> For the complete documentation index, see [llms.txt](https://docs.fbtc.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.fbtc.com/ecosystem/locked-fbtc-token.md).

# Locked FBTC Token

Locked FBTC, namely FBTC1 for easy reference, is an innovative asset within the FBTC ecosystem, designed to support a wide range of yield generation scenarios. As a versatile ERC-20 token, Locked FBTC offers multiple yield strategies, enhancing the value proposition for users seeking to maximize their returns. Unlike FBTC0, which is pegged 1:1 with BTC and does not support automatic yield generation, Locked FBTC is specifically tailored for yield generation, ensuring users can leverage various strategies effectively.

## Key Features

### Yield Generation

Locked FBTC is designed to support various yield generation scenarios, allowing users to earn returns on their assets through multiple strategies. This makes Locked FBTC a powerful tool for users looking to maximize their returns within the decentralized finance (DeFi) ecosystem.

* **Multiple Yield Strategies**: Locked FBTC supports a variety of yield strategies, including staking, lending, and liquidity provision.
* **Flexible Yield Scenarios**: Users can choose from different yield generation scenarios based on their risk appetite and return expectations.

## High-level Workflow

### Mint Locked FBTC

<figure><img src="https://4102630944-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FSdfKsVfWUlwTQH1ZXZQG%2Fuploads%2F8KfEDSzdMiv7bDkgD10z%2FCross-chain%20Flow%20(6).png?alt=media&amp;token=2c9f2ea7-b0ca-421d-9f33-ba5296aed3f1" alt=""><figcaption></figcaption></figure>

1. A FBTC0 holder transfers his FBTC0 to a partner’s vault.
2. Periodically, Partner deposits FBTC0 to FBTC1 contract to initiate a request to mint FBTC1 and burn FBTC0.
3. Bridge Monitor sends the withdrawal request to transfer the corresponding BTC from BTC0 address to BTC1 address. BTC1 address is for Partner’s yield strategy use only.
4. FBTC TSS Gateway confirms the FBTC0 is burned properly.

### Burn Locked FBTC

<figure><img src="https://4102630944-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FSdfKsVfWUlwTQH1ZXZQG%2Fuploads%2FIudyetQ7VIZhkrcNBiZl%2FCross-chain%20Flow%20(5).png?alt=media&amp;token=4ae6a8bb-1533-418a-a3a2-8e43feaaa5e9" alt=""><figcaption></figcaption></figure>

1. A merchant initiates a request to redeem FBTC. Partner may collect such requests, and transfers BTC from BTC1 address to standard FBTC’s custody address BTC0 periodically.
2. Once BTC is received at BTC0 address, FBTC1 contract initiates a request to mint FBTC0.
3. FBTC TSS Gateway will confirm FBTC0 is minted.
4. Partner Vault withdraws FBTC0 from FBTC1 contract and burns FBTC1 at the same time.
5. Partner returns FBTC0 to the merchant from Partner Vault.


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation by asking a question.

Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters:

```
GET https://docs.fbtc.com/ecosystem/locked-fbtc-token.md?ask=<question>&goal=<user_goal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.