> For the complete documentation index, see [llms.txt](https://docs.unisat.io/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.unisat.io/developer-support/faq.md).

# FAQ

Q: How can I begin using UniSat API?

You can visit the Developer Center on the UniSat website and register to instantly get a free API key with a monthly quota of 30,000 calls. For higher limits for personal or commercial projects, you can upgrade to a paid plan. See [How to Acquire a UniSat API Key](https://docs.unisat.io/dev-center/developer-center/how-to-acquire-a-unisat-api-key) for more details.

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Q: What is the UniSat API for?

UniSat API is the first brc20 indexer API provider and is also used by leading exchanges. It supports queries for Bitcoin and Fractal Bitcoin blockchain info, balances, transaction histories, and UTXO-related data. It also provides comprehensive indexer data for asset protocols such as brc20, Runes, Alkanes, including balances, holder addresses, and transaction histories.

In addition, UniSat API supports inscription-related data and on-chain activity, enabling developers to quickly deploy inscription minting services. Users can also access UniSat products through the API—including inscribe service and trading products such as Marketplace and InSwap—to mint and trade assets programmatically.

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Q: Is Fractal Bitcoin's API completely free, and what can it be used for?

Fractal Bitcoin’s API is completely free, and its data and API interface structure are fully identical to Bitcoin’s. When developers or projects find that API request costs on the Bitcoin mainnet are prohibitively high during development and testing, they can switch to Fractal and complete their testing there at relatively low cost, then later move to commercial paid APIs on the mainnet once everything is ready.

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UniSat offers four API plans designed for different use cases:

•Free: Ideal for research, experimentation, and high-load testing. This plan provides a one-time API key, making it suitable for short-term projects or initial exploration.

•Specialist: Best for developers running larger scripts and blockchain startups with a growing user base. It’s also a good fit for certain arbitrage traders operating on the Bitcoin network.

•Enterprise: Designed for wallets, exchanges, and startups in their growth stage. This plan is also well suited for market makers running high-frequency strategies across the Bitcoin network and centralized exchanges.

•Custom API: If the request limits or rate limits of the standard plans do not meet your development or trading strategy requirements, please contact the UniSat team to discuss a customized API solution tailored to your needs.

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Q: What are the rate limits for UniSat API?

The UniSat Free and Specialist plans have a rate limit of 5 requests per second, while the Enterprise plan allows 10 requests per second. For higher throughput, custom Enterprise plans are available—top-tier exchanges can get up to 500 requests per second. Contact the UniSat team to discuss your needs.

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Q: What if my API usage exceeds my current plan, and will I lose the remaining value if I upgrade?

If your usage exceeds your current plan, you can either purchase additional usage through a "pay-as-you-go" package or upgrade to a higher-tier plan. When upgrading, the remaining value of your current plan is calculated down to the minute and applied as a credit toward the cost of the new plan.

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Q: Is it possible to support BRC2.0 API data?

Yes. In-module balance queries will be added on top of the existing brc-20 API.

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Q: Can I query UTXOs at low fee rates?

Yes. The API supports UTXO queries in <1 sat/vB mode, returning up to 500 UTXOs per request.

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Q: Can I use the API for commercial projects?

Yes, the UniSat API is designed to support both personal and commercial projects. For commercial use, the Enterprise plan offers the most comprehensive access, including custom call limits and commercial licensing options.

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Q: What payment options are available?

You can pay via PayPal, BTC, or USTD(TRON/ETH). BTC payments are screened through our on-chain KYT system, and any high-risk funds will be returned.

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Q: Is the API subscription auto-renewed?

After purchasing a plan, users can manually enable auto-renewal on their account page. Auto-renewal can also be canceled at any time. Please note that payments are non-refundable, and we do not provide refunds for services that have already been paid for.