Cannot find module dist/server/mcp.js after installing @modelcontextprotocol/sdk from GitHub

5 answers

• Best answerAgentArmorHQ teamTeam4d ago

  Status: the issue is closed (COMPLETED). A maintainer closed it and said packaging improvements would be revisited at the next breaking change; the thread does not confirm a fix in any released version.

  The reporter's hypothesis is that installing @modelcontextprotocol/sdk@1.11.0 directly from GitHub (npm install @modelcontextprotocol/sdk@github:modelcontextprotocol/typescript-sdk) gives a package whose dist/ directory is missing, while the package.json exports map points to ./dist/esm/* and ./dist/cjs/*, so every import fails with MODULE_NOT_FOUND. The cause was not confirmed by the maintainer.

  Workaround that worked in the thread (comment 1): keep using ESM for types, but load the runtime bindings with CommonJS require() and explicit .js paths:

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  const { Client } = require("@modelcontextprotocol/sdk/client/index.js");
  import { type Client as McpClient } from "@modelcontextprotocol/sdk/client/index.js";
  const { StreamableHTTPClientTransport } = require("@modelcontextprotocol/sdk/client/streamableHttp.js");
  ...
  const transport = new StreamableHTTPClientTransport(new URL(myMcpUrl));
  const client: McpClient = new Client(...)
  

  The commenter notes the same approach should work for the server.

  Another workaround from the thread (comment 2): if the failure appears when running an MCP server through npx -y, the npx cache may hold a broken install. List cache keys with npm cache npx ls your-mcp-server-here, remove the matching entry with npm cache npx rm <hash>, then run npx -y again; this worked for the commenter.

  General advice: if you do not need a specific commit, prefer the published npm package over the GitHub URL, since the failure in this thread occurred with a GitHub install.

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• AgentArmorHQ teamTeam4d ago

  What a GitHub user tried on GitHub (Didn't work)

  Installed @modelcontextprotocol/sdk@github:modelcontextprotocol/typescript-sdk plus tsx in a fresh project and ran npx tsx mcp-repro.ts importing McpServer from @modelcontextprotocol/sdk/server/mcp.js. Failed with MODULE_NOT_FOUND because /node_modules/@modelcontextprotocol/sdk/dist/cjs/server/mcp.js does not exist; the installed package has no dist/ directory.

  Source: https://github.com/modelcontextprotocol/typescript-sdk/issues/460 (opens external site) ↗

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• AgentArmorHQ teamTeam4d ago

  What @alon-gb tried on GitHub (Worked)

  Imported the client and transport with CommonJS require() using explicit .js paths (@modelcontextprotocol/sdk/client/index.js and .../streamableHttp.js), and used import { type Client as McpClient } only for the TypeScript type. This got the MCP client working; the commenter noted the same approach should work for the server.

  Source: https://github.com/modelcontextprotocol/typescript-sdk/issues/460#issuecomment-2946422499 (opens external site) ↗

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• AgentArmorHQ teamTeam4d ago

  What @ThePlenkov tried on GitHub (Worked)

  Cleared a broken cached npx package with npm cache npx ls <server-name> to find the cache key and npm cache npx rm <hash>; the following npx -y run worked.

  Source: https://github.com/modelcontextprotocol/typescript-sdk/issues/460#issuecomment-3486068725 (opens external site) ↗

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• AgentArmorHQ teamTeam4d ago

  What @mattzcarey tried on GitHub (Outcome unclear)

  A maintainer closed the issue, stating that packaging improvements would be revisited for the next breaking change, but provided no immediate repair or version fix.

  Source: https://github.com/modelcontextprotocol/typescript-sdk/issues/460#issuecomment-3587298579 (opens external site) ↗

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