> For the complete documentation index, see [llms.txt](https://docs.facet.org/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.facet.org/reference/important-repositories.md).

# Important Repositories

A curated list of the core Facet repositories, their roles, and where they fit in the architecture. Use this page as a quick directory and jump-off point.

## Core Derivation (L2 Clients)

* facet-node — Consensus/derivation client
  * URL: <https://github.com/0xFacet/facet-node>
  * Purpose: Monitors Ethereum L1 for Facet inbox payloads, derives Facet blocks, and communicates with the execution client via the Engine API. Stateless; data stored in facet-geth.
* facet-geth — Execution client
  * URL: <https://github.com/0xFacet/facet-geth>
  * Purpose: Executes Facet blocks and maintains chain state. Forked from OP Stack’s op-geth with Facet-specific semantics.

## Fault Proof System (ZK Fault Proofs)

* zk-fault-proofs — On-chain contracts + services
  * URL: <https://github.com/0xFacet/zk-fault-proofs>
  * Purpose: Rollup.sol + proposer/challenger services for ZK fault proofs. Manages proposals, challenges, and proof verification.
* facet-kona — Rust STF / derivation (Kona fork)
  * URL: <https://github.com/0xFacet/facet-kona>
  * Purpose: Rust implementation of Facet’s state transition function and derivation logic, used by the ZK fault proof pipeline.
* facet-revm — Rust EVM (REVM fork)
  * URL: <https://github.com/0xFacet/facet-revm>
  * Purpose: Fork of REVM tailored for Facet’s execution semantics within the Rust STF.
* facet-op-alloy — OP/Alloy components
  * URL: <https://github.com/0xFacet/facet-op-alloy>
  * Purpose: Supporting Rust components used by facet-kona for OP/Alloy compatibility.

## OP Node Fork (Auxiliary RPC)

* facet-optimism — Read-only op-node fork
  * URL: <https://github.com/0xFacet/facet-optimism>
  * Purpose: Provides auxiliary RPCs (e.g., sync status, output-at-clock) not yet implemented in facet-node. Read-only in Facet; used by proposers/challengers.

## Developer Tools

* facet-sdk — TypeScript SDK
  * URL: <https://github.com/0xFacet/facet-sdk>
  * Purpose: High-level TypeScript utilities to construct and submit Facet transactions from web and server apps.
* facet-sol — Foundry library
  * URL: <https://github.com/0xFacet/facet-sol>
  * Purpose: Foundry helpers to emit Facet transactions from contracts and Foundry scripts.

## Governance & Dashboards

* FIPs — Facet Improvement Proposals
  * URL: <https://github.com/0xFacet/FIPs>
  * Purpose: Governance proposals and design discussions for protocol evolution via forks and social consensus.
* fct-fyi — FCT metrics site
  * URL: <https://github.com/0xFacet/fct-fyi>
  * Site: <https://fct.fyi/>
  * Purpose: Public dashboard for FCT mint rate, issuance progress, and real-time metrics.

## Where They’re Referenced

* Running a node: Guides → Running a Facet Node (facet-node, facet-geth)
* Proposer/Challenger: Guides → Proposing and Challenging (zk-fault-proofs, facet-optimism)
* Proofs design: Proof System & Bridging → ZK Fault Proofs (zk-fault-proofs, facet-kona, facet-revm, facet-op-alloy)
* Developer experience: Developer Tools (facet-sdk, facet-sol)
* Token metrics: Native Gas Token → FCT Issuance Calculation (fct.fyi)
* Governance: Reference → Important Repositories (FIPs)