onur

Everything looked perfect.

I had mcporter 0.7.3 configured with the Exa MCP server:

mcporter list exa
# ✅ exa (2 tools) — "Search the web for any topic..."

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Healthy. Ready. Then I made the first real call:

mcporter call "exa.web_search_exa(query: \"ollama cloud models\", numResults: 5)"

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JSON parse error at position 1.

Every. Single. Time.

I tried every quoting trick known to PowerShell:

  • Backslash escaping
  • --% stop-parsing operator
  • cmd /c wrapper
  • Single-quoted outer strings

Same error. The shell was eating my quotes before mcporter ever saw them.

This is the full story of how I debugged it, verified on Windows PowerShell 5.1 on July 31, 2026.

Chapter 1: The Root Cause - PowerShell 5.1's Dirty Secret

PowerShell 5.1 strips ALL embedded double-quotes at the native-argument boundary when passing args to external programs.

There is no $PSNativeCommandArgumentPassing in 5.1. That is a PowerShell 7.3+ feature.

So this:

mcporter call --args '{"query":"test"}'

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Literally becomes this before Node.js even starts:

{query:test}

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The JSON is destroyed. No shell-level trick can fix it. Stop fighting the shell.

Chapter 2: The Hero - A 10-Line Node.js Spawn Wrapper

The fix is to bypass the shell entirely with spawn(..., { shell: false }). Node passes a real argv array, no re-quoting happens.

Create mcporter_exa.js:

// mcporter_exa.js - The hero
const { spawn } = require('node:child_process');
const args = process.argv.slice(2);

// --tool <tool> <base64Json> mode, or default web_search_exa
const tool = args[0] === '--tool'? args[1] : 'exa.web_search_exa';
const payload = args[0] === '--tool'? args[2] : JSON.stringify({ query: args[0], numResults: Number(args[1] || 5) });

const child = spawn(process.execPath,
  [require.resolve('mcporter/dist/cli.js'), 'call', tool, '--args', payload],
  { shell: false, stdio: 'inherit' });
child.on('exit', (code) => process.exit(code?? 0));

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Usage:

# Web search - query is built INSIDE Node, no shell quoting needed
node mcporter_exa.js "ollama cloud models" 5

# It worked on the first try.

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Chapter 3: Nested JSON Needs Base64

Web search is flat. But get_code_context_exa, company_research_exa, crawling_exa need nested JSON:

{"query":"python argparse","tokensNum":800}

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Raw JSON still gets its quotes stripped by PowerShell before Node launches, so even the wrapper cannot save it.

Solution: Base64. Characters A-Za-z0-9+/= contain no spaces or quotes, they survive any shell.

$b64 = [Convert]::ToBase64String([Text.Encoding]::UTF8.GetBytes('{"query":"python argparse","tokensNum":800}'))
node mcporter_exa.js --tool exa-full.get_code_context_exa "$b64"
# ✅ Real code results from docs.python.org

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Golden rule: Queries can ride the command line. Nested JSON must be base64-encoded on Windows PowerShell. Always.

Chapter 4: Reddit Is Blocked, But Exa Has a Side Door

Reddit's .json API now returns 403 for unauthenticated clients due to TLS fingerprinting.

curl "https://www.reddit.com/r/ollama/hot.json" -H "User-Agent: test"
# ❌ 403 Forbidden

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You do not need Reddit's API. Exa already indexed it:

node mcporter_exa.js "site:reddit.com ollama cloud models" 3
# ✅ Returns reddit.com URLs with full content

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Chapter 5: The Missing "Bearer " Bug - 30 Minutes of 401

To use Exa's advanced tools (9+ tools), I added:

"exa-full": {
  "baseUrl": "https://mcp.exa.ai/mcp?tools=web_search_exa,...,deep_researcher_check",
  "bearerTokenEnv": "EXA_API_KEY"
}

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Docs say this sets Authorization: Bearer <token>.

Result: 401 Unauthorized. Every time.

Found in mcporter source config-normalize.js:
It builds the header as Authorization = $env:${bearerTokenEnv} - the "Bearer " prefix is missing. It sends Authorization: <raw-token> instead of Bearer <raw-token>. Exa rejects it.

Working fix - use x-api-key header instead:

"exa-full": {
  "baseUrl": "https://mcp.exa.ai/mcp?tools=web_search_exa,...,deep_researcher_check",
  "headers": {
    "x-api-key": "$env:EXA_API_KEY"
  }
}

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mcporter's materializeHeaders() in runtime-header-utils.js resolves $env:VAR from process.env, so the key never sits in plain text. Set it once:

setx EXA_API_KEY "your_key_here"

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Result: 9+ tools connected.

TL;DR - The Working Toolbox

Task Command
Web search node mcporter_exa.js "query" 5
Reddit content node mcporter_exa.js "site:reddit.com topic" 3
Code search node mcporter_exa.js --tool exa-full.get_code_context_exa "<base64>"
Company research node mcporter_exa.js --tool exa-full.company_research_exa "<base64>"
Deep search node mcporter_exa.js --tool exa-full.deep_search_exa "<base64>"
Crawl pages node mcporter_exa.js --tool exa-full.crawling_exa "<base64>"

Base64 builder:

$b64 = [Convert]::ToBase64String([Text.Encoding]::UTF8.GetBytes('{"key":"value"}'))

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Takeaways:

  1. Don't fight PowerShell 5.1 quoting - use Node spawn wrapper with { shell: false }
  2. Nested JSON = base64 on Windows PowerShell, no exceptions
  3. Reddit API is blocked for unauth clients - use Exa site:reddit.com
  4. bearerTokenEnv in mcporter is broken - use headers: { "x-api-key" }
  5. Keys live in env vars, never in config files

Hope this saves you the 4 hours it cost me. 🦞

Exa MCP: https://github.com/exa-labs/exa-mcp-server