Due to potential display issues with some charts in format across various devices and platforms, please refer to the detailed information in this Google Document:
https://docs.google.com/document/d/1DKX62a9LtAWd7CF7oBTUQe0rZ23xcwnnrs1fj_14JlQ/edit?usp=sharing
https://polkadot.polkassembly.io/post/3390
Based on this discussion version, this proposal corrects some typos. For the development costs, Subscan will self-fund 30% and request 70%. Additionally, responses to community feedback will be added in the comments section.
Subscan requests funding from the Polkadot Treasury to ensure the continued operation and enhancement of one of Polkadot’s most critical public data infrastructures. As the default block explorer and primary indexing backend for the Polkadot ecosystem, Subscan provides high-availability, low-latency, and fully historical on-chain data for the Polkadot Relay Chain and all Polkadot system parachains. These services are relied upon daily by developers, validators, wallets, governance platforms, infrastructure providers, auditors, and millions of unique users per year.
This proposal covers Subscan’s work across two key areas:
Ensuring uninterrupted operational maintenance for the six Polkadot system networks:
These services include full database indexing, runtime compatibility, node operations, 24/7 monitoring, bandwidth provisioning, storage scaling, DevOps automation, and end-user/API support—ensuring continuous data availability across the entire Polkadot ecosystem.
Requested: USD 151,200
Compensation for major ecosystem-critical work already completed, including:
Total: USD 73,167
Subscan Team Contribution: To support the sustainable growth of the ecosystem, the Subscan Team is self-funding 30% of these development costs.
Requested: USD 51,216
Total requested amount: USD 202,416
From Q2 2025 to Q4 2025, Subscan completed extensive development and infrastructure work that directly supports Polkadot’s transition into the next-generation ecosystem architecture—particularly the AssetHub migration, which has been one of the most significant structural changes to the Polkadot network in recent years.
Subscan’s work during this period can be summarized in the following core areas:
AssetHub underwent multiple breaking updates, including changes to assets, extrinsics, metadata layouts, governance modules, and transfer logic. Subscan delivered complete compatibility support, including:
These contributions ensured that wallets, explorers, governance dashboards, and integration tools remained fully functional throughout the AssetHub migration, preventing ecosystem disruption.
Major foundational improvements included:
These enhancements strengthened chain-wide data accuracy and reduced the risk of indexer stalls during runtime upgrades or heavy XCM traffic.
Given Polkadot’s XCM-heavy activity, Subscan delivered system-wide improvements:
Combined, these improvements make Subscan the most complete and accurate public XCM observability layer in the ecosystem.
Subscan improved auditability and cross-module visibility by:
This has become critical infrastructure for OpenGov data, treasury analysts, and governance dashboards.
Key UX improvements include:
These ensure Subscan remains responsive even under multi-network heavy traffic conditions.
Continuous operations included:
These ongoing services are fundamental to maintaining reliable explorer and API availability for the entire Polkadot ecosystem.
As the default block explorer and indexing layer for Polkadot, Subscan provides the foundational data required by nearly all ecosystem participants.
Without Subscan, many essential tools would face significant data degradation, and the accessibility of historical and governance data would be severely impacted.
This proposal covers two major funding components:
Operational maintenance for 6 Polkadot networks:
These fees cover database storage, indexing, monitoring, bandwidth, DevOps, node maintenance, and end-user support.
Compensation for:
Together, these represent essential public infrastructure development that ensures Subscan remains aligned with Polkadot’s technical evolution.
Throughout 2025, Subscan has focused on deep infrastructure optimization. By refining our technical stack, we have successfully reduced internal overhead and operational costs without compromising the high service standards the ecosystem expects. Our goal is to pass these efficiencies directly to the networks we support through a more competitive pricing structure.
To ensure a stable transition, we are rolling out these optimizations and subsequent price reductions in stages:
Note: For a detailed breakdown of how these infrastructure improvements will impact future budgets, please refer to the "2026 Cost Outlook (Infrastructure Optimization Based)" section.
For the period of 2025 Q3–Q4, Subscan’s fee structure remains consistent with the model successfully utilized over the past two years.
Our maintenance packages are designed to support a wide range of data and operational needs, ensuring stable and efficient system performance. Because our overall cost structure is composed of multiple infrastructure and operational expenses—such as cloud services, network acceleration, monitoring systems, node providers, and the Subscan team’s ongoing operations—we use storage consumption as the primary metric for determining service fees.
Pricing Tiers:
a. Basic Plan
b. Advanced Plan
c. Professional Plan
Correlation to Real Costs:
Storage growth scales directly with block production and transaction activity, making it a more stable and predictable metric than raw API traffic. As chain activity evolves, storage becomes the clearest and most consistent indicator of the underlying infrastructure load required to maintain long-term historical data.
Subscan Baseline:
Subscan determines the appropriate fee tier based on the median storage consumption measured during the billing period. For example, for the Q3–Q4 2025 billing cycle, the baseline storage usage is derived from data recorded on September 30th.
Predictable Billing:
Basing fees on storage reduces the volatility caused by sudden traffic spikes and ensures a more transparent, usage-based cost model for both the community and the treasury.
Our pricing also incorporates the broader operational overhead required to run a production-grade, high-availability data service—such as cloud infrastructure, network acceleration, monitoring systems, node providers, and Subscan’s ongoing engineering and support efforts.
Because these components fluctuate dynamically based on cloud regions, traffic patterns, redundancy requirements, and security considerations, they cannot be broken down into a stable or meaningful line-item list. In addition, some of these details involve sensitive architectural and security-related information that should not be fully disclosed publicly in order to preserve system robustness and reduce attack surface.
For these reasons, Subscan adopts a service-fee-based pricing model, which is consistent with industry practices used by major explorer and indexing providers. Pegging the service fee to storage usage strikes the right balance between:
This model also enables Subscan to invest continuously in optimization and long-term cost reduction—ensuring that infrastructure improvements directly translate into better performance and lower overall fees for the ecosystem over time.
| Network | Actual Usage/GB | Date | Package | Fees/Month | Billing Period | Fees |
| Polkadot | 4305.22 | 30/09/2025 | Professional | 19,405 | Q3 & Q4: 01/07/2025-31/12/2025 | 116,430 |
| AssetHub-Polkadot | 382.63 | 30/09/2025 | Basic+ | 1,699 | Q3 & Q4: 01/07/2025-31/12/2025 | 10,194 |
| Coretime-Polkadot | 40.73 | 30/09/2025 | Basic | 799 | Q3 & Q4: 01/07/2025-31/12/2025 | 4,794 |
| Collectives-Polkadot | 161.7 | 30/09/2025 | Basic | 799 | Q3 & Q4: 01/07/2025-31/12/2025 | 4,794 |
| BridgeHub-Polkadot | 448.78 | 30/09/2025 | Advanced | 1,699 | Q3 & Q4: 01/07/2025-31/12/2025 | 10,194 |
| People-Polkadot | 37.84 | 30/09/2025 | Basic | 799 | Q3 & Q4: 01/07/2025-31/12/2025 | 4,794 |
During Q2 2025, Subscan completed a comprehensive series of platform enhancements focused on network-wide reliability, data accuracy, performance optimization, and user experience improvements across the Polkadot ecosystem.
These efforts strengthened Subscan’s role as a core public infrastructure component used daily by developers, validators, nominators, governance participants, and parachain teams.
Key areas of contribution include:
Below is the complete task list for Q2 2025：
| Task | Name | Description | PM/Test | Designer | Backend | Front-end | DevOps |
| 1 | ES Sync Checkpoint Persistence | Persist checkpoints for Elasticsearch sync tasks to significantly improve multi-network data synchronization stability and recovery robustness. | 1h | – | 4h | – | – |
| 2 | Portfolio Multi-Network Display Fix | Fix inconsistency between network counts shown on the Portfolio overview and detail pages, improving accuracy for cross-chain asset visualization. | 1h | – | 4h | 3h | – |
| 3 | Treasury Proposal Amount Display Optimization | Add support for USDT/USDC denomination and auto-conversion in the Treasury module to improve transparency and readability in governance workflows. | 1h | 1h | – | 4h | – |
| 4 | Portfolio Identity Display Optimization | Optimize cross-chain Identity loading logic to ensure consistent identity rendering across networks. | 1h | – | 10h | 3h | – |
| 5 | Accounts Pagination Optimization | Improve account pagination performance for large networks, enhancing response time and stability under high-concurrency access. | 1h | – | 8h | 3h | – |
| 6 | Portfolio Value Display Bug Fix | Fix incorrect asset value calculations in the Portfolio module to improve accuracy of user asset statistics. | 1h | – | 5h | 2h | – |
| 7 | User Feedback Collection & Processing | Add a unified “Feedback Entry” on the UI to centralize user feedback collection and complete a batch of UX improvement iterations. | 4h | 1.5h | – | 3h | – |
| 8 | Homepage Chart Default Range Standardization | Standardize default ranges (e.g., price/volume charts) on the homepage to “1 month” for improved readability and user experience consistency. | 1h | – | – | 2h | – |
| 9 | Token List Entry Optimization | Improve navigation and entry points to the Token List, enabling quicker access to token detail pages. | 1h | 0.5h | – | 3h | – |
| 10 | Identity Report Bio Field Addition (Admin Platform) | Add a Bio field to identity reports in the admin panel to enhance completeness of on-chain identity management. | 1h | – | 1h | 2h | – |
| 11 | Batch Data Download Script | Develop a script for bulk data export to support large-scale analytics needs and reduce manual operations. | 1h | 1h | 5h | 4h | – |
| 12 | IPFS Provider Migration | Migrate document/image resources to a more stable IPFS provider to improve loading performance and success rate. | – | – | 1h | – | 2h |
| 13 | Monitoring System Optimization | Redesign Subscan’s backend monitoring architecture to improve real-time alerting for on-chain events, data sync, and error detection. | – | – | 8h | – | 4h |
| 14 | StorageChanged Data Consistency Fix | Fix data inconsistency related to on-chain StorageChanged events to improve accuracy of historical data. | 1h | – | 2h | – | – |
| 15 | Dark Mode UI Enhancement | Fix contrast issues in dark mode for text and charts to improve readability and overall UX. | 1h | 3h | – | 5h | – |
| 16 | Identity Privacy Mode Fix | Fix issues where the Identity privacy toggle does not take effect, ensuring correct privacy protection across networks. | 1h | – | – | 3h | – |
| 17 | Profile Privacy Display Fix | Fix issues where avatars and social information are still visible in privacy mode, enhancing personal data protection. | 1h | – | 2h | 3h | – |
| 18 | Cookie Prompt Optimization | Significantly reduce intrusive mobile cookie pop-ups to improve browsing experience. | 1h | 1h | – | 2h | – |
| 19 | SS58 Format Conversion Tool Review | Review and fix issues in the SS58 encode/decode tool to improve cross-chain address compatibility and accuracy. | 1h | – | 1h | 2h | – |
| 20 | API Performance Optimization & Slow Endpoint Investigation | Investigate performance issues, indexing, and caching improvements for high-frequency APIs (e.g., unique_id, multiChain, reward_slash, staking_history), significantly improving platform response speed. | 2h | – | 10h | – | 3h |
Our Compensation Rates and Total Costs:
With a total of 144 hours worked, the calculated cost based on the above rates amounts to $10,650.
During Q3 2025, Subscan continued its role as a core piece of Substrate ecosystem public infrastructure, focusing on strengthening data correctness, cross-chain observability, governance transparency, and runtime upgrade compatibility for Polkadot and its ecosystem parachains. The work in this period concentrated on hardening the production explorer that is used daily by validators, nominators, governance participants, infrastructure providers, and application teams.
Across all categories, this Q3 scope represents 46 concrete engineering tasks, covering:
Below is the complete task list for Q3 2025：
| Task | Name | Description | PM/Test | Designer | Backend | Front-end | DevOps |
| 1 | [AH Migration] Staking Module Support | Handle extensive changes caused by staking module migration between the Relay Chain and AssetHub (AH), including new data indexing, updated era calculation logic, and validator block production association back to the Relay Chain. | 2h | 2h | 4h | 4h | - |
| 2 | [AH Migration] Vesting Module Support | Handle migration-driven changes related to vesting on the Relay Chain and AssetHub, including new data indexes and chart visualization updates. | 1h | 1h | 1h | 2h | - |
| 3 | [AH Migration] Governance Module Support | Handle governance-related changes during migration, such as indexing AH referendum data, synchronizing records, and completing metadata fields (CreatedAtBlock) to ensure full lifecycle integrity. | 2h | 1h | 4h | 4h | - |
| 4 | [AH Migration] Account & Balance Support | Handle account balance–related migration between Relay Chain and AH, including balance sync, calibration checks, and basic multi-asset tracking setup. | 2h | 2h | 1h | 5h | - |
| 5 | Runtime Upgrade Monitoring & Notification Script | Add runtime version change monitoring and notification scripts, enabling the team to react quickly to upgrades and reduce ecosystem downtime risk. | 1h | - | 3h | - | 3h |
| 6 | Polkadot Ecosystem Runtime Upgrade Compatibility | Complete runtime upgrade compatibility and validation across Polkadot mainnet and its system parachains (AssetHub, BridgeHub, People, Coretime, Collectives) for multiple Q3 upgrades. • Polkadot Upgrade: 1006001 / 1006002 • AssetHub-Polkadot: 1006000 • BridgeHub-Polkadot: 1006001 • People-Polkadot: 1006001 • Coretime-Polkadot: 1006001 • Collectives-Polkadot: 1006001 | 3h | - | 8h | - | 2h |
| 7 | Event Date Misalignment Fix | Fix incorrect or misaligned date/time fields across event records in multiple networks to ensure historical event timelines are accurate. | 1h | - | - | - | - |
| 8 | Event ↔ Extrinsic Bidirectional Navigation Fix | Fix navigation issues between event detail pages and corresponding extrinsic detail pages to restore reliable bidirectional linking. | 1h | - | 1h | 3h | - |
| 9 | Event Search Feedback Logic Fix | Improve event search feedback logic under edge cases and invalid inputs to enhance usability. | 1h | 1h | 2h | 2h | - |
| 10 | Child Bounty Statistics & Overview | Add Child Bounty counts and aggregated overview in bounty-related lists to help governance participants assess fund distribution structures. | 1.5h | 1.5h | 4h | 3h | - |
| 11 | Child Bounty Distribution & Claim Status Display | Implement detailed tracking and visualization of Child Bounty distribution and claim events for improved transparency of governance fund flows. | 1h | 1h | 4h | 4h | - |
| 12 | Multi-Entity Governance Timeline Enhancement | Enhance referendum timelines to interlink Treasury, Preimage, XCM and other module events within a unified view. | 1h | 0.5h | 4h | 2h | - |
| 13 | Referendum ↔ Treasury Spend Mapping Fix | Fix incorrect or missing mappings between referenda and Treasury Spends across multiple cases to ensure consistency and auditability of governance data. | 1.5h | - | 4h | 3h | - |
| 14 | Democracy Unlock Block Calculation Optimization | Optimize unlock block calculation logic for Democracy referenda, ensuring correct unlock height display across all supported networks. | 1h | - | 2h | 2h | - |
| 15 | Remove Unsupported Gov V1 Entry Points | Identify networks like Polkadot that no longer support Gov V1 and remove related UI entry points to avoid user confusion. | 0.5h | - | - | 1h | - |
| 16 | Preimage Status Change Timeline | Add a status-change timeline for the Preimage lifecycle to improve traceability from submission to execution. | 1h | 0.5h | 3h | 2h | - |
| 17 | Treasury Spend Cycle Display | Add cycle and period information to Treasury Spend items to help users understand spending cadence. | 1h | - | 2h | 2h | - |
| 18 | ConvictionVoting poll_index Link Support | Add navigation links for poll_index in ConvictionVoting items to directly open corresponding Subscan pages. | 1h | - | 2h | 2h | - |
| 19 | XCM Asset Flow Upgrade | Add filtering and upgrade outdated XCM wheel visualizations to the new “XCM Asset Flow Chart” across multiple pages to significantly improve readability and UX. | 1h | 2h | 2h | 4h | - |
| 20 | XCM Asset Flow Dashboard Load Optimization | Optimize data fetching and batch loading for XCM Asset Flow dashboards to reduce latency and jitter in multi-network scenarios. | 1h | - | 3h | 4h | - |
| 21 | XCM Execute Event Completion & Support | Complete missing XCM execute events across multiple parachains and unify processing logic to improve execution log integrity. | 1.5h | - | 8h | - | - |
| 22 | XCM Process Navigation & Linking Fix | Fix multiple navigation issues in the XCM Process view (links to event details, extrinsics, etc.) to ensure end-to-end cross-chain traceability. | 2h | - | 2h | 5h | - |
| 23 | XCM Data Dashboard Enhancement | Expand XCM data charts and optimize refresh/aggregation logic to support multi-network cross-chain traffic analytics. | 1h | 1h | 3h | 2h | - |
| 24 | XCM Token Search Result Fix | Fix issues where XCM tokens fail to appear in global and per-network searches, improving asset discoverability. | 1h | - | 2h | 2h | - |
| 25 | XCM Instruction Execution Optimization | Optimize execution flow for xcm Instruction calls that trigger extrinsic calls on the destination chain. | 1h | - | 3h | 1h | - |
| 26 | polkadotXcm ProcessXcmError Support | Fully support parsing and displaying ProcessXcmError from polkadotXcm to improve observability during cross-chain routing failures. | 1h | - | 4h | - | - |
| 27 | s2e_transfer Chart Load Optimization | Optimize backend aggregation and frontend rendering for cm_s2e transfer charts to significantly reduce initial and refresh load times. | 1h | - | 1h | 3h | - |
| 28 | Average Block Time Chart Fix | Fix average block time charts affected by abnormal or missing samples to restore accurate performance indicators. | 1h | - | 3h | 2h | - |
| 29 | refTime Performance Chart Support | Add and optimize refTime performance charts for relevant networks to monitor resource usage and execution efficiency. | 1h | 1h | 10h | 2h | - |
| 30 | Block List Statistics Dashboard | Add a high-performance statistics dashboard to block lists, providing a cross-network overview of block production patterns and chain activity. | 1h | 1h | 3h | 3h | - |
| 31 | Failed Extrinsic Error Type Parsing Enhancement | Add standardized error type parsing and display for failed extrinsics to improve troubleshooting for developers and users. | 1h | - | 2h | 1h | - |
| 32 | Historical ParaID Mapping Fix | Rebuild mapping between historical and current ParaIDs to ensure continuity of parachain timelines across upgrades and slot changes. | 1h | - | 3h | - | - |
| 33 | Snapshot Data Audit & Repair | Systematically audit and repair account and token snapshot data across multiple networks, addressing missing, outdated, or incorrect snapshots to restore reliable historical asset views. | 1h | - | 5h | - | 1h |
| 34 | Asset Precision & Missing Balance Fix | Fix missing asset precision or balance data caused by parsing issues or outdated metadata to ensure correct asset value calculations and display. | 1h | - | 2h | - | - |
| 35 | Polkadot/Kusama Account & Holder Count Recovery | Restore missing holder and total account count data for Polkadot and Kusama from 2025/04/04–04/08, recovering critical historical metrics. | 1h | - | 3h | - | - |
| 36 | Trace Full-Load Research & Optimization | Research and optimize full-load and pagination strategies for large-scale Trace lists to maintain stable querying and rendering performance. | 2h | - | 7h | 3h | - |
| 37 | Large Event Block Handling Strategy | Design and implement an extensible handling pipeline for blocks containing over 100,000 events to ensure stable indexing and querying under extreme load. | 1h | - | 4h | 2h | 1h |
| 38 | Pagination Guidance & UI/UX Enhancements | Standardize pagination tips and visual guidance to reduce friction in large-data lists and improve usability. | 1.5h | 1.5h | - | 4h | - |
| 39 | Metadata API Filter Performance Optimization | Optimize filter implementations for metadata-related APIs to reduce response latency under complex module combination queries. | 1h | - | 1h | 1h | - |
| 40 | Large Extrinsic Parameter Handling | Optimize parsing and rendering logic for extrinsics with extremely large parameters to prevent UI freezes and improve readability. | 1h | - | 2h | 4h | - |
| 41 | Large Next.js Page Processing Optimization | Adjust server-side rendering and slicing strategies for pages exceeding 128 KB to prevent rendering failures or content truncation. | 1h | 1h | - | 4h | - |
| 42 | Block Sync Memory Usage Optimization | Reduce memory usage during block synchronization to improve stability for large networks like Polkadot during long-running sync processes. | 1h | - | 4h | - | - |
| 43 | External Proposals Support | Fully support external proposals in governance pages, enabling users to trace external origins of referenda. | 1h | - | 3h | 2h | - |
| 44 | Portfolio Animation Regression Fix | Fix animation regression issues in the Portfolio module to restore interaction experience. | 0.5h | - | - | 1h | - |
| 45 | Mobile UI Optimization for Data Dashboards | Optimize layout and loading strategy of data dashboards on mobile devices to avoid rendering lag and layout issues. | 1h | 2h | - | 4h | - |
| 46 | Account Token “View All” Pagination / Sorting / Stats | Implement pagination, sorting, and total statistics for the Account Token “View All” list to improve usability for large/token-rich accounts. | 1h | 0.5h | 3h | 5h | - |
Our Compensation Rates and Total Costs:
With a total of 359 hours worked, the calculated cost based on the above rates amounts to $26,530.
In the Q4, Subscan focused on comprehensive optimization and improvement of the Polkadot ecosystem, having already completed the basic development work for the AssetHub migration in the Q3. This phase transitioned from foundational infrastructure setup to deep compatibility adaptation, ensuring that critical modules—including Staking, Governance, and Vesting—remained fully auditable and accessible across the migration boundary.
Key technical achievements included the delivery of historical data backfilling to bridge migration gaps, the implementation of cross-chain validator linking to maintain traceability between AssetHub and the Relay Chain, and the hardening of runtime upgrade monitoring for the entire system parachain suite. In parallel, Subscan executed a major UX/UI overhaul, refactoring core explorers pages (Account, Block, and Dashboard) and aligning the visual identity with the latest Polkadot brand refresh. This dual focus on data integrity and user experience ensures a seamless transition for the community while providing the high-fidelity analytical tools required for the "Asynchronous Backing" era.
Q4 Summary of Work (Highlights)：
| Task | Name | Description | PM/Test | Designer | Backend | Front-end | DevOps |
| 1 | Polkadot AssetHub Migration — Staking Compatibility | Achieve full staking compatibility after migration: align APIs, adjust indexing pipelines, and validate UI behaviors to ensure the staking page remains continuously available and auditable. | 2h | – | 5h | 3h | 2h |
| 2 | Polkadot AssetHub Migration — Staking Backfill + User Guidance | Deliver staking historical backfill and migration guidance: fill historical gaps at migration boundaries, and add user-friendly notices (e.g., “Migration Completed / Historical Boundary”) to reduce misunderstanding. | 3h | 1h | 10h | 6h | 3h |
| 3 | Polkadot AssetHub Migration — Vesting Compatibility | Complete vesting module compatibility: fix schedule/event/state indexing and display to ensure vesting data remains queryable and verifiable after migration. | 1.5h | – | 4h | 2h | 1.5h |
| 4 | Polkadot AssetHub Migration — Governance Compatibility | Ensure governance features remain usable after migration: support referenda/bounty decoding, cross-module linking, and governance page compatibility adaptations. | 2h | – | 6h | 4h | 2h |
| 5 | Polkadot AssetHub Migration — Governance Historical Repair | Merge governance historical repairs with navigation hints: fix referenda/bounty timelines and event association consistency, and add migration guidance / redirection hints to keep audit trails clear. | 3h | 1h | 10h | 6h | 3h |
| 6 | Polkadot Relaychain Staking — Remove “Staking” Slice | Update the relaychain homepage token distribution chart by removing the staking slice, avoiding misleading structure changes after migration. | 0.5h | 0.5h | 1h | 2h | – |
| 7 | Polkadot Relaychain Staking — Inflation Rate Entry | Improve the inflation rate display logic: hide it when the data is no longer maintained or may be misleading, ensuring metric credibility. | 0.5h | – | 1h | 2h | – |
| 8 | Polkadot Relaychain Staking — Dashboard Logic Optimization | Add a dashboard hiding strategy and a “Stopped Updating” notice to prevent users from misinterpreting historical data as real-time. | 1h | 0.5h | 1h | 4h | – |
| 9 | Validator Page Optimization — Block Producer Display | Optimize validator block production display and navigation: link AssetHub validators with relaychain block producers to improve ownership consistency and traceability. | 1h | – | 4h | 3h | – |
| 10 | Validator Page Optimization — Progress Bar Improvements | Fix epoch/era progress calculation and display consistency to reduce UI discrepancies and false alerts on staking/validator pages. | 1h | – | 2h | 2h | – |
| 11 | Runtime Upgrade Monitoring & Alert Hardening | Strengthened runtime upgrade monitoring and alerting workflows for Polkadot relaychain & public parachains to ensure timely compatibility patching. | 1.5h | – | 4h | – | 4h |
| 12 | AssetHub Migration — Reusable Backend/Frontend Checklist | Produced a structured migration change summary and reusable checklist (indexing + UX validation), enabling safer future migrations. | 2h | – | 3h | 2h | 1h |
| 13 | AssetHub Migration — Data Collision Risk Assessment | Investigated low-probability data collision risks between relaychain index ranges and AssetHub datasets, and implemented safeguards to prevent data corruption. | 1.5h | – | 5h | – | 2h |
| 14 | Relaychain → AssetHub Redirects & Migration Notes Fix | Corrected navigation links so relaychain staking/governance entry points consistently direct users to AssetHub pages after migration. | 1h | – | 1h | 4h | – |
| 15 | Multi-Spend Referenda Timeline Support | Enhanced referenda timeline rendering to support one referendum distributing to multiple recipients, improving treasury distribution clarity. | 1.5h | – | 4h | 4h | – |
| 16 | Extrinsic/Event Alert Parameter Cloning | Added one-click cloning for alert parameters, enabling faster reuse of monitoring rules and improving operational efficiency. | 1h | – | 1h | 3h | – |
| 17 | Polkadot API Latency Profiling & Optimization | Profiled and optimized Polkadot-family high-traffic endpoints to improve explorer responsiveness under peak request volume. | 1h | – | 8h | 2h | 2h |
| 18 | System Parachain Indexer Resilience Improvements | Improved indexer recovery and retry mechanisms for system parachains to mitigate transient decode failures during runtime upgrades. | 1h | – | 7h | 2h | 2h |
| 19 | Governance Timeline Rendering Optimization | Reduced governance timeline query overhead and improved rendering performance for long governance histories. | 1h | – | 5h | 3h | 1h |
| 20 | XCM Transfer Filtering Improvement | Added relaychain dimension support to XCM transfer/message filtering, improving investigative workflows. | 1h | – | 4h | 3h | – |
| 21 | XCM Export — Multi-Asset Value Display | Enhanced XCM export output so “value” includes explicit multi-asset breakdowns (e.g., 100 DOT + 1 DED), improving accuracy. | 1h | – | 3h | 3h | – |
| 22 | Transfers Tab — Add Currencies Tracking | Added currencies tracking to transfers view to support multi-asset accounting and improve token-level discoverability. | 1h | – | 4h | 4h | – |
| 23 | Treasury UI — Missing Menu Entry Fix | Fixed missing governance/treasury menu entries that blocked correct navigation across Polkadot-family networks. | 0.5h | – | 1h | 2h | – |
| 24 | Governance — “Completed Referenda” Status Filter | Implemented status filtering for completed referenda lists, enabling more efficient governance review and analysis workflows. | 1h | 0.5h | 2h | 3h | – |
| 25 | Governance Tooltips — Terminology + Clarity | Added governance tooltips covering key terminology and calculation logic to improve transparency and user comprehension. | 1h | 1h | 2h | 4h | – |
| 26 | AssetHub Migration History Review & Summarization | Reviewed and summarized AssetHub migration changes to consolidate a reusable playbook for future compatibility upgrades. | 2h | – | 3h | 1h | – |
| 27 | Proxy Data Verification (AssetHub / Polkadot Family) | Verified proxy-related data consistency and repaired mismatched indexing cases to ensure reliable proxy status visibility. | 1h | – | 4h | 2h | – |
| 28 | Snapshot Script Optimization (Nomination Pool) | Optimized nomination pool RPC snapshot scripts to reduce runtime and node load while improving reliability. | 1h | – | 4h | – | 3h |
| 29 | Event Detail Deep-Link by Timeline Event ID | Enabled deep linking from governance/timeline event IDs to event detail pages, improving investigation speed and traceability. | 0.5h | – | 2h | 3h | – |
| 30 | Average Block Time Precision Improvement | Increased average block time metric precision to three decimals to improve analytical quality for performance monitoring. | 0.5h | – | 1h | 2h | – |
| 31 | Error Description Completion (Global) | Filled missing error descriptions and unified error UX surfaces to improve debugging clarity and consistency. | 1h | – | 2h | 4h | – |
| 32 | Block Utilization Metric Display | Added block utilization metrics to block detail pages to surface throughput/congestion conditions. | 1h | – | 4h | 3h | – |
| 33 | Hover Tooltip Show/Hide Logic Optimization | Improved tooltip display timing and interaction handling to reduce flicker across high-frequency UI components. | 1h | – | 1h | 3h | – |
| 34 | Navigation Restructure & Cleanup | Restructured navigation layout and removed deprecated entries to improve information architecture. | 1h | 1h | 1h | 4h | – |
| 35 | Notification Entry Multi-Action Integration | Integrated notification entry points into core explorer workflows, improving feature discoverability. | 1h | 1h | 1h | 2h | – |
| 36 | Runtime Upgrade Compatibility (End-to-end) | Delivered end-to-end runtime upgrade validation and compatibility coverage for Polkadot and system parachains (AssetHub, BridgeHub, People, Coretime, Collectives), ensuring stable indexing/decoding across the ecosystem. Coverage included: Polkadot (1007001 / 2000000 / 2000001); AssetHub (2000000 / 2000001 / 2000003); BridgeHub (1007001 / 2000000 / 2000003); People (1007001 / 2000000); Coretime (1007001 / 2000000); Collectives (1007001 / 2000000). | 6h | – | 20h | – | 8h |
| 37 | UX Upgrade — Navigation Bar Optimization | Refactored the navigation bar based on UX bounty review, fixing overlong menus and unclear categorization. | 1.5h | 8h | – | 12h | – |
| 38 | UI Branding — Polkadot Brand Banner Update | Updated relaychain and public parachain banner designs to align with the latest Polkadot black-dominant brand identity. | 0.5h | 6h | – | 3h | – |
| 39 | Dark Mode Global Optimization | Delivered global dark mode improvements with dedicated tuning for the Polkadot black-based theme to ensure visual quality. | 1h | 6h | 1h | 8h | – |
| 40 | Homepage Dashboard UX Upgrade | Rebuilt and polished the homepage dashboard UX to improve usability and reduce legacy layout issues. | 2h | 8h | 2h | 15h | – |
| 41 | Block List/Detail Pages UX Upgrade | Upgraded block list and detail pages with improved layout and interaction quality, addressing legacy UX debt. | 2h | 6h | 2h | 12h | – |
| 42 | Account List/Detail Pages UX Upgrade | Upgraded account pages with improved identity and balance presentation, enhancing clarity and audit-friendliness. | 2h | 8h | 2h | 15h | – |
Our Compensation Rates and Total Costs:
With a total of 487 hours worked, the calculated cost based on the above rates amounts to $35,987
Polkadot Relay Chain currently exceeds 4 TB of indexed data. This is primarily the result of long-term historical accumulation and the high density of chain activity. The key technical factors driving the large storage footprint include:
1. Long network lifespan and full historical retention
Polkadot is one of the earliest and longest-running networks in the Polkadot ecosystem.
Its extended operational history results in a significantly larger volume of blocks, extrinsics, events, and state transitions.
Subscan preserves complete historical data without pruning, ensuring full auditability and long-term access for developers, explorers, governance tools, and research.
2. Increasing data complexity over time
As runtime modules, governance logic, asset operations, and state transition models have evolved, the structure and richness of on-chain events have grown substantially.
This results in more complex data schemas and heavier indexing requirements for historical blocks.
3. High density of XCM-related activity
Polkadot carries some of the most experimental and active XCM traffic in the entire ecosystem.
The large number of cross-chain messages and event records generates:
This XCM-heavy traffic is a major contributor to the relay chain’s significantly larger storage footprint compared to individual parachains.
(Already operational on testnet and gradually rolling out across the Polkadot and Polkadot ecosystems, with quantifiable cost-reduction results to be reflected in billing beginning Q1 2026.)
To mitigate long-term storage growth and reduce operational costs—particularly for the Polkadot relay chain—we are executing several structural optimization initiatives. These include efforts to reduce reliance on GCP and lower total cost of ownership.
We are segmenting frequently accessed data into high-performance storage tiers while moving older blocks and events into cost-efficient archival layers.
This significantly reduces the cost of maintaining multi-terabyte historical datasets.
Given that XCM events represent a major portion of Polkadot’s data weight, we are optimizing:
These adjustments reduce long-term index growth without affecting query accuracy.
To optimize long-term infrastructure costs, we are:
These changes directly address one of the largest cost drivers in the current operational model.
Subscan’s goal is to deliver high-quality infrastructure services with stable performance, predictable budgeting, and cost-efficient pricing, while also offering additional discounts for prepaid commitments.
As our ongoing optimization continues, Subscan expects to introduce more favorable and more predictable pricing in Q1 2026, including:
BASIC PLAN
ADVANCED PLAN
CUSTOM PLAN
2026 Estimated Annual Cost (Updated Pricing + Testnet Annual Discount)
| Network / Service | Plan | Monthly Fee (USD) | Annual Billing Discount | Annual Fee (USD) |
| Polkadot | Custom | 10,000 | 10% | 108,000 |
| Polkadot Trace Service (Optional) | Custom | 4,000 | 10% | 43,200 |
| AssetHub (Polkadot) | Advanced (Up to 1 TB/month) | 1,699 | 10% | 18,349.2 |
| AssetHub (Polkadot) Trace Service (Optional)（This is a new feature and has not yet been officially implemented.） | Custom | 2,000 | 10% | 21,600 |
| Coretime (Polkadot) | Basic (Up to 500 GB/month) | 799 | 10% | 8,629.2 |
| Collectives (Polkadot) | Basic (Up to 500 GB/month) | 799 | 10% | 8,629.2 |
| BridgeHub (Polkadot) | Basic (Up to 500 GB/month) | 799 | 10% | 8,629.2 |
| People (Polkadot) | Basic (Up to 500 GB/month) | 799 | 10% | 8,629.2 |
Based on the current scope and configuration, the estimated Total Annual Fee (USD) for 2026 is: 225,666.
Please note that this amount is provided for 2026 cost forecasting purposes only, and is intended to support an evaluation of the long-term sustainability of the service. We welcome further discussion on the most suitable payment structure and scope adjustments, including:
Subscan will prepare the 2026 service proposal based on the community’s feedback and preferred direction.
The total requested amount for all 6 networks, including all maintenance, operational overhead, and mandatory compatibility work, is USD 202,416.
Conclusion
Subscan remains a foundational pillar of the Polkadot ecosystem—providing the high-fidelity block indexing, XCM observability, and governance transparency required by developers, auditors, and millions of users worldwide.
The 2025 development cycle marked a period of intense technical transformation for Polkadot. By ensuring seamless compatibility through the AssetHub migration and multiple breaking runtime upgrades, Subscan has preserved the continuity of the historical record and the stability of downstream applications.
Our Commitment to the Ecosystem We recognize the current challenges facing the broader market and the Polkadot ecosystem. While Subscan’s operational costs are already highly competitive, we are committed to standing with the community during these demanding times through two key initiatives:
We remain dedicated to:
We appreciate the Treasury’s continued trust and support. We will continue to evolve alongside Polkadot, providing a high-performance, cost-efficient, and transparent data layer for the entire communi
Subscan Funding Request Summary
Due to potential display issues with some charts in format across various devices and platforms, please refer to the detailed information in this Google Document:
https://docs.google.com/document/d/1DKX62a9LtAWd7CF7oBTUQe0rZ23xcwnnrs1fj_14JlQ/edit?usp=sharing
https://polkadot.polkassembly.io/post/3390
Based on this discussion version, this proposal corrects some typos. For the development costs, Subscan will self-fund 30% and request 70%. Additionally, responses to community feedback will be added in the comments section.
Subscan requests funding from the Polkadot Treasury to ensure the continued operation and enhancement of one of Polkadot’s most critical public data infrastructures. As the default block explorer and primary indexing backend for the Polkadot ecosystem, Subscan provides high-availability, low-latency, and fully historical on-chain data for the Polkadot Relay Chain and all Polkadot system parachains. These services are relied upon daily by developers, validators, wallets, governance platforms, infrastructure providers, auditors, and millions of unique users per year.
This proposal covers Subscan’s work across two key areas:
Ensuring uninterrupted operational maintenance for the six Polkadot system networks:
These services include full database indexing, runtime compatibility, node operations, 24/7 monitoring, bandwidth provisioning, storage scaling, DevOps automation, and end-user/API support—ensuring continuous data availability across the entire Polkadot ecosystem.
Requested: USD 151,200
Compensation for major ecosystem-critical work already completed, including:
Total: USD 73,167
Subscan Team Contribution: To support the sustainable growth of the ecosystem, the Subscan Team is self-funding 30% of these development costs.
Requested: USD 51,216
Total requested amount: USD 202,416
From Q2 2025 to Q4 2025, Subscan completed extensive development and infrastructure work that directly supports Polkadot’s transition into the next-generation ecosystem architecture—particularly the AssetHub migration, which has been one of the most significant structural changes to the Polkadot network in recent years.
Subscan’s work during this period can be summarized in the following core areas:
AssetHub underwent multiple breaking updates, including changes to assets, extrinsics, metadata layouts, governance modules, and transfer logic. Subscan delivered complete compatibility support, including:
These contributions ensured that wallets, explorers, governance dashboards, and integration tools remained fully functional throughout the AssetHub migration, preventing ecosystem disruption.
Major foundational improvements included:
These enhancements strengthened chain-wide data accuracy and reduced the risk of indexer stalls during runtime upgrades or heavy XCM traffic.
Given Polkadot’s XCM-heavy activity, Subscan delivered system-wide improvements:
Combined, these improvements make Subscan the most complete and accurate public XCM observability layer in the ecosystem.
Subscan improved auditability and cross-module visibility by:
This has become critical infrastructure for OpenGov data, treasury analysts, and governance dashboards.
Key UX improvements include:
These ensure Subscan remains responsive even under multi-network heavy traffic conditions.
Continuous operations included:
These ongoing services are fundamental to maintaining reliable explorer and API availability for the entire Polkadot ecosystem.
As the default block explorer and indexing layer for Polkadot, Subscan provides the foundational data required by nearly all ecosystem participants.
Without Subscan, many essential tools would face significant data degradation, and the accessibility of historical and governance data would be severely impacted.
This proposal covers two major funding components:
Operational maintenance for 6 Polkadot networks:
These fees cover database storage, indexing, monitoring, bandwidth, DevOps, node maintenance, and end-user support.
Compensation for:
Together, these represent essential public infrastructure development that ensures Subscan remains aligned with Polkadot’s technical evolution.
Throughout 2025, Subscan has focused on deep infrastructure optimization. By refining our technical stack, we have successfully reduced internal overhead and operational costs without compromising the high service standards the ecosystem expects. Our goal is to pass these efficiencies directly to the networks we support through a more competitive pricing structure.
To ensure a stable transition, we are rolling out these optimizations and subsequent price reductions in stages:
Note: For a detailed breakdown of how these infrastructure improvements will impact future budgets, please refer to the "2026 Cost Outlook (Infrastructure Optimization Based)" section.
For the period of 2025 Q3–Q4, Subscan’s fee structure remains consistent with the model successfully utilized over the past two years.
Our maintenance packages are designed to support a wide range of data and operational needs, ensuring stable and efficient system performance. Because our overall cost structure is composed of multiple infrastructure and operational expenses—such as cloud services, network acceleration, monitoring systems, node providers, and the Subscan team’s ongoing operations—we use storage consumption as the primary metric for determining service fees.
Pricing Tiers:
a. Basic Plan
b. Advanced Plan
c. Professional Plan
Correlation to Real Costs:
Storage growth scales directly with block production and transaction activity, making it a more stable and predictable metric than raw API traffic. As chain activity evolves, storage becomes the clearest and most consistent indicator of the underlying infrastructure load required to maintain long-term historical data.
Subscan Baseline:
Subscan determines the appropriate fee tier based on the median storage consumption measured during the billing period. For example, for the Q3–Q4 2025 billing cycle, the baseline storage usage is derived from data recorded on September 30th.
Predictable Billing:
Basing fees on storage reduces the volatility caused by sudden traffic spikes and ensures a more transparent, usage-based cost model for both the community and the treasury.
Our pricing also incorporates the broader operational overhead required to run a production-grade, high-availability data service—such as cloud infrastructure, network acceleration, monitoring systems, node providers, and Subscan’s ongoing engineering and support efforts.
Because these components fluctuate dynamically based on cloud regions, traffic patterns, redundancy requirements, and security considerations, they cannot be broken down into a stable or meaningful line-item list. In addition, some of these details involve sensitive architectural and security-related information that should not be fully disclosed publicly in order to preserve system robustness and reduce attack surface.
For these reasons, Subscan adopts a service-fee-based pricing model, which is consistent with industry practices used by major explorer and indexing providers. Pegging the service fee to storage usage strikes the right balance between:
This model also enables Subscan to invest continuously in optimization and long-term cost reduction—ensuring that infrastructure improvements directly translate into better performance and lower overall fees for the ecosystem over time.
| Network | Actual Usage/GB | Date | Package | Fees/Month | Billing Period | Fees |
| Polkadot | 4305.22 | 30/09/2025 | Professional | 19,405 | Q3 & Q4: 01/07/2025-31/12/2025 | 116,430 |
| AssetHub-Polkadot | 382.63 | 30/09/2025 | Basic+ | 1,699 | Q3 & Q4: 01/07/2025-31/12/2025 | 10,194 |
| Coretime-Polkadot | 40.73 | 30/09/2025 | Basic | 799 | Q3 & Q4: 01/07/2025-31/12/2025 | 4,794 |
| Collectives-Polkadot | 161.7 | 30/09/2025 | Basic | 799 | Q3 & Q4: 01/07/2025-31/12/2025 | 4,794 |
| BridgeHub-Polkadot | 448.78 | 30/09/2025 | Advanced | 1,699 | Q3 & Q4: 01/07/2025-31/12/2025 | 10,194 |
| People-Polkadot | 37.84 | 30/09/2025 | Basic | 799 | Q3 & Q4: 01/07/2025-31/12/2025 | 4,794 |
During Q2 2025, Subscan completed a comprehensive series of platform enhancements focused on network-wide reliability, data accuracy, performance optimization, and user experience improvements across the Polkadot ecosystem.
These efforts strengthened Subscan’s role as a core public infrastructure component used daily by developers, validators, nominators, governance participants, and parachain teams.
Key areas of contribution include:
Below is the complete task list for Q2 2025：
| Task | Name | Description | PM/Test | Designer | Backend | Front-end | DevOps |
| 1 | ES Sync Checkpoint Persistence | Persist checkpoints for Elasticsearch sync tasks to significantly improve multi-network data synchronization stability and recovery robustness. | 1h | – | 4h | – | – |
| 2 | Portfolio Multi-Network Display Fix | Fix inconsistency between network counts shown on the Portfolio overview and detail pages, improving accuracy for cross-chain asset visualization. | 1h | – | 4h | 3h | – |
| 3 | Treasury Proposal Amount Display Optimization | Add support for USDT/USDC denomination and auto-conversion in the Treasury module to improve transparency and readability in governance workflows. | 1h | 1h | – | 4h | – |
| 4 | Portfolio Identity Display Optimization | Optimize cross-chain Identity loading logic to ensure consistent identity rendering across networks. | 1h | – | 10h | 3h | – |
| 5 | Accounts Pagination Optimization | Improve account pagination performance for large networks, enhancing response time and stability under high-concurrency access. | 1h | – | 8h | 3h | – |
| 6 | Portfolio Value Display Bug Fix | Fix incorrect asset value calculations in the Portfolio module to improve accuracy of user asset statistics. | 1h | – | 5h | 2h | – |
| 7 | User Feedback Collection & Processing | Add a unified “Feedback Entry” on the UI to centralize user feedback collection and complete a batch of UX improvement iterations. | 4h | 1.5h | – | 3h | – |
| 8 | Homepage Chart Default Range Standardization | Standardize default ranges (e.g., price/volume charts) on the homepage to “1 month” for improved readability and user experience consistency. | 1h | – | – | 2h | – |
| 9 | Token List Entry Optimization | Improve navigation and entry points to the Token List, enabling quicker access to token detail pages. | 1h | 0.5h | – | 3h | – |
| 10 | Identity Report Bio Field Addition (Admin Platform) | Add a Bio field to identity reports in the admin panel to enhance completeness of on-chain identity management. | 1h | – | 1h | 2h | – |
| 11 | Batch Data Download Script | Develop a script for bulk data export to support large-scale analytics needs and reduce manual operations. | 1h | 1h | 5h | 4h | – |
| 12 | IPFS Provider Migration | Migrate document/image resources to a more stable IPFS provider to improve loading performance and success rate. | – | – | 1h | – | 2h |
| 13 | Monitoring System Optimization | Redesign Subscan’s backend monitoring architecture to improve real-time alerting for on-chain events, data sync, and error detection. | – | – | 8h | – | 4h |
| 14 | StorageChanged Data Consistency Fix | Fix data inconsistency related to on-chain StorageChanged events to improve accuracy of historical data. | 1h | – | 2h | – | – |
| 15 | Dark Mode UI Enhancement | Fix contrast issues in dark mode for text and charts to improve readability and overall UX. | 1h | 3h | – | 5h | – |
| 16 | Identity Privacy Mode Fix | Fix issues where the Identity privacy toggle does not take effect, ensuring correct privacy protection across networks. | 1h | – | – | 3h | – |
| 17 | Profile Privacy Display Fix | Fix issues where avatars and social information are still visible in privacy mode, enhancing personal data protection. | 1h | – | 2h | 3h | – |
| 18 | Cookie Prompt Optimization | Significantly reduce intrusive mobile cookie pop-ups to improve browsing experience. | 1h | 1h | – | 2h | – |
| 19 | SS58 Format Conversion Tool Review | Review and fix issues in the SS58 encode/decode tool to improve cross-chain address compatibility and accuracy. | 1h | – | 1h | 2h | – |
| 20 | API Performance Optimization & Slow Endpoint Investigation | Investigate performance issues, indexing, and caching improvements for high-frequency APIs (e.g., unique_id, multiChain, reward_slash, staking_history), significantly improving platform response speed. | 2h | – | 10h | – | 3h |
Our Compensation Rates and Total Costs:
With a total of 144 hours worked, the calculated cost based on the above rates amounts to $10,650.
During Q3 2025, Subscan continued its role as a core piece of Substrate ecosystem public infrastructure, focusing on strengthening data correctness, cross-chain observability, governance transparency, and runtime upgrade compatibility for Polkadot and its ecosystem parachains. The work in this period concentrated on hardening the production explorer that is used daily by validators, nominators, governance participants, infrastructure providers, and application teams.
Across all categories, this Q3 scope represents 46 concrete engineering tasks, covering:
Below is the complete task list for Q3 2025：
| Task | Name | Description | PM/Test | Designer | Backend | Front-end | DevOps |
| 1 | [AH Migration] Staking Module Support | Handle extensive changes caused by staking module migration between the Relay Chain and AssetHub (AH), including new data indexing, updated era calculation logic, and validator block production association back to the Relay Chain. | 2h | 2h | 4h | 4h | - |
| 2 | [AH Migration] Vesting Module Support | Handle migration-driven changes related to vesting on the Relay Chain and AssetHub, including new data indexes and chart visualization updates. | 1h | 1h | 1h | 2h | - |
| 3 | [AH Migration] Governance Module Support | Handle governance-related changes during migration, such as indexing AH referendum data, synchronizing records, and completing metadata fields (CreatedAtBlock) to ensure full lifecycle integrity. | 2h | 1h | 4h | 4h | - |
| 4 | [AH Migration] Account & Balance Support | Handle account balance–related migration between Relay Chain and AH, including balance sync, calibration checks, and basic multi-asset tracking setup. | 2h | 2h | 1h | 5h | - |
| 5 | Runtime Upgrade Monitoring & Notification Script | Add runtime version change monitoring and notification scripts, enabling the team to react quickly to upgrades and reduce ecosystem downtime risk. | 1h | - | 3h | - | 3h |
| 6 | Polkadot Ecosystem Runtime Upgrade Compatibility | Complete runtime upgrade compatibility and validation across Polkadot mainnet and its system parachains (AssetHub, BridgeHub, People, Coretime, Collectives) for multiple Q3 upgrades. • Polkadot Upgrade: 1006001 / 1006002 • AssetHub-Polkadot: 1006000 • BridgeHub-Polkadot: 1006001 • People-Polkadot: 1006001 • Coretime-Polkadot: 1006001 • Collectives-Polkadot: 1006001 | 3h | - | 8h | - | 2h |
| 7 | Event Date Misalignment Fix | Fix incorrect or misaligned date/time fields across event records in multiple networks to ensure historical event timelines are accurate. | 1h | - | - | - | - |
| 8 | Event ↔ Extrinsic Bidirectional Navigation Fix | Fix navigation issues between event detail pages and corresponding extrinsic detail pages to restore reliable bidirectional linking. | 1h | - | 1h | 3h | - |
| 9 | Event Search Feedback Logic Fix | Improve event search feedback logic under edge cases and invalid inputs to enhance usability. | 1h | 1h | 2h | 2h | - |
| 10 | Child Bounty Statistics & Overview | Add Child Bounty counts and aggregated overview in bounty-related lists to help governance participants assess fund distribution structures. | 1.5h | 1.5h | 4h | 3h | - |
| 11 | Child Bounty Distribution & Claim Status Display | Implement detailed tracking and visualization of Child Bounty distribution and claim events for improved transparency of governance fund flows. | 1h | 1h | 4h | 4h | - |
| 12 | Multi-Entity Governance Timeline Enhancement | Enhance referendum timelines to interlink Treasury, Preimage, XCM and other module events within a unified view. | 1h | 0.5h | 4h | 2h | - |
| 13 | Referendum ↔ Treasury Spend Mapping Fix | Fix incorrect or missing mappings between referenda and Treasury Spends across multiple cases to ensure consistency and auditability of governance data. | 1.5h | - | 4h | 3h | - |
| 14 | Democracy Unlock Block Calculation Optimization | Optimize unlock block calculation logic for Democracy referenda, ensuring correct unlock height display across all supported networks. | 1h | - | 2h | 2h | - |
| 15 | Remove Unsupported Gov V1 Entry Points | Identify networks like Polkadot that no longer support Gov V1 and remove related UI entry points to avoid user confusion. | 0.5h | - | - | 1h | - |
| 16 | Preimage Status Change Timeline | Add a status-change timeline for the Preimage lifecycle to improve traceability from submission to execution. | 1h | 0.5h | 3h | 2h | - |
| 17 | Treasury Spend Cycle Display | Add cycle and period information to Treasury Spend items to help users understand spending cadence. | 1h | - | 2h | 2h | - |
| 18 | ConvictionVoting poll_index Link Support | Add navigation links for poll_index in ConvictionVoting items to directly open corresponding Subscan pages. | 1h | - | 2h | 2h | - |
| 19 | XCM Asset Flow Upgrade | Add filtering and upgrade outdated XCM wheel visualizations to the new “XCM Asset Flow Chart” across multiple pages to significantly improve readability and UX. | 1h | 2h | 2h | 4h | - |
| 20 | XCM Asset Flow Dashboard Load Optimization | Optimize data fetching and batch loading for XCM Asset Flow dashboards to reduce latency and jitter in multi-network scenarios. | 1h | - | 3h | 4h | - |
| 21 | XCM Execute Event Completion & Support | Complete missing XCM execute events across multiple parachains and unify processing logic to improve execution log integrity. | 1.5h | - | 8h | - | - |
| 22 | XCM Process Navigation & Linking Fix | Fix multiple navigation issues in the XCM Process view (links to event details, extrinsics, etc.) to ensure end-to-end cross-chain traceability. | 2h | - | 2h | 5h | - |
| 23 | XCM Data Dashboard Enhancement | Expand XCM data charts and optimize refresh/aggregation logic to support multi-network cross-chain traffic analytics. | 1h | 1h | 3h | 2h | - |
| 24 | XCM Token Search Result Fix | Fix issues where XCM tokens fail to appear in global and per-network searches, improving asset discoverability. | 1h | - | 2h | 2h | - |
| 25 | XCM Instruction Execution Optimization | Optimize execution flow for xcm Instruction calls that trigger extrinsic calls on the destination chain. | 1h | - | 3h | 1h | - |
| 26 | polkadotXcm ProcessXcmError Support | Fully support parsing and displaying ProcessXcmError from polkadotXcm to improve observability during cross-chain routing failures. | 1h | - | 4h | - | - |
| 27 | s2e_transfer Chart Load Optimization | Optimize backend aggregation and frontend rendering for cm_s2e transfer charts to significantly reduce initial and refresh load times. | 1h | - | 1h | 3h | - |
| 28 | Average Block Time Chart Fix | Fix average block time charts affected by abnormal or missing samples to restore accurate performance indicators. | 1h | - | 3h | 2h | - |
| 29 | refTime Performance Chart Support | Add and optimize refTime performance charts for relevant networks to monitor resource usage and execution efficiency. | 1h | 1h | 10h | 2h | - |
| 30 | Block List Statistics Dashboard | Add a high-performance statistics dashboard to block lists, providing a cross-network overview of block production patterns and chain activity. | 1h | 1h | 3h | 3h | - |
| 31 | Failed Extrinsic Error Type Parsing Enhancement | Add standardized error type parsing and display for failed extrinsics to improve troubleshooting for developers and users. | 1h | - | 2h | 1h | - |
| 32 | Historical ParaID Mapping Fix | Rebuild mapping between historical and current ParaIDs to ensure continuity of parachain timelines across upgrades and slot changes. | 1h | - | 3h | - | - |
| 33 | Snapshot Data Audit & Repair | Systematically audit and repair account and token snapshot data across multiple networks, addressing missing, outdated, or incorrect snapshots to restore reliable historical asset views. | 1h | - | 5h | - | 1h |
| 34 | Asset Precision & Missing Balance Fix | Fix missing asset precision or balance data caused by parsing issues or outdated metadata to ensure correct asset value calculations and display. | 1h | - | 2h | - | - |
| 35 | Polkadot/Kusama Account & Holder Count Recovery | Restore missing holder and total account count data for Polkadot and Kusama from 2025/04/04–04/08, recovering critical historical metrics. | 1h | - | 3h | - | - |
| 36 | Trace Full-Load Research & Optimization | Research and optimize full-load and pagination strategies for large-scale Trace lists to maintain stable querying and rendering performance. | 2h | - | 7h | 3h | - |
| 37 | Large Event Block Handling Strategy | Design and implement an extensible handling pipeline for blocks containing over 100,000 events to ensure stable indexing and querying under extreme load. | 1h | - | 4h | 2h | 1h |
| 38 | Pagination Guidance & UI/UX Enhancements | Standardize pagination tips and visual guidance to reduce friction in large-data lists and improve usability. | 1.5h | 1.5h | - | 4h | - |
| 39 | Metadata API Filter Performance Optimization | Optimize filter implementations for metadata-related APIs to reduce response latency under complex module combination queries. | 1h | - | 1h | 1h | - |
| 40 | Large Extrinsic Parameter Handling | Optimize parsing and rendering logic for extrinsics with extremely large parameters to prevent UI freezes and improve readability. | 1h | - | 2h | 4h | - |
| 41 | Large Next.js Page Processing Optimization | Adjust server-side rendering and slicing strategies for pages exceeding 128 KB to prevent rendering failures or content truncation. | 1h | 1h | - | 4h | - |
| 42 | Block Sync Memory Usage Optimization | Reduce memory usage during block synchronization to improve stability for large networks like Polkadot during long-running sync processes. | 1h | - | 4h | - | - |
| 43 | External Proposals Support | Fully support external proposals in governance pages, enabling users to trace external origins of referenda. | 1h | - | 3h | 2h | - |
| 44 | Portfolio Animation Regression Fix | Fix animation regression issues in the Portfolio module to restore interaction experience. | 0.5h | - | - | 1h | - |
| 45 | Mobile UI Optimization for Data Dashboards | Optimize layout and loading strategy of data dashboards on mobile devices to avoid rendering lag and layout issues. | 1h | 2h | - | 4h | - |
| 46 | Account Token “View All” Pagination / Sorting / Stats | Implement pagination, sorting, and total statistics for the Account Token “View All” list to improve usability for large/token-rich accounts. | 1h | 0.5h | 3h | 5h | - |
Our Compensation Rates and Total Costs:
With a total of 359 hours worked, the calculated cost based on the above rates amounts to $26,530.
In the Q4, Subscan focused on comprehensive optimization and improvement of the Polkadot ecosystem, having already completed the basic development work for the AssetHub migration in the Q3. This phase transitioned from foundational infrastructure setup to deep compatibility adaptation, ensuring that critical modules—including Staking, Governance, and Vesting—remained fully auditable and accessible across the migration boundary.
Key technical achievements included the delivery of historical data backfilling to bridge migration gaps, the implementation of cross-chain validator linking to maintain traceability between AssetHub and the Relay Chain, and the hardening of runtime upgrade monitoring for the entire system parachain suite. In parallel, Subscan executed a major UX/UI overhaul, refactoring core explorers pages (Account, Block, and Dashboard) and aligning the visual identity with the latest Polkadot brand refresh. This dual focus on data integrity and user experience ensures a seamless transition for the community while providing the high-fidelity analytical tools required for the "Asynchronous Backing" era.
Q4 Summary of Work (Highlights)：
| Task | Name | Description | PM/Test | Designer | Backend | Front-end | DevOps |
| 1 | Polkadot AssetHub Migration — Staking Compatibility | Achieve full staking compatibility after migration: align APIs, adjust indexing pipelines, and validate UI behaviors to ensure the staking page remains continuously available and auditable. | 2h | – | 5h | 3h | 2h |
| 2 | Polkadot AssetHub Migration — Staking Backfill + User Guidance | Deliver staking historical backfill and migration guidance: fill historical gaps at migration boundaries, and add user-friendly notices (e.g., “Migration Completed / Historical Boundary”) to reduce misunderstanding. | 3h | 1h | 10h | 6h | 3h |
| 3 | Polkadot AssetHub Migration — Vesting Compatibility | Complete vesting module compatibility: fix schedule/event/state indexing and display to ensure vesting data remains queryable and verifiable after migration. | 1.5h | – | 4h | 2h | 1.5h |
| 4 | Polkadot AssetHub Migration — Governance Compatibility | Ensure governance features remain usable after migration: support referenda/bounty decoding, cross-module linking, and governance page compatibility adaptations. | 2h | – | 6h | 4h | 2h |
| 5 | Polkadot AssetHub Migration — Governance Historical Repair | Merge governance historical repairs with navigation hints: fix referenda/bounty timelines and event association consistency, and add migration guidance / redirection hints to keep audit trails clear. | 3h | 1h | 10h | 6h | 3h |
| 6 | Polkadot Relaychain Staking — Remove “Staking” Slice | Update the relaychain homepage token distribution chart by removing the staking slice, avoiding misleading structure changes after migration. | 0.5h | 0.5h | 1h | 2h | – |
| 7 | Polkadot Relaychain Staking — Inflation Rate Entry | Improve the inflation rate display logic: hide it when the data is no longer maintained or may be misleading, ensuring metric credibility. | 0.5h | – | 1h | 2h | – |
| 8 | Polkadot Relaychain Staking — Dashboard Logic Optimization | Add a dashboard hiding strategy and a “Stopped Updating” notice to prevent users from misinterpreting historical data as real-time. | 1h | 0.5h | 1h | 4h | – |
| 9 | Validator Page Optimization — Block Producer Display | Optimize validator block production display and navigation: link AssetHub validators with relaychain block producers to improve ownership consistency and traceability. | 1h | – | 4h | 3h | – |
| 10 | Validator Page Optimization — Progress Bar Improvements | Fix epoch/era progress calculation and display consistency to reduce UI discrepancies and false alerts on staking/validator pages. | 1h | – | 2h | 2h | – |
| 11 | Runtime Upgrade Monitoring & Alert Hardening | Strengthened runtime upgrade monitoring and alerting workflows for Polkadot relaychain & public parachains to ensure timely compatibility patching. | 1.5h | – | 4h | – | 4h |
| 12 | AssetHub Migration — Reusable Backend/Frontend Checklist | Produced a structured migration change summary and reusable checklist (indexing + UX validation), enabling safer future migrations. | 2h | – | 3h | 2h | 1h |
| 13 | AssetHub Migration — Data Collision Risk Assessment | Investigated low-probability data collision risks between relaychain index ranges and AssetHub datasets, and implemented safeguards to prevent data corruption. | 1.5h | – | 5h | – | 2h |
| 14 | Relaychain → AssetHub Redirects & Migration Notes Fix | Corrected navigation links so relaychain staking/governance entry points consistently direct users to AssetHub pages after migration. | 1h | – | 1h | 4h | – |
| 15 | Multi-Spend Referenda Timeline Support | Enhanced referenda timeline rendering to support one referendum distributing to multiple recipients, improving treasury distribution clarity. | 1.5h | – | 4h | 4h | – |
| 16 | Extrinsic/Event Alert Parameter Cloning | Added one-click cloning for alert parameters, enabling faster reuse of monitoring rules and improving operational efficiency. | 1h | – | 1h | 3h | – |
| 17 | Polkadot API Latency Profiling & Optimization | Profiled and optimized Polkadot-family high-traffic endpoints to improve explorer responsiveness under peak request volume. | 1h | – | 8h | 2h | 2h |
| 18 | System Parachain Indexer Resilience Improvements | Improved indexer recovery and retry mechanisms for system parachains to mitigate transient decode failures during runtime upgrades. | 1h | – | 7h | 2h | 2h |
| 19 | Governance Timeline Rendering Optimization | Reduced governance timeline query overhead and improved rendering performance for long governance histories. | 1h | – | 5h | 3h | 1h |
| 20 | XCM Transfer Filtering Improvement | Added relaychain dimension support to XCM transfer/message filtering, improving investigative workflows. | 1h | – | 4h | 3h | – |
| 21 | XCM Export — Multi-Asset Value Display | Enhanced XCM export output so “value” includes explicit multi-asset breakdowns (e.g., 100 DOT + 1 DED), improving accuracy. | 1h | – | 3h | 3h | – |
| 22 | Transfers Tab — Add Currencies Tracking | Added currencies tracking to transfers view to support multi-asset accounting and improve token-level discoverability. | 1h | – | 4h | 4h | – |
| 23 | Treasury UI — Missing Menu Entry Fix | Fixed missing governance/treasury menu entries that blocked correct navigation across Polkadot-family networks. | 0.5h | – | 1h | 2h | – |
| 24 | Governance — “Completed Referenda” Status Filter | Implemented status filtering for completed referenda lists, enabling more efficient governance review and analysis workflows. | 1h | 0.5h | 2h | 3h | – |
| 25 | Governance Tooltips — Terminology + Clarity | Added governance tooltips covering key terminology and calculation logic to improve transparency and user comprehension. | 1h | 1h | 2h | 4h | – |
| 26 | AssetHub Migration History Review & Summarization | Reviewed and summarized AssetHub migration changes to consolidate a reusable playbook for future compatibility upgrades. | 2h | – | 3h | 1h | – |
| 27 | Proxy Data Verification (AssetHub / Polkadot Family) | Verified proxy-related data consistency and repaired mismatched indexing cases to ensure reliable proxy status visibility. | 1h | – | 4h | 2h | – |
| 28 | Snapshot Script Optimization (Nomination Pool) | Optimized nomination pool RPC snapshot scripts to reduce runtime and node load while improving reliability. | 1h | – | 4h | – | 3h |
| 29 | Event Detail Deep-Link by Timeline Event ID | Enabled deep linking from governance/timeline event IDs to event detail pages, improving investigation speed and traceability. | 0.5h | – | 2h | 3h | – |
| 30 | Average Block Time Precision Improvement | Increased average block time metric precision to three decimals to improve analytical quality for performance monitoring. | 0.5h | – | 1h | 2h | – |
| 31 | Error Description Completion (Global) | Filled missing error descriptions and unified error UX surfaces to improve debugging clarity and consistency. | 1h | – | 2h | 4h | – |
| 32 | Block Utilization Metric Display | Added block utilization metrics to block detail pages to surface throughput/congestion conditions. | 1h | – | 4h | 3h | – |
| 33 | Hover Tooltip Show/Hide Logic Optimization | Improved tooltip display timing and interaction handling to reduce flicker across high-frequency UI components. | 1h | – | 1h | 3h | – |
| 34 | Navigation Restructure & Cleanup | Restructured navigation layout and removed deprecated entries to improve information architecture. | 1h | 1h | 1h | 4h | – |
| 35 | Notification Entry Multi-Action Integration | Integrated notification entry points into core explorer workflows, improving feature discoverability. | 1h | 1h | 1h | 2h | – |
| 36 | Runtime Upgrade Compatibility (End-to-end) | Delivered end-to-end runtime upgrade validation and compatibility coverage for Polkadot and system parachains (AssetHub, BridgeHub, People, Coretime, Collectives), ensuring stable indexing/decoding across the ecosystem. Coverage included: Polkadot (1007001 / 2000000 / 2000001); AssetHub (2000000 / 2000001 / 2000003); BridgeHub (1007001 / 2000000 / 2000003); People (1007001 / 2000000); Coretime (1007001 / 2000000); Collectives (1007001 / 2000000). | 6h | – | 20h | – | 8h |
| 37 | UX Upgrade — Navigation Bar Optimization | Refactored the navigation bar based on UX bounty review, fixing overlong menus and unclear categorization. | 1.5h | 8h | – | 12h | – |
| 38 | UI Branding — Polkadot Brand Banner Update | Updated relaychain and public parachain banner designs to align with the latest Polkadot black-dominant brand identity. | 0.5h | 6h | – | 3h | – |
| 39 | Dark Mode Global Optimization | Delivered global dark mode improvements with dedicated tuning for the Polkadot black-based theme to ensure visual quality. | 1h | 6h | 1h | 8h | – |
| 40 | Homepage Dashboard UX Upgrade | Rebuilt and polished the homepage dashboard UX to improve usability and reduce legacy layout issues. | 2h | 8h | 2h | 15h | – |
| 41 | Block List/Detail Pages UX Upgrade | Upgraded block list and detail pages with improved layout and interaction quality, addressing legacy UX debt. | 2h | 6h | 2h | 12h | – |
| 42 | Account List/Detail Pages UX Upgrade | Upgraded account pages with improved identity and balance presentation, enhancing clarity and audit-friendliness. | 2h | 8h | 2h | 15h | – |
Our Compensation Rates and Total Costs:
With a total of 487 hours worked, the calculated cost based on the above rates amounts to $35,987
Polkadot Relay Chain currently exceeds 4 TB of indexed data. This is primarily the result of long-term historical accumulation and the high density of chain activity. The key technical factors driving the large storage footprint include:
1. Long network lifespan and full historical retention
Polkadot is one of the earliest and longest-running networks in the Polkadot ecosystem.
Its extended operational history results in a significantly larger volume of blocks, extrinsics, events, and state transitions.
Subscan preserves complete historical data without pruning, ensuring full auditability and long-term access for developers, explorers, governance tools, and research.
2. Increasing data complexity over time
As runtime modules, governance logic, asset operations, and state transition models have evolved, the structure and richness of on-chain events have grown substantially.
This results in more complex data schemas and heavier indexing requirements for historical blocks.
3. High density of XCM-related activity
Polkadot carries some of the most experimental and active XCM traffic in the entire ecosystem.
The large number of cross-chain messages and event records generates:
This XCM-heavy traffic is a major contributor to the relay chain’s significantly larger storage footprint compared to individual parachains.
(Already operational on testnet and gradually rolling out across the Polkadot and Polkadot ecosystems, with quantifiable cost-reduction results to be reflected in billing beginning Q1 2026.)
To mitigate long-term storage growth and reduce operational costs—particularly for the Polkadot relay chain—we are executing several structural optimization initiatives. These include efforts to reduce reliance on GCP and lower total cost of ownership.
We are segmenting frequently accessed data into high-performance storage tiers while moving older blocks and events into cost-efficient archival layers.
This significantly reduces the cost of maintaining multi-terabyte historical datasets.
Given that XCM events represent a major portion of Polkadot’s data weight, we are optimizing:
These adjustments reduce long-term index growth without affecting query accuracy.
To optimize long-term infrastructure costs, we are:
These changes directly address one of the largest cost drivers in the current operational model.
Subscan’s goal is to deliver high-quality infrastructure services with stable performance, predictable budgeting, and cost-efficient pricing, while also offering additional discounts for prepaid commitments.
As our ongoing optimization continues, Subscan expects to introduce more favorable and more predictable pricing in Q1 2026, including:
BASIC PLAN
ADVANCED PLAN
CUSTOM PLAN
2026 Estimated Annual Cost (Updated Pricing + Testnet Annual Discount)
| Network / Service | Plan | Monthly Fee (USD) | Annual Billing Discount | Annual Fee (USD) |
| Polkadot | Custom | 10,000 | 10% | 108,000 |
| Polkadot Trace Service (Optional) | Custom | 4,000 | 10% | 43,200 |
| AssetHub (Polkadot) | Advanced (Up to 1 TB/month) | 1,699 | 10% | 18,349.2 |
| AssetHub (Polkadot) Trace Service (Optional)（This is a new feature and has not yet been officially implemented.） | Custom | 2,000 | 10% | 21,600 |
| Coretime (Polkadot) | Basic (Up to 500 GB/month) | 799 | 10% | 8,629.2 |
| Collectives (Polkadot) | Basic (Up to 500 GB/month) | 799 | 10% | 8,629.2 |
| BridgeHub (Polkadot) | Basic (Up to 500 GB/month) | 799 | 10% | 8,629.2 |
| People (Polkadot) | Basic (Up to 500 GB/month) | 799 | 10% | 8,629.2 |
Based on the current scope and configuration, the estimated Total Annual Fee (USD) for 2026 is: 225,666.
Please note that this amount is provided for 2026 cost forecasting purposes only, and is intended to support an evaluation of the long-term sustainability of the service. We welcome further discussion on the most suitable payment structure and scope adjustments, including:
Subscan will prepare the 2026 service proposal based on the community’s feedback and preferred direction.
The total requested amount for all 6 networks, including all maintenance, operational overhead, and mandatory compatibility work, is USD 202,416.
Conclusion
Subscan remains a foundational pillar of the Polkadot ecosystem—providing the high-fidelity block indexing, XCM observability, and governance transparency required by developers, auditors, and millions of users worldwide.
The 2025 development cycle marked a period of intense technical transformation for Polkadot. By ensuring seamless compatibility through the AssetHub migration and multiple breaking runtime upgrades, Subscan has preserved the continuity of the historical record and the stability of downstream applications.
Our Commitment to the Ecosystem We recognize the current challenges facing the broader market and the Polkadot ecosystem. While Subscan’s operational costs are already highly competitive, we are committed to standing with the community during these demanding times through two key initiatives:
We remain dedicated to:
We appreciate the Treasury’s continued trust and support. We will continue to evolve alongside Polkadot, providing a high-performance, cost-efficient, and transparent data layer for the entire communi