# Stacks · Integra

> On Stacks, the SIP-010 transfer’s memo holds the ATR hash.

URL: https://integraledger.com/rails/stacks

Payment rail

## Stacks

On Stacks, the SIP-010 transfer’s memo holds the ATR hash. [Source: lcp docs: rails⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/docs/guides/rails.md)

**Sources (1)**

[lcp docs: rails⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/docs/guides/rails.md)

### Where the ATR hash rides

On this rail, the ATR hash rides in the SIP-010 transfer’s memo.

#### The standard

- The SIP-010 `transfer`’s memo: H’s 32 bytes. [Source: lcp docs: rails⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/docs/guides/rails.md)

  `mpp/charge/usdc/stacks`

Entry points: `@integraledger/lcp/stacks` · Install beside the package: `@stacks/transactions`

#### The data

Read from the published packages when the site was built; nothing here is typed by hand.

The ATR hash of the site’s example ATR, as this rail carries it

H’s 32 bytes, as the memo

0x8448dc1b716a5103287cb8f35e36b614ffd91e630ab8b7911833c54748ad5ca6

Computed from the site’s example ATR by this rail’s own helper in the package, when the site was built.

### What a payment on this rail proves

Of these 1 pairings, 1 have the buyer’s signature cover the ATR hash, 1 leave a public proof of it, and 1 let anyone read it back from the chain alone. [Source: lcp docs: pairings reference⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/docs/reference/pairings.md)

Switch to Technical to see each pairing, and the sentence its record states about what a payment through it proves.

#### The standard

- **`mpp/charge/usdc/stacks` Native Field Buyer signs H: yes H on chain: yes Public proof: yes Recoverable from chain: yes**

  Pattern: [Native Field (LCP §8.3.1)⁠ (opens in a new tab)](https://github.com/legal-context-protocol/legal-context-protocol/blob/c8df26d/spec/legal-context-protocol-v1.md#831-native-field)

  Where the ATR hash rides: The SIP-010 `transfer`’s memo: H’s 32 bytes.

  What a payment through it proves: The payer signed a Stacks transaction whose SIP-010 transfer carries this ATR's hash as its memo argument. The chain verified the signature, the transaction executed with status success, and the memo is in the mined transaction on chain. This does not show that amount, payee, asset or timing match the ATR's content.

  LCP profile: [mpp/charge/usdc/stacks⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/lcp/profiles/mpp-charge-usdc-stacks.md)

### Reading the settlement

The package reads a payment’s settlement through a reader you supply: the endpoint, the credentials, the timeouts and the retries are yours. A reader that fails never makes a payment read as failed. [Source: lcp docs: reading settlement⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/docs/guides/rails.md#reading-settlement)

**Sources (1)**

[lcp docs: reading settlement⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/docs/guides/rails.md#reading-settlement)

#### The standard

**Reader**

`StacksReader`

**Its calls**

the origin’s confirmed nonce, read first; the transaction by id; a block’s tenure height; the tip’s tenure height

**A settled read carries**

`block` or `bitcoin` [Source: lcp docs: reading settlement⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/docs/guides/rails.md#reading-settlement)

### The protocols that pay on it

- [MPP](https://integraledger.com/protocols/mpp)

[lcp docs: rails⁠ (opens in a new tab)](https://github.com/IntegraLedger/integra-protocol/blob/66274bf/docs/guides/rails.md)