# How It Works

Applications request a quote, verify or submit approvals, build the final transaction, and execute it through a wallet callback. This separation ensures consistent pricing discovery before commitment and reduces integration complexity for developers building on City Protocol.

{% stepper %}
{% step %}

#### **Quote**

The application submits a quote request via `getQuote`. The call is read-only, returning expected output, price impact, and routing details without committing to any state change.
{% endstep %}

{% step %}

#### **Approval**

The SDK invokes `checkApprovals` to verify the token allowance. If insufficient, `getApproveTransaction` returns the ERC-20 approval calldata ready for signing.
{% endstep %}

{% step %}

#### **Build:** 

The SDK calls `buildSwap` to fetch the aggregator's swap transaction payload, applying the selected slippage tolerance and gas level.
{% endstep %}

{% step %}

#### **Execute**

The application triggers the final transaction through the `executeTransaction` callback, which signs and broadcasts via the user's wallet, relayer, or abstraction layer.
{% endstep %}
{% endstepper %}


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# Agent Instructions: Querying This Documentation

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```
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```

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