# Harmonic Validator API (gRPC)

**Canonical:** https://apis.io/apis/harmonic-gg/harmonic-validator-api-grpc/  
**Provider:** Harmonic GG — https://apis.io/providers/harmonic-gg/  
**Base URL:** https://fra.auction.harmonic.gg  
**Documentation:** https://docs.harmonic.gg/run-a-validator/endpoints

Harmonic Validator API (gRPC) is one of 2 APIs that [Harmonic GG](https://apis.io/providers/harmonic-gg/) publishes on the [APIs.io](https://apis.io/) network. Tagged areas include Solana, Validator, Block Building, and gRPC.

gRPC services the Harmonic validator clients (Salsa/Samba) use to bind to a block builder: subscribe to packet and bundle streams, set the scheduling strategy, discover block engine endpoints, report leader windows, and proxy TPU traffic via the relayer.

## Machine-readable artifacts (3)

- **Protobuf** — https://raw.githubusercontent.com/api-evangelist/harmonic-gg/refs/heads/main/grpc/harmonic-gg-validator-block_engine.proto
- **Protobuf** — https://raw.githubusercontent.com/api-evangelist/harmonic-gg/refs/heads/main/grpc/harmonic-gg-validator-relayer.proto
- **Protobuf** — https://raw.githubusercontent.com/api-evangelist/harmonic-gg/refs/heads/main/grpc/harmonic-gg-validator-auth.proto

## Other Harmonic GG APIs (1)

- [Harmonic Searcher API (gRPC)](https://apis.io/apis/harmonic-gg/harmonic-searcher-api-grpc/)

## Tags

Solana, Validator, Block Building, gRPC

---

Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/apis/harmonic-gg/harmonic-validator-api-grpc/). The API's provider profile, Kin Score and agent-readiness rating are at https://apis.io/providers/harmonic-gg/.