What is the key difference between GPT55 x402 MCP Gateway and Postmancer?

GPT55 x402 MCP Gateway belongs to the Developer Tools category with cloud HTTP/SSE execution, while Postmancer belongs to the Developer Tools category with local stdio execution.

How do I install GPT55 x402 MCP Gateway or Postmancer in Claude Desktop or Cursor?

Copy the mcpServers JSON configuration snippet provided on this page into your claude_desktop_config.json or ~/.cursor/mcp.json file and restart your AI client.

Are GPT55 x402 MCP Gateway and Postmancer free or paid?

GPT55 x402 MCP Gateway operates under a Paid Service model (other). Postmancer operates under a Free / Open Source model (No auth required).

Which MCP server has more tools and community activity?

GPT55 x402 MCP Gateway lists 218 tools with 1 views and 0 GitHub stars. Postmancer lists 7 tools with 3 views and 28 GitHub stars.

Can I use both GPT55 x402 MCP Gateway and Postmancer together in the same MCP host?

Yes! MCP hosts like Claude Desktop, Cursor, Windsurf, Cline, and VS Code support configuring multiple servers under the mcpServers object simultaneously.

Side-by-Side Model Context Protocol Comparison

GPT55 x402 MCP Gateway vs Postmancer

In-depth architectural comparison of the GPT55 x402 MCP Gateway and Postmancer MCP servers. Compare execution transports, security boundaries, tool capabilities, quality scores, and ready-to-paste client installation snippets for Claude, Cursor, Windsurf, and VS Code.

At a Glance & Executive Verdict

GPT55 x402 MCP Gateway

Developer Tools · Remote HTTP/SSE

Quality: 56/100 (Good) | Auth: other

Postmancer

Developer Tools · Local stdio

Quality: 59/100 (Good) | Auth: No auth required

Verdict Summary: Choose GPT55 x402 MCP Gateway if you need specialized Developer Tools tools running via a hosted cloud SSE transport. Choose Postmancer if your workspace requires Developer Tools integration with local subprocess execution. Both servers can be configured concurrently in your client's mcpServers manifest.

Which MCP Server Should You Choose?

Choose GPT55 x402 MCP Gateway when:

You need dedicated capabilities in the Developer Tools domain.
You prefer remote streaming HTTP/SSE transport architecture.
Your security boundary fits: other (Paid Service).
Primary tools included: gpt55_x402_ping, gpt55_balance_topup, gpt55_balance_metered_chat_completion.

Explore GPT55 x402 MCP Gateway Details

Choose Postmancer when:

You need dedicated capabilities in the Developer Tools domain.
You prefer local stdio subprocess transport architecture.
Your security boundary fits: No auth required (Free / Open Source).
You have access to required keys: COLLECTIONS_PATH, LOG_LEVEL, POSTMANCER_ENCRYPTION_KEY, ENCRYPTION_KEY.
Primary tools included: http_request, list_collections, list_requests.

Explore Postmancer Details

Feature & Specification Comparison

Specification	G GPT55 x402 MCP Gateway Developer Tools	Postmancer hijaz Developer Tools
Summary	GPT-5.6 Luna Standard paid API via x402: $0.00293 per request (2930 atomic) on Base USDC (eip155:8453), with browser-wallet checkout and an agent fallback client. Start at https://gpt55.558686.xyz/x402/service; POST https://gpt55.558686.xyz/v1/chat/completions/standard.	A MCP server for replacing Rest Clients like Postman/Insomnia, by allowing your LLM to maintain and use api collections.
Category & Scope	Developer Tools

Tools & Capabilities Breakdown

GPT55 x402 MCP Gateway Tools (218)

gpt55_x402_ping

Low-cost x402 payment proof endpoint with no upstream model call. Pay up to $0.002 per request with x402 USDC on Base or choose the fixed-price Solana USDC option when advertised. Exact fixed-price payment and Base upto token-metered payment are both accepted when clients support them; upto settlements use actual response usage, a 0.0001 minimum, and the selected tier price as the cap. Canonical live prices: https://gpt55.558686.xyz/x402/live-prices.json.

gpt55_balance_topup

Top up a GPT55 prepaid balance account with x402 exact USDC before using balance-metered GPT-5.5 chat. Pay up to $0.005 per request with x402 USDC on Base or choose the fixed-price Solana USDC option when advertised. Exact fixed-price payment and Base upto token-metered payment are both accepted when clients support them; upto settlements use actual response usage, a 0.0001 minimum, and the selected tier price as the cap. Canonical live prices: https://gpt55.558686.xyz/x402/live-prices.json.

gpt55_balance_metered_chat_completion

OpenAI-compatible GPT-5.5 chat that debits a persistent prepaid balance ledger after actual upstream usage is known using the read-only sub2api formula. Pay up to usage-metered balance debit per request with x402 USDC on Base or choose the fixed-price Solana USDC option when advertised. Exact fixed-price payment and Base upto token-metered payment are both accepted when clients support them; upto settlements use actual response usage, a 0.0001 minimum, and the selected tier price as the cap. Canonical live prices: https://gpt55.558686.xyz/x402/live-prices.json.

Ready-to-Paste Client Configurations

Paste either (or both) of these JSON server blocks into your client config file (e.g. claude_desktop_config.json or ~/.cursor/mcp.json).

GPT55 x402 MCP Gateway Configuration

mcpServers (Claude Desktop / Cursor)

{
  "mcpServers": {
    "gpt55-x402-mcp-gateway": {
      "url": "https://gpt55.558686.xyz/x402/service"
    }
  }
}

Postmancer Configuration

mcpServers (Claude Desktop / Cursor)

{
  "mcpServers": {
    "hijaz-postmancer": {
      "command": "npx",
      "args": [
        "-y",
        "npx"
      ],
      "env": {
        "COLLECTIONS_PATH": "YOUR_COLLECTIONS_PATH_HERE",
        "LOG_LEVEL": "YOUR_LOG_LEVEL_HERE",
        "POSTMANCER_ENCRYPTION_KEY": "YOUR_POSTMANCER_ENCRYPTION_KEY_HERE",
        "ENCRYPTION_KEY": "YOUR_ENCRYPTION_KEY_HERE"
      }
    }
  }
}

Frequently Asked Questions

GPT55 x402 MCP Gateway is categorized under Developer Tools and uses a remote streaming HTTP/SSE transport. In contrast, Postmancer belongs to Developer Tools using local stdio subprocess. Select GPT55 x402 MCP Gateway when you need capabilities focused on developer tools and Postmancer when you require tools for developer tools.

More alternatives to GPT55 x402 MCP Gateway More alternatives to Postmancer Developer Tools category hub