- A session whose state expired was recovered from its auto-save file only
for the preview page; the tools built on their older copy and then
overwrote the file. They now recover it first (restoreSavedSession).
- A preview tab that missed the last AI write pushed its older diagram
over the recovered one after a restart. It now shows the recovered
diagram and keeps its own copy in History.
- An empty record of what the model has seen (after load_diagram or a
page tool on unseen changes) no longer lets one page of a multi-page
document count for all, and get_diagram counts a page only once found.
- History: a thumbnail goes only to the entry it shows, the cached image
never belongs to an older diagram, a re-serialized copy adds no entry,
and a cleared document with its own pages is kept before a restore.
- The root cell id check reads attributes one by one: rack-id="1" or id
text inside a label no longer counts.
- A compressed page counts as having cells; a saved file that could not
be read is never written over.
Found by the second PR review:
- get_diagram with a page selector, or a rejected edit's error, counted
the whole document as seen, so an edit on another page could overwrite
the user's change there. A one-page view now counts for all pages only
if the others are unchanged; otherwise the reply says to get them.
- add_page accepted shapes with the root cell ids "0" and "1" and renamed
them, breaking their edges. The check also missed ids on UserObject
wrappers and ids written with spaces around the "=".
- Root cells written over two lines were kept as an extra layer, cells
with id = "a" did not count as cells, and CDATA text before a page's
model passed the check although draw.io cannot open the page.
- Auto-save cleanup deleted the user's own files that start with mcp-.
Only names in the session id format are removed now.
- Restoring a history entry dropped edits made in the browser since the
last entry. They are added to history first.
- A session whose state expired showed a blank page, and the next change
overwrote its auto-save file. The saved file is loaded instead.
- An edit on a page export's one-page projection, made before the real
document was back, replaced the whole document.
- A late sync reply could overwrite a newer edit: each sync export is
numbered, and the server ignores replies older than the current state.
- screenshot_diagram could return another session's image after
start_session ran during its retries.
The web app will reuse the MCP server's XML engine instead of its own
copy in lib/utils.ts, so these modules now run in the browser too.
- Relative imports end in .ts, rewritten to .js by tsc
(rewriteRelativeImportExtensions); Next.js resolves them directly
- Every module uses the global DOMParser/XMLSerializer: native in the
browser, linkedom in Node via installDomPolyfill. pages.ts parsed with
linkedom but serialized with the global serializer, which throws in
the browser
- The saxes syntax check moves to xml-syntax.ts, so the browser does not
pull in linkedom; it now also rejects undeclared prefixes such as
xlink:, as the browser does
- Page decompression uses pako and atob instead of node:zlib and Buffer
- hasCells moves to pages.ts, away from the file system code
- The duplicate cell id check counts UserObject/object ids
- wrapCellsInModel drops comments and text before the first cell, which
the web app accepts today
- validateAndFixXml takes { strict: false } for diagrams with user content
- Web tests run these modules with a browser DOM (jsdom)
- saxes becomes a direct dependency of the web app
- Validate and escape the mcp session id; only serve localhost Host/Origin
- Malformed URLs and session ids return errors instead of crashing the process
- Strict XML syntax check with saxes (linkedom never reports parse errors)
- autoFixXml no longer corrupts valid XML; attribute newlines serialized as entities
- Sessions stay alive while polled; browser pushes carry a base version (409 on conflict)
- Page tools respect the edit gate; UTF-8 bodies decoded correctly
- Export replies matched to requests and serialized; xml sync export handled
- UserObject/object cells addressable by id; history restored by stable id; logs off stdout
* fix(mcp): keep diagram context valid during edits
Closes#885
* fix(mcp): replace edit_diagram time gate with content comparison
The 30s wall-clock gate rejected slow-but-correct clients (#885).
Instead of a timeout, remember the exact state-store XML the model
last saw (get_diagram / create_new_diagram / edit_diagram / page CRUD)
and reject edit_diagram only when the live browser state differs -
i.e. the user made edits the model hasn't seen yet. Slow reasoning
no longer trips the gate, while unseen manual edits still do.
* docs(mcp): align edit_diagram/get_diagram descriptions with content-based gate
The 'You MUST call get_diagram BEFORE this tool' requirement and the
'Skipping get_diagram WILL cause user's changes to be LOST' warning no
longer match server behavior: a stale edit is rejected with no side
effects, never silently applied. Describe the freshness check instead,
and direct get_diagram usage at its real purpose - learning the current
diagram content when the model doesn't already know it.
* fix(mcp): compare diagram content structurally in the edit gate
draw.io re-serialises the document when pushing state back (attribute
order, pretty-printing, regenerated diagram ids, viewport attributes,
mxfile host), so byte comparison could flag an unchanged diagram as
stale. Fingerprint what a user can actually change instead - page set,
page names, and each page's root cell tree with sorted attributes -
keeping byte equality as the fast path. A bare mxGraphModel now also
fingerprints identically to its single-page mxfile wrapping.
* fix(mcp): don't compare page names against bare mxGraphModel pushes
A bare <mxGraphModel> pushed by the embed/sync path carries no page name,
so normalizeToMxfile invents "Page-1" — falsely reading any custom page
name as a content change and re-triggering the stale rejection on every
edit. When either side of the gate comparison is a bare mxGraphModel,
fingerprint cell trees only; full-mxfile comparisons still detect renames.
* chore(mcp): bump version to 0.2.2
* chore(mcp): sync package-lock.json version to 0.2.2
---------
Co-authored-by: dayuan.jiang <[email protected]>
dayuan.jiang