Free API Access for Every Stacks Builder

Today, we’re announcing expanded free access to the Stacks Blockchain API with radically higher limits, starting October 30. Every Stacks builder will be able to access production-ready API infrastructure for free, without worrying about upgrade tiers or subscription costs.

These changes are possible because we've spent the last several months improving the infrastructure behind the Hiro Stacks API to be faster, more reliable, and significantly more efficient to operate.

At the same time, we're simplifying the Hiro Platform. It will become a streamlined interface focused on API key management. We'll be retiring Projects, Contract Monitoring, and the Chainhooks UI from the Platform. (If you use Chainhooks, nothing is changing about the service itself. You’ll be able to continue creating, managing, and running your Chainhooks through the Chainhooks API.)

Stacks is entering a new chapter: Bitcoin staking is now available and more upgrades are coming. With this in mind, we're simplifying the developer experience and investing in the infrastructure that powers the ecosystem.

Stacks API Access is Now Free

We’re retiring all paid API subscription plans in lieu of our new free access models:

• Anonymous access. No signup or API key required. Rate limits are designed to support development, prototyping, and light production traffic, with burst affordances.
• Free API keys to authenticate requests, for higher, more predictable limits.
• If you have a special case where our already generous free limits don’t work, let us know at support@hiro.so and we’ll work something out.

API limits will be generous across the board, with adjusted limits for a small number of compute-intensive operations. We currently expect rate limits to range from 5 to 83+ requests per second, depending on the API operation, with no monthly usage caps. Final limits will be published in the API docs before the October 30 transition.

These limits will be extremely generous and are intended to protect the service from abuse, not to get in the way of legitimate applications. If your application is being rate limited, please reach out.

API keys will continue to help us isolate abusive traffic, understand per-application usage, and communicate directly with builders when needed. But higher API usage limits will no longer be tied to paid plans.

For any builders currently on paid plans, we'll automatically issue prorated refunds for the unused portion of your subscription. We'll also be reaching out to paid subscribers personally via email to answer any questions, ensure the transition is smooth, and confirm you’ve received your expected refund.

A More Focused Hiro Platform

Over the years, the Hiro Platform has supported many parts of the development lifecycle: writing and deploying smart contracts, running hosted Stacks Devnets, and monitoring mainnet contract activity. It has helped developers get started on Stacks with browser-based development environments and project templates integrated with GitHub.

Developer workflows have evolved. To best serve builders, we’re focusing on the core production workflows that matter most: building and deploying Clarity smart contracts with Clarinet, building Stacks applications with Stacks.js, powering event-driven applications with Chainhooks, and accessing blockchain data through the Stacks API.

That’s why we're simplifying the Hiro Platform and narrowing its focus to API key management.

Wen Free API?

These changes will take effect on October 30, 2026.

• Paid API subscriptions will be discontinued, and current subscribers will receive prorated refunds.
• API keys will still live in the Hiro Platform. Projects, Contract Monitoring, and the Chainhooks UI will be retired from the Platform.
• Existing API keys will continue working without interruption.
• The Hiro Stacks Blockchain API and Chainhooks service will remain fully supported.
• Legacy API key headers x-hiro-api-key and x-partner will stop authenticating. Only x-api-key will be supported to authenticate requests.

Some data associated with retired Platform features will be deleted: Contract Monitoring data (configurations and alert history) and API usage history.

We'll retain this data until December 30, 2026, 2 months after the sunset. If you need to retrieve anything before then, contact platform@hiro.so. Existing API keys, Chainhooks, and GitHub repositories are unaffected.

Hiro Platform feature changes: Everything you need to know

API Hub

What’s changing

• Subscription management and usage history will be removed (after the data retention period) as we transition to free API access.
• Higher API usage limits will be available to all API key holders at no cost.

What’s staying

• You'll continue to be able to view, create, and revoke API keys.

Why

• API access will no longer be tied to paid usage tiers with monthly quotas, so subscription management and usage history are no longer needed.

What it means for you

• Your existing API keys will continue working.
• If you have an active paid plan, it will be cancelled, and a prorated refund for the unused portion of your subscription will be credited to your original payment method. We’ll check in via email to make sure you’re all set through this transition.
• API key header standardization: As part of our infrastructure transition, we're standardizing on a single API key header, x-api-key. If you're still using the legacy x-hiro-api-key or x-partner headers, update your applications now to use x-api-key. Beginning October 30, legacy headers will stop authenticating, and your API calls will be subject to anonymous access rate limits.

Projects

What’s changing

• The Projects feature in the Hiro Platform is being retired, including contract deployments and hosted Devnet.

Why

• Clarinet is the primary local-first development experience for Stacks development. We're focusing our investment there instead of maintaining overlapping development workflows in the Hiro Platform.

What it means for you

• No action is required. Use Clarinet for building, testing, and deploying Clarity smart contracts.
• If you've created Projects in the Hiro Platform, your code isn't going anywhere. Any repositories you've created or connected through the Platform will remain in your GitHub account.
• Project templates will continue to be available on Hiro's GitHub for bootstrapping common Clarity smart contract and frontend application patterns.
• Use Clarinet to run local Devnets and contract deployments.
• You can still deploy contracts from the browser in the Explorer Sandbox.

Contract Monitoring

What’s changing

• Contract Monitoring will be retired. Chainhooks are the recommended replacement for detecting on-chain activity and sending notifications.

Why

• Chainhooks support a broader range of event-driven workflows than Contract Monitoring. Rather than maintaining two overlapping solutions, we'll continue investing in Chainhooks as our primary event system.

What it means for you

• Existing monitoring alerts will stop sending after the transition.
• If you currently rely on Contract Monitoring for alerts, you'll need to recreate those workflows with Chainhooks (via the Chainhooks API) before the sunset date.
• Please reach out to platform@hiro.so if you have questions about migrating your Contract Monitoring alerts to Chainhooks.

Chainhooks UI

What’s changing

• The Chainhooks interface in the Hiro Platform will be retired. Existing Chainhooks can continue to be managed through the Chainhooks API.

Why

• The API supports more advanced capabilities and provides greater flexibility for configuring and managing Chainhooks in production.

What it means for you

• No action required. Existing Chainhooks will continue running with no changes.
• Chainhooks can be managed with the API.

Looking Ahead

Free API access means one less barrier to shipping on Stacks: no tier comparisons, no upgrade thresholds, no wondering whether your traffic will outgrow your budget.

At the same time, simplifying the Hiro Platform lets us spend less time maintaining billing systems and overlapping features across our tools, and more time improving the infrastructure developers rely on every day.

With the first of the Satoshi Upgrades now live, Bitcoin staking has arrived on Stacks — and there's more to build than ever. We can't wait to see what Stacks devs build next.

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