# gpt55-token-gateway

**Canonical:** https://apis.io/providers/558686-xyz/  
**Website:** https://558686.xyz/  
**APIs profiled:** 3

gpt55-token-gateway is the self-chosen service name of an unnamed operator running two OpenAI-compatible AI API gateways on the 558686.xyz domain. GPT55 Model Gateway (gpt55.558686.xyz) sells single GPT-5.6 Luna, GPT-5.5 and GPT-5.3-codex chat completions, deterministic text and wallet tools, and prepaid call packs per request over the x402 payment protocol (HTTP 402 quote, exact USDC on Base eip155:8453, payTo 0x1f01...9a2f) with no account and no API key, and publishes an OpenAPI 3.1 contract (37 operations), a remote MCP server at /mcp that answers initialize and tools/list anonymously with 218 tools, an A2A 1.0 agent card, an MCP registry server.json, an ai-plugin.json, an x402 discovery document, pricing and live-price JSON, a Postman collection, llms.txt and a Content-Signal robots.txt. A second, free, unauthenticated REST surface of 44 developer utilities is served under /api-market for API.market import. Sub2API (sub2api.558686.xyz, also api.558686.xyz) is a self-hosted deployment of the open-source Wei-Shaw/sub2api relay that resells GPT, Claude and Gemini models by Bearer API key at a 1 USD paid = 10 USD platform-quota ratio, with a 3-operation OpenAPI, an APIs.json index, Chinese-language docs and public registration currently closed. Four retired split hosts (x402-utils, x402-wallet, x402-seller, x402-key.558686.xyz) answer HTTP 410 with retirement notices pointing back to GPT55. Source repository github.com/wangletiand/gpt55-x402-gateway (MIT); the security contact ops@400860.xyz and the Sub2API recharge shop shop.400860.xyz tie the operator to the sibling 400860.xyz record.

## Kin Score — 57.6 / 100 (strong)

Scored 2026-10-09 under rubric 0.23.0. Trend: flat (+0.4 from 57.2).

| Facet | Score |
|---|---|
| Discoverability | 80.0 |
| Contract Quality | 48.3 |
| Contract Governance | 18.2 |
| Operational Transparency | 60.5 |
| Developer Ergonomics | 73.2 |
| Access Clarity | 65.8 |

Regulatory layer — **Payments**: 22.5 (matched via tags).

## Agent readiness — 43.9 (agent-ready)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | no |
| Reversibility Documented | no |
| MCP Server | documented |
| Auth Clarity | bearer |
| Idempotency | no |
| Error Semantics | verified |
| OpenAPI Examples | verified |
| Rate Limit Signal | documented |
| Event Surface Described | no |
| Agent Skills | derived |
| Well Known Catalog | yes |
| Consent Identity | yes |
| Agent Card | conformant |
| Dry Run Mode | no |
| Delegated Identity | no |
| Protected Resource Metadata | no |
| Dynamic Client Registration | no |
| Agentic Commerce | no |

## APIs (13)

- **GPT55 x402 Gateway MCP Server** — Remote Model Context Protocol server at https://gpt55.558686.xyz/mcp (Streamable HTTP; a GET returns the server.json-shaped manifest and /mcp/sse streams the discovery config). ...
- **GPT55 Model Gateway A2A Agent** — Agent2Agent surface: an agent card served at https://gpt55.558686.xyz/.well-known/agent-card.json (and identically at the legacy /.well-known/agent.json) - name "GPT55 Model Gat...
- **gpt55-token-gateway Base Usdc API** — The base-usdc API from gpt55-token-gateway — 1 operation(s) for base-usdc.
- **gpt55-token-gateway Gpt55 Model Gateway API** — The gpt55-model-gateway API from gpt55-token-gateway — 27 operation(s) for gpt55-model-gateway.
- **gpt55-token-gateway Gpt55 Retained High Intent API** — The gpt55-retained-high-intent API from gpt55-token-gateway — 1 operation(s) for gpt55-retained-high-intent.
- **gpt55-token-gateway Gpt55 Retained Nonmodel API** — The gpt55-retained-nonmodel API from gpt55-token-gateway — 6 operation(s) for gpt55-retained-nonmodel.
- **gpt55-token-gateway Models API** — The Models API from gpt55-token-gateway — 1 operation(s) for models.
- **gpt55-token-gateway Responses API** — The Responses API from gpt55-token-gateway — 1 operation(s) for responses.
- **gpt55-token-gateway Utility Tools API** — Deterministic text, JSON, encoding, hashing, URL parsing, and developer utilities.
- **gpt55-token-gateway Wallet Security API** — The wallet-security API from gpt55-token-gateway — 1 operation(s) for wallet-security.
- **gpt55-token-gateway Wallet Signing Safety Pack API** — The wallet-signing-safety-pack API from gpt55-token-gateway — 1 operation(s) for wallet-signing-safety-pack.
- **gpt55-token-gateway X402 API** — The x402 API from gpt55-token-gateway — 1 operation(s) for x402.
- **gpt55-token-gateway Chat Completions API** — The Chat Completions API from gpt55-token-gateway — 1 operation(s) for chat completions.

## MCP servers (1)

- **gpt55-token-gateway MCP Server** — GPT55 ships a hosted, remote, Streamable HTTP MCP server at https://gpt55.558686.xyz/mcp that answers initialize (protocolVersion 2025-06-18), tools/list (218 tools with JSON Sc...

## Security (3)

- **558686 Xyz Authentication** — x402-payment/http-bearer/api-key-header · 4 schemes
- **558686 Xyz Domain Security** — TLSv1.3 · HSTS · DMARC
- **558686 Xyz Vulnerability Disclosure** — disclosure policy published

## Plans (1)

- **558686 Xyz Plans Pricing**

## Tags

x402, Agentic Payments, MCP, A2A, AI Gateway, OpenAI-Compatible, LLM, AI Agents, USDC, Base, API Relay, Developer Tools

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/558686-xyz/). Scores are computed from the provider's own public artifacts under a published rubric.