generated: '2026-09-19'
method: searched
status: published
checked: '2026-09-19'
source: 'https://gpt55.558686.xyz/llms.txt and llms-full.txt ("MCP Streamable HTTP endpoint: https://gpt55.558686.xyz/mcp",
  "MCP SSE discovery endpoint: https://gpt55.558686.xyz/mcp/sse"), https://gpt55.558686.xyz/.well-known/mcp/server-card.json,
  https://gpt55.558686.xyz/server.json, https://gpt55.558686.xyz/.well-known/mcp.json, https://gpt55.558686.xyz/mcp/config,
  https://gpt55.558686.xyz/llms-install.md, the agent card links, and the GitHub repository wangletiand/gpt55-x402-gateway
  (README "Local MCP Wrapper"). Live anonymous JSON-RPC probes of the endpoint on 2026-09-20 UTC: initialize,
  tools/list and resources/list all HTTP 200.'
summary: '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 Schema inputSchema
  and annotations) and resources/list (14 JSON resources) with no credential. It is, by its own instructions,
  a discovery facade over the x402-paid HTTP API: "Tool calls return the direct HTTP endpoint, x402 payment
  requirements, and example payload. Execute the returned HTTP endpoint with x402 Base USDC payment or
  a private Bearer key; this MCP facade does not bypass payment." So an agent can enumerate and understand
  every tool anonymously, and every useful result still costs a per-request USDC payment made outside
  MCP. The public repository ships a local Node wrapper (`npm start` -> node server.mjs) that exposes
  "one local read-only directory tool" and is not published to a registry; it is not a second, equivalent
  server. No entry exists in the official MCP registry (registry.modelcontextprotocol.io) and llms-install.md
  says "No external marketplace submission has been made", although the manifest is written in the registry''s
  server.json schema.'
pointer_basis: Wired as type MCPServer on the strength of a live, anonymous, protocol-conformant tools/list
  - the surface an agent reaches now. The facade behaviour (tool call -> payment instructions, not the
  result) is recorded here and in the crosswalk so the pointer is not read as "218 callable tools for
  free".
deployment:
  mode: remote
  endpoint: https://gpt55.558686.xyz/mcp
  transport: streamable-http
  fallback_transport:
    type: sse
    url: https://gpt55.558686.xyz/mcp/sse
    note: GET returns a text/event-stream whose first events are "endpoint" (data https://gpt55.558686.xyz/mcp/config)
      and "server-info" - a discovery stream, not exercised as an MCP session transport
  install: null
  package: null
  auth: none
  auth_basis: 'initialize/tools/list/resources/list answered anonymously; /mcp/config declares authentication
    {type: x402-payment-header, apiKeyRequired: false, accountRequired: false, kycRequired: false, quoteFirst:
    true, note: "Private Bearer keys are only an operator bypass; public buyers should use the x402 quote
    and payment flow"}; no OAuth metadata on any host. Payment (x402 exact USDC on Base) is required for
    the HTTP routes the tools point at, not for the MCP methods themselves.'
  verified: probed
  reachable: true
  probe:
    date: '2026-09-20'
    initialize:
      status: 200
      protocolVersion: '2025-06-18'
      serverInfo:
        name: gpt55-x402-gateway
        title: GPT-5.5 x402 Agent Payment Control Plane
        version: 2026.06.21
      capabilities:
        tools:
          listChanged: false
        resources:
          subscribe: false
          listChanged: false
      file: 558686-xyz-mcp-initialize.json
    tools_list:
      status: 200
      bytes: 285728
      tool_count: 218
      file: 558686-xyz-mcp-tools-list.json
    resources_list:
      status: 200
      resource_count: 14
      file: 558686-xyz-mcp-resources-list.json
    prompts_list: not-run
    tools_call: not-run (every tool resolves to a paid HTTP route; this pass does not pay)
    cors: OPTIONS /mcp -> 204, access-control-allow-origin *, allow-methods GET,HEAD,PUT,PATCH,POST,DELETE,
      expose-headers PAYMENT-REQUIRED, X-PAYMENT-REQUIRED, PAYMENT-RESPONSE, X-PAYMENT-RESPONSE, x-x402-receipt-id,
      x-x402-receipt-url, Retry-After
    rate_limit_headers: ratelimit-limit 120, ratelimit-policy 120;w=60, ratelimit-remaining, ratelimit-reset
      on the same host
server:
  name: gpt55-x402-gateway
  registry_name: xyz.558686.gpt55/token-gateway
  display_name: GPT55 x402 Gateway MCP Server
  transport: http
  url: https://gpt55.558686.xyz/mcp
  version: 2026.06.21
  manifest_version: 2026.07.01-split
  instructions_verbatim: This remote MCP endpoint exposes paid GPT-5.5 and utility HTTP tools. Tool calls
    return the direct HTTP endpoint, x402 payment requirements, and example payload. Execute the returned
    HTTP endpoint with x402 Base USDC payment or a private Bearer key; this MCP facade does not bypass
    payment.
  manifests:
    server_json:
      url: https://gpt55.558686.xyz/server.json
      file: 558686-xyz-server.json
      schema: https://static.modelcontextprotocol.io/schemas/2025-12-11/server.schema.json (declared on
        /.well-known/mcp.json and GET /mcp)
      name: gpt55-model-gateway
      version: 2026.07.01-split
      repository: https://github.com/wangletiand/gpt55-x402-gateway
      websiteUrl: https://gpt55.558686.xyz
    well_known_mcp_json:
      url: https://gpt55.558686.xyz/.well-known/mcp.json
      file: ../well-known/558686-xyz-mcp.json
    server_card:
      url: https://gpt55.558686.xyz/.well-known/mcp/server-card.json
      file: ../well-known/558686-xyz-mcp-server-card.json
      spec: SEP-1649
      transports:
      - streamable-http
      - sse
    config:
      url: https://gpt55.558686.xyz/mcp/config
      mcpServers:
        gpt55_x402:
          url: https://gpt55.558686.xyz/mcp
    install_guide:
      url: https://gpt55.558686.xyz/llms-install.md
      status_verbatim: draft install guide. No external marketplace submission has been made.
    install_hub: https://gpt55.558686.xyz/projects/558686/install (Claude Desktop, Cursor, Windsurf, VS
      Code, OpenAI Apps SDK pages)
  registry:
    official: not found - registry.modelcontextprotocol.io has no entry for gpt55 / 558686 (searched 2026-09-19);
      server.json is written in the registry schema
    others_claimed: []
  local_wrapper:
    repository: https://github.com/wangletiand/gpt55-x402-gateway
    run: npm install && npm start (node server.mjs)
    package_name: gpt55-x402-gateway
    package_version: 1.0.0
    npm_published: 'false (package.json "private": true)'
    scope_verbatim: The wrapper exposes one local read-only directory tool. It does not proxy MCP tool
      calls, custody funds, store wallet keys, or execute payments.
payment:
  protocol: x402 v2
  network: eip155:8453 (Base)
  asset: USDC 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913
  pay_to: '0x1f0130669ca6fd02e025a984cc038f139df19a2f'
  quote_first: true
  private_key_sent_to_service: false (stated in /mcp/config, server.json _meta and SECURITY.md)
  facilitator: provider-pool; the only active facilitator on 2026-09-18 per /x402/status is https://facilitator.xpay.sh
    (dexter, fluxa, mogami, primer, payai, kobaru, cdp all frozen/disabled)
tool_count: 218
tools_note: 'The full list with inputSchema and annotations is saved verbatim in 558686-xyz-mcp-tools-list.json;
  the crosswalk in 558686-xyz-tool-crosswalk.yml binds each to its OpenAPI operationId where one exists.
  Families: 7 chat_* model routes, 41 gpt55_translate/summarize/rewrite/answer/ code_review/extract_json
  tier variants, 108 gpt55_x402_* buyer/seller/wallet packs and premium playbooks, ~40 deterministic utility
  tools (hash, base64, jwt, regex, uuid, ...), 3 sub2api billing helpers, balance top-up + metered chat.
  176 tools are annotated readOnlyHint true / idempotentHint true / destructiveHint false; the 42 model-backed
  chat/text tools are idempotentHint false. Every tool is openWorldHint true. No tool carries outputSchema.'
tools:
- name: gpt55_x402_ping
  title: x402 payment ping
  category: payment-canary
  price: $0.002
  rest: null
  note: GET/POST /v1/x402-ping - on the host, not in the OpenAPI
  description: 'Low-cost x402 payment proof endpoint with no upstream model call. Pay $0.002 per request
    with x402 exact USDC on Base or Solana when advertised. Canonical live prices: https://gpt55.558686.xyz/x402/live-prices.json.'
- name: chat_standard
  title: GPT-5.6 Luna Chat Completion
  category: chat
  price: $0.00293
  rest: v1ChatCompletionsStandard
  description: 'GPT-5.6 Luna Standard chat for mainstream short answers, routing decisions, extraction
    helpers, and buyer trials. The legacy mini path remains available as a compatibility alias. Pay $0.00293
    per request with x402 exact USDC on Base or Solana when advertised. Canonical live prices: https://gpt55.558686.xyz/x402/live-prices.json.'
- name: chat_gpt_5_6_soul
  category: chat
  price: $0.099995
  rest: v1ChatCompletionsGpt56Sol
  description: 'GPT-5.6 Soul flagship chat for advanced reasoning, production work, code, and structured
    responses at GPT-5.5-matched pricing. Pay $0.099995 per request with x402 exact USDC on Base or Solana
    when advertised. Canonical live prices: https://gpt55.558686.xyz/x402/live-prices.json.'
- name: chat_gpt_5_6_luna
  category: chat
  price: $0.019999
  rest: v1ChatCompletionsGpt56Luna
  description: 'GPT-5.6 Sol chat on the independently verified upstream gpt-5.6-luna model. Pay $0.019999
    per request with x402 exact USDC on Base or Solana when advertised. Canonical live prices: https://gpt55.558686.xyz/x402/live-prices.json.'
- name: chat_gpt_5_6_terra
  category: chat
  price: $0.049998
  rest: v1ChatCompletionsGpt56Terra
  description: 'GPT-5.6 Terra chat on the independently verified upstream gpt-5.6-terra model. Pay $0.049998
    per request with x402 exact USDC on Base or Solana when advertised. Canonical live prices: https://gpt55.558686.xyz/x402/live-prices.json.'
- name: chat_gpt_5_5
  category: chat
  price: $0.019999
  rest: v1ChatCompletionsGpt55
  description: 'GPT-5.5 chat for stronger reasoning, production work, code, and structured responses.
    Pay $0.019999 per request with x402 exact USDC on Base or Solana when advertised. Canonical live prices:
    https://gpt55.558686.xyz/x402/live-prices.json.'
- name: chat_gpt_5_3_codex
  category: chat
  price: $0.007472
  rest: v1ChatCompletionsGpt53Codex
  description: 'GPT-5.3 Codex chat for coding-oriented agent work, patch planning, and structured development
    output. Pay $0.007472 per request with x402 exact USDC on Base or Solana when advertised. Canonical
    live prices: https://gpt55.558686.xyz/x402/live-prices.json.'
- name: chat_gpt_5_4
  category: chat
  price: $0.010109
  rest: null
  note: /v1/chat/completions/gpt-5.4 is served and priced but absent from the OpenAPI
  description: 'GPT-5.4 chat for high-quality general reasoning, coding, and structured responses. Pay
    $0.010109 per request with x402 exact USDC on Base or Solana when advertised. Canonical live prices:
    https://gpt55.558686.xyz/x402/live-prices.json.'
- name: gpt55_balance_topup
  category: prepaid-balance
  rest: null
  description: 'Top up a GPT55 prepaid balance account with x402 exact USDC before using balance-metered
    GPT-5.5 chat. Pay $0.005 per request with x402 exact USDC on Base or Solana when advertised. Canonical
    live prices: https://gpt55.558686.xyz/x402/live-prices.json.'
- name: gpt55_balance_metered_chat_completion
  category: chat
  rest: v1ChatCompletionsMetered
  description: '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 usage-metered balance debit per request
    with x402 exact USDC on Base or Solana when advertised. Canonical live prices: https://gpt55.558686.xyz/x402/live-prices.json.'
- name: gpt55_translate
  category: text-tool
  price: $0.00293
  rest: v1ToolsTranslate
  description: Translate short text, messages, notes, and snippets to a requested target language for
    agent workflows, localization, bilingual support replies, and quick multilingual output. Standard
    quality tier uses gpt-5.6-luna; price is derived from official OpenAI relative token costs with a
    local margin and floor. Pay $0.00293 per request with x402 exact USDC on Base or Solana when advertised.
    Canonical li…
- name: gpt55_summarize
  category: text-tool
  rest: v1ToolsSummarize
  description: Summarize text, pasted articles, notes, markdown, transcripts, and URL-extracted content
    into TLDR, bullets, key facts, paragraph summaries, or executive summaries. Low-cost GPT-5.5 summary
    endpoint for agents that need cheap document digestion and research briefs. Standard quality tier
    uses gpt-5.6-luna; price is derived from official OpenAI relative token costs with a local margin
    and floor. Pay…
- name: gpt55_rewrite
  category: text-tool
  rest: v1ToolsRewrite
  description: 'Rewrite short text for clarity, tone, grammar, style, professional messages, and concise
    agent output. Standard quality tier uses gpt-5.6-luna; price is derived from official OpenAI relative
    token costs with a local margin and floor. Pay $0.00293 per request with x402 exact USDC on Base or
    Solana when advertised. Canonical live prices: https://gpt55.558686.xyz/x402/live-prices.json.'
- name: gpt55_answer
  category: text-tool
  rest: v1ToolsAnswer
  description: Answer a short question, optionally using provided context, for lightweight QA, context
    question answering, support answers, research lookup, and agent reasoning steps. Standard quality
    tier uses gpt-5.6-luna; price is derived from official OpenAI relative token costs with a local margin
    and floor. Pay $0.00293 per request with x402 exact USDC on Base or Solana when advertised. Canonical
    live pric…
- name: gpt55_code_review
  category: text-tool
  rest: v1ToolsCodeReview
  description: Review a short code snippet or diff for bugs, edge cases, security issues, maintainability,
    and missing tests. Designed for agents and developers that need a quick second pass before merging.
    Standard quality tier uses gpt-5.6-luna; price is derived from official OpenAI relative token costs
    with a local margin and floor. Pay $0.00293 per request with x402 exact USDC on Base or Solana when
    advertis…
- name: gpt55_extract_json
  category: text-tool
  rest: v1ToolsExtractJson
  description: Extract structured JSON from short text according to a caller-provided schema or field
    list. Useful for agents that need cheap parsing, lead cleanup, invoice notes, support tickets, and
    lightweight ETL steps. Standard quality tier uses gpt-5.6-luna; price is derived from official OpenAI
    relative token costs with a local margin and floor. Pay $0.00293 per request with x402 exact USDC
    on Base or Sol…
- name: gpt55_evm_wallet_balance
  category: wallet
  price: $0.001
  rest: v1ToolsEvmWalletBalancePost
  description: Read a public EVM wallet balance on Base or Ethereum and determine whether its Base USDC
    balance can cover a suggested $0.001 x402 payment. Returns a coherent provider snapshot, USDC runway,
    shortfall, native-gas presence, and a handoff to the full funding-readiness doctor without signing,
    broadcasting, or handling private keys. Balance-only readiness does not prove client, signing, spend-cap,
    or …
- name: gpt55_wallet_signing_safety_pack
  category: wallet-security
  price: $0.018
  rest: walletSigningSafetyPackPaidPost
  description: Build a single wallet/agent pre-signing decision pack from optional EIP-712 typed data,
    EVM calldata, expected chain, known addresses, and x402 spend policy. Returns risk levels, risk flags,
    buyer decision, copy-paste checklist, and first-payment routing hints without using a private key,
    producing a signature, sending a transaction, broadcasting, or calling external RPC. Pay $0.018 per
    request wi…
- name: gpt55_x402_mcp_integration_kit
  category: x402-buyer-tool
  price: $0.006
  rest: v1ToolsX402McpIntegrationKit
  description: 'Generate a deterministic buyer integration package for an x402/MCP service: MCP remote
    server config, Claude Desktop-style config hints, curl discovery checks, x402 quote test commands,
    endpoint selection, spending caps, and verification checklist without calling an upstream model. Pay
    $0.006 per request with x402 exact USDC on Base or Solana when advertised. Canonical live prices:
    https://gpt55.5…'
- name: gpt55_x402_bazaar_search
  category: x402-market
  rest: v1ToolsX402BazaarSearch
  description: Search the CDP x402 Bazaar for external and merchant-specific resources, preserving Bazaar
    relevance order by default while normalizing live prices, 30-day calls, unique payers, calls-per-payer,
    freshness, service metadata, schemes, networks, and payTo signals. This deterministic endpoint does
    not call an upstream model. Pay $0.004 per request with x402 exact USDC on Base or Solana when advertised…
- name: gpt55_timestamp
  category: utility
  price: $0.002
  rest: v1ToolsTimestamp
  description: 'Convert Unix seconds, Unix milliseconds, or date strings into ISO, Unix seconds, Unix
    milliseconds, and UTC fields without calling an upstream model. Pay $0.002 per request with x402 exact
    USDC on Base or Solana when advertised. Canonical live prices: https://gpt55.558686.xyz/x402/live-prices.json.'
- name: gpt55_query_parse
  category: utility
  rest: v1ToolsQueryParse
  description: 'Parse a query string or URL into repeated query parameters and first-value maps without
    calling an upstream model. Pay $0.002 per request with x402 exact USDC on Base or Solana when advertised.
    Canonical live prices: https://gpt55.558686.xyz/x402/live-prices.json.'
- name: '... 196 more'
  note: see 558686-xyz-mcp-tools-list.json (verbatim) and the crosswalk
resources:
  count: 14
  file: 558686-xyz-mcp-resources-list.json
  uris:
  - https://gpt55.558686.xyz/.well-known/x402
  - https://gpt55.558686.xyz/x402/live-prices.json
  - https://gpt55.558686.xyz/.well-known/x402-live-prices.json
  - https://gpt55.558686.xyz/pricing.json
  - https://gpt55.558686.xyz/buyer-guide.json
  - https://gpt55.558686.xyz/x402/first-payment-client.json
  - https://gpt55.558686.xyz/use-cases.json
  - https://gpt55.558686.xyz/integrations.json
  - https://gpt55.558686.xyz/x402/seller-tools.json
  - https://gpt55.558686.xyz/x402/market-report.json
  - https://gpt55.558686.xyz/api-market/listing.json
  - https://gpt55.558686.xyz/.well-known/agent-card.json
  - https://gpt55.558686.xyz/.well-known/agents402.json
  - https://gpt55.558686.xyz/openapi.json
x-evidence:
  fetched: '2026-09-20'
  url: https://gpt55.558686.xyz/mcp
  method: 'POST {"jsonrpc":"2.0","id":1,"method":"tools/list"} with Accept: application/json, text/event-stream'
  http_status: 200
  content_type: application/json; charset=utf-8
  bytes: 285728
descriptions_source: live tools/list (authorship probe or saved capture); filled by backfill-tools-from-authorship.py
  --descriptions, 2026-09-28