# LaunchCheck x402

> Paid, agent-native review APIs. ReactionCheck stress-tests launch and marketing copy; ProposalCheck stress-tests product and technical proposals; ProposalCheck Premium adds Sol-backed high-rigor red-team analysis without changing the integration contract.

Use the OpenAPI document as the authoritative HTTP contract. Agent Skills provide task-selection and invocation guidance. ReactionCheck is also exposed as a paid MCP tool over Streamable HTTP. Payments use x402 v2 exact EVM with USDC on Base mainnet.

## Agent resources

- [ReactionCheck Agent Skill](https://launchcheck-x402.fly.dev/.well-known/agent-skills/reactioncheck-x402/skill.md): Focused task-selection and invocation guidance for ReactionCheck.
- [ProposalCheck Agent Skill](https://launchcheck-x402.fly.dev/.well-known/agent-skills/proposalcheck-x402/skill.md): Focused guidance for choosing standard versus Premium proposal review.
- [LaunchCheck umbrella skill](https://launchcheck-x402.fly.dev/skill.md): Backward-compatible guidance covering the shared LaunchCheck host.
- [Remote MCP server](https://launchcheck-x402.fly.dev/mcp): Streamable HTTP MCP server exposing the paid `reaction_check` tool.
- [OpenAPI 3.1 contract](https://launchcheck-x402.fly.dev/openapi.json): Current enabled HTTP routes, JSON Schemas, prices, and response contracts.
- [Developer documentation](https://launchcheck-x402.fly.dev/docs): Human-readable API documentation and integration notes.

## Paid APIs

- [ReactionCheck](https://launchcheck-x402.fly.dev/v1/reaction-check): $0.50 x402 POST for launch-copy, landing-page, announcement, positioning, conversion, evidence, and audience-reaction review.
- [ProposalCheck](https://launchcheck-x402.fly.dev/v1/proposal-check): $1.00 x402 POST for structured product, feature, API, implementation, and business-proposal review.
- [ProposalCheck Premium](https://launchcheck-x402.fly.dev/v1/proposal-check/deep): $2.00 x402 POST with the same contract and a Sol/high high-rigor red-team analysis for consequential decisions. Typical completion time is ~2-3 minutes. Clients should allow up to 4 minutes before timing out.
- MCP `reaction_check` at https://launchcheck-x402.fly.dev/mcp: $0.50 x402 tool call with the same ReactionCheck semantics; add a stable `idempotencyKey` tool argument.

## Optional

- [Health](https://launchcheck-x402.fly.dev/health): Minimal service health signal.