Unified data API for Cardano, Midnight & Bitcoin
Reliable, Redundant, Real-Time.
One API key for Cardano, Midnight, and Bitcoin data. Multi-provider failover, plain REST + WebSocket, and an OpenAPI 3.1 spec so you can generate a typed client in any language.
Full stack, one key
Market data, wallet analytics, transactions, and WebSocket streaming — all through a single API key
Resilient by Design
Intelligent failover across multiple providers keeps your app responsive when any single source is degraded
GERO Benefits
Hold GERO tokens for subscription discounts (up to 20%) and extra API calls
Enterprise-grade Cardano data infrastructure
Provider redundancy, aggressive caching, and a unified API surface across every chain we support.
Resilient by Design
Provider redundancy and automatic failover keep your application responsive when any single source degrades.
Aggressive Caching
Hot blockchain data is served from cache so repeat queries are fast and your provider quotas last.
Provider Redundancy
Multiple blockchain data providers ensure your application never goes down.
Real-time Analytics
Comprehensive usage analytics and performance monitoring.
GERO Token Benefits
Hold GERO tokens for discounts and enhanced API limits.
Health Monitoring
Per-provider health checks route around degraded upstreams before they affect your requests.
Comprehensive Data
Access blockchain, DeFi, NFT, and market data through unified APIs.
Smart Routing
AI-powered provider selection for optimal performance and cost.
Data Privacy
GDPR compliant with advanced data protection and anonymization.
One API key for every chain and every capability
Market data, wallet analytics, transactions, and WebSocket streaming — over plain REST with an OpenAPI 3.1 spec, no proprietary SDK to wait on.
# Get the latest Cardano block
curl https://nexus.gerowallet.io/api/blocks/latest \
-H "X-Api-Key: nexus_your_api_key_here"
# Response (truncated)
{
"hash": "a1b2c3...",
"height": 11423901,
"slot": 147482931,
"epoch": 542,
"era": "conway",
"time": 1748268738,
"tx_count": 42,
"size": 88412,
"previous_block": "9f8e7d...",
"confirmations": 1
}Why Choose Nexus?
Plain REST, any language
HTTPS + an X-Api-Key header is the whole protocol. Works with the HTTP client built into Node, the JDK, Python, Go, Rust, or your shell, with no proprietary SDK to wait on.
OpenAPI 3.1 spec included
A full machine-readable spec is published at /v3/api-docs and rendered with a live playground at /docs. Generate a typed client for 50+ languages with one openapi-generator command.
Multi-provider failover
Every request fans out across Yaci, Koios, Blockfrost, and our own indexers. When one goes down, your app keeps serving.
Same key, every chain
One API key gets you Cardano, Bitcoin, and Midnight endpoints under the same base URL, with no separate accounts and no per-chain billing.
Read the full reference
Every endpoint, parameter, and response shape, with a live playground built into each page.
Simple, scalable Nexus pricing
Pick a base tier, enable only the add-ons you need. Nexus is launching very soon. Join the early-access list and we'll let you know the moment it's live.
Builder
Indie devs and side projects.
- 2,000,000 requests / month
- 25 req/s sustained · burst 250
- 3 API keys
- Full blockchain API
- Preprod + mainnet access
- Add-ons available
Growth
Startups and DApp teams.
- 10,000,000 requests / month
- 50 req/s sustained · burst 500
- 5 API keys
- Everything in Builder
Scale
Production applications.
- 50,000,000 requests / month
- 100 req/s sustained · burst 1,000
- 10 API keys
- Everything in Growth
- Priority support
For exchanges, institutional, and regulated teams
Higher volumes, bundled add-ons, and isolated infrastructure with a contractual SLA.
Enterprise
Exchanges, aggregators, and institutional users.
Everything in Scale, plus all add-ons bundled and per-API-key rate limit overrides for mixed workloads.
- 200,000,000 requests / month
- 500 req/s sustained · burst 5,000
- Unlimited API keys
- Market Data, Wallet Analytics, Transaction Builder, MCP Server, and WS Unlimited included
- Per-API-key rate limit overrides
- Email support · 48h response
Dedicated
For compliance, data residency, and custom SLAs.
Your own isolated infrastructure. Negotiated request volumes, rate limits, SLA, and support channels.
- Dedicated GKE cluster + postgres
- Physical data isolation
- Contractual SLA (negotiable)
- Dedicated Slack/Teams · 4h response
- Custom endpoints and filtered streams
- On-premise option available
Add-ons
Mix and match capabilities. REST add-ons share your tier's unified request pool, one number to track. WebSocket has its own connection and message limits.
Market Data
Prices, OHLCV candles, DEX pools, order books, and NFT sales across all 11 Cardano DEXes.
- Prices across all 11 DEXes (Minswap, SundaeSwap, WingRiders, VyFi, Splash, TeddySwap, MuesliSwap, CSwap)
- OHLCV candles: 15m, 1h, 1D, 1W
- DEX pool TVL, reserves, fees
- Order books: AMM-simulated + MuesliSwap, GeniusYield
- NFT marketplace sales (jpg.store V2/V3)
- Token metadata: name, ticker, logo, decimals
Wallet Analytics
Holdings, transaction history, and FIFO-based P&L per wallet.
- Current holdings with USD valuation
- Full send/receive transaction history
- FIFO-based P&L calculation per token
Transaction Builder
Server-side UTXO selection, fee calc, and unsigned CBOR for transfers, staking, and governance.
- UTXO selection, fee calc, change outputs
- ADA + native token transfers
- Staking: pool delegation, key (de)registration
- Governance (Conway): DRep delegation, votes
- Reward withdrawal
MCP Server
Model Context Protocol endpoint — connect Claude and other AI agents directly to Nexus data + tools.
- Hosted Model Context Protocol endpoint
- Connect Claude, Cursor, and other MCP-compatible AI agents
- 25+ tools: Cardano, Bitcoin, Midnight, market data
- Balances, tx info, and unsigned tx building from chat
- Per-API-key authentication
WebSocket Streaming
Live market data via STOMP-over-SockJS. Subscribe to price updates, trade events, and pool changes with a 10-second broadcast interval.
Configure Your Plan
Pick a base tier, toggle the add-ons you need, and preview your $GERO staking discount.
Base Tier
Select your plan tier.
Add-Ons
REST add-ons share your tier's unified request pool, one number to track.
WebSocket Streaming
Live market data via STOMP. Pick a package or skip entirely.
$GERO staking discount
Hold $GERO to save up to 20%
Hold $GEROGeroWallet's native Cardano token. Holding $GERO in any Cardano wallet automatically unlocks Nexus API discounts, Gero Card fee waivers, and on-chain governance voting. to unlock a sliding discount on your Nexus subscription, from 5% at $50 staked up to 20% at $1,000+. Connect your Cardano wallet to preview your qualifying tier now.
Price Summary
Frequently asked questions
Everything you need to know about the Nexus API.
What is Nexus?
Nexus is a managed multi-chain data and transaction API. A single API key gives you market data across all 11 Cardano DEXes, FIFO wallet analytics, a transaction builder, and real-time WebSocket streaming over plain REST — with an OpenAPI 3.1 spec, so you never have to run blockchain infrastructure yourself.
Which blockchains does Nexus support?
Cardano is live today with full market data, wallet analytics, transaction building, and streaming. Midnight and Bitcoin are on the roadmap, and the same Nexus key is designed to serve them too — so you integrate once and add chains without re-architecting.
How is Nexus different from Blockfrost, Maestro, or Koios?
Those APIs focus on raw Cardano chain queries. Nexus adds a full stack on one key: DEX market data, FIFO profit-and-loss wallet analytics, a server-side transaction builder, and real-time WebSocket streaming — all behind multi-provider failover for redundancy and flat, predictable pricing.
How much does Nexus cost?
Nexus uses flat, predictable monthly plans instead of per-call metering, so your bill doesn't spike with traffic. Compare the current tiers in the pricing section above, or join the early-access list to get started.