Polkadot/Substrate Manifest File

SubQuery TeamAbout 9 min

Polkadot/Substrate Manifest File

The Manifest project.yaml 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 YAML or JSON format. In this document, we will use YAML in all the examples.

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

specVersion: 1.0.0
name: subquery-starter
version: 0.0.1
    name: "@subql/node"
    version: "*"
    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
  file: ./schema.graphql
  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
  # You can get them from OnFinality for free https://app.onfinality.io
  # https://documentation.onfinality.io/support/the-enhanced-api-service
  endpoint: ["wss://polkadot.api.onfinality.io/public-ws"]
  # 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"]
  - kind: substrate/Runtime
    startBlock: 1 # Block to start indexing from
      file: ./dist/index.js
        - handler: handleBlock
          kind: substrate/BlockHandler
        - handler: handleEvent
          kind: substrate/EventHandler
            module: balances
            method: Deposit
        - handler: handleCall
          kind: substrate/CallHandler

Migrating to v1.0.0 upgrade

If you have a project with specVersion below v1.0.0 you can use subql migrate to quickly upgrade. See the CLI documentation for more information.

Change Log for v1.0.0

Under runner:

  • Now that SubQuery supports multiple layer 1 networks, you must provide runner information for various services.
  • runner.node specify the node image that is used to run the current project [@subql/node or @subql/node-avalanche].
  • runner.query specify the query service image associate with the project database - use @subql/query.
  • version specifies the version of these service, they should follow the SEMVERopen in new window rules and match a published version on our package repositoryopen in new window. Latest and Dev are not supported.

Under templates:

Template are introduced from manifest v0.2.1, it allows creating datasources dynamically from these templates. This is useful when you don't know certain specific details when creating your project. A good example of this is when you know a contract will be deployed at a later stage but you don't know what the address will be.

For a more detailed explanation head here.

Change log for v0.2.0

Under network:

  • There is a new required genesisHash field which helps to identify the chain being used.
  • For v0.2.0 and above, you are able to reference an external chaintype file if you are referencing a custom chain.

Under dataSources:

  • Can directly link an index.js entry point for mapping handlers. By default this index.js will be generated from index.ts during the build process.
  • Data sources can now be either a regular runtime data source or custom data source.

Migrating from v0.2.0 to v0.3.0 upgrade

If you have a project with specVersion v0.2.0, The only change is a new required chainId field which helps to identify the chain being used.

CLI Options

subql migrate can be run in an existing project to migrate the project manifest to the latest version.


Top Level Spec

specVersionStringStringThe spec version of the manifest file
nameStringStringName of your project
versionStringStringVersion of your project
descriptionStringStringDiscription of your project
repositoryStringStringGit repository address of your project
schemaSchema SpecSchema SpecThe location of your GraphQL schema file
networkNetwork SpecNetwork SpecDetail of the network to be indexed
dataSourcesDataSource SpecDataSource SpecThe datasource to your project
templatesTemplates SpecTemplates SpecAllows creating new datasources from this templates
runnerRunner SpecRunner SpecRunner specs info

Schema Spec

fileStringThe 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 PolkadotJSopen in new window and looking for the hash on block 0 (see the image below).

Genesis Hash

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 like OnFinalityopen in new window.

chainIdStringxA network identifier for the blockchain (genesisHash in Substrate)
genesisHashStringStringThe genesis hash of the network (from v1.0.0 this is an alias for chainId and not necessary)
endpointStringStringDefines the wss or ws endpoint of the blockchain to be indexed - This must be a full archive node. You can retrieve endpoints for all parachains for free from OnFinalityopen in new window
portNumberNumberOptional port number on the endpoint to connect to
dictionaryStringStringIt 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}{file:String}Path to chain types file, accept .json or .yaml format
bypassBlocksArrayxBypasses stated block numbers, the values can be a range(e.g. "10- 50") or integer, see Bypass Blocks

Runner Spec

nodeRunner node specDescribe the node service use for indexing
queryRunner query specDescribe the query service

Runner Node Spec

nameStringWe currently support @subql/node
versionStringVersion of the indexer Node service, it must follow the SEMVERopen in new window rules or latest, you can also find available versions in subquery SDK releasesopen in new window

Runner Query Spec

FieldAll manifest versionsDescription
nameStringWe currently support @subql/query
versionStringVersion of the Query service, available versions can be found hereopen in new window, it also must follow the SEMVER rules or latest.

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.

startBlockIntegerThis changes your indexing start block, set this higher to skip initial blocks with less data
mappingMapping Spec

Mapping Spec

FieldAll manifest versionsDescription
handlers & filtersDefault 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:

  - kind: substrate/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
      file: dist/index.js # Entry path for this mapping

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.

HandlerSupported filter
substrate/BlockHandlerspecVersion, modulo, timestamp
substrate/CallHandlermodule,method ,success

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
  module: balances
  method: Deposit
  success: true

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

  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.

  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.

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


We use the cron-converteropen in new window 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"

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.

  genesisHash: "0x91b171bb158e2d3848fa23a9f1c25182fb8e20313b2c1eb49219da7a70ce90c3"
  endpoint: "ws://host.kittychain.io/public-ws"
    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.

    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:

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 repositoryopen in new window. 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 repoopen in new window, where each network lists their their chaintypes.

For example, Acala publish an offical chain type definition to NPMopen in new window. 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.yaml manifest, we can import this official types bundle as per standard:

  genesisHash: "0xfc41b9bd8ef8fe53d58c7ea67c794c7ec9a73daf05e6d54b14ff6342c99ba64c"
  endpoint: wss://acala-polkadot.api.onfinality.io/public-ws
    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.

  chainId: "0xfc41b9bd8ef8fe53d58c7ea67c794c7ec9a73daf05e6d54b14ff6342c99ba64c"
  endpoint: wss://acala-polkadot.api.onfinality.io/public-ws
  bypassBlocks: [1, 2, 3, "105-200", 290]

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:

KindSupported HandlersFiltersDescription
substrate/FrontierEvmsubstrate/FrontierEvmEvent, substrate/FrontierEvmCallSee filters under each handlersProvides easy interaction with EVM transactions and events on the Frontier EVM (widely used across Polkadot including in Moonbeam and Astar networks)


You can validate your project manifest by running subql validate. This will check that it has the correct structure, valid values where possible and provide useful feedback as to where any fixes should be made.