Harmonic GG

aid: harmonic-gg
name: Harmonic GG
description: Harmonic is a highly-configurable, open block-building system for Solana. Validators keep full autonomy over
  how their blocks are built, choosing their own block builder and scheduling strategy (FBA, FIFO, MREV, or custom) while
  the block engine streams the constructed block for broadcast. A Remote TPU aggregation layer collects proposals from independent
  builders in real time, HFT-router style, to raise validator revenue and strengthen network decentralization. Searchers submit
  atomic transaction bundles over a gRPC interface that is backwards-compatible with Jito's searcher protos, with revert protection,
  bundle privacy, and tips paid as ordinary priority fees (no protocol cut). Harmonic raised a $6M seed round led by Paradigm.
deliveryModel:
  model: unknown
  open_source: unknown
  commercial: true
  callable_host: false
  label: Delivery model not determined — needs a product licence on record
  confidence: low
  source:
  - pricing
  - repository-unlicensed
  generated: '2026-08-28'
  method: derived
accessModel:
  pricing: unknown
  onboarding: unknown
  trial: false
  try_now: false
  public: false
  label: Unknown
  confidence: low
  source:
  - authentication
  generated: '2026-07-22'
  method: derived
image: https://harmonic.gg/api/og?v=home
url: https://raw.githubusercontent.com/api-evangelist/harmonic-gg/refs/heads/main/apis.yml
x-type: company
x-source: vc-portfolio
x-backed-by:
- paradigm
x-tier: enriched
x-tier-reason: portfolio-lead-enriched
x-sector: blockchain-infrastructure
specificationVersion: '0.23'
created: '2026-07-17'
modified: '2026-07-19'
tags:
- Company
- Blockchain
- Solana
- Block Building
- MEV
- Validator
- Searcher
- Infrastructure
- gRPC
- DeFi
apis:
- name: Harmonic Searcher API (gRPC)
  description: gRPC bundle-submission interface for searchers. Authenticate with a Solana keypair (challenge-response to Bearer
    tokens), then submit atomic transaction bundles with revert protection. Backwards-compatible with Jito's searcher protos;
    tips are priority fees with no protocol cut. Requires a whitelisted searcher pubkey.
  humanURL: https://docs.harmonic.gg/searchers/harmonic-bundles
  baseURL: https://fra.be.harmonic.gg
  tags:
  - Solana
  - MEV
  - Bundles
  - gRPC
  properties:
  - type: Protobuf
    url: grpc/harmonic-gg-searcher-searcher.proto
  - type: Protobuf
    url: grpc/harmonic-gg-searcher-auth.proto
  - type: Protobuf
    url: grpc/harmonic-gg-searcher-bundle.proto
  - type: Authentication
    url: authentication/harmonic-gg-authentication.yml
  - type: ErrorCatalog
    url: errors/harmonic-gg-error-codes.yml
- name: Harmonic Validator API (gRPC)
  description: '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.'
  humanURL: https://docs.harmonic.gg/run-a-validator/endpoints
  baseURL: https://fra.auction.harmonic.gg
  tags:
  - Solana
  - Validator
  - Block Building
  - gRPC
  properties:
  - type: Protobuf
    url: grpc/harmonic-gg-validator-block_engine.proto
  - type: Protobuf
    url: grpc/harmonic-gg-validator-relayer.proto
  - type: Protobuf
    url: grpc/harmonic-gg-validator-auth.proto
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com
- FN: APIs.json
  email: info@apis.io
common:
- type: IssueTracker
  url: https://github.com/harmonic/searcher-protos/issues
- type: Website
  url: https://harmonic.gg
- type: DeveloperPortal
  url: https://docs.harmonic.gg
- type: Documentation
  url: https://docs.harmonic.gg
- type: APIReference
  url: https://docs.harmonic.gg/searchers/harmonic-bundles
- type: GettingStarted
  url: https://docs.harmonic.gg/run-a-validator/setup
- type: Support
  url: https://discord.com/invite/23GfZkkyAG
- type: GitHubOrganization
  url: https://github.com/harmonic
- type: SourceCode
  url: https://github.com/harmonic/searcher-protos
- type: SignUp
  url: https://form.typeform.com/to/UlJMfbPH
- type: TermsOfService
  url: https://harmonic.gg/terms-and-conditions
- type: Protobuf
  name: Searcher gRPC protos
  url: grpc/harmonic-gg-searcher-searcher.proto
- type: Protobuf
  name: Validator gRPC protos
  url: grpc/harmonic-gg-validator-block_engine.proto
- type: LLMsTxt
  url: llms/harmonic-gg-llms.txt
- type: Authentication
  url: authentication/harmonic-gg-authentication.yml
- type: Sandbox
  url: sandbox/harmonic-gg-sandbox.yml
- type: Conventions
  url: conventions/harmonic-gg-conventions.yml
- type: Conformance
  url: conformance/harmonic-gg-conformance.yml
- type: ErrorCatalog
  url: errors/harmonic-gg-error-codes.yml
- type: Lifecycle
  url: lifecycle/harmonic-gg-lifecycle.yml
- type: DataModel
  url: data-model/harmonic-gg-data-model.yml
- type: X-MCPServerCandidate
  url: mcp/harmonic-gg-mcp.yml
  note: 'Renamed from MCPServer 2026-09-03 (roadmap#247): the manifest self-describes as status: candidate — a tool list derived
    from the published API contracts, not an existing server. The scorer already read the manifest and reported mcp_server
    correctly; the MCPServer type was crediting the artifact-type surfaces with a server that does not exist.'
- type: AgentSkill
  url: skills/_index.yml
- type: Packages
  url: packages/harmonic-gg-packages.yml
- type: DomainSecurity
  url: security/harmonic-gg-domain-security.yml
x-enrichment:
  date: '2026-07-19'
  status: backfilled
  pass: local-v1
  note: backfilled from .gitignore signal + verified work evidence