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?tab=t.0

Past proposals

• #151 Subscan | Infrastructure Costs of Subscan for Polkadot & Westend & Rococo Networks
• #20 Subscan | Infrastructure Costs of Subscan for Polkadot & Westend & Rococo & Statemint & Rockmine Networks (from July to December 2022)
• #1056 Subscan | Infrastructure Costs of Subscan for Polkadot & Westend & Rococo & Statemint & Rockmine Networks (from October 2023 to June 2024)
• #1366 Subscan Q3/Q4 2024 Funding Proposal: Basic service fee & Development cost for the Polkadot, Westend, and Rococo Ecosystems）
• #1727 Subscan Q4 2024 – Q2 2025 Funding Proposal: Basic Service Fee & Development Cost for the Polkadot and Westend Ecosystems

Overview

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:

A. Basic Service Fees (2025 Q3–Q4)

Ensuring uninterrupted operational maintenance for the six Polkadot system networks:

• Polkadot Relay Chain
• AssetHub-Polkadot
• BridgeHub-Polkadot
• Coretime-Polkadot
• Collectives-Polkadot
• People-Polkadot

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

B. Development Fees (2025 Q2–Q3)

Compensation for major ecosystem-critical work already completed, including:

• Full compatibility support and historical corrections for the AssetHub migration
• XCM execution and observability upgrades
• Governance transparency improvements (Treasury–Referenda linking, Preimage timelines, child bounty tracking)
• Data correctness repairs and ParaID history recovery
• Performance enhancements across API, dashboard, and frontend layers
• Monitoring architecture redesign and infrastructure optimization

Requested: USD 37,180

Total requested amount: USD 188,380

Recent Contributions and Ongoing Maintenance Work

From Q2 2024 to Q3 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:

1. Full Compatibility & Data Migration for AssetHub

AssetHub underwent multiple breaking updates, including changes to assets, extrinsics, metadata layouts, governance modules, and transfer logic. Subscan delivered complete compatibility support, including:

• Support for the new transfer_assets extrinsic (breaking change)
• Completion of missing governance metadata such as CreatedAtBlock, UpdatedAtBlock
• Migration fixes for precision, balances, metadata, and cross-chain asset visibility
• Repaired XCM token search, asset flow dashboards, and multi-network balance consistency
• Updated runtime compatibility across multiple versions released during the migration window

These contributions ensured that wallets, explorers, governance dashboards, and integration tools remained fully functional throughout the AssetHub migration, preventing ecosystem disruption.

2. Relay Chain & Parachain Data Reliability Improvements

Major foundational improvements included:

• Persistent Elasticsearch sync checkpoints
• Block/event sync memory optimization
• Historical ParaID mapping repair
• Account holder data recovery for Polkadot & Kusama
• Large-block (>100k events) processing pipeline

These enhancements strengthened chain-wide data accuracy and reduced the risk of indexer stalls during runtime upgrades or heavy XCM traffic.

3. XCM Observability, Monitoring, and Dashboards

Given Polkadot’s XCM-heavy activity, Subscan delivered system-wide improvements:

• XCM Process navigation and linking repair
• Standardized XCM execute events
• New XCM Asset Flow chart
• Optimized XCM reward sync
• ProcessXcmError decoding support

Combined, these improvements make Subscan the most complete and accurate public XCM observability layer in the ecosystem.

4. Governance Transparency Enhancements

Subscan improved auditability and cross-module visibility by:

• Fixing Treasury ↔ Referenda missing links
• Adding Preimage change tracking
• Supporting external proposals
• Enhancing referenda timelines for multi-module events
• Adding child bounty statistics and distributions

This has become critical infrastructure for OpenGov data, treasury analysts, and governance dashboards.

5. User Experience, Performance & Frontend Improvements

Key UX improvements include:

• High-load page optimizations
• Mobile optimization for dashboards
• Portfolio value accuracy fixes
• Identity and privacy mode repairs
• Pagination, sorting, and navigation upgrades

These ensure Subscan remains responsive even under multi-network heavy traffic conditions.

6. Infrastructure, Monitoring & Operational Maintenance

Continuous operations included:

• 24/7 monitoring for 12+ networks
• Hotfixes for runtime upgrades
• Sync health alerts
• Cost-control measures
• IPFS provider migration
• CI/CD & DevOps automation

These ongoing services are fundamental to maintaining reliable explorer and API availability for the entire Polkadot ecosystem.

Why Subscan Matters

As the default block explorer and indexing layer for Polkadot, Subscan provides the foundational data required by nearly all ecosystem participants.

Developers & Applications

• Reliable APIs: blocks, extrinsics, events, XCM, assets, NFTs
• Faster debugging and monitoring
• Data infrastructure for indexers, dashboards, bots, dApps

Parachain Teams & Validators

• Real-time block production, sync status, and finality
• XCM tracking across chains
• Early detection of node anomalies

Governance Platforms & Participants

• Referendum status, account history, delegation data
• Governance dashboards dependent on Subscan APIs
• Long-term auditability of past governance decisions

End Users, Wallets, and Ecosystem Tools

• Transfers, staking, NFT queries, asset visibility
• Multi-chain UI consistency and reliability

Without Subscan, many essential tools would face significant data degradation, and the accessibility of historical and governance data would be severely impacted.

Scope of This Proposal

This proposal covers two major funding components:

1. Service Fees (2025 Q3–Q4)

Operational maintenance for 6 Polkadot networks:

• Polkadot Relay Chain
• AssetHub
• BridgeHub
• Coretime
• Collectives
• People

These fees cover database storage, indexing, monitoring, bandwidth, DevOps, node maintenance, and end-user support.

2. Development Fees (2024 Q2–2025 Q3)

Compensation for:

• Core data reliability improvements
• Governance & OpenGov enhancements
• XCM dashboards, linking, and data corrections
• Runtime upgrade compatibility across the Polkadot family
• AssetHub migration support and breaking-change compatibility
• UI/UX and performance optimization
• Monitoring & DevOps automation
• Bulk data & research tooling
• Infrastructure migration (IPFS, monitoring, cold storage)

Together, these represent essential public infrastructure development that ensures Subscan remains aligned with Polkadot’s technical evolution.

Service Fee Model & Pricing Methodology

Due to recent infrastructure optimizations that have already delivered positive results on our testnet deployments, we will first apply cost adjustments to Westend testnet billing, offering a 40% discount.

As these optimizations are still in the testing phase, the full extent of cost reductions cannot yet be precisely measured. Therefore, this discount serves as a temporary transitional measure.

Subscan is committed to releasing a new, fully optimized pricing model for all networks in Q1 2026, along with additional discounts, ensuring that every supported network benefits from the completed optimization work.

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

• Up to 200 GB: $799/month
• Beyond 200 GB: $5.3/GB
• Automatically upgrades to the next tier after 350 GB

b. Advanced Plan

• Up to 500 GB: $1,699/month
• Beyond 500 GB: $5.2/GB
• Automatically upgrades to the next tier after 750 GB

c. Professional Plan

• Up to 1 TB: $2,999/month
• Beyond 1 TB: $5/GB

Monthly Service Fee Breakdown

1. Database Storage & Indexing
   • What It Covers: Continuous indexing of on-chain data—from blocks and transactions to event logs, governance info, and NFTs—so users can reliably access both real-time and historical records.
   • Why It Matters: As chain activity increases, so does data volume. By tying fees to storage needs, we accurately account for the costs of scaling infrastructure (e.g., additional database capacity).
2. Network Egress Bandwidth
   • What It Covers: The outgoing traffic required to serve user requests quickly and consistently, including API calls, UI data retrieval, and integrations with third-party tools.
   • Why It Matters: A stable, high-bandwidth connection ensures that explorers, wallets, and dApps receive timely data responses, even during peak activity.
3. Monitoring & DevOps
   • What It Covers: Round-the-clock health checks, internal alert pipelines, CI/CD automation, and system auditing. This includes running multiple nodes, maintaining synchronization, and ensuring high availability.
   • Why It Matters: These processes help detect issues early (e.g., node crashes, indexer slowdowns) and streamline updates or deployments, minimizing service disruption for the community.
4. Node Status Monitoring & Notifications
   • What It Covers: Dedicated tools and alert mechanisms to track the real-time status of network nodes—particularly those relating to the Polkadot Relay Chain and the associated parachains (Assethub, Coretime, Bridgehub, People).
   • Why It Matters: Quick notifications enable parachain teams, validators, and the wider ecosystem to react rapidly to performance changes, forks, or potential security incidents.
5. Technical Support & Troubleshooting
   • What It Covers: Responsive assistance for users, developers, and validators, including issue resolution, feature guidance, and integration help.
   • Why It Matters: Timely support keeps the ecosystem running smoothly and fosters a positive development environment—especially crucial for teams building dApps, explorers, and automation tools.

Why We Use Storage as a Pricing Metric

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.

Beyond Storage: The Full Cost Landscape

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:

• transparent and verifiable metrics (storage is measurable on-chain and externally),
• predictable treasury budgeting, and
• preserving the flexibility and sustainability necessary to maintain and upgrade a mission-critical public data infrastructure.

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.

Fee Details

2025 Q3 & Q4 Maintenance Fee

 

• Total Maintenance Fees for 2025 Q3 & Q4 (6 networks): USD 151,200

2025 Q2 New Features Development Costs

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:

• Core data reliability improvements, such as persistent Elasticsearch sync checkpoints and state-change consistency fixes.
• Significant UX and interface upgrades, including portfolio accuracy fixes, identity privacy repairs, dark-mode enhancements, and improved navigation patterns.
• High-impact backend and API performance work, addressing slow endpoints across multi-chain token, account, reward, staking, and XCM routes.
• Cross-network operational improvements, including redesigned monitoring systems and IPFS infrastructure migration.
• Support for analytical and research workflows, through bulk export scripts and scheduled data generation systems.

Below is the complete task list for Q2 2025：

Our Compensation Rates and Total Costs:

• DevOps Engineer: $75/hour
• Front-End Engineer: $75/hour
• Back-End Engineer: $75/hour
• Product Manager/Test: $70/hour
• Designer: $70/hour

With a total of 144  hours worked, the calculated cost based on the above rates amounts to $10,650.

2025 Q3 New Features Development Costs

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:

• deep data accuracy & historical repair work (events, balances, ParaID timelines, child bounties),
• performance and scalability improvements around traces, large blocks, heavy dashboards and XCM visualizations,
• governance, referenda and treasury UX upgrades for more auditable decision-making,
• XCM and AssetHub integration and monitoring improvements,
• consolidated Polkadot-family runtime upgrade compatibility, and
• practical UX & notification flow refinements that reduce friction for everyday users.

Below is the complete task list for Q3 2025：

Our Compensation Rates and Total Costs:

• DevOps Engineer: $75/hour
• Front-End Engineer: $75/hour
• Back-End Engineer: $75/hour
• Product Manager/Test: $70/hour
• Designer: $70/hour

With a total of 359 hours worked, the calculated cost based on the above rates amounts to $26,530.

2025 Q4 New Features Development Costs

The primary focus of the 2025 Q4 development cycle is addressing issues discovered after the AssetHub migration, ensuring full data correctness and compatibility across the updated asset and cross-chain transfer logic. In addition, with support from the UX Bounty program, we have received a set of highly valuable UX improvement recommendations. These suggestions will be implemented gradually throughout the upcoming releases to enhance overall usability and help new users more easily understand and navigate the Substrate-based ecosystem.

We have also begun initial work on Polkadot EVM contract verification support, expanding Subscan’s coverage into the growing Polkadot EVM development landscape.

These efforts are still in progress. The detailed task list and corresponding workload estimates will be included in the 2026 Q1 funding proposal once the work is completed and fully documented.

Why Polkadot’s Fee Is Higher Than Other Chains

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:

• substantially more event data,
• more complex event-linking requirements, and
• larger historical datasets that must be preserved to maintain auditability.

This XCM-heavy traffic is a major contributor to the relay chain’s significantly larger storage footprint compared to individual parachains.

Optimization & Cost Reduction Roadmap

(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.

1. Hot/Cold storage separation

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.

2. XCM-focused indexing optimizations

Given that XCM events represent a major portion of Polkadot’s data weight, we are optimizing:

• event-linking logic,
• redundant index structures, and
• cross-chain reference mappings.

These adjustments reduce long-term index growth without affecting query accuracy.

3. Reduced reliance on GCP (major cost-efficiency initiative)

To optimize long-term infrastructure costs, we are:

• migrating certain storage layers to lower-cost object-storage providers,
• reducing GCP I/O operations via caching and pre-aggregation strategies,
• gradually shifting parts of the system toward self-hosted or hybrid infrastructure.

These changes directly address one of the largest cost drivers in the current operational model.

Long-Term Sustainability & Vision
Our long-term goal is to reduce reliance on treasury funding through multiple channels:

• Continuous optimization to limit infrastructure costs as chain data grows.
• Exploring responsible revenue streams (e.g., optional premium features or partnerships).
• Actively incorporating community suggestions to ensure value delivery aligns with user needs, increasing platform utility and potential monetization avenues without compromising openness or neutrality.

Forward Pricing Outlook (Commitments for 2026)

We acknowledge ongoing community concerns regarding long-term cost control.

To provide clarity and predictability, Subscan makes the following commitments:

✔ Fees are expected to decrease further in 2026

Infrastructure optimization efforts are underway, and test results have shown significant reductions in storage and bandwidth costs.

✔  Monthly fees in 2026 will not exceed the amount proposed in this proposal.

Even if on-chain data grows substantially, Subscan commits to a strict cost ceiling for 2026.

✔ New annual / semiannual discount mechanisms are in internal testing

These models will be publicly released once stabilized.

Annual prepayment will always receive the highest discount tier.

These commitments aim to improve transparency and reinforce Subscan’s long-term alignment with the community’s expectations.

Total Requested Amount

The total requested amount for all 5 networks, including all maintenance, operational overhead, and mandatory compatibility work, is USD  188,380. 

Conclusion
Subscan continues to serve as one of the most critical pieces of public infrastructure in the Polkadot ecosystem—providing reliable block indexing, XCM observability, governance transparency, and stable access to historical data across all major system parachains.

The 2024–2025 development cycle represented one of the most significant periods of technical change for Polkadot, particularly with the AssetHub migration. Subscan ensured full compatibility throughout multiple breaking upgrades, preserving ecosystem continuity for wallets, explorers, governance tools, asset managers, and downstream applications.

We remain committed to:

• Reducing long-term infrastructure costs through storage separation, GCP reduction, and indexing optimizations
• Delivering a new, optimized pricing model in early 2026, guaranteeing that monthly fees will not exceed the current levels
• Maintaining neutrality, openness, and full transparency as a public good
• Safeguarding historical integrity and ecosystem reliability for the Polkadot community

We appreciate the Treasury’s continued support and will continue optimizing Subscan to ensure it remains a high-performance, cost-efficient, and future-ready data layer for Polkadot.