Deprecated term used for Subsquid Network and for the data sourcing service of the deprecated FireSquid SDK version. Occasionally refers to a specific dataset available from either source (e.g. "Ethereum archive"). The new terminology is:
- "Archives" as an abstract collection of services for some networks is replaced by "Subsquid Network" (when referring to data location) or "Subsquid Network gateway" (when referring to the service)
- "public Archives" are replaced by the open private version of Subsquid Network
- "an archive" for a particular network is replaced by "a Subsquid Network dataset"
- "an archive endpoint" becomes "a dataset endpoint"
Not to be confused with archive blockchain nodes.
Cloud (former Aquarium)
An atomic state transition of a blockchain. Typically an ordered collection of transactions.
On Substrate, a call is a sub-routine changing the runtime state. An extrinsic consists of a root call which in turn may have sub-calls, thus calls executed by an extrinsic have parent-child relationship. For example,
util.batch extrinsic has a single root call and multiple child calls. Subsquid processor is call-based rather than extrinsic based, as normally one is interested in specific calls changing the substrate state, no matter if it was part of a batch extrinsic, or it was wrapped in a sudo or proxy call.
Stands for Extract-Transform-Load. A pipeline to extract data from the source, enrich, transform, normalize and load into the target data store.
An operation performed during a blockchain state transition that results in emission of a structured log message. Subsequently, the message can be retrieved from blockchain nodes.
Stands for the Ethereum Virtual Machine. An instruction set and the runtime specification originally developed for the Ethereum network which was later adopted by many other chains (e.g. BSC, Polygon).
A declarative query language and an API specification language developed by Facebook as an alternative to REST. See the official GraphQL docs for more details.
An SDK (software development kit) and a smart-contract language for developing WASM-based smart contracts, maintained by Parity. The contracts developed with ink! are compiled into a WASM blob compatible with the API exposed by the
Contracts pallet. More details here.
An open-source GraphQL server that automatically generates an expressive API from an input schema file.
A portable module that can be added to a Substrate runtime. Typically, contains a self-contained implementation of a business logic that can be re-used across multiple chains.
A file describing the target data schema for a squid, normally called
schema.graphql. The file uses a GraphQL dialect to define entities, properties and relations. See details here.
A key-value map defining the internal worldview of a EVM contract of a Substrate runtime at a specific point in time. The consensus algorithm ensures that the honest majority of the nodes agree on the runtime state.
A project consisting of an ETL for extracting and transforming on-chain data (squid processor), and optionally an API to present the data (squid API).
The ETL part of the squid. Extracts on-chain data from an Subsquid Network dataset and/or directly from chain RPC, then transforms and optionally enriches it with external data. Saves the result into a target data sink.
The data presentation part of the squid. Typically, it's an OpenReader GraphQL API auto-generated from a schema file.
Substrate is a framework for developing blockchain runtimes. Used to develop the Polkadot, Kusama chains and all the parachains.
The code that defines the state transition logic of a blockchain, and by extention its business logic. See details on the Substrate docs page.
A tool generating strongly typed data access classes from a metadata in some format. Subsquid SDK includes typegen tools:
- for accessing EVM smart contract data based on the contract ABI
- for accessing event, extrinsics and storage data based on Substrate metadata
- for accessing ink! smart contract data based on the contract metadata
See this section for documentation on these tools.
A portable binary code format and an execution environment specification. WASM programs enjoy deterministic outputs and near-native execution speeds, which makes WASM an attractive alternative to EVM.