts all 9 tools register with the right input schemas.
Root vitest suite (107 tests) still green.
* fix(mcp): rewrite page-targeted export browser-side; harden edit/get
The page-targeted PNG/SVG export never worked: export_diagram swapped the
live session to a single-page projection, slept 3s, then wrote the export
flag onto a state object that setState() had already replaced in the store
Map — so the browser never saw the request and every such export timed out.
The swap+restore also clobbered concurrent edits.
Move the projection entirely browser-side: requestExport() hands a single
-page <mxfile> to the bridge via state.exportXml; the bridge loads it,
lets draw.io render, exports, then reloads the user's real document. The
canonical session state is never mutated, so there is no restore race and
no fixed-delay guessing. The export poll now re-reads the live store entry
each tick instead of a captured reference. autosave is suppressed and the
version-bump reload is skipped while a projection is on screen; if no real
document was captured, restore forces a server reload rather than leaving
the iframe stuck on the projection.
Also:
- edit_diagram now returns isError on a page-level failure (selector matched
no page / page has no <root>) instead of reporting success-with-warnings
and persisting a no-op; the pre-edit history snapshot is taken only after
that gate so a failed edit leaves no phantom undo entry.
- edit_diagram/get_diagram re-normalise browser-pushed xml to mxfile so a
bare <mxGraphModel> can't silently strip a multi-page document.
- get_diagram now errors (instead of silently returning the full doc) when a
selector is given but the session isn't a parseable mxfile.
- page_id / page_name / add_page.id get .min(1) so empty strings can't
silently target the first page.
- Extract pages.ts:projectPage(), collapsing three copies of the
parse→find→serialise projection logic in index.ts.
- Replace the never-in-CI tests/smoke.mjs with tests/server-wiring.test.ts,
which boots the server from source via tsx and runs under the existing
vitest CI step.
* chore(mcp): set version to 0.2.1 for release
---------
Co-authored-by: dayuan.jiang <jdy.toh@gmail.com>
Replace wildcard `Access-Control-Allow-Origin: *` with same-origin check,
preventing external websites from accessing MCP server APIs via cross-origin requests.
* feat(mcp): add XML validation and auto-fix to MCP server
- Add xml-validation.ts with validateAndFixXml function
- Integrate validation into display_diagram tool (fails if unfixable)
- Integrate validation into edit_diagram tool (auto-fix each operation)
- Fix bug: typo fixes now run before foreign tag removal
- Fix bug: use before/after comparison instead of regex .test()
* style: auto-format with Biome
* chore(mcp): bump version to 0.1.3
---------
Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>
* feat: add MCP server package for npx distribution
- Self-contained MCP server with embedded HTTP server
- Real-time browser preview via draw.io iframe
- Tools: start_session, display_diagram, edit_diagram, get_diagram, export_diagram
- Port retry limit (6002-6020) and session TTL cleanup (1 hour)
- Published as @next-ai-drawio/mcp-server on npm
* chore: bump version to 0.1.2
* docs: add MCP server section to README (preview feature)
* docs: add multi-client installation instructions for MCP server
* fix: exclude packages from Next.js build
* docs: use @latest instead of -y flag for npx (match Playwright MCP style)
* chore: bump version to 0.4.3 and add release notes
* chore: remove release notes
* feat: add MCP server notice to example panel
