ICMarkets Blockchains API

.NET 10 Web API for fetching BlockCypher blockchain data, storing snapshots in SQLite, and exposing paginated blockchain history.

Architecture

The solution uses Clean Architecture:

Project	Purpose
ICMarkets.Blockchains.Domain	Snapshot entity and domain validation
ICMarkets.Blockchains.Application	CQRS commands, queries, handlers, DTOs, contracts
ICMarkets.Blockchains.Infrastructure	EF Core SQLite, BlockCypher HTTP client, source strategy, background worker
ICMarkets.Blockchains.Api	Controllers, Swagger, CORS, health checks, JSON serialization
ICMarkets.Blockchains.UnitTests	Domain, strategy, and client unit tests
ICMarkets.Blockchains.IntegrationTests	API tests with SQLite and mocked BlockCypher HTTP server

Design patterns used:

• CQRS without MediatR: explicit command/query handlers are registered in DI.
• Strategy: supported BlockCypher sources are resolved by IBlockchainSourceStrategy.

Repository and Unit of Work patterns are intentionally not used. EF Core DbContext is exposed through an application DbContext contract.

Supported Sources

Chain	Network	Source
eth	main	https://api.blockcypher.com/v1/eth/main
dash	main	https://api.blockcypher.com/v1/dash/main
btc	main	https://api.blockcypher.com/v1/btc/main
btc	test3	https://api.blockcypher.com/v1/btc/test3
ltc	main	https://api.blockcypher.com/v1/ltc/main

API Endpoints

POST /api/blockchains/{chain}/{network}/snapshots

Fetches one live BlockCypher snapshot and stores the raw JSON response with CreatedAt.

POST /api/blockchains/snapshots

Fetches all configured BlockCypher sources in parallel and stores all successful snapshots.

GET /api/blockchains/{chain}/{network}/snapshots?page=1&pageSize=20

Returns paginated history ordered by CreatedAt descending.

GET /health

Health check endpoint.

Swagger UI is available at /swagger.

Configuration

Main settings are in src/ICMarkets.Blockchains.Api/appsettings.json.

Setting	Default	Description
ConnectionStrings__Blockchains	Data Source=./data/blockchains.db	SQLite database path
BlockCypher__BaseUrl	https://api.blockcypher.com/v1	BlockCypher API base URL
BlockCypher__ApiToken	empty	Optional BlockCypher token
SnapshotWorker__Enabled	true	Enables the background worker
SnapshotWorker__Interval	00:05:00	Snapshot worker interval

The background worker fetches all five sources on startup and then every five minutes.

Run Locally

Prerequisite: .NET 10 SDK.

dotnet restore
dotnet run --project src/ICMarkets.Blockchains.Api

Open:

http://localhost:5080/swagger

Optional API token:

BlockCypher__ApiToken=your-token dotnet run --project src/ICMarkets.Blockchains.Api

Run With Docker

Prerequisite: Docker or Docker Compose.

docker compose up --build

Open:

http://localhost:8080/swagger

Optional API token:

BLOCKCYPHER_API_TOKEN=your-token docker compose up --build

SQLite data is persisted in the blockchains-data Docker volume.

Tests

dotnet test

Integration tests run the API in memory, use SQLite, and point BlockCypher traffic to a local mocked HTTP server. They do not call the real BlockCypher API.

Tests can also be run through Docker Compose:

docker compose --profile tests run --rm tests

Notes

• Raw BlockCypher JSON is stored as provided in BlockchainSnapshots.RawJson.
• API responses expose the stored raw JSON as the data object.
• API Gateway is omitted based on clarified requirements.
• Functional tests are omitted based on clarified requirements.