This proposal requests funding for a set of targeted feature developments for Polkadot-API and its surrounding ecosystem components.

Polkadot-API is a modular, light-client-first suite of libraries designed to provide a high-performance and developer-friendly interface to the Polkadot ecosystem. Since its first stable release in 2024, the project has become an important piece of infrastructure for building decentralized applications, with adoption across multiple teams and products.

This proposal focuses on delivering additional features and improvements identified through ongoing collaboration with ecosystem stakeholders, complementing the basic maintenance proposal approved in https://polkadot.subsquare.io/referenda/1856

Scope of Work

The proposal covers four main areas:

1. Polkadot-API Core Enhancements
Implementation of full support for Extrinsic v5 and the new createTransaction API, including:

• First-class support for transaction creation workflows
• Libraries for wallet and extension integration
• Support for custom transaction extensions and typings

2. SDK Improvements (Statement Store)
Continuous adaptation of the Statement Store SDK to evolving RPC specifications, ensuring compatibility and reliability for data propagation mechanisms across the network.

3. PAPI Console Expansion
Further development of the PAPI Console as a developer tool and ecosystem interface, including:

• UX improvements
• Extrinsic analysis tools
• Enhanced account management (locks, vesting, etc.)
• Chain metrics and block data visualization
• Teleport integration

As the ecosystem evolves and legacy tooling is gradually phased out, improving onboarding and providing modern, well-supported interfaces becomes increasingly important. The PAPI Console contributes to this transition by offering new capabilities while aligning with the current architecture of Polkadot.

4. JSON-RPC Specification Improvements
Contributions to protocol-level improvements required by modern dApps, including:

• Pagination and storage proof support (chainHead v2)
• Improved transaction tracking

Full Proposal

For a detailed breakdown of the scope, milestones, and technical context, please refer to the full proposal: https://docs.google.com/document/d/1DU8LXaDtGf6N3nDz7t6yj0CoYOAbu1cS99X9FAw0W6g/edit?usp=sharing

Budget & Execution

• Total requested: 76,380 €
• Total workload: 804 hours
• Rate: 95 €/hour

Funds will be managed through the Polkadot Community Foundation (PCF).

A total of 4,000 € is included as a buffer to cover PCF operational and administrative expenses (legal and operational costs). Any unused portion of this buffer will be returned to the Polkadot Treasury.

The EUR - USDC rate has been set at the time of submission by xe.com's rate 1.15359324 USDC / EUR

Upon approval:

• The PCF will establish the necessary contractual agreement with our legal entity
• The team will issue a single invoice to the PCF for the full amount
• Payment will be executed in USDC to 13dXmfrN4Prb3FmdxKDNRyUeNDuNwUTZibYAMFNKmZJut2Lq a multisig wallet controlled by the team.
• The PCF will retain the portion required for operational costs and return any excess to the Treasury

The team will maintain transparency through ongoing updates on GitHub and the Polkadot Forum.