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  • Team Name: TopMonks
  • Payment Address: 32NoFbB4x8bZ7YNvjra1DUYcje2B2XQwP3 (BTC)
  • Level: 2

Project Overview πŸ“„β€‹

This application is a response to a Multi-chain Block Explorer RFP


Calamar is a block explorer for Polkadot and Kusama relay chains and their parachains, that uses Subsquid API for data fetching.

The idea for another explorer has emerged during the dotsama events in Amsterdam and Prague. The team of TopMonks company's Blockchain Studio has gathered feedback from friendly projects such as HydraDx and KodaDot among others. We have applied for and won the bounty from Subsquid in the Polkadot Hackaton: North America edition, that requested developing a block explorer. Our submission:

We call the app Calamar, as it is in line with the Subsquid identity.

It is available here:
and we manage the code here:

Based on the positive feedback we would like to push the project further and bring more valuable features for the users, closely cooperating with the Subsquid team and gathering an ongoing feedback from the users.

While developing Calamar, we focus on UI and UX friendliness so that users enjoy dotsama chains exploring, as well as relevance of displayed data.

Project Details​

Calamar explorer will allow users to search and display various items and statistics.

The plan is to have at least these features implemented:


Homepage with google-like search box and with links to chain dashboards.

Home page

Search where you don't have to know which chain the searched item belongs to. You just put the hash into the search box and the explorer will take care of the determining on which chain it is. This is going to be an addition to the ability to restrict search to a specific chain.

Block detail​

Display block's data and its extrinsics, transfers, calls and events.

  • searchable by hash and height

Extrinsic detail​

Display extrinsic's data, its calls and events.

  • searchable by hash and id

Call detail​

Display call's data, and its events.

  • searchable by id

Event detail​

Display event's data

  • searchable by id

Search extrinsics and events by name​

Display a list of matching extrinsics and events by name.

  • full-text search - doesn't require exact name, substring is sufficient, case insensitive

Account detail​

As we are gathering feedback, one of the most important features for the users seems to be the account overview where users can find information about their balances and transactions across all chains.

  • searchable by public key or chain-specific address
  • display
    • account's name if set
    • owned assets accross all listed chains, including dollar values and graphs for visualization.
    • list all chain-specific addresses
    • list all related transfers, extrinsics and calls

Account page

Chain dashboards​

Each chain will have own dashboard with statistics and listing of latest blocks, latest transfers, top holders, etc. It makes the explorer more useful even for users who are not searching for specific items.

Statistics page

Metadata explorer​

The runtime metadata of each chain are still evolving and changing but it is not so easy to display them in a structured and human-readable way. There is e.g. a tool which displays them but only latest version and supports only a few networks. The metadata explorer we are going to implement will support all the networks and also historical versions of the runtime spec.

Metadata explorer

Item metadata​

The metadata information will be deeply integrated into whole Calamar so we can display it in the detail pages of the items. E.g. in extrinsic's detail page we will show info for the call name, error, parameters and link to the metadata explorer for more info.

Extrinsic metadata

Search input autocomplete for call and event names​

Thanks to the metadata we can also autocomplete and suggest the call and event names when typing into the search input.

Technology stack​

Typescript, React, GraphQL

Ecosystem Fit​

  • Calamar will help the community keep track of what's happening on the network, including XMC transfers, account overviews and chains statistics.
  • Target audience are Dotsama developers, investors and ecosystem users.
  • Calamar users will have opensource user-friendly UI prepared to use with Subsquid API.
  • There are projects with similar functionality like Subscan or Polkaholic. Instead of trying to reinvent the wheel, we won't build our custom data indexing solution and rather rely on the powerful framework and API from Subsquid which is still evolving and has own dedicated development team. We focus on good UI and UX. Our solution will be aware of multichain environment (XCM transfers, cross-chain search, multichain account view). And the code will be opensource.

Team πŸ‘₯​

Team members​

  • Antonina Nesmelova - developer
  • Richard Jedlička - developer
  • Radek Jakl - designer
  • Jan Lopusek - project manager


  • Registered Address: StruhaΕ™ovskΓ‘ 2931/9, 141 00, Praha 4, Czech Republic
  • Registered Legal Entity: TopMonks s.r.o

Team's experience​

All of our team members developed the first version of Calamar explorer.

Antonina Nesmelova is young and enthusiastic web-developer with 3,5 years experience with web applications development, including a year and a half of experience in the world of crypto: development of dApps and smart contracts.

Richard Jedlička has several years of expertise in web applications full-stack development.

Radek Jakl invented the design for Calamar. He has many years of experience in graphics and UI/UX design.

Jan Lopusek co-founded the startup studio for TopMonks software house. He is experienced project manager and business developer

Team Code Repos​

Project references​

Team LinkedIn Profiles​

Development Status πŸ“–β€‹

Current version of Calamar is running on

It is mostly a result of our participation in hackaton as an implementation of the bounty declared by Subsquid team. See Additional Information.

For now, it allows users to:

  • search block by hash and height display its parameters and extrinsics
  • search extrinsic by hash and display its parameters and events
  • search account by address and list its extrinsics
  • search extrinsics and events by their exact name.

While it may seem to be already working explorer it has only basic features and lacks many of the important or useful ones. See Milestone 1 for details.

Development Roadmap πŸ”©β€‹


  • Total Estimated Duration: 11 weeks
  • Full-Time Equivalent (FTE): 1
  • Total Costs: $27,500

Milestone 1 β€” Core functionality​

  • Estimated duration: 4 weeks
  • FTE: 1
  • Costs: $10,000

Even though we have the already working application, there are still many things missing. Some of them prevent the users from using Calamar fully as the main explorer. We need to first assure the correct core functionality, display all the meaningful data which are retrievable without further complex processing, improve design and UX and integrate more into the Polkadot ecosystem.

0a.LicenseApache 2.0
0b.DocumentationWe will provide inline documentation of the code where necessary, technical description of how to run the own instance of Calamar and tutorials how to use the application from the user perspective.
0c.Testing GuideWe will provide end-to-end tests covering UI functionality.
0d.DockerWe will provide a Dockerfile(s) for testing and running own Calamar instance.
0e.ArticleWe will publish an article that explains what was done as part of the grant.
1.Fix usage blockersFix things which block the app's real usage
  • search results are not shareable due to missing info about the chain in the URL
  • extrinsic's args are missing
2.Add related items listingsAdd missing related items listing to detail pages
  • block's extrinsics, call and events
  • extrinsic's calls
3.Add call detail pageSee Call detail.
4.Add event detail pageSee Event detail.
5.ResponsivenessImprove overall responsiveness for mobile devices especially of item tables and extrinsics/event args.
6.Extrinsics/event args displaying improvementsAdd args display options: raw/json, human readable. Find a better way to show nested properties' data types.
7.Items countCurrent implementation doens't show the total number of searched items. We would like to retrieve the items count and display it properly.
8.Extrinsic/event case-insensitive search by nameAdd ability to search extrinsics and events by their name case-insensitive.
9.Account address parsing in events argsDetect account address in event args and link it to the account detail (chain detected automatically).
10.Website polishingAdd useful information to the website (footer with team logos, contact information, terms, etc.).
11.Polkadot.js integrationCreate a PR to integrate links to the Calamar Explorer into Polkadot.js app.

Milestone 2 - Account detail & Chain dashboards​

  • Estimated duration: 4 weeks
  • FTE: 1
  • Costs: $10,000

In this milestone we are going to improve account detail page and replace latest extrinsics page with proper dashboard page for each chain.

Subsquid (data provider) might not support each feature for all chains at the time of the implementation, so the features will be implemented universally to support each chain whenever the data are provided in the future.

0a.LicenseApache 2.0
0b.DocumentationWe will provide inline documentation of the code where necessary and user documentation for new features.
0c.Testing GuideWe will provide end-to-end tests covering UI functionality.
0d.DockerN/A - will be provided by the first milestone.
0e.ArticleWe will publish an article that explains what was done as part of the grant
1.Account / Balance overviewOverview of owned assets accross all listed chains with chain specific addresses, including dollar values
2.Account / Balance chartsChart visualization of balance by assets and by type (reserved, tranferable, ...), including dollar values
3.Account / Transfers listAdd account's transfers list table
4.Account / Calls listAdd account's calls list table
5.Account / Identity infoAdd account's identity information if set (name, twitter, ...)
6.Chain dashboard / StatsShow chain's stats (blocks count, signed extrinsics count, total issuence, transfers count, holders count, total issuence, staked value, inflation rate, validators count) including USD values
7.Chain dashboard / Asset value chartChart visualization of asset value by type (staked, circulating, other)
8.Chain dashboard / Latest blocksAdd latest blocks list table
9.Chain dashboard / Latest transfersAdd latest transfers list table
10.Chain dashboard / Top holdersAdd top holders list table

Milestone 3 - Universal search & Metadata explorer​

  • Estimated duration: 8 weeks
  • FTE: 0.375
  • Costs: $7,500

In this milestone we are going to implement universal search and one of the most requested features: cross-chain transfers detection.

0a.LicenseApache 2.0
0b.DocumentationWe will provide inline documentation of the code where necessary and tutorials on how to use new features.
0c.Testing GuideWe will provide end-to-end tests covering UI functionality.
0d.DockerN/A - will be provided by the first milestone.
0e.ArticleWe will publish an article that explains what was done as part of the grant
1.Universal searchSearch items through all the chains without the knowledge where it belongs. See Universal search.
2.Metadata explorerUI interface for exploring metadata retrieved from network's latest and historical versions of runtime spec. See Metadata explorer.
3.Show related runtime metadata in items' detailShow related metadata information directly in detail pages of individual items and interlink to metadata explorer. See Item metadata.
4.Search input autocompleteAutocomplete extrinsic and event name in the search input. See Search input autocomplete for call and event names.

Future Plans​

There is a huge potential for future improvements which the Polkadot's community can benefit from.

We would like to definitely display information about XCM transfers and teleports.

As developers of most parachains implement their own custom modules/pallets it opens the opportunity to cooperate and customize Calamar explorer with UI/UX components and logic tailored to their needs.

It relates to various XCM transactions which makes it even more complex and the more types will our explorer support the more it makes the users' lives easier.

Another requests which came to us are:

  • supporting EVM and WASM smart contracts
  • exporting transactions for accounting and taxation purposes
  • displaying NFTs collections and crowdloans rich data

Additional Information βž•β€‹

How did you hear about the Grants Program? Personal recommendation