A full-stack Blockfrost alternative for Cardano, Bitcoin, and Midnight
Nexus is a full-stack Blockfrost alternative: one account and one base URL cover on-chain data, DEX market data across all 11 Cardano DEXes, FIFO wallet P&L, a server-side transaction builder, WebSocket streaming, and Bitcoin and Midnight coverage.
And it is a one-line migration: point your existing Blockfrost SDK at the Nexus /api/v0 endpoint and your code keeps working, same calls, same responses, fresher data.
Your Blockfrost SDK, two changed lines
const api = new BlockFrostAPI({
- projectId: "mainnetYourProjectId",
+ projectId: "nxs_your_nexus_key",
+ customBackend: "https://nexus.gerowallet.io/api/v0",
});That is the migration. Your SDK, your calls, your response shapes, now served by Nexus.
Nothing on Nexus is at no charge. The trial is 7 days on the Builder plan, $29/mo after.
Also weighing Maestro or Koios? The Maestro page has its own map, and Koios is answered on this page under "Why not the free one".
Five answers before you switch
What breaks, what does not, how long it takes, what it costs, and how to try it without committing. In that order.
What breaks
Five compatible paths answer 503 with Retry-After while their upstream fix lands: pool detail, pool history, the extended pool list, the unfiltered asset list and the previous-epoch listing. Mempool endpoints and account-usage metrics are not served on purpose, and the account root is not served yet.
What does not
Your SDK and your code. Blocks, transactions, addresses, account sub-resources, assets by ID or policy, epochs, scripts, metadata and stake pools all answer on /api/v0 with Blockfrost response shapes and error envelopes.
How long it takes
The compatible endpoint is one changed line: customBackend plus your nxs_ key as the project id. Most teams have production reads on Nexus the same afternoon and move individual calls to the native API over the following weeks, where a paged loop becomes one request.
What it costs
Builder is $29/mo for 2M requests, Growth $79/mo for 10M, Scale $199/mo for 50M with WebSocket streaming included. Blockfrost DEVELOPER is EUR 79/mo for 1M a day. Both APIs count per request; Nexus counts per month with no midnight reset.
How to try it without committing
Start the 7-day Builder trial, point the SDK at /api/v0, and run real traffic against both providers for a week. Card required, nothing charged before day 7, cancel from the dashboard.
Why teams are re-evaluating their Cardano API in 2026
Four structural limits worth checking against your workload. Each one is documented in Blockfrost's own public docs.
The throughput ceiling
Every tier below Enterprise shares one per-IP limit: 10 requests per second sustained, with a 500-request burst. Upgrading raises the daily quota; the rate and the burst stay the same, so STARTER free and DEVELOPER at EUR 79 hit the same ceiling.
Pagination multiplies requests
List endpoints return at most 100 items per page. A wallet with 5,000 transactions takes 50 paged calls just to enumerate, and every page counts against the daily quota.
Hard stops at the edges
At the daily quota Blockfrost returns HTTP 402 and stops serving. Continued flooding past the rate limit triggers an HTTP 418 auto-ban. Production teams need backoff logic around both failure modes.
A blockchain API, by design
Blockfrost covers Cardano chain data, IPFS, and Midnight. DEX market data, wallet P&L, server-side transaction building, and Cardano streaming sit outside that scope, so teams add vendors or custom indexers for them.
What Nexus is, in six products
Chain data is one of them. The other five are what teams would otherwise build themselves or buy from separate vendors.
Blockchain API
Blocks, txs, addresses & assets
Ten endpoint groups, accounts to governance, plus submit and evaluate.
WebSocket Streaming
Live blocks & txs, pushed to you
Push, not poll: market data on a 10 second cadence, Blueprints with REST backfill.
Transaction Building
Build & submit on-chain
Transfers, staking, and Conway governance built server-side. Unsigned CBOR out; keys never touch Nexus.
DEX Aggregator
Best-price swap routing
Best-price routing across Minswap, WingRiders, Splash, and SaturnSwap. You sign every swap.
MCP Server
Nexus data for AI agents
A hosted MCP endpoint: AI agents query Cardano, Bitcoin, and Midnight with your own key.
Market Data
Prices, pools & tokens
Prices, candles, pools, order books, and NFT sales across all 11 indexed DEXes.
Blockfrost vs Nexus, value by value
Nexus leads where production apps feel it: freshness, burst headroom, products, and chains. Prefer the long-form version with sources? Read the full technical comparison.
Nexus leads 11 of the 18 dimensions compared below, across performance, coverage, and developer experience. The table carries the full values.
Freshness measured August 2026 from a single client in Frankfurt against both live APIs over the public internet, 119 blocks over 45 minutes at matched request rates. Method and raw data available on request.
Burst capacity, requests admitted at peak
On Blockfrost, every tier below Enterprise gets the same 500-request burst at 10 req/s sustained; paying more only raises the daily quota. On Nexus both grow with the plan: bursts of 250 to 5,000 on sustained rates of 25 to 500 req/s.
Request quota, monthly
Blockfrost lists larger daily quotas at entry prices, but the arithmetic caps them: 10 req/s sustained moves at most 864k requests per day, under DEVELOPER’s own 1M/day allowance. Nexus quotas ship with the throughput to spend them.
Want to verify the surface first? Browse the full API reference with a live playground on every endpoint.
| Dimension | Blockfrost (verified 2026-09-06) | Nexus |
|---|---|---|
| Performance and limits | ||
| Rate-limit model | 10 req/s sustained per IP with a 500-request burst, on every tier below Enterprise. Higher tiers raise the daily quota; the rate and burst stay the same. | Advantage: Nexus Both scale with tier: Builder 25 req/s (burst 250), Growth 50 req/s (burst 500), Scale 100 req/s (burst 1,000), Enterprise 500 req/s (burst 5,000). |
| Data freshness | Median 3,845 ms from block timestamp to served, measured August 2026 over the public internet. | Advantage: Nexus Median 575 ms in the same run, 6.7x fresher, and first to serve the new block on 102 of 107 contested blocks with a median lead of 3.0 seconds. Methodology in the footnote below. |
| Request quota | Advantage: Blockfrost Daily: 50,000 free (STARTER), 300,000 (HOBBY, EUR 29/mo), 1M (DEVELOPER, EUR 79/mo), Enterprise custom. | Monthly: 2M (Builder, $29), 10M (Growth, $79), 50M (Scale, $199), 200M (Enterprise, $499), Dedicated custom. |
| Over-quota behavior | Hard HTTP 402 cutoff at the daily quota; HTTP 418 auto-ban for continued flooding. | Advantage: Nexus HTTP 429 with X-RateLimit-Limit, X-RateLimit-Remaining, X-RateLimit-Reset, and Retry-After headers plus a reset_at JSON body. No auto-ban. |
| Calls per job | 100 items per page on all list endpoints, and detail requires per-item calls: a wallet page (address plus 20 transactions with detail) takes 42 calls. | Advantage: Nexus The same wallet page is one native call, so it spends 1/42nd of the quota. Batch endpoints (bulk UTXO resolve, bulk CBOR) replace per-item loops. |
| Pricing | ||
| Pricing model | EUR flat tiers, plus Pay-As-You-Go paid in ADA (about 0.0000171 ADA per request). | USD flat tiers, plus opt-in add-ons: Market Data $19, Wallet Analytics $15, Transaction Builder $19, MCP Server $19, IPFS $5; WebSocket packages $29/$59/$99. |
| No-cost plan / trial | Advantage: Blockfrost STARTER plan at no charge: 50,000 requests per day. | No plan at no charge. 7-day trial on the Builder plan. |
| Enterprise | Custom plans, contact Blockfrost. | Enterprise $499/mo (200M requests, 500 req/s). Dedicated from $2,000/mo: your own cluster and a contractual SLA, contact sales. |
| Coverage and products | ||
| Chains | Cardano, plus IPFS and Midnight (launched April 2026). | Advantage: Nexus Cardano (deepest coverage), Bitcoin (including ordinals, runes, and mempool), Midnight (including transaction build and DUST); IPFS as a $5 add-on. |
| Market data | Not offered. | Advantage: Nexus First-party across all 11 Cardano DEXes: prices, OHLCV candles, pools, order books, NFT floor and sales. |
| Wallet analytics | Not offered. | Advantage: Nexus Holdings, transaction history, and FIFO-based P&L per wallet. |
| Transaction building | Client-side, via the official SDKs. | Advantage: Nexus Server-side builder for transfers, staking, and Conway governance operations. Returns unsigned CBOR; keys never touch Nexus servers. |
| Streaming | No Cardano streaming; activity monitoring means polling on a timer. | Advantage: Nexus WebSocket streaming plus Blueprints on-chain event streams. Blockfrost lets you ask 10 times a second; Nexus tells you the moment it happens. |
| AI agents | Not offered. | Advantage: Nexus Hosted MCP server add-on: connect Claude and other AI agents to Nexus data and tools. |
| Developer experience | ||
| Blockfrost API compatibility | Native. | Blockfrost-compatible endpoint at /api/v0: point your existing SDK at it with an nxs_ key as the project id and your code keeps working, same response shapes, same error envelopes. |
| SDKs | Advantage: Blockfrost 15 official SDKs; the default provider in Lucid, Mesh, PyCardano, and cardano-client-lib. | Official TypeScript SDK (@adlabs/nexus on npm, MIT), plus the /api/v0 endpoint runs the official Blockfrost SDKs unmodified. A NexusProvider is merged in Mesh, a Lucid Evolution provider PR is open, and the OpenAPI 3.1 spec generates typed clients. |
| Auth | Per-network tokens; HTTP 403 on network mismatch. | A key per chain and network, sent as an X-Api-Key header. |
| Provider architecture | Single provider. | Advantage: Nexus Multi-provider failover behind one endpoint. |
Blockfrost figures verified 2026-09-06 from public Blockfrost documentation and pricing. Nexus figures reflect current plans; see the pricing section for detail. Spot an error? Email [email protected] and we will fix it.
What the compatible endpoint serves today
Direct equivalents, guarded paths, and the ones with no equivalent. Read it here, not in production.
Served, same shapes
- Blocks and transactions
- Addresses
- Accounts, through the stake-address sub-resources
- Assets by asset ID and by policy ID
- Epochs and scripts
- Transaction metadata
- Stake pools: the list, retired, retiring, and per-pool metadata, relays, updates, blocks, votes and delegators
Guarded: 503 with Retry-After
/pools/{pool_id}
Pool detail
/pools/{pool_id}/history
Per-epoch pool history
/pools/extended
Pool list with per-pool enrichment
/assets
The unfiltered asset list. /assets/{asset} and /assets/policy/{policy_id} are served
/epochs/{number}/previous
Preceding-epoch listing
Each is released on its own as the matching upstream indexer fix lands.
No equivalent
Mempool endpoints
Blockfrost product surface, not chain data. Not served, by design
Account-usage metrics
Same reason. Quota headers on every Nexus response replace them
/accounts/{stake_address}
The account root is an upstream gap, not a decision. Every sub-resource under it is served
The endpoint-by-endpoint list, error envelopes and quota rules are in the Blockfrost compatibility reference.
What Nexus adds beyond a blockchain API
Compatibility gets you in the door. The larger win is fewer vendors: the data stack most Cardano teams assemble from three or four services, behind one integration.
Chain reads run behind our own indexers plus Yaci, Koios, and Blockfrost, with per-provider health checks routing around any degraded upstream, including Blockfrost itself.
The Nexus team also maintains the stack it runs on: six merged pull requests in bloxbean/yaci-store, the open-source Cardano indexer, fixing performance and correctness issues upstream.
The full stack on one integration
One Cardano integration covers chain data, first-party market data across all 11 Cardano DEXes, FIFO wallet P&L, a server-side transaction builder, and WebSocket streaming with Blueprints, as opt-in add-ons on one base URL and one auth header.
Rate limits that scale with your tier
Builder gets 25 req/s, Growth 50, Scale 100, and Enterprise 500, with bursts from 250 up to 5,000. Paying more buys real throughput, not just a bigger daily counter.
UTXO-native multi-chain
Cardano with the deepest coverage, Bitcoin including ordinals, runes, and mempool data, and Midnight including unshielded transaction build and DUST registration. A key per chain and network, one account.
Flat, predictable pricing
Flat monthly tiers from $29 to $499, with opt-in add-ons: Market Data $19, Wallet Analytics $15, Transaction Builder $19, MCP Server $19, IPFS $5, WebSocket packages $29 to $99. Bills do not spike with traffic.
Want the endpoint-level view of the Cardano surface? See the Nexus Cardano API page.
Running an exchange or aggregator?
Enterprise is $499/mo for 200M requests at 500 req/s. Dedicated starts at $2,000/mo with your own cluster and a contractual SLA.
Who should stay on Blockfrost
Not every workload should move. Blockfrost is the better choice for:
Projects inside STARTER
Hobby and pre-revenue projects comfortably under 50,000 requests per day. Blockfrost's STARTER plan covers them at no charge, and Nexus has no plan at no charge.
Mempool-dependent pipelines
Stacks that watch the mempool through Blockfrost's mempool endpoints. The Nexus Blockfrost-compatible endpoint does not serve them, so that path stays on Blockfrost today.
Low-throughput workloads
Workloads that stay under 10 req/s sustained and inside the daily quota. The shared ceiling only matters if you hit it.
Migrating from Blockfrost to Nexus
The migration is one changed line: Nexus serves a Blockfrost-compatible endpoint, so your existing SDK reads from Nexus before you touch anything else. Run both side by side on the trial, then adopt the native API where it pays.
1. Point your SDK at Nexus
Set
customBackendtohttps://nexus.gerowallet.io/api/v0and use your nxs_ key as the project id. Your code keeps working, with response shapes and error envelopes matching Blockfrost's; the compatibility reference covers the full surface.2. Run both side by side
Use the 7-day Builder trial to run Nexus next to Blockfrost against production traffic, compare responses, and cut over only when the numbers match.
3. Adopt native endpoints where they pay
The native Cardano API cuts request counts: the wallet page that takes 42 paged Blockfrost-style calls is one call, and batch UTXO and CBOR endpoints replace per-item loops. WebSocket streams push events instead of polling.
4. Add what Blockfrost does not offer
DEX market data, FIFO wallet P&L, the server-side transaction builder, and Blueprints event streams sit on the same key as opt-in add-ons. TypeScript teams install @adlabs/nexus; other languages generate typed clients from the OpenAPI 3.1 spec.
# The native API (step 3): the wallet page
# that takes 42 paged calls is one request.
BASE="https://nexus.gerowallet.io/api"
ADDR="addr1qx..."
curl "$BASE/addresses/$ADDR/transactions/history" \
-H "X-Api-Key: nxs_your_api_key_here"
# Over quota? You get HTTP 429 plus headers,
# never an auto-ban:
# X-RateLimit-Limit
# X-RateLimit-Remaining
# X-RateLimit-Reset
# Retry-After
# { "reset_at": "..." } in the bodyRate-limit and over-quota behavior verified 2026-09-06. Full request and response shapes live in the docs.
Migrating something non-trivial? Email [email protected] and we will map your endpoint list with you.
Why not the free one?
Blockfrost STARTER and Koios both cost nothing. For Cardano-only reads under 50,000 requests a day, at 10 requests a second, either is a good answer. Here is where each stops.
| Dimension | Blockfrost STARTER | Koios | Nexus Builder |
|---|---|---|---|
| Price | No charge | No charge (Pro ~$29.99/mo, Premium ~$74.99/mo) | Builder $29/mo after a 7-day trial |
| Requests | 50,000 a day, reset at midnight UTC | 5,000 a day public, 50,000 with a registered key | 2M a month on Builder, no daily reset |
| Rate limit | 10 req/s per IP, 500 burst | 100 requests per 10 seconds | 25 req/s with a 250 burst on Builder |
| Over the limit | HTTP 402 at the quota, 418 auto-ban after flooding | HTTP 429 for 60 seconds, 504 after 30 seconds of query time | HTTP 429 with reset headers, no ban |
| Chains | Cardano, Midnight (beta), IPFS | Cardano only | Cardano, Bitcoin and Midnight on one account |
| Beyond chain reads | Webhooks, IPFS storage | Chain data only | Market data across 11 DEXes, streaming, transaction builder, wallet analytics, MCP server |
| Support | Community and docs | Community-run node operators, best effort | A.D. Labs, the GeroWallet team, with a named engineer on your migration |
Blockfrost figures from blockfrost.io and docs.blockfrost.io, Koios from koios.rest/tiers.html, both checked September 2026. Koios and Blockfrost are also fallback providers behind Nexus chain reads, so choosing Nexus keeps both in the path.
Blockfrost alternative FAQ
Short answers to the questions migrating teams ask most.
Is Nexus a drop-in replacement for Blockfrost?
Yes. Nexus serves a Blockfrost-compatible endpoint at https://nexus.gerowallet.io/api/v0: point your existing Blockfrost SDK at it with customBackend, use your nxs_ key as the project id, and your code keeps working with matching response shapes and error envelopes. The native Nexus API then adds DEX market data, wallet P&L, transaction building, and streaming beyond the Blockfrost surface. The endpoint-by-endpoint list is in the Blockfrost compatibility reference at https://nexus.gerowallet.io/docs/blockfrost-compatibility.
Does Nexus have a no-cost plan like Blockfrost STARTER?
No. Plans start at Builder, $29 per month for 2M requests, with a 7-day trial. Blockfrost's STARTER plan (50,000 requests per day at no charge) is the better fit for hobby projects.
How do Nexus rate limits compare to Blockfrost's?
Blockfrost applies 10 req/s sustained per IP with a 500-request burst on every tier below Enterprise; paying more raises the daily quota, not the rate. On Nexus both the rate and the burst scale with tier: 25 req/s with a 250 burst on Builder, up to 500 req/s with a 5,000 burst on Enterprise.
How fresh is Nexus data compared to Blockfrost?
In an August 2026 measurement, Nexus served new blocks at a 575 ms median from block timestamp against 3,845 ms on Blockfrost, and served the new block first on 102 of 107 contested blocks with a median lead of 3.0 seconds. Measured from a single client in Frankfurt against both live APIs over the public internet, 119 blocks over 45 minutes at matched request rates. Method and raw data available on request.
Does Nexus support Midnight?
Yes: network info, unshielded transaction build and submit, and DUST registration. Blockfrost also offers Midnight support (launched April 2026), so compare depth for your use case.
Can I keep using Blockfrost SDKs with Nexus?
Yes, for the compatible surface: official Blockfrost SDKs accept a custom backend URL, so pointing customBackend at https://nexus.gerowallet.io/api/v0 with an nxs_ key keeps your existing code running. For the native Nexus surface, TypeScript teams install @adlabs/nexus from npm, and other languages generate typed clients from the OpenAPI 3.1 spec. Mesh has merged a NexusProvider, and a Lucid Evolution provider PR is open.
What happened with Blockfrost's governance proposal?
Blockfrost proposed transitioning to a community-governed free public good, funded from the Cardano treasury. The vote concluded in July 2026 and the proposal did not pass, so Blockfrost continues to operate as a commercial provider. This page compares the two services as they operate today.
Run Nexus next to Blockfrost for a week
Point your SDK at the compatible endpoint, run real traffic against both providers, and keep whichever fits. The trial is 7 days on the Builder plan, $29/mo after.