@substrate/api-sidecar

REST service that makes it easy to interact with blockchain nodes built using Substrate's FRAME framework.

Note

v1.0.0 was released on 2020-10-23. This major release introduced several renamed endpoints as breaking changes. It is important that users complete the transition to the new endpoints ASAP so they are ready for any subsequent emergency updates. Please visit the MIGRATION_GUIDE to learn more.

Prerequisites

This service requires Node versions 14 or higher.

Compatibility:

Node Version	Stablility
v14.x.x	Stable
v16.x.x	Stable
v17.x.x	Not Stable
v18.x.x	Pending

NOTE: Node LTS (long term support) versions start with an even number, and odd number versions are subject to a 6 month testing period with active support before they are unsupported. It is recommended to use sidecar with a stable actively maintained version of node.js.

Table of contents

• NPM package installation and usage
• Source code installation and usage
• Configuration
• Debugging fee and payout calculations
• Available endpoints
• Chain integration guide
• Docker
• Note for maintainers

NPM package installation and usage

Global installation

Install the service globally:

npm install -g @substrate/api-sidecar
# OR
yarn global add @substrate/api-sidecar

Run the service from any directory on your machine:

substrate-api-sidecar

To check your version you may append the --version flag to substrate-api-sidecar.

Local installation

Install the service locally:

npm install @substrate/api-sidecar
# OR
yarn add @substrate/api-sidecar

Run the service from within the local directory:

node_modules/.bin/substrate-api-sidecar

Finishing up

Jump to the configuration section for more details on connecting to a node.

Click here for full endpoint docs.

Source code installation and usage

Quick install

Simply run yarn.

Rust development installation

If you are looking to hack on the calc Rust crate make sure your machine has an up-to-date version of rustup installed to manage Rust dependencies.

Install wasm-pack if your machine does not already have it:

cargo install wasm-pack

Use yarn to do the remaining setup:

yarn

Running

# For live reload in development
yarn dev

# To build and run
yarn build
yarn start

Jump to the configuration section for more details on connecting to a node.

Configuration

To use a specific env profile (here for instance a profile called 'env.sample'):

NODE_ENV=sample yarn start

For more information on our configuration manager visit its readme here. See Specs.ts to view the env configuration spec.

Express server

• SAS_EXPRESS_BIND_HOST: address on which the server will be listening, defaults to 127.0.0.1.
• SAS_EXPRESS_PORT: port on which the server will be listening, defaults to 8080.
• SAS_EXPRESS_LOG_MODE: enable console logging of "all" HTTP requests, only "errors", or nothing by setting it to anything else. LOG_MODE defaults to only "errors".

Substrate node

• SAS_SUBSTRATE_WS_URL: WebSocket URL to which the RPC proxy will attempt to connect to, defaults to ws://127.0.0.1:9944.

Custom substrate types

Some chains require custom type definitions in order for Sidecar to know how to decode the data retrieved from the node. Sidecar pulls types for chains from @polkadot/apps-config, but in some cases the types for the chain you are trying to connect to may be out of date or may simply not exist in @polkadot/apps-config.

Sidecar affords environment variables which allow the user to specify an absolute path to a JSON file that contains type definitions in the corresponding formats. Consult polkadot-js/api for more info on the type formats (see RegisteredTypes).

N.B Types set from environment variables will override the corresponding types pulled from @polkadot/apps-config.

• SAS_SUBSTRATE_TYPES_BUNDLE: a bundle of types with versioning info, type aliases, derives, and rpc definitions. Format: OverrideBundleType (see typesBundle).
• SAS_SUBSTRATE_TYPES_CHAIN: type definitions keyed by chainName. Format: Record<string, RegistryTypes> (see typesChain).
• SAS_SUBSTRATE_TYPES_SPEC: type definitions keyed by specName. Format: Record<string, RegistryTypes> (see typesSpec).
• SAS_SUBSTRATE_TYPES: type definitions and overrides, not keyed. Format: RegistryTypes (see types).

You can read more about defining types for polkadot-js here.

Connecting a modified node template

Polkadot-js can recognize the standard node template and inject the correct types, but if you have modified the name of your chain in the node template you will need to add the types manually in a JSON types file like so:

// my-chains-types.json
{
  "Address": "AccountId",
  "LookupSource": "AccountId"
}

and then set the enviroment variable to point to your definitions:

export SAS_SUBSTRATE_TYPES=/path/to/my-chains-types.json

Logging

• SAS_LOG_LEVEL: the lowest priority log level to surface, defaults to info. Tip: set to http to see all HTTP requests.
• SAS_LOG_JSON: wether or not to have logs formatted as JSON, defaults to false. Useful when using stdout to programmatically process Sidecar log data.
• SAS_LOG_FILTER_RPC: wether or not to filter polkadot-js API-WS RPC logging, defaults to false.
• SAS_LOG_STRIP_ANSI: wether or not to strip ANSI characters from logs, defaults to false. Useful when logging RPC calls with JSON written to transports.

Log levels

Log levels in order of decreasing importance are: error, warn, info, http, verbose, debug, silly.

http status code range	log level
code < 400	http
400 <= code < 500	warn
500 < code	error

RPC logging

If looking to track raw RPC requests/responses, one can use yarn start:log-rpc to turn on polkadot-js's logging. It is recommended to also set SAS_LOG_STRIP_ANSI=true to increase the readability of the logging stream.

N.B. If running yarn start:log-rpc, the NODE_ENV will be set to test. In order still run your .env file you can symlink it with .env.test. For example you could run ln -s .env.myEnv .env.test && yarn start:log-rpc to use .env.myEnv to set ENV variables. (see linux commands ln and unlink for more info.)

Debugging fee and payout calculations

It is possible to get more information about the fee and payout calculation process logged to the console. Because this fee calculation happens in the statically compiled web assembly part a re-compile with the proper environment variable set is necessary:

CALC_DEBUG=1 sh calc/build.sh

Available endpoints

Click here for full endpoint docs.

Chain integration guide

Click here for chain integration guide.)

Docker

With each release, the maintainers publish a docker image to dockerhub at parity/substrate-api-sidecar

Pull the latest release

docker pull docker.io/parity/substrate-api-sidecar:latest

The specific image tag matches the release version.

Or build from source

yarn build:docker

Run

# For default use run:
docker run --rm -it --read-only -p 8080:8080 substrate-api-sidecar

# Or if you want to use environment variables set in `.env.docker`, run:
docker run --rm -it --read-only --env-file .env.docker -p 8080:8080 substrate-api-sidecar

NOTE: While you could omit the --read-only flag, it is strongly recommended for containers used in production.

then you can test with:

curl -s http://0.0.0.0:8080/blocks/head | jq

N.B. The docker flow presented here is just a sample to help get started. Modifications may be necessary for secure usage.

Contribute

Need help or want to contribute ideas or code? Head over to our CONTRIBUTING doc for more information.

Notes for maintainers

Commits

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.

Updating polkadot-js dependencies

1. Every Monday the polkadot-js ecosystem will usually come out with a new release. It's important that we keep up, and read the release notes for any breaking changes or high priority updates. You can use the following command yarn upgrade-interactive to find and update all available releases. To Upgrade just @polkadot scoped deps use yarn up @polkadot/*.

   • @polkadot/api release notes
   • @polkadot/apps-config release notes
     • If there are any major changes to this package that includes third party type packages, its worth noting to contact the maintainers of sidecar and do a peer review of the changes in apps-config, and make sure no bugs will be inherited.
   • @polkadot/util-crypto release notes
   • @substrate/calc npm release page

2. Next make sure the resolutions are up to date inside of the package.json for all @polkadot/* packages, please refer to the releases of each polkadot package we update as a dependency, and reach out to the maintainers for any questions. You will have to run yarn again to ensure the dependency cache, and yarn.lock have the correct versions.

3. Ensure everything is working by running the following tests, yarn build, yarn lint, yarn test, yarn test:init-e2e-tests.

4. Lastly, create a PR with the updates.

Releases

Preparation

1. Make sure the polkadot-js dependencies are up to date. Refer to the "Updating polkadot-js dependencies" if they need to be updated.

2. Make sure that you've run yarn in this folder, and run cargo install wasm-pack so that that binary is available on your $PATH.

3. Checkout a branch with the format name-v5-0-1. When deciding what version will be released it is important to look over 1) PRs since the last release and 2) release notes for any updated polkadot-js dependencies as they may affect type definitions.

4. The next step is making sure the release will work against all relevant runtimes for Polkadot, Kusama, and Westend. This can be handled by running yarn test:init-e2e-tests. If you would like to test on an individual chain, you may run the same command followed by its chain, ex: yarn test:init-e2e-tests:polkadot. Before moving forward ensure all tests pass, and if it warns of any missing types feel free to make an issue here.

   Note: that the e2e tests will connect to running nodes in order to test sidecar against real data, and they may fail owing to those connections taking too long to establish. If you run into any failures, try running tests just for the chain that failed with something like yarn test:init-e2e-tests:polkadot.

5. Update the version in the package.json (this is very important for releasing on NPM).

6. Update the substrate-api-sidecar version in the docs by going into docs/src/openapi-v1.yaml, and changing the version field under info to the releases respected version. Then run yarn build:docs.

7. Update CHANGELOG.md by looking at merged PRs since the last release. Follow the format of previous releases. Only record dep updates if they reflect type definition updates as those affect the users API. It will also help to sort previous PR's by "recently updated" in order to see all PR's merged since the last release.

   Make sure to note if it is a high upgrade priority (e.g. it has type definitions for an upcoming runtime upgrade to a Parity maintained network).

8. Commit with ex: chore(release): 5.0.1, then git push your release branch up, make a PR, get review approval, then merge.

   NOTE: Before pushing up as a sanity check run the following 4 commands and ensure they all run with zero errors. There is one exception with yarn test where you will see errors logged, that is expected as long as all the test suites pass.

   yarn dedupe
   yarn build
   yarn lint
   yarn test

9. If one of the commits for this release includes the calc directory and package, make sure to follow the instructions below for releasing it on npm (if a new version hasn't yet been released seperately).

Publish on GitHub

1. Double check that master is properly merged, pull down master branch.

2. Create a new release on github, select Choose a tag and create a new tag name matching the version like v5.0.1. The tag will be automatically published along with the release notes.

3. Generally you can copy the changelog information and set the release notes to that. You can also observe past releases as a reference.

Publish on NPM

NOTE: You must be a member of the @substrate NPM org and must belong to the Developers team within the org. (Please make sure you have 2FA enabled.)

1. Now that master has the commit for the release, pull down master branch.

2. Run the following commands. (Please ensure you have 2FA enabled)

   npm login # Only necessary if not already logged in
   yarn deploy # Builds JS target and then runs npm publish

Calc Package Release Prep

1. Head into the calc directory in sidecar, and increment the version inside of the Cargo.toml, as well as the pkg/package.json.

2. Confirm that the package compiles correctly, cargo build --release.

3. Continue with the normal sidecar release process.

Publish Calc Package

1. cd into calc/pkg and npm login, then npm publish.