@substrate/txwrapper

Helper funtions for offline transaction generation.

Note

If you are a chain builder looking to build a chain specific txwrapper please take a look at txwrapper-core and the guide for chain builders. Any feedback is welcome, just make an issue at that repo.

Get Started

yarn add @substrate/txwrapper

In a JS/TS file:

import {
  createSignedTx,
  createSigningPayload,
  methods,
} from '@substrate/txwrapper';

const unsigned = methods.balance.transfer(
  {
    dest: 'FoQJpPyadYccjavVdTWxpxU7rUEaYhfLCPwXgkfD6Zat9QP',
    value: 100,
  },
  {
    // Additional information needed to construct the transaction offline.
  }
);

const signingPayload = createSigningPayload(unsigned, { registry });
// On your offline device, sign the payload.
const signature = myOfflineSigning(signingPayload);

// `tx` is ready to be broadcasted.
const tx = createSignedTx(unsigned, signature, { metadataRpc, registry });

Have a look at the examples to see how you can perform the whole lifecycle of a transaction, from generation to signing to broadcast.

Go to documentation to see all available functions.

Contribute

We welcome contributions. Before submitting your PR, make sure to run the following commands:

• yarn docs: Will generate docs based on code comments.
• yarn test: Make sure all tests pass.
• yarn lint: Make sure your code follows our linting rules. You can also run yarn lint --fix to automatically fix some of those errors.

Note for Maintainers

All the commits in this repo follow the Conventional Commits spec. When merging a PR, make sure 1/ to use squash merge and 2/ that the title of the PR follows the Conventional Commits spec.

The history of commits will be used to generate the CHANGELOG. To do so, run yarn deploy on the master branch. This command will look at all the commits since the latest tag, bump the package version according to semver rules, and generate a new CHANGELOG.

If you don't want to follow semver or need to do a dry run, consult the standard-version CLI usage docs. Flags for standard-version can be passed to yarn deploy.

yarn deploy, which only does local operations and doesn't push anything, will output more or less the following lines:

$ yarn deploy
yarn run v1.21.1
$ yarn build && standard-version -r minor
$ rimraf lib/ && tsc
✔ bumping version in package.json from 0.3.2 to 0.4.0
✔ outputting changes to CHANGELOG.md
✔ committing package.json and CHANGELOG.md
✔ tagging release v0.4.0
ℹ Run `git push --follow-tags origin master && npm publish` to publish

To publish the new package, run: git push --follow-tags origin master && npm publish. You must have access to the @substrate organization on npm to publish.

Roadmap

• API revamp to clarify handling of registry and metadataRpc.

Parachain support

• Factor out utility functions and types (such as decode, getRegistry, createMethod etc) into a library for parachain teams that allows them to release and maintain txwrapper libraries specific to their parachains. This could be called @substrate/txwrapper-core. This lib will allow a parachain team to set up an offline signing lib with unit tests quickly and painlessly while allowing users access to a consistent txwrapper API across parachains.
• While the core utility will be factored out to its own dependency, dispatchables from generic substrate methods will be published in a package @substrate/txwrapper-substrate and Polkadot/Kusama specific dispatchables will be available in @substrate/txwrapper-polkadot. (This could be in a mono repo, but separate packages.) Parachains then create their own txwrapper lib using the txwrapper-core and publish it as @{parachain-name}/txwrapper.