> ## Documentation Index
> Fetch the complete documentation index at: https://docs.neuro-tech.io/llms.txt
> Use this file to discover all available pages before exploring further.

# Contract structure

> Learn how machine-readable XML, human text, roles, parameters, and signatures form a contract

A Neuron contract is a signed, machine-readable agreement with human-readable text. It is not program code deployed to a blockchain.

A contract defines:

* the machine-readable XML payload;
* the text each signer sees;
* roles and required signatures;
* typed parameters and validation;
* visibility, validity, and lifecycle rules.

Use the [contract quickstart](/contracts/quickstart) to choose LegalLab, the Agent API, or the .NET XMPP client. Return here when you need to understand the format those tools read and write.

## Templates and instances

A template defines the roles and parameters that can be filled later. It must be proposed and approved before an application can create contract instances from it.

```text theme={null}
contract XML → proposed template → approved template → contract instance → signatures
```

Start with [Templates and instances](/contracts/templates-and-instances) when this distinction is unfamiliar.

## MCP's role

The built-in Neuron MCP servers do not currently propose templates, create contracts, or sign contracts. An MCP-capable development client can still help edit XML, inspect files, retrieve reference content, or query events. Use LegalLab or the Agent API for the contract operation itself.

<Card title="Contract quickstart" icon="route" href="/contracts/quickstart">
  Choose a tool and make a controlled change to an example contract.
</Card>