Polkadot/Substrate Manifest File

SubQuery TeamAbout 10 min

Polkadot/Substrate Manifest File

The Manifest project.ts file can be seen as an entry point of your project and it defines most of the details on how SubQuery will index and transform the chain data. It clearly indicates where we are indexing data from, and to what on chain events we are subscribing to.

The Manifest can be in either Typescript, Yaml, or JSON format.

With the number of new features we are adding to SubQuery, and the slight differences between each chain that mostly occur in the manifest, the project manifest is now written by default in Typescript. This means that you get a fully typed project manifest with documentation and examples provided your code editor.

Below is a standard example of a basic project.ts.

import {
  SubstrateDatasourceKind,
  SubstrateHandlerKind,
  SubstrateProject,
} from "@subql/types";

// Can expand the Datasource processor types via the genreic param
const project: SubstrateProject = {
  specVersion: "1.0.0",
  version: "0.0.1",
  name: "polkadot-starter",
  description:
    "This project can be used as a starting point for developing your SubQuery project",
  runner: {
    node: {
      name: "@subql/node",
      version: ">=3.0.1",
    },
    query: {
      name: "@subql/query",
      version: "*",
    },
  },
  schema: {
    file: "./schema.graphql",
  },
  network: {
    /* The genesis hash of the network (hash of block 0) */
    chainId:
      "0x91b171bb158e2d3848fa23a9f1c25182fb8e20313b2c1eb49219da7a70ce90c3",
    /**
     * This endpoint must be a public non-pruned archive node
     * Public nodes may be rate limited, which can affect indexing speed
     * When developing your project we suggest getting a private API key
     */
    endpoint: "https://polkadot.rpc.subquery.network/public",
  },
  dataSources: [
    {
      kind: SubstrateDatasourceKind.Runtime,
      startBlock: 1,
      mapping: {
        file: "./dist/index.js",
        handlers: [
          /*{
            kind: SubstrateHandlerKind.Block,
            handler: "handleBlock",
            filter: {
              modulo: 100,
            },
          },*/
          /*{
            kind: SubstrateHandlerKind.Call,
            handler: "handleCall",
            filter: {
              module: "balances",
            },
          },*/
          {
            kind: SubstrateHandlerKind.Event,
            handler: "handleEvent",
            filter: {
              module: "balances",
              method: "Deposit",
            },
          },
        ],
      },
    },
  ],
};

// Must set default to the project instance
export default project;

Below is a standard example of the legacy YAML version (project.yaml).

Legacy YAML Manifest

specVersion: 1.0.0
name: subquery-starter
version: 0.0.1
runner:
  node:
    name: "@subql/node"
    version: "*"
  query:
    name: "@subql/query"
    version: "*"
description: "This project can be use as a starting point for developing your Polkadot based SubQuery project"
repository: https://github.com/subquery/subql-starter
schema:
  file: ./schema.graphql
network:
  chainId: "0x91b171bb158e2d3848fa23a9f1c25182fb8e20313b2c1eb49219da7a70ce90c3"
  # This endpoint must be a public non-pruned archive node
  # We recommend providing more than one endpoint for improved reliability, performance, and uptime
  # Public nodes may be rate limited, which can affect indexing speed
  # When developing your project we suggest getting a private API key
  endpoint: ["https://polkadot.rpc.subquery.network/public"]
  # Optionally provide the HTTP endpoint of a full chain dictionary to speed up processing
  dictionary: "https://api.subquery.network/sq/subquery/polkadot-dictionary"
  # Optionally provide a list of blocks that you wish to bypass
  bypassBlocks: [1, 2, 100, "200-500"]
dataSources:
  - kind: substrate/Runtime
    startBlock: 1 # Block to start indexing from
    mapping:
      file: ./dist/index.js
      handlers:
        - handler: handleBlock
          kind: substrate/BlockHandler
        - handler: handleEvent
          kind: substrate/EventHandler
          filter:
            module: balances
            method: Deposit
        - handler: handleCall
          kind: substrate/CallHandler

Overview

Top Level Spec

Field	v1.0.0	v0.2.0	Description
specVersion	String	String	The spec version of the manifest file
name	String	String	Name of your project
version	String	String	Version of your project
description	String	String	Discription of your project
repository	String	String	Git repository address of your project
schema	Schema Spec	Schema Spec	The location of your GraphQL schema file
network	Network Spec	Network Spec	Detail of the network to be indexed
dataSources	DataSource Spec	DataSource Spec	The datasource to your project
templates	Templates Spec	Templates Spec	Allows creating new datasources from this templates
runner	Runner Spec	Runner Spec	Runner specs info

Schema Spec

Field	Type	Description
file	String	The location of your GraphQL schema file

Network Spec

If you start your project by using the subql init command, you'll generally receive a starter project with the correct network settings. If you are changing the target chain of an existing project, you'll need to edit the Network Spec section of this manifest.

The chainId or genesisHash is the network identifier of the blockchain. In Substrate it is always the genesis hash of the network (hash of the first block). You can retrieve this easily by going to PolkadotJS and looking for the hash on block 0 (see the image below).

Additionally you will need to update the endpoint. This defines the (HTTP or WSS) endpoint of the blockchain to be indexed - this must be a full archive node. This property can be a string or an array of strings (e.g. endpoint: ['rpc1.endpoint.com', 'rpc2.endpoint.com']). We suggest providing an array of endpoints as it has the following benefits:

Increased speed - When enabled with worker threads, RPC calls are distributed and parallelised among RPC providers. Historically, RPC latency is often the limiting factor with SubQuery.
Increased reliability - If an endpoint goes offline, SubQuery will automatically switch to other RPC providers to continue indexing without interruption.
Reduced load on RPC providers - Indexing is a computationally expensive process on RPC providers, by distributing requests among RPC providers you are lowering the chance that your project will be rate limited.

Public nodes may be rate limited which can affect indexing speed, when developing your project we suggest getting a private API key from a professional RPC provider.

Field	v1.0.0	Description
chainId	String	A network identifier for the blockchain (`genesisHash` in Substrate)
endpoint	String or String[] or Record<String, IEndpointConfig>	Defines the endpoint of the blockchain to be indexed, this can be a string, an array of endpoints, or a record of endpoints to endpoint configs - This must be a full archive node.
dictionary	String	It is suggested to provide the HTTP endpoint of a full chain dictionary to speed up processing - read how a SubQuery Dictionary works.
chaintypes	{file:String}	Path to chain types file, accept `.json` or `.yaml` format
bypassBlocks	Array	Bypasses stated block numbers, the values can be a `range`(e.g. `"10- 50"`) or `integer`, see Bypass Blocks

Runner Spec

Field	v1.0.0	Description
node	Runner node spec	Describe the node service use for indexing
query	Runner query spec	Describe the query service

Runner Node Spec

Field	v1.0.0	Description
name	String	We currently support `@subql/node`
version	String	Version of the indexer Node service, it must follow the SEMVER rules or `latest`, you can also find available versions in subquery SDK releases
options	Runner Node Options	Runner specific options for how to run your project. These will have an impact on the data your project produces. CLI flags can be used to override these.

Runner Query Spec

Field	All manifest versions	Description
name	String	We currently support `@subql/query`
version	String	Version of the Query service, available `@subql/query` versions and `@subql/query-subgraph` versions, it also must follow the SEMVER rules or `latest`.

Runner Node Options

Field	v1.0.0 (default)	Description
historical	Boolean (true)	Historical indexing allows you to query the state at a specific block height. e.g A users balance in the past.
unfinalizedBlocks	Boolean (false)	If enabled unfinalized blocks will be indexed, when a fork is detected the project will be reindexed from the fork. Requires historical.
unsafe	Boolean (false)	Removes all sandbox restrictions and allows access to all inbuilt node packages as well as being able to make network requests. WARNING: this can make your project non-deterministic.
skipTransactions	Boolean (false)	If your project contains only event handlers and you don't access any other block data except for the block header you can speed your project up. Handlers should be updated to use `LightSubstrateEvent` instead of `SubstrateEvent` to ensure you are not accessing data that is unavailable.

Datasource Spec

Defines the data that will be filtered and extracted and the location of the mapping function handler for the data transformation to be applied.

Field	Type	Description
kind	String	substrate/Runtime
startBlock	Integer	This changes your indexing start block for this datasource, set this as high as possible to skip initial blocks with no relevant data
endBlock	Integer	This sets a end block for processing on the datasource. After this block is processed, this datasource will no longer index your data. Useful when your contracts change at a certain block height, or when you want to insert data at genesis. For example, setting both the `startBlock` and `endBlock` to 320, will mean this datasource only operates on block 320
mapping	Mapping Spec

Mapping Spec

Field	All manifest versions	Description
handlers & filters	Default handlers and filters, Custom handlers and filters	List all the mapping functions and their corresponding handler types, with additional mapping filters. For custom runtimes mapping handlers please view Custom data sources

Data Sources and Mapping

In this section, we will talk about the default Substrate runtime and its mapping. Here is an example:

{
  ...
  dataSources: [
    {
      kind: SubstrateDataSourceKind.Runtime, // Indicates that this is default runtime
      startBlock: 1, // This changes your indexing start block, set this higher to skip initial blocks with less data
      mapping: {
        file: "./dist/index.js", // Entry path for this mapping
        handlers: [
          /* Enter handers here */
        ],
      }
    }
  ]
}

Mapping Handlers and Filters

The following table explains filters supported by different handlers.

Your SubQuery project will be much more efficient when you only use event and call handlers with appropriate mapping filters.

Handler	Supported filter
substrate/BlockHandler	`specVersion`, `modulo`, `timestamp`
substrate/EventHandler	`module`,`method`
substrate/CallHandler	`module`,`method` ,`success`, `isSigned`

Default runtime mapping filters are an extremely useful feature to decide what block, event, or extrinsic will trigger a mapping handler.

Only incoming data that satisfies the filter conditions will be processed by the mapping functions. Mapping filters are optional but are highly recommended as they significantly reduce the amount of data processed by your SubQuery project and will improve indexing performance.

# Example filter from Substrate callHandler
filter:
  module: balances
  method: Deposit
  success: true
  isSigned: true

The specVersion filter specifies the spec version range for a Substrate block. The following examples describe how to set version ranges.

filter:
  specVersion: [23, 24]   # Index block with specVersion in between 23 and 24 (inclusive).
  specVersion: [100]      # Index block with specVersion greater than or equal 100.
  specVersion: [null, 23] # Index block with specVersion less than or equal 23.

The modulo filter allows handling every N blocks, which is useful if you want to group or calculate data at a set interval. The following example shows how to use this filter.

filter:
  modulo: 50 # Index every 50 blocks: 0, 50, 100, 150....

The timestamp filter is very useful when indexing block data with specific time intervals between them. It can be used in cases where you are aggregating data on a hourly/daily basis. It can be also used to set a delay between calls to blockHandler functions to reduce the computational costs of this handler.

The timestamp filter accepts a valid cron expression and runs on schedule against the timestamps of the blocks being indexed. Times are considered on UTC dates and times. The block handler will run on the first block that is after the next iteration of the cron expression.

filter:
  # This cron expression will index blocks with at least 5 minutes interval
  # between their timestamps starting at startBlock given under the datasource.
  timestamp: "*/5 * * * *"

Note

We use the cron-converter package to generate unix timestamps for iterations out of the given cron expression. So, make sure the format of the cron expression given in the timestamp filter is compatible with the package.

Some common examples

  # Every minute
  timestamp: "* * * * *"
  # Every hour on the hour (UTC)
  timestamp: "0 * * * *"
  # Every day at 1am UTC
  timestamp: "0 1 * * *"
  # Every Sunday (weekly) at 0:00 UTC
  timestamp: "0 0 * * 0"

Simplifying your Project Manifest for a large number contract addresses

If your project has the same handlers for multiple versions of the same type of contract your project manifest can get quite repetitive. e.g you want to index the transfers for many similar ERC20 contracts, there are ways to better handle a large static list of contract addresses.

Note that there is also dynamic datasources for when your list of addresses is dynamic (e.g. you use a factory contract).

Custom Chains

You can index data from custom Substrate chains by also including chain types in the manifest.

We support the additional types used by Substrate runtime modules, typesAlias, typesBundle, typesChain, and typesSpec are also supported.

In the example below, the network.chaintypes are pointing to a file that has all the custom types included, This is a standard chainspec file that declares the specific types supported by this blockchain in either .json, .yaml or .js format.

network:
  genesisHash: "0x91b171bb158e2d3848fa23a9f1c25182fb8e20313b2c1eb49219da7a70ce90c3"
  endpoint: "ws://host.kittychain.io/public-ws"
  chaintypes:
    file: ./types.json # The relative filepath to where custom types are stored

To use typescript for your chain types file include it in the src folder (e.g. ./src/types.ts), run yarn build and then point to the generated js file located in the dist folder.

network:
  chaintypes:
    file: ./dist/types.js # Will be generated after yarn run build

Things to note about using the chain types file with extension .ts or .js:

Your manifest version must be v0.2.0 or above.
Only the default export will be included in the polkadot api when fetching blocks.

Here is an example of a .ts chain types file:

import { typesBundleDeprecated } from "moonbeam-types-bundle";
export default { typesBundle: typesBundleDeprecated };

Working Example

You can see the suggested method for connecting and retrieving custom chain types in SubQuery's Official Dictionary repository. Here you will find a dictionary project for each network with all the chain types correct inserted. We retrieve these definitions from the official Polkadot.js repo, where each network lists their their chaintypes.

For example, Acala publish an offical chain type definition to NPM. This is imported in your project's package.json like so:

{
  ...
  "devDependencies": {
    ...
    "@acala-network/type-definitions": "latest"
  },
  ...
}

The under /src/chaintypes.ts we define a custom export for Acala's types bundle from this package.

import { typesBundleForPolkadot } from "@acala-network/type-definitions";

export default { typesBundle: typesBundleForPolkadot };

This is then exported in the package.json like so:

{
  ...
  "devDependencies": {
    ...
    "@acala-network/type-definitions": "latest"
  },
  "exports": {
    "chaintypes": "src/chaintypes.ts"
  }
  ...
}

Finally, in the project.ts manifest, we can import this official types bundle as per standard:

{
  network: {
    chainId:
      "0x91b171bb158e2d3848fa23a9f1c25182fb8e20313b2c1eb49219da7a70ce90c3",
    endpoint: [
      "wss://acala-polkadot.api.onfinality.io/public-ws",
      "wss://acala-rpc-0.aca-api.network",
    ],
    dictionary: "https://api.subquery.network/sq/subquery/acala-dictionary",
    chaintypes: {
      file: "./dist/chaintypes.js",
    },
  },
}

Real-time indexing (Unfinalised Blocks)

As indexers are an additional layer in your data processing pipeline, they can introduce a massive delay between when an on-chain event occurs and when the data is processed and able to be queried from the indexer.

SubQuery provides real time indexing of unfinalised data directly from the RPC endpoint that solves this problem. SubQuery takes the most probabilistic data before it is finalised to provide to the app. In the unlikely event that the data isn’t finalised, SubQuery will automatically roll back and correct its mistakes quickly and efficiently - resulting in an insanely quick user experience for your customers.

To enable this feature, you must ensure that your project has the --unfinalized-blocks command enabled as well as historic indexing (enabled by default)

Bypass Blocks

Bypass Blocks allows you to skip the stated blocks, this is useful when there are erroneous blocks in the chain or when a chain skips a block after an outage or a hard fork. It accepts both a range or single integer entry in the array.

When declaring a range use an string in the format of "start - end". Both start and end are inclusive, e.g. a range of "100-102" will skip blocks 100, 101, and 102.

{
  network: {
    bypassBlocks: [1, 2, 3, "105-200", 290];
  }
}

Endpoint Config

This option allows specifying options that are applied specific to an endpoint. As of now this just allows setting headers on a per endpoint basis.

Here is an example of how to set an API key in the header of RPC requests in your endpoint config.

{
  network: {
    endpoint: {
      "https://polkadot.rpc.subquery.network/public": {
        headers: {
          "x-api-key": "your-api-key",
        }
      }
    }
  }
}

Custom Data Sources

Custom Data Sources provide network specific functionality that makes dealing with data easier. They act as a middleware that can provide extra filtering and data transformation.

A good example of this is EVM support, having a custom data source processor for EVM means that you can filter at the EVM level (e.g. filter contract methods or logs) and data is transformed into structures farmiliar to the Ethereum ecosystem as well as parsing parameters with ABIs.

Custom Data Sources can be used with normal data sources.

Here is a list of supported custom datasources:

Kind	Supported Handlers	Filters	Description
substrate/FrontierEvm	substrate/FrontierEvmEvent, substrate/FrontierEvmCall	See filters under each handlers	Provides easy interaction with EVM transactions and events on the Frontier EVM (widely used across Polkadot including in Moonbeam and Astar networks)