🔍 Blast FAQ

Everything you need to know about Alchemy’s high-throughput RPC for historical data

What is Blast?

Blast is Alchemy’s purpose-built RPC service for read-only, high-scale access to historical blockchain data. It’s engineered for teams that need to query past chain states at extreme volume—like indexers, analytics platforms, explorers, and oracles—without paying for real-time features they don’t need.

Blast eliminates write capabilities, webSockets, and redundancy to offer a more cost-efficient solution for historical reads.

Who should use Blast?

Blast is ideal for engineering teams with batch-based, data-heavy workloads, such as:

🧾 Marketplaces & Indexers

Backfill user activity, asset metadata, or contract interactions across chains.
📊 Analytics & Data Science Teams

Query full blockchain histories for modeling, reporting, or anomaly detection.
🔮 Oracles & Infrastructure Providers

Retrieve accurate historical values or validate chain state over time.

What are the limitations of Blast?

Blast is optimized for historical reads and intentionally excludes features that are unnecessary for that use case:

Feature	Supported?	Notes
Write support (eth_sendTx)	❌	Use Supernode for tx submission
Tip-of-chain reads	❌	Reads begin ~25 blocks behind tip (~30s delay)
WebSockets / subscriptions	❌	No eth_subscribe, no event streams
Mempool access	❌	No pending tx data
Developer tooling	🔸 Limited	No usage charts or response logs
New chain support	⏳ Slight delay	Launches a few days to weeks after Supernode
Uptime SLA	✅ 99.9%	Versus Supernode’s 99.99%

🔍 Want full-featured, real-time RPC? Use Alchemy Supernode

How do I get started with Blast?

Blast is currently available to Alchemy enterprise customers. To get access:

Contact your Alchemy sales or solutions rep to request access.
Once approved, create a new Blast app in your Alchemy dashboard.
Copy the API key and drop it into your existing SDK config.

✅ Blast supports the same SDKs and request formats as Supernode—just with historical-only access.

Read more about Blast API endpoints here.

How far behind is the chain tip?

All Blast reads are delayed by ~25 blocks (~30 seconds) behind the current chain head. This applies to all supported networks and allows for:

Enhanced caching
Greater throughput
Lower infrastructure overhead

This delay is fixed and not configurable.

What chains does Blast support?

Blast supports 100+ EVM-compatible networks, including:

Ethereum Mainnet
Polygon
Arbitrum
Optimism
Base
Avalanche
And many more

Note: New chain support launches first on Supernode, with Blast availability following after stability and caching pipelines are in place.

Can I use Blast and Supernode together?

Absolutely—and we recommend it.

Use Blast for:

Historical reads
Indexing and backfills
Long-range analytics

Use Supernode for:

Real-time dashboards
Wallet interactions
Live dApps

Routing traffic between both services helps optimize for both cost and performance.

How can I monitor my usage?

Blast currently offers minimal in-product monitoring:

No built-in usage charts
No request logs or traces

We recommend integrating with your own observability stack (e.g. DataDog, Grafana, OpenTelemetry) to monitor request behavior and usage volume.

Where can I learn more?

Want help evaluating if Blast is the right fit for your workload? Contact our team