Unknown client: ${client}. Available clients: ${CLIENTS.map(

Error message

Unknown client: ${client}. Available clients: ${CLIENTS.map((c) => c.name).join(", ")}

What it means

runMcpInit throws when --client doesn't match any entry in the CLIENTS array (claude, cursor, vscode, codex, opencode). The value selects both the config file path and the config format (JSON vs TOML).

Source

Thrown at packages/shadcn/src/commands/mcp.ts:234

        installSpinner.succeed("Installing dependencies.")
      }

      logger.break()
      logger.success(`Configuration saved to ${configPath}.`)
      logger.break()
    } catch (error) {
      handleError(error)
    }
  })

const overwriteMerge = (_: any[], sourceArray: any[]) => sourceArray

async function runMcpInit(options: z.infer<typeof mcpInitOptionsSchema>) {
  const { client, cwd } = options

  const clientInfo = CLIENTS.find((c) => c.name === client)
  if (!clientInfo) {
    throw new Error(
      `Unknown client: ${client}. Available clients: ${CLIENTS.map(
        (c) => c.name
      ).join(", ")}`
    )
  }

  const configPath = path.join(cwd, clientInfo.configPath)
  const dir = path.dirname(configPath)
  await fsExtra.ensureDir(dir)

  // Handle JSON format.
  let existingConfig = {}
  try {
    const content = await fs.readFile(configPath, "utf-8")
    existingConfig = JSON.parse(content)
  } catch {}

  const mergedConfig = deepmerge(

View on GitHub (pinned to efac598707)

Solutions

Use exactly one of: claude, cursor, vscode, codex, opencode.
Omit --client to choose interactively from the prompt.
Upgrade shadcn to a version that ships support for your client.

Example fix

// before
shadcn mcp init --client claude-code
// after
shadcn mcp init --client claude

Defensive patterns

Strategy: validation

Validate before calling

const SUPPORTED_CLIENTS = ["claude", "cursor", "vscode", "codex", "opencode"] as const

function assertSupportedClient(client: string) {
  if (!SUPPORTED_CLIENTS.includes(client as never)) {
    throw new Error(`client must be one of: ${SUPPORTED_CLIENTS.join(", ")}`)
  }
}

Type guard

const SUPPORTED_CLIENTS = ["claude", "cursor", "vscode", "codex", "opencode"] as const
type SupportedClient = typeof SUPPORTED_CLIENTS[number]

function isSupportedClient(c: unknown): c is SupportedClient {
  return typeof c === "string" && (SUPPORTED_CLIENTS as readonly string[]).includes(c)
}

Prevention

Rely on the zod enum in mcpInitOptionsSchema to reject unknown clients at the boundary.
Upgrade shadcn before adopting a newly released MCP client.

When it happens

Trigger: Calling `shadcn mcp init --client <name>` with <name> outside the supported list. The commander option / zod enum (mcpInitOptionsSchema) normally rejects unknown values first, so this fires on programmatic API use or a bypassed schema.

Common situations: Typo (e.g., 'claude-code' instead of 'claude', 'vs-code' instead of 'vscode'), a newer client this shadcn version doesn't yet support, schema bypass via direct runMcpInit call.

Related errors

AI-assisted analysis of shadcn-ui/ui@efac598707 (2026-08-12). Data as JSON: /api/errors/01f0a8dce4be6074. Report an issue: GitHub.