Polymesh Subquery

Polymesh Subquery allows for querying historical events on the Polymesh chain through a GraphQL interface. This project is based on SubQuery, and contains the mappings specific to Polymesh.

Running

1. In the docker-compose.yml file, set the appropriate environment variables for subquery-node container
2. Install subql cli: npm i -g @subql/cli
3. ./rerun.sh (requires docker compose). To persist data between runs, remove the -v flag, which causes the docker volume to be removed

Version

This SubQuery version works with chain versions 6.2.x

ENV settings

The behavior of the dev image can be controlled by setting ENV variables. The default entrypoint is docker-entrypoint.sh, which should be looked at to fully understand these settings. Notable ones include:

• NETWORK_ENDPOINT - the wss endpoint of the blockchain to be indexed
• NETWORK_CHAIN_ID - The genesis hash of the chain. This value can be retrieved by going to the explorer and looking for the block hash of block 0. e.g. for mainnet
• NETWORK_DICTIONARY - The GraphQL endpoint of SubQuery Dictionary Project that pre-indexes events on chain to dramatically improve indexing of this SubQuery Project (sometimes up to 10x faster). The dictionary has already pre-scanned over the network, and has records of the module and method for every event/extrinsic on each block. If you don't have dictionary setup you can see examples of how to create a dictionary in the dictionary repository. Polymesh dictionary can be referenced from here.
• START_BLOCK - block from which indexing should start. Generally this should be set to 1, but other values can be useful for debugging.

More advanced options are:

• MAX_OLD_SPACE_SIZE — this will be passed onto the node process as --max-old-space-size flag. The recommendation is for this to be ~75% of available RAM. Defaults to 1536, a setting appropriate for 2GB.

Historical state tracking

Polymesh SubQuery now, by default, tracks the historical state of all the entities. This allows to query the state of any entity at any block height.

NOTE - This requires the PostgreSQL to have a btree_gist extension. You can use the following query to create the extension -

CREATE EXTENSION IF NOT EXISTS btree_gist;

To disable this feature, you can pass --disable-historical=true as one of the command arguments to the subquery-node container. Refer to docker-compose.yml for example

Read more about querying historical state here.

License

This project uses SubQuery, which is Apache 2.0 licensed.

The project itself is also Apache 2.0 licensed.