> For the complete documentation index, see [llms.txt](https://docs.stacks.co/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.stacks.co/reference/stacks.js/stacks-transactions/post-conditions.md).

# Post Conditions

Helpers for constructing and serializing transaction post conditions.

Post conditions are assertions attached to a transaction that must hold once it executes, or the whole transaction aborts. The `Pc` builder is the recommended way to construct them.

***

### Builder entry points

| Function                                                                           | Use                                                                  |
| ---------------------------------------------------------------------------------- | -------------------------------------------------------------------- |
| [principal](/reference/stacks.js/stacks-transactions/post-conditions/principal.md) | Start a post condition for a specific standard or contract principal |
| [origin](/reference/stacks.js/stacks-transactions/post-conditions/origin.md)       | Start a post condition for the transaction's origin (sender)         |

### Serialization

| Function                                                                                             | Use                                                   |
| ---------------------------------------------------------------------------------------------------- | ----------------------------------------------------- |
| [fromHex](/reference/stacks.js/stacks-transactions/post-conditions/fromhex.md)                       | Deserialize a hex string into a post condition object |
| [postConditionToHex](/reference/stacks.js/stacks-transactions/post-conditions/postconditiontohex.md) | Serialize a post condition object to a hex string     |

***

### Post condition types

```ts
type PostCondition =
  | StxPostCondition
  | FungiblePostCondition
  | NonFungiblePostCondition
  | StakingPostCondition
  | PoxPostCondition;
```

`StakingPostCondition` and `PoxPostCondition` were added for Stacks epoch 4.0 and are available in `@stacks/transactions` 7.5.0 and later. See [PostCondition](/reference/stacks.js/stacks-transactions/types/postcondition.md) for the shape of each, and [PostConditionType](/reference/stacks.js/stacks-transactions/types/postconditiontype.md) for the wire values and the condition codes each type pairs with.


---

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