# Encoding Options

When you request a quote, you can include `encoding_options` to have Fynd encode the swap into a ready-to-submit transaction. Without encoding options, you get a quote only (price, route, gas estimate) but no transaction.

For full details on how the TychoRouter contract works, see the [Tycho execution docs](https://docs.propellerheads.xyz/tycho/for-solvers/execution).

## Fields

| Field               | Type               | Required | Default           | Description                                                                                                             |
| ------------------- | ------------------ | -------- | ----------------- | ----------------------------------------------------------------------------------------------------------------------- |
| `slippage`          | `string`           | yes      | —                 | Slippage tolerance as a decimal string (e.g. `"0.005"` = 0.5%). Applied to the quoted output to compute `minAmountOut`. |
| `transfer_type`     | `string`           | no       | `"transfer_from"` | How the router receives your input tokens. See [transfer types](#transfer-types).                                       |
| `permit`            | `PermitSingle`     | no       | —                 | Permit2 authorization. Required when `transfer_type` is `"transfer_from_permit2"`.                                      |
| `permit2_signature` | `string`           | no       | —                 | Hex-encoded 65-byte signature over the permit. Required when `permit` is set.                                           |
| `client_fee_params` | `ClientFeeParams`  | no       | —                 | Optional integrator fee. See the [client fees guide](/guides/client-fees.md).                                           |
| `price_guard`       | `PriceGuardConfig` | no       | —                 | Per-request overrides for price-guard validation. See the [price guard guide](/guides/price-guard.md).                  |

## Transfer types

The `transfer_type` field controls how the TychoRouter contract receives your input tokens. For a deeper explanation see the [Tycho execution docs](https://docs.propellerheads.xyz/tycho/for-solvers/execution).

### `transfer_from` (default)

Standard ERC-20 approval flow. Before submitting the transaction, the sender must have called `approve()` on the input token granting the TychoRouter contract a sufficient allowance.

### `transfer_from_permit2`

Uses Uniswap's [Permit2](https://docs.propellerheads.xyz/tycho/for-solvers/execution) contract for gasless approvals. The sender signs a `PermitSingle` off-chain and passes it along with the signature in the quote request. No on-chain `approve()` needed (but the token must be approved to the Permit2 contract).

When using this transfer type, both `permit` and `permit2_signature` are required.

### `use_vaults_funds`

Draws tokens from the sender's vault balance in the TychoRouter contract (ERC-6909). No approval or permit needed — tokens must have been deposited into the vault beforehand. See the [vault mechanism](https://docs.propellerheads.xyz/tycho/for-solvers/execution) in the Tycho docs.

## Slippage

The `slippage` value is a decimal fraction:

| Value     | Meaning |
| --------- | ------- |
| `"0.001"` | 0.1%    |
| `"0.005"` | 0.5%    |
| `"0.01"`  | 1%      |

Fynd computes `minAmountOut = quotedAmountOut * (1 - slippage)` and encodes it into the transaction. If on-chain execution produces less than `minAmountOut`, the transaction reverts.

Typical values are `0.005` (0.5%) for stablecoin pairs and `0.01` (1%) for volatile pairs.

## The response transaction

When encoding options are present and the quote succeeds, the response includes a `transaction` object:

| Field   | Type     | Description                                                                                                                                 |
| ------- | -------- | ------------------------------------------------------------------------------------------------------------------------------------------- |
| `to`    | `string` | The TychoRouter contract address. See [contract addresses](https://docs.propellerheads.xyz/tycho/for-solvers/execution/contract-addresses). |
| `value` | `string` | Native token value (wei). Non-zero only when the input token is the native token.                                                           |
| `data`  | `string` | Hex-encoded calldata. Submit this as the `data` field of your Ethereum transaction.                                                         |

Use `to`, `value`, and `data` directly in your transaction. Set `from` to the sender address from your order, choose a gas limit (the quote's `gas_estimate` is a good starting point), and submit.


---

# Agent Instructions: 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:

```
GET https://docs.fynd.xyz/guides/encoding-options.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
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.