> For the complete documentation index, see [llms.txt](https://docs.fira.money/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.fira.money/developers/protocol-contracts/yield-contracts/bond-token.md).

# Bond Token

{% hint style="info" %}
**Source:** `src/fira_bonding/core/YieldContracts/BondToken.sol`
{% endhint %}

## Contract summary

BondToken is intentionally minimal. It stores immutable references to FW, factory, and expiry. The CT address is set once during `initialize()`, and the LiquidityInjector address is stored as a configurable variable.

## Access control

* **`mintByCT` / `burnByCT`** — Only the paired CouponToken can call these
* **`mintByLI` / `burnByLI`** — Only the LiquidityInjector can call these
* No other address can mint or burn BT

This strict access prevents principal inflation outside the yield-split lifecycle.

## Expiry

`isExpired()` delegates to `MiniHelpers.isCurrentlyExpired`. BT has no post-expiry logic itself — all post-expiry behavior lives in the CouponToken contract.

## Inherited contracts

* `FiraERC20` — ERC-20 with reentrancy guard


---

# 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 dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://docs.fira.money/developers/protocol-contracts/yield-contracts/bond-token.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

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.