upstash/context7 · error · Error

Existing MCP args do not invoke ${STDIO_PACKAGE}

Error message

Existing MCP args do not invoke ${STDIO_PACKAGE}

What it means

The server's args array parsed successfully, but no element matches the expected stdio package (STDIO_PACKAGE, e.g. the context7 MCP package). The tool only patches args that actually invoke that package, so it aborts instead of modifying an unrelated command.

Source

Thrown at packages/cli/src/setup/toml-editor.ts:194

  apiKey: string | undefined
): Promise<boolean> {
  let raw: string;
  try {
    raw = await readFile(filePath, "utf-8");
  } catch {
    return false;
  }

  if (raw.includes('"""') || raw.includes("'''")) {
    throw new Error("TOML files containing multiline strings are not safely editable");
  }

  const range = findTomlServerArgs(raw, serverName);
  if (!range) return false;

  const args = range.tokens.map((token) => token.value);
  if (!args.some(isContext7Package)) {
    throw new Error(`Existing MCP args do not invoke ${STDIO_PACKAGE}`);
  }

  const apiKeyIndexes = args.flatMap((arg, index) => (arg === "--api-key" ? [index] : []));
  let content: string;
  if (apiKey && apiKeyIndexes.length === 1 && apiKeyIndexes[0] + 1 < range.tokens.length) {
    const valueToken = range.tokens[apiKeyIndexes[0] + 1];
    content = raw.slice(0, valueToken.start) + JSON.stringify(apiKey) + raw.slice(valueToken.end);
  } else {
    const patched = withoutApiKey(args);
    if (apiKey) patched.push("--api-key", apiKey);
    content = raw.slice(0, range.start) + JSON.stringify(patched) + raw.slice(range.end);
  }

  if (content !== raw) {
    await mkdir(dirname(filePath), { recursive: true });
    await writeFile(filePath, content, "utf-8");
  }
  return true;

View on GitHub (pinned to edc9eeb77b)

Solutions

1. Fix the args array so an element actually names the expected package (e.g. "-y", "@upstash/context7-mcp")
2. Point the setup command at the correct server entry
3. If intentional, skip the patch step for this server

Example fix

// before
[context7]
args = ["-y", "@other/mcp"]

// after
[context7]
args = ["-y", "@upstash/context7-mcp"]

const args = range.tokens.map(t => t.value);
if (!args.some(isContext7Package)) throw new Error('args do not invoke the expected package');

function argsInvokePackage(args: string[], pkg: string): boolean {
  return args.some(a => a === pkg || a.endsWith(`/${pkg}`) || a.includes(pkg));
}

catch (e) { if (/do not invoke/.test(e.message)) { /* correct the package name in args, or target the right server */ } throw e; }

When it happens

Trigger: args = ["-y", "some-other-mcp"] where the user pointed the setup at a server table that runs a different package, or renamed/misspelled the package element.

Common situations: See trigger scenarios.

Related errors

• Multiline strings are not supported in MCP args
• Unsupported TOML escape \\${escape}
• Expected a TOML array for MCP args
• MCP args must be a TOML array containing only strings
• Existing MCP server has no safely editable args array

AI-assisted analysis of upstash/context7@edc9eeb77b (2026-08-28). Data as JSON: /api/errors/e380a08d5f6a99c7. Report an issue: GitHub.