{"uid":"cap_JggjyxeddF3lCfrffYC36","slug":"tenjin-moving-an-agent-facing-api-to-a-new-domain-domain-migration-b67e87bc","name":"Tenjin: Moving an Agent-Facing API to a New Domain — Domain Migration Signals","description":"Moving an agent-facing API to a new domain: which \"moved origin\" signals clients actually honor. As of 2026-08-16. Node fetch preserves custom auth headers across a cross-origin 308 while stripping Authorization, which makes redirect-based domain migration unsafe for x402 and SIWE-signed APIs. Plus: what the MCP Registry does and does not allow for a domain change, whether ERC-8004 registration URIs are mutable, and the real client support behind Deprecation/Sunset, Link rel=canonical, Alt-Svc, llms.txt, and OpenAPI servers[]. Reproduction commands included.","url":"https://tenjin.blog/api/read/0xe4c16d163d80fd972e6e1e9b94bc71c5fbe5a9c5/moving-an-agent-facing-api-to-a-new-domain-which-moved-origin-signals-clients-ac","method":"GET","headers":{},"bodySchema":{"type":"object","$schema":"https://json-schema.org/draft/2020-12/schema","required":["input"],"properties":{"input":{"type":"object","required":["type","method"],"properties":{"type":{"type":"string","const":"http"},"method":{"enum":["GET"],"type":"string"},"pathParams":{"type":"object","required":["handle","slug"],"properties":{"slug":{"type":"string","description":"The article's URL slug, unique per creator. The reserved slug `latest` resolves to the creator's newest published piece; its stable scheduled-read form is the wallet-address URL /api/read/<0x-address>/latest (a handle `latest` is not payable)."},"handle":{"type":"string","description":"The creator's handle, or their wallet address. The address form is REQUIRED for a durable `latest` alias (a handle `latest` is not payable), and is the only form for an unclaimed creator."}}},"queryParams":{"type":"object","required":[],"properties":{},"additionalProperties":false}},"additionalProperties":false},"output":{"type":"object","required":["type"],"properties":{"type":{"type":"string"},"example":{"type":"object"}}}}},"responseSchema":null,"example":null,"exampleRequest":null,"tags":["x402"],"displayCostAmount":"0.25","displayCostAsset":"USDC","priceDynamic":false,"priceHint":null,"priceStatus":"priced","priceSource":"probe","requiresHandshake":false,"reviewCount":0,"rating":{"score":"0.00","successRate":"0.00","reviews":0,"stars":null,"state":"unrated"},"availabilityStatus":"unknown","priceObserved":null,"sessionDeposit":null,"pricing":{"kind":"static","summary":"$0.25/call","primary":{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.25","per":"call","confidence":"exact"},"accepted":[{"kind":"static","protocol":"x402","network":"base","amountUsd":"0.25","per":"call","confidence":"exact"}]},"paymentMethods":[{"uid":"pm_N2Tkz3EB6PMrOHh10VMzl","protocol":"x402","methodType":"crypto","chain":"base","mode":"charge","costAmount":"0.25","costPer":"request","priority":0,"asset":"0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913","unit":"request","depositMicros":null,"planRef":null}],"brandName":null,"brandSlug":null,"brandBaseUrl":null,"brandDocsUrl":null,"whatItDoes":"Returns a paid article analyzing which HTTP and protocol signals clients honor when migrating an agent-facing API to a new domain, covering redirect headers, MCP Registry, ERC-8004, Alt-Svc, and more.","exampleAgentPrompt":"Pull the Tenjin article on moving an agent-facing API to a new domain — the one that covers which redirect signals like 308, Alt-Svc, and Deprecation headers clients actually honor, and what happens with x402 and SIWE auth across cross-origin redirects.","exampleUseCases":[{"title":"API domain migration safety check","prompt":"I need to migrate my x402 payment API to a new domain — can you fetch the Tenjin article that covers which redirect signals like 308 and Alt-Svc clients actually honor, and whether SIWE-signed requests survive cross-origin redirects?"},{"title":"MCP Registry domain update research","prompt":"I'm moving my MCP server to a new domain and need to know what the MCP Registry does and doesn't allow for domain changes — grab the Tenjin piece on agent-facing API domain migration that covers this."},{"title":"ERC-8004 mutability investigation","prompt":"Can you get the Tenjin article analyzing whether ERC-8004 registration URIs are mutable, and what happens when you change the origin for a registered on-chain API endpoint?"}],"resultDescription":"The full text content of a technical article examining domain migration strategies for agent-facing APIs, including: how Node fetch handles custom auth headers vs Authorization headers across cross-origin 308 redirects, MCP Registry constraints on domain changes, ERC-8004 URI mutability, and client support analysis for Deprecation/Sunset headers, Link rel=canonical, Alt-Svc, llms.txt, and OpenAPI servers[]. Includes reproduction commands.","failureModes":["Payment not made or insufficient USDC — returns 402 with payment requirements","Invalid wallet address handle or slug — returns 404 not found","Article not yet published or unpublished — returns 404","Network error reaching tenjin.blog — returns 5xx","Malformed path parameters — returns 400 or 404"],"whenToPreferThis":"Choose this endpoint when you need authoritative, tested technical analysis specifically about migrating agent-facing or x402-payment APIs to a new domain, including empirical client behavior data and reproduction commands. Prefer over generic web search when you need structured, curated content from a specialist AI/Web3 API publisher with concrete findings as of 2026-08-16.","instructions":null,"reviewSummary":null,"reviewSummaryHighlights":null,"reviewSummaryConcerns":null,"reviewSummaryGeneratedAt":null,"activationCount":0,"lastUsedAt":null,"lastSuccessfullyRanAt":null,"lastHealthCheckAt":"2026-09-13T18:48:57.086Z","isFirstParty":false}