1/**

2 * Transport factory: creates the appropriate MCP transport based on the

3 * plugin's resolved config. Stdio spawns a child process (with credential

4 * scrubbing); Streamable HTTP connects to a URL.

5 *

6 * @module

7 */

8

9import type { Transport } from '@modelcontextprotocol/client'

10import { StdioClientTransport } from '@modelcontextprotocol/client/stdio'

11import { StreamableHTTPClientTransport } from '@modelcontextprotocol/client'

12import { scrubbedParentEnv } from '@deepseek-ai/dsh-subprocess'

13import type { Config } from './index.ts'

14

15/**

16 * The subprocess seam's scrubbed parent env (credential-shaped and stale

17 * `DSH_*` names dropped), plus the spec's explicit env. The MCP SDK owns the

18 * actual spawn, so this transport shares the scrub definition rather than the

19 * spawn path.

20 */

21function buildChildEnv(extra: Record<string, string>): Record<string, string> {

22 return { ...scrubbedParentEnv(), ...extra }

23}

24

25/**

26 * Create an MCP transport from the resolved plugin config.

27 *

28 * @param config - Resolved plugin config discriminated on `transport`.

29 * @returns A connected-ready MCP Transport (stdio or Streamable HTTP).

30 */

31export function createTransport(config: Config): Transport {

32 switch (config.transport) {

33 case 'stdio':

34 return new StdioClientTransport({

35 command: config.command,

36 args: config.args,

37 env: buildChildEnv(config.env),

38 cwd: config.cwd,

39 })

40 case 'streamable-http':

41 return new StreamableHTTPClientTransport(

42 new URL(config.url),

43 { requestInit: { headers: config.headers } },

44 )

45 }

46}