Figma MCP

Use the official remote server https://mcp.figma.com/mcp through each host's native registration. Authentication belongs to that host's OAuth flow. The user only remembers /figma-mcp ($figma-mcp in Codex); handle host discovery, OAuth state, identity, and readiness internally. On failure, report one failing layer and one required action.

Pick the proof before calling a tool

Most invocations are /figma-mcp <figma URL> <UI task> on the current account in one host, whether that task is inspecting the design or implementing/matching it. That is the read-only fast path: the first requested official read proves server discovery, tool availability, and authentication, so a separate whoami only adds a round trip.

On task success, continue the requested work; do not emit FIGMA_MCP_READY or identity details mid-task. Server configuration, an OAuth page, a callback, and a tool list are separate evidence layers; none of them replaces the required call.

Read-only fast path

1. Parse the URL: /design/:fileKey/:name?node-id=1-2 gives nodeId 1:2; /design/:fileKey/branch/:branchKey/... uses branchKey as fileKey; /make/:key uses nodeId 0:1 with get_design_context only; /board/ is FigJam and uses get_figjam.
2. Choose the first read. To confirm access or list pages, use get_metadata (no prerequisite). When the task is to implement or match a design, load figma-design-to-code first and follow it — see "Implement or match a design" below — before calling get_design_context.
3. Match node IDs to the tool. Instance sublayer IDs such as I10:20;30:40 are accepted only by get_design_context and get_metadata. get_screenshot, get_variable_defs, and download_assets require a plain 123:456 ID, so pass the instance root (10:20, the part after I and before the first ;) or a non-instance ancestor instead of retrying the same ID.
4. If the read returns forbidden or not-found, stop. A Figma-originated error already proves tools and auth, so add at most one whoami, and only when no read reached Figma. Report FILE_ACCESS: UNVERIFIED with the one missing item (URL, share permission, or plan feature). Do not probe other files. A node ID copied from docs or memory that is not found was usually deleted or re-created; re-derive it from the user's current URL or the parent's get_metadata rather than guessing.
5. If the tool is absent or the server requires authentication, recover by layer (below), then retry the requested read directly; its success is the post-recovery proof.

When a status line helps, report Proof call: REQUESTED_READ and Account: NOT_READ.

The official MCP exposes no file-comments tool. When the task needs design review comments (read, filter resolved threads, or audit whether they were applied), say so at the start instead of treating it as an auth failure, then follow references/rest-comments.md.

Implement or match a design

/figma-mcp plus a design URL or file key where the user wants the UI built or matched (low 还原度 complaints land here) still starts on this skill's proof path above, but the pixel-fidelity work itself is not this skill's job: load figma-design-to-code (the Figma plugin's /figma-design-to-code, or MCP resource skill://figma/figma-design-to-code/SKILL.md) and follow its workflow through to a finished, matched screen. The reasoning is division of labor, not duplication — this file's job is proving host, account, and tool access across four very different clients; getting fidelity right needs iterative screenshot comparison and Code Connect lookups that already live in figma-design-to-code, so repeating that procedure here would just drift out of sync with it. Treat one get_metadata call, one get_design_context dump, or a screenshot as evidence for that workflow, never as the finished implementation on its own. If a design-to-code skill is already driving the task, defer the build steps to it and keep supplying only the proof and read rules above.

Tool prerequisites

Honor any stricter prerequisite in the tool description. Test writes in a duplicate or disposable file, never an important working file. Before a write, refresh the target node context, and do not let two agents modify the same file or node without an approved coordination mechanism.

In Grok Build, Figma tools are namespaced Figma__<tool> behind use_tool. One search_tool query that names every tool you need is enough; do not search per tool.

Do not use Figma MCP for ordinary web browsing, desktop navigation, generic screenshots, or non-Figma files.

Hosts and credentials

Supported hosts must appear in Figma's current MCP Catalog (https://www.figma.com/mcp-catalog/). As of 2026-09 that includes Claude Code, Codex, Cursor, and Grok. Treat Hermes, WorkBuddy, pi, and any other client missing from the catalog as unsupported for the official MCP: fail closed on the MCP, name a supported host, and never work around the catalog with a proxy, shared wrapper, or borrowed client identity. Read-only design data on such a host can still come from the REST API under the user's own token; see REST fallback below.

Keep one chain per host: native registration, the official endpoint, that host's OAuth grant, the current or explicitly requested account, then the path's proof call. OAuth credentials stay per host. Never copy tokens, credential caches, cookies, or browser profiles between hosts.

Keep registration account-neutral. Never store a default account, email, alias, token, cookie, browser profile, or callback in the skill, MCP configuration, environment variables, or repository files. The one user-owned exception is the REST personal access token, which the user exports in their own environment; the agent never writes it anywhere. Switching accounts changes only the current host surface's OAuth grant; keep the server identifier, endpoint, scope, and unrelated MCP entries. App plugins and CLI registrations can hold separate grants, so switch and verify only the surface in use.

Never print whoami payloads. Reduce identity to CURRENT, MATCH, MISMATCH, or UNVERIFIED.

Recover by failed layer

• Tool absent or server missing: read references/host-verification.md. Merge the official server into the host's native configuration; never replace the whole configuration.
• Authentication required: run only that host's native login or plugin Connect flow. Let the user complete passwords, passkeys, Touch ID, 2FA, CAPTCHA, or any credential challenge. Then retry whoami once on identity paths, or the requested read on the fast path. A login in one host proves nothing about another.
• Wrong account, account switch, or Computer Use help with OAuth UI: read references/authentication.md. Without a named target, do not switch. With one, fail closed on mismatch and clear only the current surface's Figma grant; never sign out of the whole browser or Figma desktop session.
• Tool call failed after authentication: separate provider, plan, rate-limit, client-compatibility, and file-permission failures from registration failures, and check Figma's official known issues.

For multi-host acceptance, run the per-host prompt and report table in references/host-verification.md. Do not build that table for the single-host fast path.

REST fallback

The public REST API with the user's personal access token can serve some reads the MCP cannot, but it returns less (node JSON and renders, no reference code or Code Connect), runs as whoever owns the token, and would mask MCP breakage. So it is a declared branch, not an automatic retry:

• Use it for read-only data when the host is not in the catalog, or when the task needs comments.
• Do not use it for a missing tool, missing registration, or expired OAuth (recover the MCP), for 403/404 or a named-account request (it cannot prove this account's access), or for any write.
• Before the first call, state Proof call: REST (not MCP), Account: PAT owner, and what the task loses. A REST success never yields FIGMA_MCP_READY.

Read references/rest-fallback.md for the full decision table, token setup, and scripts/figma_rest.py (nodes, images, comments), which keeps the token off the command line.