@tetcore/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 version 12 or higher.

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

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

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 -p 8080:8080 substrate-api-sidecar

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

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.

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 0.18.1 to 0.18.2
✔ outputting changes to CHANGELOG.md
✔ committing package.json and CHANGELOG.md
✔ tagging release v0.18.2
ℹ Run `git push --follow-tags origin master && npm publish` to publish

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