fix(mcp): configure Figma OAuth client

packages/opencode/src/plugin/figma.ts

@@ -0,0 +1,16 @@
+import type { Hooks, PluginInput } from "@opencode-ai/plugin"
+
+const CLIENT_ID = "3zVHNs9kINDDrk8loekLZV"
+
+export async function FigmaPlugin(_input: PluginInput): Promise<Hooks> {
+  return {
+    config: async (config) => {
+      Object.values(config.mcp ?? {}).forEach((server) => {
+        if (server.type !== "remote" || server.oauth === false) return
+        if (!URL.canParse(server.url) || new URL(server.url).hostname !== "mcp.figma.com") return
+        if (server.oauth?.clientId) return
+        server.oauth = { ...server.oauth, clientId: CLIENT_ID }
+      })
+    },
+  }
+}

packages/opencode/src/plugin/index.ts

@@ -20,6 +20,7 @@ import { AzureAuthPlugin } from "./azure"
 import { DigitalOceanAuthPlugin } from "./digitalocean"
 import { XaiAuthPlugin } from "./xai"
 import { SnowflakeCortexAuthPlugin } from "./snowflake-cortex"
+import { FigmaPlugin } from "./figma"
 import { Effect, Layer, Context } from "effect"
 import { EffectBridge } from "@/effect/bridge"
 import { InstanceState } from "@/effect/instance-state"
@@ -78,6 +79,7 @@ function internalPlugins(flags: RuntimeFlags.Info): PluginInstance[] {
     DigitalOceanAuthPlugin,
     SnowflakeCortexAuthPlugin,
     XaiAuthPlugin,
+    FigmaPlugin,
   ]
 }
 

packages/opencode/test/plugin/figma.test.ts

@@ -0,0 +1,69 @@
+import { describe, expect, test } from "bun:test"
+import { FigmaPlugin } from "@/plugin/figma"
+
+describe("plugin.figma", () => {
+  test("adds the OpenCode client ID to configured Figma servers", async () => {
+    const config = {
+      mcp: {
+        figma: {
+          type: "remote" as const,
+          url: "https://mcp.figma.com/mcp",
+          oauth: { scope: "mcp:connect" } as { scope: string; clientId?: string },
+        },
+      },
+    }
+    const hooks = await FigmaPlugin({} as never)
+
+    await hooks.config!(config as never)
+
+    expect(config.mcp.figma.oauth).toEqual({ clientId: "3zVHNs9kINDDrk8loekLZV", scope: "mcp:connect" })
+  })
+
+  test("preserves an existing client ID", async () => {
+    const config = {
+      mcp: {
+        figma: {
+          type: "remote" as const,
+          url: "https://mcp.figma.com/mcp",
+          oauth: { clientId: "configured-client-id" },
+        },
+      },
+    }
+    const hooks = await FigmaPlugin({} as never)
+
+    await hooks.config!(config as never)
+
+    expect(config.mcp.figma.oauth.clientId).toBe("configured-client-id")
+  })
+
+  test("does not create or enable Figma servers", async () => {
+    const config = {
+      mcp: {
+        disabled: {
+          type: "remote" as const,
+          url: "https://mcp.figma.com/mcp",
+          oauth: false as const,
+        },
+        other: {
+          type: "remote" as const,
+          url: "https://mcp.example.com/mcp",
+        },
+      },
+    }
+    const hooks = await FigmaPlugin({} as never)
+
+    await hooks.config!(config as never)
+
+    expect(config.mcp).toEqual({
+      disabled: {
+        type: "remote",
+        url: "https://mcp.figma.com/mcp",
+        oauth: false,
+      },
+      other: {
+        type: "remote",
+        url: "https://mcp.example.com/mcp",
+      },
+    })
+  })
+})