Overview
Nexus is a paid, hosted data service that lets app builders read blockchain records on Cardano, Midnight and Bitcoin and prepare transactions on Cardano and Midnight from a single account. Wallets, trading tools, dashboards and AI agents call it instead of running their own blockchain servers and databases. One account and one web address cover all three chains, and for Cardano chain data, Nexus switches to backup providers when one of its sources fails or falls behind1.
Nexus is built and run by A.D. Labs LTD, the team behind GeroWallet, a self-custody wallet that runs on Nexus in production. Cardano gets the deepest coverage: chain records, trading data, wallet history and transaction building1. On Midnight, Nexus tracks DUST, the resource that pays network fees, and builds and submits transactions2. On Bitcoin, it serves addresses, fees, pending transactions, and ordinals and runes, which are inscriptions and tokens written onto Bitcoin3.
The service opened to the public in July 2026, with FluidTokens as its first design partner4. Apex Fusion networks run on the same account5. The team also runs Cardano Market, a token price site built on Nexus market data6.
Key Features
- Blockchain data without running a node. Developers call one web address with an API key, a password-like code for apps, and get balances, transactions, stake pools and governance records without keeping their own copy of the blockchain1.
- Backup sources behind Cardano reads. Nexus reads first from its own indexers, which sort raw chain records for fast lookup, then falls back to Yaci, Koios and Blockfrost in that order, and takes any source that fails or falls behind out of rotation4.
- Transactions prepared, keys kept by the user. The transaction builder works out the coins and fees for transfers, staking and governance actions, then hands back an unsigned transaction for the user's own wallet to sign, so Nexus never holds private keys1.
- Market data and swap routing for apps. Add-ons supply token prices, price charts, pool data and wallet profit-and-loss, and a DEX aggregator finds the best swap price across several Cardano exchanges1.
- Tools for AI agents. A hosted MCP server, a standard way for AI assistants such as Claude to use outside tools, lets agents query Nexus data and build transactions after signing in with a Nexus account or an API key7.
What to Expect
Nexus is built for developers and the teams that hire them. A visitor finds a product page for each chain, full public documentation, and a status page that shows the live health of the core systems in place of an uptime percentage4.
Pricing uses flat monthly plans, and every add-on is priced on the pricing page, with no per-call credits to forecast8. There is no free tier, and the Builder plan comes with a 7-day trial1. When configuring a plan, people who stake GERO, the GeroWallet token, can preview a discount8.
Teams moving from Blockfrost can keep their existing code: they point it at the Nexus address and use a Nexus key in place of a Blockfrost project ID9. For new projects, the official TypeScript toolkit is open-source under the MIT license10, and the whole API is described in an OpenAPI 3.1 specification, a standard format that generates ready-made client code1. An account can hold several API keys, each scoped to one chain and one network, so a key made for a test network reads only that network1.
Nexus is listed among the APIs and providers on the Cardano developer portal11.
