About Nexus, the blockchain API built by A.D. Labs
Nexus is the data and transaction API for Cardano, Bitcoin, and Midnight, built and run by A.D. Labs LTD, the team behind GeroWallet. The endpoints you integrate are the ones our own wallet depends on.
Nexus at a glance
chains live today: Cardano, Bitcoin, and Midnight
Cardano DEXes indexed for first-party market data
machine-readable spec published at /v3/api-docs
GeroWallet source, public on GitHub
status page with live health for core subsystems
Mission
Teams building on UTXO chains have been stitching together a node, an indexer, a market-data vendor and their own transaction code, with nobody accountable for the whole. Nexus exists to be that one accountable partner: chain data, market data, wallet analytics, transaction building and streaming on one base URL, with pricing you can read before you sign up.
What we build
Nexus
The full-stack API for Cardano, Bitcoin and Midnight: REST and WebSocket, an OpenAPI 3.1 spec, keys scoped to one chain and one network, and flat monthly plans.
GeroWallet
The non-custodial wallet for Cardano and Midnight, with DUST generation built in and its source published under Apache 2.0. The wallet's market data, swap routing and transaction building run on Nexus in production.
How we got here
We built a wallet
GeroWallet had to serve balances, prices, swap routes and transaction building to real users every day, and later Midnight DUST status too.
We built the stack it needed
No single provider covered all of that. The team built its own indexers, market-data pipeline and transaction builder, with failover underneath, and ran the wallet on it.
We opened it as Nexus
In July 2026 the same stack went public as Nexus, with FluidTokens as the first design partner and Cardano, Bitcoin and Midnight live from day one.
How Nexus runs
- Failover under every Cardano read
- Our own indexers first, then Yaci, Koios and Blockfrost in order. A provider that fails or falls behind is taken out of rotation, not retried in the request path.
- No keys on our servers
- The transaction builder returns unsigned CBOR and the Midnight routes take pre-signed transactions. Signing stays in your wallet or your app.
- One origin, one spec
- The API and the site share one origin, the whole surface is described by an OpenAPI 3.1 spec, and the TypeScript SDK is generated from it.
- A status page, not a number
- Live health for the core subsystems is public. We publish that instead of an uptime percentage; contractual SLAs belong to the Dedicated tier.
Commitment
- Prices you can read
- Flat monthly tiers with every add-on priced on the pricing page. No compute units, no per-method credits, no surprise at month end.
- Built in the open
- GeroWallet's source is public, Nexus ships an OpenAPI spec and a TypeScript SDK, and Nexus is listed in the Cardano developer portal and the Mesh SDK as a provider.
- Honest comparisons
- Our comparison pages say when the other provider is the better fit. Rival claims are checked against that project's own documentation before they are published.
- A reply from the people who run it
- Enterprise and Dedicated customers talk to the engineers operating the service, with response times written into the plan rather than a ticket queue.
Partners, customers, and design partners
Design partner
Open-source partner
Network partner
Integration partner
Community integration partner
A word from our CEO
We built Nexus because we needed it. GeroWallet has to show balances, prices, swap routes and Midnight DUST status to real users every day, and no single provider gave us all of that with the reliability a wallet needs. So we built the stack for ourselves, ran it in production, and then opened it to other teams. Everything you get on a Nexus key is something our own product already depends on. If it is not good enough for GeroWallet, it does not ship.
Build on what we run ourselves
Builder comes with a 7-day trial. Enterprise and Dedicated start with a conversation.
Dedicated infrastructure starts at $2,000 per month. A contractual SLA is available on Dedicated: contact sales.