Hiatus Notice

Congratulations on making it through all 20 chapters of this course! You now have a strong foundation in building canisters in Rust, working with system APIs, and managing state-changes of atomic and asynchronous calls. That’s a big milestone — and a great place to pause.

While this course is taking a short break, you are well-equipped to keep exploring on your own. To support you during this hiatus, we’ve put together a self-guided roadmap with carefully selected external resources. These will help you continue learning further more about Chain Fusion Technology at your own pace.

HTTP Outcalls, Threshold Signatures and ICP’s Blockchain Architecture

Http Outcalls

Overview:

• https://docs.internetcomputer.org/building-apps/network-features/using-http/https-outcalls/overview

Make GET requests

• https://docs.internetcomputer.org/building-apps/network-features/using-http/https-outcalls/post
• https://docs.internetcomputer.org/building-apps/network-features/using-http/https-outcalls/get

Make POST requests:

• https://docs.internetcomputer.org/building-apps/network-features/using-http/https-outcalls/post
• https://github.com/dfinity/examples/tree/master/rust/send_http_post

ICP Blockchain Architecture

Subnet architecture (independent replicated networks)

• https://docs.internetcomputer.org/building-apps/essentials/network-overview

State and transactions are private by default

• https://docs.internetcomputer.org/building-apps/security/misc#data-confidentiality-on-icp

Each subnet has a subnet public key (used to verify its signatures/certificates)

• https://learn.internetcomputer.org/hc/en-us/articles/34209540682644-Subnet-Keys-and-Subnet-Signatures

Consensus uses threshold cryptography (Block history is no longer needed, we can verify blocks through each subnet’s public keys)

• https://learn.internetcomputer.org/hc/en-us/articles/34207558615956-Consensus

Threshold Signatures ECDSA

Overview:

• https://docs.internetcomputer.org/building-apps/network-features/signatures/t-ecdsa

Derive an address (key id + derivation path)

• https://docs.internetcomputer.org/building-apps/network-features/signatures/t-ecdsa#obtaining-public-keys

Create signed artifacts

• https://docs.internetcomputer.org/building-apps/network-features/signatures/t-ecdsa#signing-messages-and-transactions

Verify signature of the signed artifact

• https://docs.internetcomputer.org/building-apps/chain-fusion/ethereum/using-eth/signing-transactions#build-a-transaction

The EVM RPC Canister and Timers

EVM RPC canister:

Query Ethereum Events and Transactions

• https://docs.internetcomputer.org/building-apps/chain-fusion/ethereum/evm-rpc/evm-rpc-canister#get-the-latest-ethereum-block-info

How to send Ethereum Transactions

• https://docs.internetcomputer.org/building-apps/chain-fusion/ethereum/evm-rpc/evm-rpc-canister#get-the-latest-ethereum-block-info

Timers

• https://docs.internetcomputer.org/building-apps/network-features/periodic-tasks-timers#timers
• https://github.com/AymericRT/On-ChainOracle

Cross-Chain Projects

Project: Build a financial subscription

• Canisters as a financial subscription service
• Credits user balance through a token approval from the owner to the canister
• https://github.com/AymericRT/SubscriptioinTimerICP

Project : Cross-Chain Messaging Protocol

• Utilize canisters to relay messages from a smart contract on Chain A to a smart contract on Chain B
• https://github.com/AymericRT/ICBridge?tab=readme-ov-file