Connect Ballet Crypto cold-storage data to your stack — without ever touching a private key
Ballet Crypto is the companion app for the Ballet REAL Series cold-storage card: scan a QR code, and the app shows balances, sends and receives assets, activates extra currencies and reads real-time portfolio value. We turn that visible data surface into clean, read-only APIs your accounting, treasury, analytics or compliance systems can call. Nothing here requires the app's private keys — Ballet generates keys with the BIP38 standard and never stores them, and our integrations stay strictly read-only against public chains and documented partner APIs.
What we deliver
Every engagement ships as a self-contained package, not a slide deck. You receive the protocol analysis write-up, the API server source, client SDKs, automated tests and the documentation needed for your own engineers to run and extend it. Below is the standard checklist plus the first technical artifacts you can expect.
Deliverables checklist
- API specification (OpenAPI / Swagger) for balance, transaction, valuation, swap and NFT endpoints
- Protocol & data-flow report: how the app derives addresses from a QR-scanned Ballet card, queries on-chain indexers and talks to the Changelly API
- Runnable source for the read-only API server (Python / Node.js) plus a thin Go client
- Automated tests, fixture data, and a Postman / HTTPie collection
- Compliance notes: VASP context, FATF Travel Rule touchpoints, GDPR-style data minimization and retention guidance
API example — portfolio valuation (pseudocode)
POST /api/v1/ballet-crypto/portfolio/value
Content-Type: application/json
Authorization: Bearer <ACCESS_TOKEN>
{
"card_ref": "ballet:real:9f2c...",
"addresses": [
{"chain": "bitcoin", "address": "bc1q..."},
{"chain": "ethereum", "address": "0xab..."}
],
"quote_currency": "USD"
}
200 OK
{
"as_of": "2026-05-11T08:00:00Z",
"total_value": "12843.57",
"by_asset": [
{"symbol":"BTC","amount":"0.1821","value":"11210.40"},
{"symbol":"ETH","amount":"0.42","value":"1633.17"}
]
}
Engagement highlights
Source-code delivery starts at $300: we hand over the runnable API server and full documentation, and you pay after delivery once you are satisfied. Prefer not to host it yourself? Use our pay-per-call hosted endpoints and pay only for the requests you make — no upfront fee. Both models cover the same Ballet Crypto data surface: balances, transactions, valuation, swaps, activated currencies and NFT holdings.
Feature modules
Address & balance API
Resolve every address linked to a Ballet card and return current balances and UTXO sets across Bitcoin, Ethereum, XRP and EVM-compatible chains. Use it to power a treasury dashboard that shows one combined figure across many physical cards instead of checking each card by hand.
Transaction history API
Stream confirmed inbound and outbound transfers — native coin and ERC-20 / BEP-20 token movements — with paging, date ranges, and per-asset filters. The typical use is bookkeeping: feed line items into a ledger for monthly reconciliation and audit trails.
Portfolio valuation API
Convert raw on-chain balances into a fiat figure using a configurable market-data source, returned both as a total and per asset. This is what a wealth report or a tax estimate needs: a dated snapshot of holdings and their value at that moment.
Swap & exchange-status API
Ballet's in-app swaps are powered by the Changelly Crypto Exchange API; we expose the quote, the executed pair, the network and provider fees, and the exchange status (waiting / confirming / exchanging / finished). Trade journals and cost-basis engines use this to close out every leg of a swap.
Activated-currency registry
Ballet cards support multicurrency activation — additional coins enabled on the same card. The registry endpoint returns which currencies are active per card and when they were activated, so an inventory system can track exactly what each device can receive, hold and send.
NFT holdings feed
The app's NFT gallery shows collectibles on Ethereum, Polygon and BNB Chain. The holdings feed returns contract address, token ID, collection name and media URL for each item, which a portfolio aggregator can merge with fungible-asset data for a single view.
Data available for integration (OpenData perspective)
The table below maps the data the Ballet Crypto app surfaces to its origin, the granularity you can expect, and a representative use. Everything is read-only and derived from public on-chain state, the app's own screens, or documented partner APIs — no private keys, no off-device personal data, in line with the app's privacy posture.
| Data type | Source (screen / feature) | Granularity | Typical use |
|---|---|---|---|
| Wallet address & balance | Wallet / "My assets" screen, derived from QR-scanned card | Per address, per chain, per asset; near real-time | Treasury dashboards, proof-of-holdings, alerting |
| Transaction history | Asset detail / activity list | Per transaction: hash, direction, amount, counterparty, timestamp, confirmations | Accounting, reconciliation, audit trail |
| Portfolio valuation | Home screen total & market value | Per asset and aggregate, in chosen fiat, dated snapshot | Wealth reporting, tax estimates, performance analytics |
| Swap orders | In-app swap flow (Changelly API) | Per order: pair, amount in/out, rate, fees, status, provider | Trade journaling, cost-basis tracking, fee analysis |
| Activated currencies | Currency activation flow | Per card: currency code, activation date, status | Device / asset inventory, entitlement tracking |
| NFT holdings | NFT gallery (Ethereum / Polygon / BNB Chain) | Per token: contract, token ID, collection, media URL | Collection management, portfolio aggregation, insurance |
| Market price feed | Backing market-data source used for valuation | Per asset, per quote currency, timestamped | Risk control, analytics, reporting consistency |
Typical integration scenarios
These are end-to-end flows we have built or scoped for Ballet-style cold-storage data. Each names the business context, the data or API involved, and how it maps to OpenData / OpenFinance thinking.
1 · Crypto accounting & tax reconciliation
Context: an accountant manages several clients who each hold a few Ballet cards. Data/API: the transaction history API plus the portfolio valuation API give every transfer a fiat value at the block time. OpenFinance mapping: the same "pull a dated statement, normalize, export" pattern OpenBanking uses for bank accounts — here the "account" is an on-chain address linked to a Ballet card, and the export is an Excel / CSV / JSON ledger.
2 · Multi-card treasury dashboard
Context: a small fund or family office stores long-term holdings across dozens of REAL Series cards. Data/API: the address & balance API enumerates all addresses and rolls them into one figure; the valuation API converts to base currency. OpenFinance mapping: account aggregation — one consent-scoped view over many "accounts", refreshed on a schedule, with per-card drill-down.
3 · Swap journaling & cost-basis tracking
Context: a user swaps assets inside the app and needs clean records for tax season. Data/API: the swap & exchange-status API returns each Changelly order's pair, amounts, rate, fees and final status; a webhook pushes status changes. OpenFinance mapping: transaction enrichment plus event notification — equivalent to a payment webhook, but the "payment" is a crypto-to-crypto exchange leg.
4 · Proof-of-holdings / attestation
Context: a lender or auditor wants signed evidence that a borrower controls certain cold-storage holdings. Data/API: a read-only snapshot from the balance and valuation APIs, optionally paired with an on-chain message signature workflow. OpenFinance mapping: verification / confirmation-of-funds — a point-in-time, tamper-evident statement instead of a custodial balance call.
5 · NFT & collectible portfolio aggregation
Context: a collector keeps NFTs on a Ballet card alongside fungible assets and wants one inventory. Data/API: the NFT holdings feed (contract, token ID, collection, media) merged with fungible balances and valuation. OpenFinance mapping: asset-class aggregation — extending the "all your accounts in one place" idea to digital collectibles.
Technical implementation
A few representative snippets from a delivered integration. Auth is a bearer token issued to your backend; every endpoint is read-only; errors use a stable JSON envelope so retries and alerting are straightforward.
Transaction statement
GET /api/v1/ballet-crypto/transactions
?chain=ethereum
&address=0xab12...c9
&from=2026-04-01&to=2026-04-30
&asset=USDC&page=1&page_size=100
Authorization: Bearer <ACCESS_TOKEN>
200 OK
{
"page": 1, "page_size": 100, "total": 37,
"items": [
{
"hash": "0x7d...e1",
"direction": "in",
"asset": "USDC",
"amount": "250.00",
"counterparty": "0x91...4f",
"block_time": "2026-04-12T14:03:11Z",
"confirmations": 14210,
"fee": {"asset":"ETH","amount":"0.00041"}
}
]
}
Swap status webhook
POST https://your-app.example.com/hooks/ballet-swap
X-OFL-Signature: t=1746950400,v1=8b3a...
Content-Type: application/json
{
"event": "swap.status_changed",
"order_id": "chg_8821",
"pair": "BTC->ETH",
"amount_in": "0.01",
"amount_out": "0.1604",
"rate": "16.04",
"fees": {"network":"0.0009 ETH","provider":"0.25%"},
"status": "finished",
"updated_at": "2026-05-11T08:12:09Z"
}
// verify HMAC over `t.body` with your signing secret,
// reject if |now - t| > 300s, then ACK 200
Auth & error envelope
POST /api/v1/auth/token
{ "client_id": "...", "client_secret": "..." }
-> { "access_token": "...", "expires_in": 3600 }
// error shape (all endpoints)
4xx / 5xx
{
"error": {
"code": "rate_limited",
"message": "Too many requests",
"retry_after": 12
}
}
// recommended client: exponential backoff,
// idempotency key on writes, circuit breaker on 5xx
Compliance & privacy
Ballet Global Inc. is a U.S. company, so the relevant baseline is FinCEN's money-services-business framework and the FATF "Travel Rule" for virtual-asset transfers; integrations that touch EU users should also be read against the EU's Markets in Crypto-Assets (MiCA) Regulation and GDPR. Because Ballet Crypto is self-custodial — keys are generated with BIP38 and never stored by the app — our work never handles private keys; we operate on public on-chain data, the app's own screens, and documented partner APIs such as Changelly. We keep request logs and consent records, apply data minimization and retention limits, and can sign NDAs. For regulatory background you can also consult FinCEN directly. Nothing on this page is legal advice; scope every deployment with your own counsel.
Data flow / architecture
A typical pipeline has four nodes: Client app / card reference (the Ballet Crypto app surface and the addresses derived from a scanned card) → Ingestion API (our read-only connectors to chain indexers, market-data and the Changelly API, with rate limiting and retries) → Normalization & storage (canonical asset, transaction and valuation records, deduplicated and time-stamped) → Analytics / API output (your dashboards, ledger exports, webhooks and reports). Each hop is logged, and the storage layer keeps only what the agreed use case needs.
Market positioning & user profile
Ballet Crypto serves a mostly B2C audience: newcomers who want self-custody without seed phrases, gift buyers who hand someone a pre-loaded REAL Series card, and long-term holders who keep Bitcoin, Ethereum, XRP and a long tail of ERC-20 / BEP-20 tokens (and NFTs) off-line. The company is U.S.-based with a global retail customer base, and the companion app ships on both Android (com.balletcrypto) and iOS. For integration buyers this means the data is consumer-grade and per-card rather than per-institution — well suited to personal finance tools, crypto accountants, small funds, and inventory or insurance systems that need to enumerate holdings across many physical cards.
Screenshots
Screens from the Ballet Crypto app. Click any thumbnail to view it larger.
Similar apps & integration landscape
Ballet Crypto sits inside a wider field of wallet apps. The names below come up alongside it in cold-storage and crypto-wallet comparisons; teams that work with one of them often need the same kind of unified balance, transaction and valuation exports we build for Ballet — so we list them here as part of the integration landscape, not as a ranking.
Ledger Live
Companion app for Ledger Nano X / Nano S Plus / Flex hardware wallets; holds device-linked balances, transaction history and staking positions across thousands of assets. Users who run both Ledger and Ballet often want a single transaction export covering every device.
Trezor Suite
Desktop and web app for Trezor Safe 3 / Model T; surfaces Bitcoin and multi-coin balances, labeled transactions and coin-control data. Common request: reconcile Trezor and Ballet holdings into one ledger.
Tangem Wallet
NFC-card hardware wallet with no seed phrase; the app shows per-card balances and transaction history. Similar form factor to Ballet, so portfolio tools frequently aggregate the two side by side.
SafePal
Air-gapped hardware wallet plus app supporting 10,000+ assets, with built-in swap and DApp data. Teams integrating SafePal swap records often reuse the same cost-basis pipeline we ship for Ballet's Changelly swaps.
Coinbase Wallet
Self-custodial mobile wallet (separate from the Coinbase exchange) holding multi-chain balances, DeFi positions and NFT data. A natural counterpart when a user keeps spending funds hot and long-term funds on a Ballet card.
Trust Wallet
Mobile-first multichain wallet with staking, swaps and a DApp browser; rich on-chain activity data per address. Often aggregated with cold-storage holdings for a full net-worth view.
Exodus
Desktop and mobile wallet supporting 260+ assets with built-in exchange, staking and portfolio tracking. Its swap and balance history maps cleanly onto the same export formats we deliver for Ballet.
MetaMask
The default EVM / DeFi wallet; transaction history, token approvals and NFT holdings on Ethereum and EVM chains. Frequently the "active" wallet alongside a Ballet card used for storage.
Blockstream Jade
Open-source, Bitcoin-focused hardware wallet with QR-based air-gapped signing. Bitcoin-only treasuries sometimes pair Jade for spending with Ballet for deep cold storage and want one combined transaction log.
NGRAVE ZERO
High-assurance air-gapped hardware wallet; the companion app tracks balances and transactions across major chains. Listed here as part of the cold-storage ecosystem buyers compare against Ballet.
About us
We are an independent studio focused on app protocol analysis and OpenData / OpenFinance API integration. Our engineers come from crypto exchanges, payment gateways, on-chain data infrastructure and cloud platforms, so we know how wallet apps derive addresses, query indexers, sign transactions and call partner APIs — and how to wrap that into clean, read-only services.
- Crypto wallets, exchanges, payments, digital banking and cross-border data
- Enterprise API gateways, webhook infrastructure and security reviews
- Custom Python / Node.js / Go SDKs and test harnesses
- Full pipeline: protocol analysis → build → validation → compliance review
- Source-code delivery from $300 — runnable API source code and full documentation; pay after delivery upon satisfaction
- Pay-per-call API billing — access our hosted endpoints and pay only per call, no upfront cost
Contact
For a quote or to submit your target app and requirements (data types, chains, refresh cadence, export formats), open our contact page:
Tell us which Ballet Crypto data you need — balances, transaction history, portfolio valuation, swap orders, activated currencies, NFT holdings — and whether you want source delivery or hosted API access.
Engagement workflow
- Scope confirmation: which data surfaces, which chains, refresh cadence, export targets.
- Protocol analysis & API design — how the app reads cards, indexers and the Changelly API (2–5 business days, complexity-dependent).
- Build and internal validation against fixture and live data (3–8 business days).
- Documentation, samples, Postman collection and test cases (1–2 business days).
- First delivery typically 5–15 business days; third-party approvals or rate-limit negotiations may extend timelines.
FAQ
What data can you extract from Ballet Crypto?
Do you need my Ballet wallet private keys?
How long does delivery take?
How do you handle compliance?
📱 Original app overview — Ballet Crypto (appendix)
Ballet Crypto (package com.balletcrypto) is the companion mobile app for the Ballet REAL Series cold-storage wallet — a stainless-steel, credit-card-shaped device from Ballet Global Inc. The app and the physical card work together: you scan the QR code on the card and get the convenience of a software wallet while the private key stays offline.
- No registration or login — no accounts, no KYC; just scan the QR code on your Ballet card to start.
- Receive & send crypto assets — manage holdings with on-screen instructions.
- Real-time portfolio value — check the market value of your assets any time.
- Privacy-respecting — the app never retains or stores the wallet's private keys and does not track or store personal or financial data outside your device.
- Multicurrency activation — activate additional cryptocurrencies on the same card to receive, store and send many asset types (additional fees may apply).
- Industry standard — the wallet and app use the BIP38 protocol for private-key generation, with a two-factor key-generation production process.
- Ecosystem add-ons — in-app crypto swaps via the Changelly Crypto Exchange API (a partnership running since 2020 that has scaled steadily, with Changelly now powering a large share of in-app swap activity), an NFT gallery for Ethereum / Polygon / BNB Chain collectibles, and support for 1,000+ coins & NFTs.
- Available on Android and iOS; see the Google Play listing.