Figma MCP Bridge README
The full upstream README, mirrored here for reference. Install config, tool schemas, adoption signals, and an original overview live on the Figma MCP Bridge listing page.
⚡ Figma MCP Bridge
Let an AI agent design in Figma — and actually see what it drew.
A zero-dependency MCP server that gives coding agents read and write access to a live Figma canvas, then closes the loop by handing the rendered PNG back to the model for visual self-critique.
Agent generates the design, visually audits the rendered output, detects layout defects, and self-corrects in real time — zero human in the loop.
The problem
Coding agents are effectively blind inside Figma. Most Figma MCP servers are read-only —
they flatten a design into text so a model can turn it into code, and the traffic stops there.
The ones that can write are either gated behind a paid Figma seat with a monthly tool-call
quota, or expose a fixed vocabulary of commands (create_rectangle, set_fill) that runs out
the moment the task gets specific.
And none of them answer the question that actually matters after a write: did it look right?
An agent that draws a card, gets back {"ok": true}, and moves on has no way to notice that its
text overflowed, its contrast failed, or its frame landed on top of someone else's work.
This bridge closes that loop, and adds the safety rails an autonomous agent needs to be trusted with a real design file.
How it's different
| This bridge | Figma Dev Mode MCP (official) | Framelink | Talk to Figma | |
|---|---|---|---|---|
| Writes to the canvas | ✅ arbitrary JS in the sandbox | ✅ code-to-canvas | ❌ read-only | ✅ fixed command set |
| Visual feedback loop | ✅ auto-framed PNG on every write | ⚠️ separate screenshot call | ❌ | ❌ |
| Undo the agent's work | ✅ figma_rollback | ❌ | n/a | ❌ |
| Works on the Figma Free plan | ✅ | ❌ Dev/Full seat, paid plan¹ | ✅ | ✅ |
| Tool-call quota | none — it's local | 6 / month on Starter seats¹ | inherits REST rate limits | none |
| Token-optimized read of the live doc | ✅ 86–91% smaller² | ⚠️ partial | ❌ REST only | ❌ |
| Persistent code modules in-sandbox | ✅ bridge.define/require | ❌ | ❌ | ❌ |
| Long jobs survive their own timeout | ✅ async job_id + progress | ❌ | n/a | ❌ |
| Install footprint | 0 npm deps, npx or git clone, Node only | Figma desktop + paid seat | npx + access token | Bun + a second server process |
The short version: Framelink is the best choice if you only want to turn an existing design into code. The official server is the safest choice if you're already on a paid Figma plan and want Code Connect. This bridge is for the case where the agent is doing the designing — where it needs to write freely, check its own work, and be undoable when it gets it wrong.
How it works
The agent speaks plain MCP over stdio. The server owns a hand-rolled RFC 6455 WebSocket on
:8765, which the Figma plugin connects to — so commands reach the canvas with no polling
latency, and results (including multi-megabyte base64 PNGs) stream straight back.
Quickstart
Or, to read the installer before it touches your machine — it's the same script either way, just fetched differently:
Both copy the server and plugin into place and register the MCP server in every AI client config
they find — Claude Desktop, Claude Code, Cursor, Windsurf, Antigravity. The npm package exists
purely for a shorter first command; it doesn't add a single runtime dependency — dependencies
is empty in its package.json too, and no Python is needed either. node is the only runtime
this project ever needs, for the installer and the server alike.
Then, in Figma Desktop:
- Plugins → Development → Import plugin from manifest… → pick
figma-plugin/manifest.json - Press
Ctrl + Alt + P(macOS:Cmd + Option + P) to launch Antigravity Bridge - Status turns green —
CONNECTED
Restart your AI client so it picks up the new tools. Verify anytime with:
Optional: Figma Cloud REST access
The live canvas tools need no token. If you also want to read unopened cloud files
(get_file, get_node, get_styles, …), supply a personal access token:
Without a token these 7 tools aren't registered at all — see Tool reference.
What it gives the agent
1. Write freely, then look at the result
capture: true returns a PNG of exactly what the call just created or modified — auto-framed
to the changed nodes, never the whole page, and never by hijacking the user's selection.
The warnings array is a cheap auto-lint over the touched subtree — text overflow, low contrast,
zero-size nodes. It catches the obvious mistakes without spending a screenshot round trip.
2. Undo anything the agent did
Every write opens a checkpoint automatically. One call reverses it — no Ctrl+Z rolling back over
the human's own unrelated work.
Created nodes are tracked automatically via a Proxy around figma.create*(). Property edits are
tracked when snapshotted. Deletions are honestly reported as unrecoverable rather than silently lost.
3. Read the live canvas for ~700 tokens instead of ~5,000
The same pruning + Pseudo-JSX pipeline that powers the cloud tools, pointed at whatever is open right now. Measured on a realistic 6-card layout: 20 KB of raw API JSON → 2.7 KB (86% smaller).
budget_tokens caps the response: if the requested depth overshoots, the server re-serializes the
already-fetched tree shallower — no second round trip — and appends a comment saying what it did
and which id to fetch for more.
4. Teach the sandbox new tricks that survive restarts
Every figma_execute_code call is a fresh function scope, so helpers normally die instantly.
bridge.define compiles and stores a module inside the .fig document:
5. Long jobs that don't die at the timeout
A generation still running after 30s hands back a job_id instead of failing while the plugin
keeps working. Poll figma_job_status for live progress — the sandbox reports it via
progress(step, of, note).
Tool reference
Tools are served in tiers, so the schema list sent to the model on every turn stays proportional to what's actually usable:
| Tier | Count | Registered when |
|---|---|---|
| Core | 8 | always |
| Extended | 5 | always |
| REST | 7 | only with FIGMA_PERSONAL_ACCESS_TOKEN set |
| Legacy | 3 | only with FIGMA_MCP_LEGACY_TOOLS=1 |
Without a REST token an agent sees 13 tools instead of 23 — and never wastes a call on
something that would only return REST_TOKEN_MISSING.
All 23 tools
Core — live canvas
| Tool | Description |
|---|---|
figma_execute_code | Run JS in the Figma sandbox. Injects figma, ensureFont, getFreePosition, progress, bridge. Supports capture, capture_node_ids, diff, async, target. |
figma_read_canvas | Token-optimized read of the live document (jsx / tree / json) with budget_tokens. |
figma_screenshot | PNG of specific node_ids or the current selection. |
figma_find_components | Cached, tokenized, fuzzy component search — variants, properties, keys. |
figma_insert_component_instance | Instantiate a component/variant, apply text overrides, place into AutoLayout. |
figma_insert_svg | Insert raw SVG with proportional scaling, recoloring, optional component wrapping. |
figma_get_variables | Variable collections, modes, and token values. |
figma_rollback | Undo a previous write call's checkpoint. |
Extended — live canvas
| Tool | Description |
|---|---|
figma_get_selection | Geometry, compact hex fills, parent/page, AutoLayout context of the selection. |
figma_get_canvas_layout | Artboard bounds + a safe suggestedNextPosition. layout:"grid" shelf-packs. |
figma_set_variables_mode | Switch theme mode (Dark/Light/Brand) on a frame or page. |
figma_job_status | Poll an escalated background job. |
figma_list_targets | List connected Figma documents for multi-file targeting. |
REST — Figma Cloud (needs a token)
| Tool | Description |
|---|---|
get_file / get_node | Token-optimized cloud file/subtree. Supports budget_tokens. |
get_image | Render nodes to PNG/SVG/PDF via Figma's renderer. |
get_styles / get_components | Published styles and design-system components. |
get_comments / post_comment | Read and post file comments. |
Legacy — opt-in via FIGMA_MCP_LEGACY_TOOLS=1
figma_create_ui_card · get_me · get_image_fills
Engineering notes
The parts that were harder than they look — and why the code is shaped the way it is.
`eval` is a trap in the Figma sandbox
The obvious way to persist helpers between calls is "stash the source, eval it next time." It
fails silently: eval is a bound function in Figma's sandbox, which by spec makes every call
an indirect eval — declarations inside it reach neither the caller's scope nor globalThis.
Nothing is defined, nothing throws.
bridge.define is built on new Function instead, whose bodies are ordinary function scopes.
The runtime's bridge.info() reports this contract to the agent on request, so it can ask instead
of guessing.
A hand-rolled RFC 6455 WebSocket, on purpose
Zero npm dependencies isn't a vanity metric here — it means git clone && node install.mjs works
on a locked-down machine with no registry access, and there's no supply chain to audit for something
that executes arbitrary JS inside your design files.
The cost is owning the framing: masking, fragmented continuation frames (a 4 MB screenshot arrives split, and treating each fragment as a whole message silently dropped it until the tool call timed out 40s later), ping/pong liveness, and a 64 MB ceiling so one frame can't exhaust memory.
Chunking `pluginData` by UTF-8 bytes, not string length
Figma caps pluginData entries at roughly 100 KB — measured in bytes. The original chunker
sliced by JS string length, so a module written in Cyrillic (~2 bytes/char) produced "60,000-char"
chunks that were really 120 KB, and setPluginData threw. The splitter now walks the real UTF-8
budget and never tears a surrogate pair.
Port ownership has to be reclaimable
Every agent spawns its own copy of the server; the first to bind :8765 owns the plugin socket and
the rest proxy to it. When the owner exits, a proxy has to be able to take over — otherwise every
surviving agent stays permanently broken until restarted. A 5-second watchdog retries the bind, and
a failed proxy call triggers an immediate takeover attempt.
Making placement O(neighbours) instead of O(n)
The original collision engine rescanned every top-level node for each of up to 200 candidate positions, then did it again in a second function in the same tick — and only ever stepped along one axis, so 20 generated screens became a mile-long ribbon nobody could zoom out to see.
Bounds are now computed once and shared; collisions go through a 500px grid hash; and layout:"grid"
shelf-packs into a compact rectangle.
Errors that tell the agent what to do instead
Raw Plugin API errors are famously unhelpful. Failures are matched against known modes and rewritten
with a HINT: line naming the API that actually works, plus a stable machine-readable code
(FONT_NOT_LOADED, INSTANCE_TRANSFORM_LOCKED, STALE_NODE_ID, AUTOLAYOUT_HUG_RESIZE,
AMBIGUOUS_TARGET, …) so agents and tooling can branch on the failure type without parsing prose.
Security: this endpoint runs arbitrary JS in your design file
:8765 is loopback, but loopback is reachable by any web page the user happens to have open.
Two independent gates: an Origin allowlist (a browser cannot forge Origin, so a page on
evil.com is rejected at the handshake) and a shared token that install.mjs generates and bakes
into both the MCP config and the installed plugin — which also covers the sandboxed-iframe case,
where a hostile page can present Origin: "null" too.
Running straight from a clone with no token, the Origin gate still applies and the server prints a warning, so it degrades rather than silently opening up.
The one network call this server makes on its own: an update check
On startup the server compares the commit it was installed from (recorded by install.mjs into a
version.json beside the copied code) against the latest commit on main via one GitHub API
request, and prints a one-line notice to stderr if they differ. It never applies anything itself —
node install.mjs --update is still a manual, deliberate step.
This is the one thing in this project that assumes network access, so it's built to disappear
cleanly when there isn't any: the check is fired without being awaited (never delays initialize
or the first tool call), a failed/slow/offline request is caught and silently skipped, and results
are cached for 24h so it doesn't hit GitHub's unauthenticated rate limit or run once per spawned
copy of the server. Set FIGMA_MCP_NO_UPDATE_CHECK=1 to turn it off entirely — worth doing on the
locked-down machines the previous note is about.
Testing
Five dependency-free suites, all runnable with bare node:
mcp-protocol.test.js spawns the actual server as a child process and speaks NDJSON to it — the
same transport a real MCP client uses — rather than importing internals.
Repository layout
Sources
- Seat and quota requirements for the official server — Figma: Guide to the Figma MCP server, Figma Developer Docs: Rate limits & access
- Token reduction measured on a 6-card layout fixture that mimics real REST output: 20,587 B raw → 2,862 B Pseudo-JSX (86.1%) / 1,912 B tree (90.7%). The fixture is checked in and asserted — run
node tests/optimizer.test.jsto reproduce the exact figures.
Comparison reflects publicly documented behaviour as of August 2026. Alternatives are actively developed — verify current capabilities before making a decision on this table alone.
License
MIT · Built by Roman Kolganov