KAGOME is a C++ implementation of the Polkadot Host that brings clients diversity to Polkadot and Kusama relay chains mitigating risks associated with fatal bugs, fostering innovation, and expanding the development community.

Previous treasury proposal (link) received a pushback expressing concerns regarding importance of multiple client implementations in the light of JAM upgrade on the horizon. Therefore, we are addressing these concerns, by proposing to extend KAGOME functionality with Parachain collating node support, making it future proof even during JAM-era.

Problem statement

While Polkadot’s relay chain benefits from multiple client implementations (e.g., Polkadot-SDK, KAGOME), parachains still remain vulnerable due to client monoculture. Today, all parachains rely exclusively on the default Polkadot-SDK collator client. This creates systemic risks:

1. Parachain-Specific Outages: A single bug in the dominant collator client could halt an entire parachain, disrupting its users, cross-chain integrations (XCM), and ecosystem utility
2. Innovation Bottleneck: Lack of competition stifles optimizations for parachain-specific needs (e.g., high TPS, zk-proofs, storage models)

The problem is relevant not only for Parachains, but, with introduction of Minimal relay (link), to Relay chain itself, which will rely on system parachains for staking, governance, and identity. This creates two distinct failure domains:

Layer	Risk of monoculture	Diversity benefits
Relay chain	Compromises cross-chain security and finality	Prevents network-wide consensus failure (security)
Parachains	Causes chain-specific outages and lost liveness	Ensures continuous block production (liveness)

Polkadot is preparing for a significant upgrade to the JAM protocol, anticipated to launch on the mainnet in 2-3 years. While this upgrade will eventually render current Relay Chain clients obsolete, it will not radically affect Parachain node implementations (link). These clients will continue to function seamlessly on top of the JAM Relay Chain service.

Context of proposal

This proposal seeks funding to extend KAGOME, the C++ implementation of the Polkadot Host, into an alternative Parachain node client with the aim to introduce client diversity within Polkadot's parachain infrastructure.

KAGOME already provides clients diversity for the Polkadot Relay Chain (enhancing network-wide security against consensus-level failures). In fact, KAGOME became the first alternative client implementation actively participating in Polkadot’s Relay chain validation (link)

The current architecture of KAGOME offers a substantial foundation for the development of the Parachain client. A significant portion of KAGOME Polkadot Host’s existing functionality is directly applicable and can be efficiently reused, thereby streamlining the Parachain client's development process and reducing the overall engineering effort required.

Therefore, the majority of funding received for this proposal (91%) will be used to enhance and develop necessary functionality for running KAGOME Parachain nodes, while the remaining funding will be used to maintain existing KAGOME Relay chain implementation.

Our ultimate goal with this proposal is to develop an alternative Parachain node implementation that is protocol compatible to run alongside Polkadot-SDK based collators.

Payment details

To come up with the total requested payment we provide each task with the man-hours estimate and multiply by hourly rate which is $120/h. The requested funding will cover 8 months of operations which includes:

• Team compensation
• Payroll taxes
• Accounting, Legal & Compliance
• Infrastructure & Tooling
• Operations & Business travel
• Marketing & Ecosystem growth
• Equipment & Workstations

Total: 546000 USDC

Please read full proposal for more detailed tasks breakdown and costs explanation: https://docs.google.com/document/d/1Rk6bH4IBL9P11aqV9Nx1b8-wc4UG0VZgh-0dzm1z8BA/edit?usp=sharing