GPT55 Model Gateway

GPT55 is an OpenAI-compatible GPT gateway over x402 Base USDC. GPT-5.6 Luna Standard is the default model path on upstream gpt-5.6-luna, priced at the former GPT-5.4 Mini live price multiplied by 1.5. Buyers choose prepaid Luna call packs for bundled repeated calls or per-request x402 calls for canaries and one-off agent tools. Explicit GPT-5.6 Soul and Terra routes remain available for higher-cost requests. Model routes support gpt-5.6-sol, gpt-5.6-luna, gpt-5.6-terra, gpt-5.6, gpt-5.5, gpt-5.3-codex, gpt-5.4.

Machine assets:

• Service hub: https://gpt55.558686.xyz/x402/service
• Service hub JSON: https://gpt55.558686.xyz/x402/service.json
• Project index: https://gpt55.558686.xyz/projects/
• Project 558686 page: https://gpt55.558686.xyz/projects/558686/
• Actual tool catalog: https://gpt55.558686.xyz/tools.json
• APIs catalog: https://gpt55.558686.xyz/apis.json
• AI catalog: https://gpt55.558686.xyz/.well-known/ai-catalog.json
• MCP server card: https://gpt55.558686.xyz/.well-known/mcp/server-card.json
• MCP first-purchase guide: https://gpt55.558686.xyz/x402/mcp-first-purchase-kit
• x402 discovery: https://gpt55.558686.xyz/.well-known/x402
• OpenAPI: https://gpt55.558686.xyz/openapi.json
• pricing.json: https://gpt55.558686.xyz/pricing.json
• server.json: https://gpt55.558686.xyz/server.json
• Standalone key project: https://x402-key.558686.xyz/x402/service.json

Featured GPT55 routes:

• POST https://gpt55.558686.xyz/v1/chat/completions/standard: GPT-5.6 Luna Standard chat completion ($0.004395)
• POST https://gpt55.558686.xyz/v1/chat/completions/gpt-5.6-sol: GPT-5.6 Soul chat completion ($0.091)
• POST https://gpt55.558686.xyz/v1/chat/completions/gpt-5.6-luna: GPT-5.6 Luna chat completion ($0.091)
• POST https://gpt55.558686.xyz/v1/chat/completions/gpt-5.6-terra: GPT-5.6 Terra chat completion ($0.091)
• POST https://gpt55.558686.xyz/v1/chat/completions/gpt-5.6: GPT-5.6 Soul chat completion alias ($0.091)
• POST https://gpt55.558686.xyz/v1/chat/completions/gpt-5.5: gpt-5.5 ($0.091)
• POST https://gpt55.558686.xyz/v1/chat/completions/gpt-5.3-codex: gpt-5.3-codex ($0.034)
• GET https://gpt55.558686.xyz/v1/paid/call-packs/gpt-5.6-sol-100: gpt 5.6 sol 100 (prepaid call pack live quote)
• GET https://gpt55.558686.xyz/v1/paid/call-packs/gpt-5.6-luna-100: gpt 5.6 luna 100 (prepaid call pack live quote)
• POST https://gpt55.558686.xyz/v1/x402-ping: x402 ping (live x402 quote)

Related standalone x402 projects:

• x402 Utility Tools: https://x402-utils.558686.xyz (Deterministic OpenAPI release-risk result with focused URL, JSON, CSV, text, and hash utilities.) Checkout: https://x402-utils.558686.xyz/x402/checkout Browser-safe quote: https://x402-utils.558686.xyz/x402/quote/openapi-route-diff Free preview: https://x402-utils.558686.xyz/preview/url-parse
• x402 Agent Wallet Tools: https://x402-wallet.558686.xyz (Buyer-owned signing controls, private-key boundaries, spend limits, and payment policy enforcement.) Checkout: https://x402-wallet.558686.xyz/x402/checkout Browser-safe quote: https://x402-wallet.558686.xyz/x402/quote/wallet-signing-safety-pack Free preview: https://x402-wallet.558686.xyz/preview/receipt-gate-policy
• x402 Seller Growth Tools: https://x402-seller.558686.xyz (Prioritized seller conversion fixes, buyer-ready copy, and a concrete retest checklist.) Checkout: https://x402-seller.558686.xyz/x402/checkout Browser-safe quote: https://x402-seller.558686.xyz/x402/quote/x402-seller-action-plan Free preview: https://x402-seller.558686.xyz/preview/x402-buyer-shortlist
• x402 API Key + URL Packs: https://x402-key.558686.xyz (Buy $100 of OpenAI-compatible API quota for $11.1112 and receive a one-time key, compatible URLs, model metadata, and receipt evidence.) Checkout: https://x402-key.558686.xyz/x402/checkout Browser-safe quote: https://x402-key.558686.xyz/x402/quote/api-codex-key-pack-100 Free preview: https://x402-key.558686.xyz/preview/api-url-readiness-check