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

# OP Stack protocol

> The protocol layer's home on this site, routing to the normative specifications, the rollup explainers, and the hardfork registry.

This section is the protocol layer's home on docs.optimism.io. Protocol
behavior is normatively defined in the
[OP Stack specifications](https://specs.optimism.io/); per the
[content guide](/op-stack/contribute/content-guide), the pages here explain
concepts and route to the exact spec section; they never restate normative
text.

<CardGroup cols={2}>
  <Card title="Get the canonical definition" href="https://specs.optimism.io/">
    Read the OP Stack specifications, the normative source for all protocol
    behavior.
  </Card>

  <Card title="Understand how the rollup works" href="/op-stack/protocol/overview">
    Learn how Optimistic Rollups work: block storage, production, execution,
    bridging, and fault proofs at a high level.
  </Card>

  <Card title="Look up a network upgrade" href="/op-stack/protocol/network-upgrades">
    Find any hardfork's activation timestamps, governing spec, and minimum
    component versions in the registry.
  </Card>

  <Card title="Meet the components that implement it" href="/op-stack/components/index">
    Find the canonical hub for each OP Stack component, grouped by protocol
    role.
  </Card>

  <Card title="Check who holds privileged roles" href="/op-stack/protocol/privileged-roles">
    See the privileged roles OP Stack chains still include, the risks they
    pose, and their mitigations.
  </Card>

  <Card title="Looking for something else?" href="/">
    Browse the documentation by role: app developer, chain operator, or node
    operator.
  </Card>
</CardGroup>