--- layout: default ---

x-api-key

de facto — unregistered request 7 spellings

Declared by 798 providers across 20047 published specification files in the APIs.io network.

What this header is for, and how to use it →

A count here is providers whose published contract declares this header — not providers who send it. Response headers set at the edge rarely appear in an OpenAPI at all, so a low number can measure documentation practice rather than deployment.

Spelled 7 ways

HTTP field names are case-insensitive (RFC 9110 §5.1), so every spelling below is the same header on the wire. A contract is not the wire: generated clients key off the string, and a developer reading two of these sees two different headers.

x-api-keyX-API-KeyX-API-KEYX-Api-Keyx-Api-Keyx-API-KeyX-api-key

Providers declaring it (798)

0xarchive 10web 2x 5dollarfootballapi 8x8 ab-tasty absentify acast acceldata accessibe aci-dev activtrak adanos-market-sentiment-api adobe adobe-analytics adobe-campaign adobe-creative-cloud adobe-creative-suite adobe-experience-cloud adobe-launch adobe-photoshop adobe-premiere adobe-suite adopets adsbexchange advance-auto-parts advanced-micro-devices adyen afriex agechecker-net agentql agicap agnost-ai agorapulse ahasend aiera airweave aito-technologies ajaib akash akool akute alasco algebras-ai-inc allium allquiet alokai-formerly-vue-storefront alphasense ambee amberdata amberflo america-movil amigo amnic ampersand amuncore ando anthropic anthropic-claude anu anyapi anyimagedetector apache-apisix apex27 api-evangelist api-league apicontext apifuse apigen apigit apinizer apis-io apitube apollo-api-documentation apollo-insurance apollo-io application-research applike apptentive appzen arc-prize-foundation archbee archrock argil armor armosec associated-press assurant athenian atmospore-pollen-forecasts atomic-fi atomicwork autogpt azure-log-analytics b3 backpack band-ai bankruptcywatch bargo-congress-trades-api base-operations basetrip bem benchmark-email benchmark-minerals betgenius bettercloud beyond-presence biconomy biodock biogen birdeye bitmovin bitpanda bizverify blablacar-bus-api blackbird blissfully blockade-games blockaid blocktorch bloom-credit bloomerang blowfish bluecart bluejay bmo boldsign bolsai bolt-financial bot-butcher brandcast breathe-hr breeze brightcove brl broadlume cable cachet calendar-api-ma california-privacy-protection-agency calorie-ninjas camb-ai cancer-gov canix canny captions cargoai cargosmart cartesia-ai cast-ai ccpa chainstack chimoney citi clari claude cleanup-pictures climateai clockify closedloop cloudbeds cloudchipr cloudsmith clusters coasty cobalt cofactr cognee cogny coinme combocurve common-sense-media composio compresr concord-com connecteam constant-contact convai-com conxai coperniq corestory coval coval-ai craft-io creatoriq creed creem crossmint crustapi cuein curai curse cyble dacast dana dassault data-commons datadome dealhub decart dedaluslabs deepdub deeptrace delphi demo-openapi democracy-works denim dentsply-sirona department-of-justice developerhub dexcare dflow didit diligent disconetwork discountedtokens-api dmarket dokploy dolby domain-group domaintools domscan dopost-co doppel dpd-group drillr dyno e2b e2b-dev echo-global edfapay-inc edge-impulse edgee egym element-biosciences element5 emburse emotive end-close engineering-platform enphase enrich-so ensighten entergram epa equipmentwatch esimgo etoro etsy eu-open-data-portal euler evedex eventzilla everbridge everhour evermuse exa exa-ai faa fabric-com facilio factorial-hr fashion-ai fastdol fastino-labs fieldpulse finalcad findigs finlight finops-foundation fintary fireblocks fixie flipside fluence food-info footprint forgerock formbricks freedom-of-information-act frejun-teler friendly-captcha frostbyte fulfil-io futureverse gala-games gallop gameanalytics geekflare gelato general-services-administration genius-sports genlogs ghent gingr gitcoin glassnode golioth got-its govly gptzero gradium grapes-finance greenspark gridstatus gsma gumgum hang harbor-compliance harness harness-cloud-cost healthsherpa hedra helika heron hevn-inc heygen heymilo hilberts-ai hipay holidu honeybadger hostdefi hotglue hr-partner humanloop hyperbrowser iab-tech-lab idanalyzer imentiv-ai impala incode infracost innago insforge insider intelycare interos ion-group jaggaer jasper jumpcloud jupiter-ag jupiter-exchange juro kaedim kaiko kapa-ai karumi keda keep keeptrack keploy kintsugi knowi knownwell koi-security komerce kontomatik kore-wireless koreai kubescape kudosity kuehne-nagel kugelaudio kuru lafourchette laka lancedb land-insight lane-api langchain langflow langgraph langsmith langtrace layerzero leadiq ledger licenseplatedata lightbox-zoning-api lightroom lightstream linearb lingo-dev lingopal linkagi-model-api linksquares linqalpha listen-labs listrak lit-protocol literalai lmnt loa-healthcare-pricing-api loot-rush-games lootrush lovo-ai luxury-presence m0 madkudu magic-moment maileroo makeswift marginedge marriott-international mashable mashvisor materials-project mbta mcp360 mediacaption-api mediaruntime medtrainer meow merit-systems merkle-science metabase metalend metriport metrobi micro1 microsoft-azure microsoft-azure-monitor mikmak minerstat minicor mirage mntn mobly modernizing-medicine modulate moloco moneris monetizenow montran moonscale moralis morningstar moveworks mtn-group mv-sistemas mvmnt myshiptracking mystars mystars-faas-fulfilment-api n3rgy nace-ai narakeet national-park-service national-weather-service navis navistone neon-commerce neuphonic newsapi newscatcher newtqnia nexosai neynar nightfall-ai noaa noaa-gov nord-security notyfi now-payments ntropy nuclei nuitee ocean-security oddsjam odoo offendersearch offendersearch-api omnisend ondo-finance one-codex oneschema onsi openaq openchargemap openfeature opengov opensea openstates openwallet-foundation openwork opera opticodds optilogic optimizely orange-business ordergroove ordway orion-health ortto osmosis oumla-ltd outrival overflow

Showing the first 500 of 798.

Explore

All headers Authentication Guidance on headers.apievangelist.com

Work with this as data

Every header here is available over the APIs.io API and to AI agents over MCP. HTTP Headers is not yet its own endpoint on the v1 API. Reach it through catalog search and the tag graph, or the MCP server.

MCP server

One button, every client — Claude, Cursor, VS Code and the rest.

https://apis.io/mcp

Tools for http headers

3 MCP tools reach this
  • apis_io_searchSTART HERE — APIs, providers and tags for one query, each with its total.
  • resolveTurn a domain, URL or GitHub org into the provider it belongs to.
  • find_cohortsEvery scored population of providers in the catalog.
All 92 tools →

Call it yourself

curl for this page
Search the catalog
curl "https://apis.io/api/v1/search?q=x-api-key&limit=10"
Everything under a tag
curl "https://apis.io/api/v1/tags/x-api-key"

Discovery needs no key. Ratings and market analysis are Pro.

Get an API key

Free tier, no form to fill in. Signing in shares your email address with us — we store it to create your key and to recognise you if you sign in with another provider. See our Privacy Policy and Terms.

A second provider on the same verified email joins the account you already have.