LaunchCheck x402 MCP

Paid agent-native review APIs that stress-test launch and marketing copy via ReactionCheck and product/technical proposals via ProposalCheck. The MCP tool exposes the reaction_check functionality over Streamable HTTP for automated agent invocation.

Endpoint and access

No sign-in to connect and list tools. Individual tools may still need a vendor account, credentials, or permissions; check the documented prerequisites.

Community listingStreamable HTTPNo sign-inEndpoint checked 2026-11-06Published by LaunchCheck

MCP endpoint (Streamable HTTP)

https://launchcheck-x402.fly.dev/mcp

Vendor documentation

What its tools do

1 tool, grouped by the hints the server advertises. Hints are self-declared, not verified behavior.

Not annotated (1)

reaction_check

1 of 1 have a description · 0 of 1 declare behavior hints · 1 of 1 with parameters document them all

Checks and signals

Each line is separate evidence, not a trust score.

Passed Endpoint answered the live check · Nov 6, 2026, 3:40 PM UTC
Availability 1 of 1 checks passed in 30 days

What you can do with it

Stress-test launch and marketing copy before publication
Review product and technical proposals for structural integrity
Perform high-rigor red-team analysis on consequential decisions

Source and maintenance

Community listingRegistry 1.0.0

mcp-registry: io.github.apolito53/launchcheck-x402@1.0.0 Project website

Protocol and capabilities

Server: ReactionCheck x402 1.0.0
MCP protocol negotiated in check: 2025-11-25
Tools: 1 advertised
Resources: Not advertised
Resource templates: Not advertised
Prompts: Not advertised

Server-advertised capabilities

{
  "tools": {
    "listChanged": true
  }
}

Tools

1 advertised

reaction_check

Advertised by the server during the last successful anonymous check.

Review and stress-test launch messaging, landing pages, product announcements, pricing pages, changelogs, app-store listings, and marketing emails before publication. LaunchCheck evaluates copy through eight audience lenses, surfaces positioning and conversion friction, flags claims needing evidence, predicts likely reader questions, recommends concrete changes, and returns a fact-preserving rewrite. Requires $0.50 via x402 on Base.

reaction_check input schema

{
  "type": "object",
  "$schema": "http://json-schema.org/draft-07/schema#",
  "required": [
    "content",
    "idempotencyKey"
  ],
  "properties": {
    "content": {
      "type": "string",
      "maxLength": 12000,
      "minLength": 40,
      "description": "Launch or marketing copy to review before publication, such as a landing page, product announcement, changelog, pricing page, app-store listing, or email."
    },
    "constraints": {
      "type": "array",
      "items": {
        "type": "string",
        "maxLength": 300,
        "minLength": 1
      },
      "default": [],
      "maxItems": 10,
      "description": "Optional factual, legal, brand, or wording constraints that the review and rewrite must preserve."
    },
    "contentType": {
      "enum": [
        "landing-page",
        "product-announcement",
        "changelog",
        "pricing-page",
        "app-store-listing",
        "email",
        "other"
      ],
      "type": "string",
      "default": "other",
      "description": "Kind of copy being reviewed; use other when none of the listed categories fit."
    },
    "desiredAction": {
      "type": "string",
      "maxLength": 500,
      "description": "Optional action the copy should persuade the reader to take, such as sign up, start a trial, buy, upgrade, or learn more."
    },
    "idempotencyKey": {
      "type": "string",
      "pattern": "^[A-Za-z0-9][A-Za-z0-9._:-]{0,127}$",
      "maxLength": 128,
      "minLength": 1,
      "description": "Stable key for this logical ReactionCheck request. Reuse it only when retrying the exact same input."
    },
    "productContext": {
      "type": "string",
      "maxLength": 2000,
      "description": "Optional context about the product, feature, offer, or company needed to judge positioning, clarity, and factual fit."
    },
    "targetAudience": {
      "type": "string",
      "maxLength": 1000,
      "description": "Optional intended audience or buyer segment whose likely reaction should inform the review."
    }
  }
}

Prompts

Not advertised

No prompt definitions available.

Resources

Not advertised

No resource definitions available.

90-day uptime

A lightweight connection check about every six hours, sampled on hosts with many listings. It shows the server answered, not that its tools work.

Too few checks for a percentage yet (2 of 2 answered).

2026-11-06: 1 of 1 checks answered
2026-11-07: 1 of 1 checks answered

30-day availability

Aggregated from read-only remote checks; this is not a tool-execution or security guarantee.

Successful checks: 1 of 1 (100%)
Average latency: 496 ms
95th percentile latency: 496 ms

Maintenance history

Public check and source-refresh events. Editorial and ownership records remain private.

Nov 6, 2026, 3:40 PM UTC · probe · passed · 496 ms · metadata changed · 1 tool(s)

Connect from your client

Each snippet registers the same endpoint; pick the client you use.

This server is operated by the named third party. Listing and endpoint checks are not an endorsement or a security audit. Review the operator's permissions, terms, and data handling before connecting. How listings are checked and corrected.

Claude Code

Run this once in a terminal. It registers the remote server. Use --scope project to write .mcp.json for the repo.

Claude Code configuration

claude mcp add --transport http launchcheck-x402-mcp https://launchcheck-x402.fly.dev/mcp

Codex

Run this once. Codex stores MCP servers in ~/.codex/config.toml (or .codex/config.toml in a trusted project).

Codex configuration

codex mcp add launchcheck-x402-mcp --url https://launchcheck-x402.fly.dev/mcp

Cursor

Merge this server into .cursor/mcp.json in your project, then enable launchcheck-x402-mcp in your MCP settings.

Cursor configuration

{
  "mcpServers": {
    "launchcheck-x402-mcp": {
      "url": "https://launchcheck-x402.fly.dev/mcp"
    }
  }
}

Cline

Merge this into cline_mcp_settings.json (Cline → MCP Servers → Configure).

Cline configuration

{
  "mcpServers": {
    "launchcheck-x402-mcp": {
      "type": "streamableHttp",
      "url": "https://launchcheck-x402.fly.dev/mcp",
      "disabled": false
    }
  }
}

VS Code

Merge this server into .vscode/mcp.json. Use MCP: List Servers to start launchcheck-x402-mcp and inspect its tools.

VS Code configuration

{
  "servers": {
    "launchcheck-x402-mcp": {
      "type": "http",
      "url": "https://launchcheck-x402.fly.dev/mcp"
    }
  }
}

Gemini CLI

Run this once. It writes .gemini/settings.json in the current project; pass --scope user for ~/.gemini/settings.json.

Gemini CLI configuration

gemini mcp add --transport http launchcheck-x402-mcp https://launchcheck-x402.fly.dev/mcp

Claude Desktop

Open Claude Settings > Connectors > Add custom connector, enter this server URL and enable it for the conversation. This is a manual remote-connector handoff, not a desktop JSON configuration.

Claude Desktop configuration

https://launchcheck-x402.fly.dev/mcp

Windsurf

Merge this into ~/.codeium/windsurf/mcp_config.json, then refresh MCP in Cascade. Windsurf remote servers use serverUrl, not url.

Windsurf configuration

{
  "mcpServers": {
    "launchcheck-x402-mcp": {
      "serverUrl": "https://launchcheck-x402.fly.dev/mcp"
    }
  }
}

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