The Public PoX-5 Testnet Is Live: Test the Bitcoin Staking Release Before Mainnet

The public PoX-5 testnet is now live. Builders can test their protocols against the upcoming Bitcoin Staking release today. The PoX-5 release supports the Bitcoin staking mechanism, BTC-denominated yield paid from miner bids via Proof of Transfer (PoX), while bitcoin stays on Bitcoin L1, under its owner's keys. The PoX-5 hardfork is targeted for mainnet July ~29, with the Genesis Bond around the end of August, so anything you test now will be ready on day one.

This is the third step in the phased rollout, following the private testnet where integration partners ran live tests. The public testnet covers the full staking lifecycle: bonding, registration, yield distribution, and unbonding. Cycles are accelerated. That means you can run the full lifecycle many times over in a short period, and by mainnet these flows will have run hundreds of times.

Who This Is For

Builders who want to test their protocol on PoX-5 ahead of mainnet. If your app touches stacking, yield, sBTC, or anything that reads PoX state, this is where you verify it works before real BTC is involved.

What You Need

Important note: to activate the PoX-5 hardfork (epoch 4.0), core engineers plan to reset the canonical testnet on July 30. The reset starts a fresh PoX-5 testnet from a new genesis, which means all existing chain state is wiped and the current testnet is discontinued. Treat anything you deploy before then as temporary, and plan to redeploy after the reset.

Network

‍Point your app at the PoX-5 testnet API:

• API base path: api.testnet-pox5.hiro.so
• Current PoX state

Contracts

‍The PoX-5 contract, plus two sBTC contracts that are new in PoX-5. Having both in one place means sBTC and staking flows can be tested in the same environment:

• PoX-5: ST000000000000000000002AMW42H.pox-5
• sBTC token: SN3VMHXEN64ZZF71JQ5VESXDWTR301XTTXGF4J8F1.sbtc-token
• sBTC registry: SN3VMHXEN64ZZF71JQ5VESXDWTR301XTTXGF4J8F1.sbtc-registry

Faucets

‍All three run against the PoX-5 testnet; use the API base path above:

• STX faucet
• BTC faucet
• sBTC faucet

Explorer

‍Verify activity on the PoX-5 testnet explorer.

Spec‍

Build against the PoX-5 SIP, with the Bitcoin Staking whitepaper for mechanism design. Developer docs are in progress.

The existing PoX-4 testnet keeps running in parallel, so current integrations are unaffected while you test.

What Is Testable, and What Is Not

The testnet is experimental and may be unstable while additional audits are ongoing. That is the point of this phase: surface issues now, while the worst case is a testnet restart. Bonding, registration, yield distribution, and unbonding are live today. Bonds and staking pools are still being coordinated, so pool-based flows may not be available on day one.

Where to Send Feedback

Post findings, bugs, and integration questions on the Stacks Forum or in the builders channel of the Stacks Discord. Feedback filed during the testnet window feeds directly into the mainnet release.

What's Next

The PoX-5 hardfork on July ~29 brings Bitcoin Staking to mainnet, and the Genesis Bond around the end of August kickstarts self-custodial Bitcoin Staking with real BTC. The window between now and then is the time to run your flows. Get set up on the testnet today and report what you find.