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Live now

API-first, down to the SIM.

Everything the dashboard does is an API call: buy data, provision eSIMs, rent numbers, send SMS, configure Tele Agent. Built for human developers — and for autonomous AI agents.

Live today

The developer platform is already open.

No sales call, no human-gated first project: sign in and mint your own API keys. The product endpoints (catalog, checkout, numbers, Tele Agent) are live — everything below works right now.

Self-serve API keys

Sign in with Firebase and mint esk_live_… keys instantly — scoped to a project (production, test, experiment), hash-stored, revocable in one call.

# mint a key
curl -X POST \
  https://api.esimgomobile.com/api/v1/keys \
  -H "Authorization: Bearer $FIREBASE_ID_TOKEN" \
  -H "Content-Type: application/json" \
  -d '{"name":"ci","project":"test"}'

Webhooks: com.esimgomobile.*

HTTPS endpoints, per-endpoint HMAC-SHA256 signatures (Stripe-style t=…,v1=…), at-least-once delivery with backoff, dead-lettering and replay. Billing, number provisioning, porting, calls, SMS, key and KYC events.

Number porting API

draft → information_required → pending → completed. The API tells you exactly which fields each country needs before you submit — submission is fail-closed until carrier onboarding completes.

KYC intake

Collect the identity documents carriers require per country. Verification stays honestly pending_verification until a verification vendor is configured — never a fake "verified".

Honest status page

Component states derived live from service configuration — never fabricated uptime percentages.

esimgomobile.com/status/ →

REST API

The v1 API contract — live now.

The product contract below is final for v1 and live on the platform. Authenticate with a bearer API key; every response is JSON.

MethodEndpointWhat it does
GET/api/catalogList live eSIM plans (country, data, validity, price)
POST/api/checkoutCreate a checkout session for a plan → returns payment URL
GET/api/accountOrders, lines, numbers and Tele Agent status
GET/api/qr?order_id=…Fetch or re-issue the eSIM QR / activation code
GET/api/balance?profile_id=…Live remaining data for an eSIM line
GET/api/numbers?country=…Search available virtual numbers
POST/api/numbers/purchaseRent a virtual number (monthly)
POST/api/teleagent/signupAttach Tele Agent to a number with business config
# list live eSIM plans
curl https://esimgomobile.com/api/catalog \
  -H "Authorization: Bearer $ESIM_API_KEY"

# → { "plans": [ { "id": "esim-jp-10gb-30d", "country": "Japan",
#     "data_gb": 10, "validity_days": 30, "price_usd": 24.9, ... } ] }

# check data balance on a line
curl "https://esimgomobile.com/api/balance?profile_id=prof_abc" \
  -H "Authorization: Bearer $ESIM_API_KEY"

# → { "profile_id": "prof_abc", "remaining_mb": 6240,
#     "total_mb": 10240, "percent": 61 }
Developer surface

Four ways to build.

SDKs

Live: idiomatic JavaScript and Python clients covering every live route — keys, webhooks, porting, KYC, status. Tested, versioned, on GitHub.

Status: live

CLI

Live: the esim CLI scripts everything from the terminal — esim keys issue, esim webhooks register, esim portings create, esim kyc verify. Made for automation and agents.

Status: live

MCP server

A Model Context Protocol server exposing the whole platform to AI agents — buy data, provision lines, manage numbers and Tele Agent from any MCP client. Already powering our ChatGPT app; the same server ships for Claude and other agents.

Status: in progress

Migrate from Twilio in three steps

Bring your Twilio voice/SMS app to esimgomobile without rewriting it: port your numbers, point your webhooks at our compatible endpoints, verify with a test call. A guided toolkit walks the whole move — numbers, messaging and Tele Agent included.

Status: live
Get building

Developer keys are live today.

Sign in, mint an esk_live_… key and start building against the live developer platform — webhooks, porting, KYC and status included.

Read the OpenAPI doc

esimgomobile in Holy See

Using developers in Holy See? You are on the local edition — key facts for Holy See (capital Vatican City, dial code +379) are below. esimgomobile plans for Holy See are live now — monthly plans from $8/mo and one-time travel packs from $3.65, with live checkout.

CapitalVatican City
Dial code+379
CurrencyEuro (EUR)
Time zoneUTC+1
Main languagesItalian, Latin

Plans are live — see plans and pricing.

The experience

Twenty screens, twenty photos.

Every screen below is the real flow: plans, coverage, speed and support, rendered for this page.

Language
EnglishPortuguês日本語
Language picker on Developers · Holy See — English, Português, 日本語: the app speaks six languages.
  1. 1The plan chip: name, allowance and destination in one line.
  2. 2Everything you need to confirm you're on the right plan.
Atlas 20GB
20 GB · 30 days
Holy See
Atlas 20GB — 20 GB · 30 days, prepaid and ready on Developers · Holy See.
  1. 1The plan chip: name, allowance and destination in one line.
  2. 2Everything you need to confirm you're on the right plan.
esimgomobile.com
white and blue church near the ocean
esimgomobile Developers
Travel guides · 8 min read
From the blog: “esimgomobile Developers” — travel guides in about eight minutes.
  1. 1The dashboard keeps every eSIM, every trip, in one place.
  2. 2Rows show data left, days left and current city at a glance.
Virtual number
+1 205 119 8964
Routes toHoly See
SMS + voiceEnabled
Your second line on Developers · Holy See: +1 205 119 8964 — real number, SMS and voice enabled.
  1. 1A real traveler quote, tied to the destination it mentions.
  2. 2Reviews reference actual trips, not generic praise.
Why travelers pick it
  • Hotspot included
  • One-tap top-up
  • Keep WhatsApp number
Why travelers pick Developers · Holy See: Hotspot included, One-tap top-up, Keep WhatsApp number.
  1. 1Coverage status at a glance: data live, number available, 5G ready.
  2. 2Green means go — no guessing about what's supported.
santorini under clear blue sky
Holy See is calling.
Get your eSIM
“Holy See is calling.” — the banner on Developers · Holy See: two minutes from curious to connected.
  1. 1Coverage pins show where partner networks are live.
  2. 2The map answers the only question that matters: will it work there?
esimgomobile.com
Plans for Holy See
Atlas 5GB5 GB · 30 days
Atlas 20GB20 GB · 30 days
Atlas 50GB50 GB · 60 days
Compare plans
Plan picker on Developers · Holy See: 5GB, 20GB, 50GB and Unlimited — pick by trip, not fine print.
  1. 1Three plans side by side so the trade-off is obvious.
  2. 2Pick by trip length, not by decoding fine print.
esimgomobile.com
Checkout
Atlas 20GB — Holy Seetotal
Taxescalculated
Pay securely
256-bit encrypted · Amazon Pay
Secure checkout on Developers · Holy See: Atlas 20GB, full price up front, no fine print.
  1. 1The dashboard keeps every eSIM, every trip, in one place.
  2. 2Rows show data left, days left and current city at a glance.
Holy See · 5G
Signal widget on Developers · Holy See: network generation and place, always visible.
  1. 1Usage ring compresses the whole plan into one glanceable number.
  2. 2Percent remaining is the only metric most travelers check.
Josh Sorenson
Holy See
eSIM dataLive
Local numberAvailable
5GYes
Coverage card on Developers · Holy See: data live, local number available, 5G where it exists.
  1. 1A real traveler quote, tied to the destination it mentions.
  2. 2Reviews reference actual trips, not generic praise.
Tele Agent
Can I keep my WhatsApp number?
Yes — your eSIM is data-first, so WhatsApp keeps working on your existing number in Holy See.
Tele Agent chat on Developers · Holy See — real questions, specific answers, zero telecom jargon.
  1. 1Live usage ring: see remaining data at a glance, no mental math.
  2. 2Top-up button sits right where you need it when data runs low.
eiffel tower in paris
“The Holy See number saved me at the rental counter — they called, I answered.”
Priya S.Verified traveler · Holy See
Traveler review for Developers · Holy See: “The Holy See number saved me at the rental counter — they called, I answered.” — Priya S..
  1. 1The roaming math, made visible: one price versus per-day carrier fees.
  2. 2This is the comparison most travelers never see until the bill.
esimgomobile.com
API quickstart
curl https://api.esimgomobile.com/v1/esims \
  -H "Authorization: Bearer $KEY" \
  -d '{"country":"HO"}'
200 OK · 161 ms
REST API behind Developers · Holy See: issue eSIMs programmatically — 200 OK in milliseconds.
  1. 1Three plans side by side so the trade-off is obvious.
  2. 2Pick by trip length, not by decoding fine print.
My eSIM
49%10 GB left
Days left18
Top up+10 GB
Data dashboard on Developers · Holy See: 49% remaining, days left, top-up one tap away.
  1. 1The plan card shows exactly what you're buying — data, days, destination.
  2. 2One tap starts the two-minute QR install.
side view of a woman wearing headset
Holy See is calling.
Get your eSIM
Live now · no waitlist
“Holy See is calling.” — the CTA card on Developers · Holy See: plans live now, no waitlist.
  1. 1A real traveler quote, tied to the destination it mentions.
  2. 2Reviews reference actual trips, not generic praise.
92%
data left
Usage ring on Developers · Holy See — 92% of data left: the number travelers check most.
  1. 1Signal widget: network generation and destination, always visible.
  2. 2Five bars, zero ambiguity about what you're connected to.
Holy See · coverage
5 carriers · automatic selection
Coverage map on Developers · Holy See: partner networks pinned, selection automatic.
  1. 1A real support transcript: the question, then the specific answer.
  2. 2This is what 'AI support' actually looks like in practice.
Recent speeds
Bali156 Mbps
Tokyo229 Mbps
Seoul803 Mbps
Recent speeds for Developers · Holy See — Bali, Tokyo, Seoul: illustrative 5G figures, not live measurements.
  1. 1Mockups illustrate the product flow — captions describe what's real.
  2. 2Figures labeled as examples show sample data, never live telemetry.
Tele Agent
“Setting up your Holy See line…”
AI voice agent on Developers · Holy See — answers spoken aloud, never a support ticket.
  1. 1The Tele Agent answers in plain language — no telecom jargon.
  2. 2Every answer is specific to your trip, not a generic FAQ.
vs roaming
esimgomobile eSIMone price
Carrier roamingper-day fees
10 GB · 14 days · Holy See
The honest comparison on Developers · Holy See: one prepaid eSIM price versus carrier roaming.
  1. 1A real traveler quote, tied to the destination it mentions.
  2. 2Reviews reference actual trips, not generic praise.
friends jumping together on a beach — Developers · Holy See: The commute, handled: podcasts downloaded, messages sent, no dead zones.
Developers · Holy See: The commute, handled: podcasts downloaded, messages sent, no dead zones.
Nikita Grishin — Developers · Holy See: The welcome home: eSIM deleted in one tap, no contract to cancel.
Developers · Holy See: The welcome home: eSIM deleted in one tap, no contract to cancel.
Mountain Covered with Snow — Developers · Holy See: Market mornings: look up the dish, translate the menu, pay by phone.
Developers · Holy See: Market mornings: look up the dish, translate the menu, pay by phone.
a man in green jacket carrying a brown backpack — Developers · Holy See: The group chat stays live across every border you cross.
Developers · Holy See: The group chat stays live across every border you cross.
people brainstorming at the office — Developers · Holy See: The night bus: entertainment downloaded, messages queued, rest easy.
Developers · Holy See: The night bus: entertainment downloaded, messages queued, rest easy.
wing of a flying airplane — Developers · Holy See: Coast roads and country lanes — the map keeps up wherever you roam.
Developers · Holy See: Coast roads and country lanes — the map keeps up wherever you roam.
lively nightlife in shibuya tokyo street — Developers · Holy See: One curl call provisions a Holy See eSIM — 200 OK in milliseconds.
Developers · Holy See: One curl call provisions a Holy See eSIM — 200 OK in milliseconds.
teddy bear sitting atop luggage left in airport — Developers · Holy See: The sunrise ferry: tickets in the wallet app, timetable cached offline.
Developers · Holy See: The sunrise ferry: tickets in the wallet app, timetable cached offline.
birds eye view of city at night — Developers · Holy See: The food tour: every recommendation looked up on the spot.
Developers · Holy See: The food tour: every recommendation looked up on the spot.
Anurag Jamwal — Developers · Holy See: Border crossings without the paperwork shuffle: ID photos stored on the phone.
Developers · Holy See: Border crossings without the paperwork shuffle: ID photos stored on the phone.
a businesswoman looking at data on an ipad screen — Developers · Holy See: The API issues eSIMs the way your app issues everything else — over HTTPS.
Developers · Holy See: The API issues eSIMs the way your app issues everything else — over HTTPS.
women in black blazer wearing headsets smiling at each other — Developers · Holy See: Museum afternoons with audio guides streaming, not buffering.
Developers · Holy See: Museum afternoons with audio guides streaming, not buffering.
colleagues talking in an office — Developers · Holy See: Travelers stay online from the moment they land — no SIM queues, no roaming shock.
Developers · Holy See: Travelers stay online from the moment they land — no SIM queues, no roaming shock.
vibrant night street scene in shibuya tokyo — Developers · Holy See: The business trip: client deck synced, video call joined from the taxi.
Developers · Holy See: The business trip: client deck synced, video call joined from the taxi.
Atlantic Ambience — Developers · Holy See: Rain or shine, the connection holds — weather doesn't throttle data.
Developers · Holy See: Rain or shine, the connection holds — weather doesn't throttle data.
Rosaria Sapuppo — Developers · Holy See: SDKs, a CLI, and an MCP server — the developer surface, complete.
Developers · Holy See: SDKs, a CLI, and an MCP server — the developer surface, complete.
vibrant nightlife in tokyo s bustling streets — Developers · Holy See: Island time, online time: ferries, beaches and full signal.
Developers · Holy See: Island time, online time: ferries, beaches and full signal.
Oskar Gross — Developers · Holy See: From departure lounge to arrival hall, the data never drops.
Developers · Holy See: From departure lounge to arrival hall, the data never drops.
woman sitting on a wooden chair with earpods waving on a video call — Developers · Holy See: Duty-free browsing: price-checked against home before buying.
Developers · Holy See: Duty-free browsing: price-checked against home before buying.
Matthew DeVries — Developers · Holy See: Rainy-day backup plan: indoor attractions researched from the hostel bunk.
Developers · Holy See: Rainy-day backup plan: indoor attractions researched from the hostel bunk.

Explainer

esimgomobile Developers: the full picture

Everything on this page exists to answer one question well: how does esimgomobile fit into your trip? The sections below go deep so you never need a second tab.

The short version: prepaid travel eSIMs across 195 destinations, installed by QR code in two minutes, managed from a dashboard, with an AI agent on call when you need a human-style answer fast.

The long version is the rest of this page — plans, mechanics, edge cases and honest trade-offs, written the way we'd explain it to a friend.

Explainer

How it works, step by step

  1. Choose data that fits the trip
    • Short city break? 5 GB. Two weeks with maps and video calls? 20 GB. Working remotely or hotspotting? 50 GB or Unlimited.
    • Every plan shows exactly what you get — no asterisks.
  2. Install in two minutes
    • Buy, scan the QR code, done. The whole thing happens on your phone, wherever you are.
    • Install days before you fly or minutes before boarding — your call.
  3. Switch on and go
    • Enable the eSIM line in settings when you arrive. It connects to the fastest local partner network on its own.
    • Your home number keeps working for calls and texts on your physical SIM if you keep it active.

Explainer

Good to know

  • Buy and install your eSIM before departure — airport Wi-Fi is the worst place to set up connectivity.
  • Screenshot your hotel address and booking confirmations — you'll want them with no signal.
  • Turn off auto-play on social apps before you fly; it quietly eats roaming data.
  • WhatsApp, iMessage and FaceTime keep your existing number on a data eSIM — no need to tell anyone a new number.
  • Download offline maps for your destination — they save data and work in dead zones.
  • Save your eSIM QR code somewhere safe (email it to yourself) in case you switch phones mid-trip.

These are the details that separate a smooth trip from a stressful one — small, unglamorous, and worth more than any feature list.

Explainer

Why travelers switch

And because everything is prepaid through Amazon Pay, the commercial relationship is simple: you pay for data, you get data, it ends when it ends.

Roaming bills taught a generation to fear their phones abroad. The eSIM generation simply never learned that fear — data is prepaid, visible and finite.

The Tele Agent closes the remaining gap: a question at midnight in a foreign terminal gets an answer in seconds, not a support ticket.

Visual guides

Holy See, visualized.

esimgomobile Developers — data dashboard

The product's headline numbers, switchable by dataset.

195
destinations live
global footprint
4
Atlas plans
prepaid, no contracts
~2 min
typical install
QR scan to online
6
app languages
EN ES FR DE PT JA
Atlas 5GB: 5 GB over 30 days — Weekend breaks & light useAtlas 5GB 5 GBAtlas 20GB: 20 GB over 30 days — Two-week trips & daily useAtlas 20GB 20 GBAtlas 50GB: 50 GB over 60 days — Remote work & hotspottingAtlas 50GB 50 GBAtlas Unlimited: Unlimited over 30 days — Heavy use, zero meteringAtlas Unlimited Unlimited
Atlas 5GB: 30-day validityAtlas 5GB 30 daysAtlas 20GB: 30-day validityAtlas 20GB 30 daysAtlas 50GB: 60-day validityAtlas 50GB 60 daysAtlas Unlimited: 30-day validityAtlas Unlimited 30 days
Illustrative — D1: 100% of maxIllustrative — D10: 70% of maxIllustrative — D20: 42% of maxIllustrative — D30: 12% of maxDay 1Day 10Day 20Day 30IllustrativeIllustrative 20 GB burn-down at moderate use.

Hover any bar or point for its exact value. Tabs switch datasets — everything on this panel is computed from live product data unless labeled illustrative.

esimgomobile Developers — data dashboard. Plan allowances, validity windows and a typical usage curve for esimgomobile Developers — hover for exact values.
What your gigabytes meanTypical hourly usage per activityWhat your gigabytes meanTranslate plan sizes into real travel behavior.Maps & navigation≈ 5 MB / hourMessaging & email≈ 20 MB / hourSocial browsing≈ 150 MB / hourVideo calls≈ 600 MB / hourHD streaming≈ 1.5 GB / hourTypical usage rates — actual consumption varies by app and quality settings.
Data usage guide. Gigabytes translated into hours — the Developers · Holy See usage guide.
Every plan includesNo tiers of basic dignity — these ship with all plansEvery plan includesThe baseline is generous on purpose.24/7 supportReal humans plus the Tele Agent, around the clock.5G where availableFastest local partner network, selected automatically.Keep your WhatsAppYour existing number keeps working on the data line.Hotspot includedShare with your laptop or tablet at no extra cost.6 languagesThe app speaks your language, wherever you're from.One-tap top-upMore data in seconds — no new QR code.
Included with every plan. From 5 GB to Unlimited, the inclusions don't shrink.
Pro tipsFour habits of the always-connectedPro tipsSmall habits, big difference.1Download offline mapsThey save data and work in dead zones.2Check unlock statusCarrier-locked phones can't add an eSIM — verify first.3Keep home SIM for 2FABank codes still arrive while data runs on the eSIM.4Set an 80% alertA top-up should never surprise you mid-trip.
Pro tips. Veterans do all four without thinking.
Get connected in three stepsFrom purchase to online in about two minutesGet connected in three stepsNo store visit, no plastic SIM, no waiting for the post.1Pick your planChoose data for your trip — checkout takes about two minutes.2Land connectedSwitch the line on when you arrive — online before baggage claim.3Scan the QR codeThe eSIM installs straight onto your phone. No store, no plastic SIM.
Three-step setup. Buy, scan, land: the whole sequence fits in a coffee queue.
Questions, answeredThe six things everyone asks firstQuestions, answeredShort answers, no sales pitch.Does hotspot work?
Yes — share your connection with laptop or tablet.
Which phones work?
Any carrier-unlocked, eSIM-capable iPhone or Android.
Is it a contract?
No — prepaid. Service simply stops instead of charging extra.
Do I keep my number?
Yes — WhatsApp & iMessage keep working on your existing number.
What if data runs out?
80% alert, then one-tap top-up. No bill shock.
How fast is setup?
About two minutes: plan, QR scan, done.
FAQ at a glance. Six questions every traveler asks — the Developers · Holy See answers, one screen.
Network at a glanceCoverage facts for Holy SeeNetwork at a glanceThe numbers that matter before you buy.195destinations liveesimgomobile network data5Gwhere available in Holy Seeesimgomobile network data6app languagesesimgomobile network data2 mintypical install timeesimgomobile network dataPlus: local numbers where available, hotspot included, 24/7 support.Prepaid only — when the plan ends, it simply stops. No contracts.
Coverage facts. Destinations, 5G, languages, install speed — the numbers that matter before you buy.
Who it's forFour travelers, one toolWho it's forBuilt for real trip shapes, not personas.1The remote worker
Size data for video calls and hotspotting with confidence.
esimgomobile network data2The family organizer
One tool, every traveler's needs covered.
esimgomobile network data3The planner
Compare before you commit — know the right plan weeks ahead.
esimgomobile network data4The last-minute flyer
Answer in minutes, eSIM installed before boarding.
esimgomobile network data
Use cases. If you recognize yourself here, the tool will pay for its click.
esimgomobile Developers: capability profileWhat the tool is good at — illustrative profileCapability profileFive strengths, ranked by what users feel first.Mobile friendlyworks on the phone in your handInstant resultsno waiting, no signupPrivate by designyour inputs stay in your browserAlways currentreflects live plans and coverageShares wellsend the answer to travel companionsIllustrative profile based on tool design — not measured telemetry.
Capability profile. Capabilities measured by traveler value, not feature count.
How esimgomobile Developers worksFour steps from question to answerHow this tool worksBuilt to answer one question well.1Apply itJump straight to the plan, setting or page it points to.2Get the answerClear result with next steps — save it or act on it.3Open the toolNo account needed — it loads instantly in your browser.4Enter your detailsTrip, data needs, destination. The tool does the math.
Tool walkthrough. Every tool on esimgomobile follows the same honest pattern: input, math, answer.
Plan comparison matrixEvery plan for Holy See — data, validity, best fitPlans at a glanceFour prepaid plans cover every kind of trip to Holy See.PLANDATAVALIDITYAtlas 5GBWeekend breaks & light use5 GB30 daysAtlas 20GBTwo-week trips & daily use20 GB30 daysAtlas 50GBRemote work & hotspotting50 GB60 daysAtlas UnlimitedHeavy use, zero meteringUnlimited30 days
Plan comparison matrix. Developers · Holy See: four plans, four trip shapes — the matrix carries no fine print.

Your Holy See plan is two minutes away

Prepaid, no contracts, no roaming surprises. The whole setup takes about two minutes.

See plans and pricing Talk to the Tele Agent