Unified Liquidity Balance API

[lrazovic]

Project Abstract

The Unified Liquidity Balance API is a real‑time balance tracking solution for Polkadot SDK-based chains. It provides a single, unified Server‑Sent Events (SSE) endpoint to monitor user balances across multiple parachains without polling or deep integration with Polkadot‑specific libraries.

Grant level

• Level 1: Up to $10,000, 2 approvals
• Level 2: Up to $30,000, 3 approvals
• Level 3: Unlimited, 5 approvals (for >$100k: Web3 Foundation Council approval)

Application Checklist

• The application template has been copied and aptly renamed (project_name.md).
• I have read the application guidelines.
• Payment details have been provided (Polkadot AssetHub (USDC & DOT) address in the application and bank details via email, if applicable).
• I understand that an agreed upon percentage of each milestone will be paid in vested DOT, to the Polkadot address listed in the application.
• I am aware that, in order to receive a grant, I (and the entity I represent) have to successfully complete a KYC/KYB check.
• The software delivered for this grant will be released under an open-source license specified in the application.
• The initial PR contains only one commit (squash and force-push if needed).
• The grant will only be announced once the first milestone has been accepted (see the announcement guidelines).
• I prefer the discussion of this application to take place in a private Element/Matrix channel. My username is: @_______:matrix.org (change the homeserver if you use a different one)

[github-actions]

CLA Assistant Lite bot All contributors have signed the CLA ✍️ ✅

[lrazovic]

I have read and hereby sign the Contributor License Agreement.

[keeganquigley]

Thanks for the application @lrazovic could you clarify what you have already built, and what you would build as part of this grant? Since I see the PoC is complete.

[keeganquigley]

Suggested change

	- **Estimated duration:** 1 month
	- **Estimated duration:** 6 months

[keeganquigley]

Since the timeline for maintenance SLA would be 6 months, can we adjust total milestone duration to 6 months?