Lightm Squid is used for index related data on chain, just like The Graph but more flexible and allowing for more complex query structures, this is why Lightm migrated from The Graph to Subsquid.
Before doing this, make sure you have Node.js and Docker installed.
And you have to clone Lightm-evm and check the README in it.
Then
- Run
npm i
; - Run
make build
to compile files insrc
tolib
; - Run
make up-local-archive
to start db to collecting local test net data (make sure you start local test net on localhost:8545); - Run
make up
to start db for processor; - Run
make process
to start the processor, index and aggregate event data on chain; - Open a new terminal window, run
make serve
to start graphql server;
This is a starter template of a squid indexer for EVM networks (Ethereum, Polygon, BSC, etc.). See
To extract EVM logs and transactions by a topic or a contract address, use EvmBatchProcessor.addLog()
and EvmBatchProcessor.addTransaction()
methods of EvmBatchProcessor
, defined in src/processor.ts
.
The requested data is transformed in batches by a single handler provided by the processor.run()
method.
For a full list of supported networks and config options,
check the EvmBatchProcessor
overview and the configuration page.
For a step-by-step migration guide from TheGraph, see the dedicated docs page.
Install Squid CLI:
npm i -g @subsquid/cli
Run the indexer and the GraphQL API:
# 1. Update the Squid SDK and install dependencies
npm run update
npm ci
# 2. Compile typescript files
sqd build
# 3. Start target Postgres database and detach
sqd up
# 4. Start the processor
sqd process
# 5. The command above will block the terminal
# being busy with fetching the chain data,
# transforming and storing it in the target database.
#
# To start the graphql server open the separate terminal
# and run. The GraphQL playground will be available at localhost:4350graphl
sqd serve
Start development by defining the schema of the target database via schema.graphql
.
Schema definition consists of regular graphql type declarations annotated with custom directives.
Full description of schema.graphql
dialect is available here.
Mapping developers use TypeORM EntityManager
to interact with target database during data processing. All necessary entity classes are
generated by the squid framework from schema.graphql
. This is done by running sqd codegen
command.
All database changes are applied through migration files located at db/migrations
.
squid-typeorm-migration(1)
tool provides several commands to drive the process.
## delete all migrations
rm -rf db/migrations/*.js
## drop create the database
make down
make up
## create a new schema migration from the entities
npx squid-typeorm-migration generate
See docs on schema updates for more details.
It is necessary to import the respective ABI definition to decode EVM logs.
To generate a type-safe facade class to decode EVM logs, place the ABI in the assets
folder and use squid-evm-typegen(1)
, e.g.:
npx squid-evm-typegen src/abi assets/ERC721.json#erc721
For more details about squid-evm-typegen
read the docs page
Squid tools assume a certain project layout.
- All compiled js files must reside in
lib
and all TypeScript sources insrc
. The layout oflib
must reflectsrc
. - All TypeORM classes must be exported by
src/model/index.ts
(lib/model
module). - Database schema must be defined in
schema.graphql
. - Database migrations must reside in
db/migrations
and must be plain js files. sqd(1)
andsquid-*(1)
executables consult.env
file for a number of environment variables.
It is possible to extend squid-graphql-server(1)
with custom
type-graphql resolvers and to add request validation. See the docs for more details.