Ajna SDK

A typescript SDK that can be used to create Dapps and keepers in the Ajna ecosystem.

Setup

• Install/select Node.js 14/16/18 using your preferred package/version manager. Note that CI runs against Node 14, but the linter requires ^16.14 or ^18.
• yarn install installs dependencies.
• yarn build builds the app at build, cleaning the folder first.

Design

Exception handling

To improve responsiveness, the SDK may raise an SdkException locally if it knows the transaction will not succeed with the current state. The SDK traps reverts to decode and and throw an exception revealing the reason. The SDK does not attempt to handle connectivity errors. As such, the consumer should assume all onchain calls could throw an exception.

Usage

Prerequisites

Instructions assume basic knowledge of TypeScript, Ethers.js, and interacting with blockchains which use the Ethereum Virtual Machine (EVM).

Working with numeric types

Quantities and prices in Ajna are represented in WAD (18-decimal) precision. Ethers.js v5 models this using BigNumber. To convert to and from these scaled values, toWad and fromWad are provided. Do not explicitly multiply or divide by 10^18.

toWad allows conversions from both number and string values. fromWad converts to string values, such that precision is not lost.

Price buckets in Ajna are identified by an integer bucket index, between 1 (highest price) and 7388 (lowest price). To convert to and from bucket indicies, priceToIndex and indexToPrice functions are provided. The SDK uses number type to model bucket indices.

Examples

Example scripts are provided in the examples/ directory.

Development

Documentation

To build documentation, run yarn document. HTML will be generated in the sdk-api/docs directory.

Unit testing

Unit tests run against a dockerized Ajna testnet. Addresses and keys in test configuration are publicly known. Do not attempt to use those addresses on a public network!

yarn test runs jest tests once. yarn test:dev runs the jest tests in watch mode, waiting for file changes.

To pass parameters to jest, run using npx.

Note that test suites must be --runInBand because ganache requests to jump time, mine empty blocks, and reset to a checkpoint will impact unrelated tests. It also enables us to use the same account in multiple suites without worrying about nonce conflicts.

Maintenance

This package offers a facility to translate ABIs as compiled to a format consumable by Ethers.js. To use:

• Set AJNA_ABIS environment var to the location where your compiler has generated the JSON ABI files. This assumes all ABIs reside in a single directory.
• Run yarn update-abis to overwrite current ABIs in src/abis.

This facility was tested against brownie compilation output.

After updating ABIs, run yarn typechain-abis to generate typescript wrappers around contracts. Be sure to prettify generated code before committing.

After updating docker-compose.yml to point to a new testchain:

• Update Ajna deployment addresses in tests/test-constants.ts
• Update token and pool addresses in each test (tests/*.spec.ts).

Publishing

• Authenticate with your npm account using either npm login or an npm token.
• Run yarn publish to release a new version adhering to SemVer 2.0.
• Commit the updated package.json.

Contributing

If you have suggestions for how SDK library boilerplate could be improved, or want to report a bug, open an issue! We'd love all and any contributions.