Interact with a node
There are multiple ways to interact with a node: the CLI, gRPC, or the REST endpoints.
Using the CLI
You can use the injectived
CLI to interact with a node. If you are interacting with a node in your local private network, make sure the node is running in the terminal before you use the CLI.
For more details on how to use injectived
, go to Using injectived
Using gRPC
The Protobuf ecosystem developed tools for different use cases, including code-generation from *.proto
files into various languages. These tools allow clients to be built easily. Often, the client connection (i.e., the transport) can be plugged and replaced very easily. Let's explore a popular transport method, gRPC.
Since the code generation library largely depends on your own tech stack, we will only present two alternatives:
grpcurl
for generic debugging and testingProgrammatically via Go, Python, or TS
grpcurl
grpcurl is like curl
, but for gRPC. It is also available as a Go library, but we will use it only as a CLI command for debugging and testing purposes. Follow the instructions in the previous link to install it.
Assuming you have a local node running (either a localnet, or connected a live network), you should be able to run the following command to list the Protobuf services available. You can replace localhost:9000
by the gRPC server endpoint of another node, which is configured under the grpc.address
field inside app.toml
:
You should see a list of gRPC services, like cosmos.bank.v1beta1.Query
. This is called reflection, which is a Protobuf endpoint returning a description of all available endpoints. Each of these represents a different Protobuf service, and each service exposes multiple RPC methods you can query against.
In order to get a description of the service, you can run the following command:
It's also possible to execute an RPC call to query the node for information:
Query for historical state using grpcurl
You may also query for historical data by passing some gRPC metadata to the query: the x-cosmos-block-height
metadata should contain the block to query. Using grpcurl as above, the command looks like:
Assuming the state at that block has not yet been pruned by the node, this query should return a non-empty response.
Programmatically
The following examples are in Go, but the Python and TS SDKs can also be used to programatically interact with a node/Injective.
The following snippet shows how to query the state using gRPC inside a Go program. The idea is to create a gRPC connection, and use the Protobuf-generated client code to query the gRPC server.
Query for historical state using Go
Querying for historical blocks is done by adding the block height metadata in the gRPC request.
Using the REST Endpoints
All gRPC services on the Cosmos SDK are made available for more convenient REST-based queries through gRPC-gateway. The format of the URL path is based on the Protobuf service method's full-qualified name, but may contain small customizations so that final URLs look more idiomatic. For example, the REST endpoint for the cosmos.bank.v1beta1.Query/AllBalances
method is GET /cosmos/bank/v1beta1/balances/{address}
. Request arguments are passed as query parameters.
The following examples assume you are using REST Endpoints to interact with your node in your local private network. You can change the domain to public networks.
As a concrete example, the curl
command to make balances request is:
Make sure to replace localhost:1317
with the REST endpoint of your node, configured under the api.address
field.
The list of all available REST endpoints is available as a Swagger specification file; it can be viewed at localhost:1317/swagger
. Make sure that the api.swagger
field is set to true in your app.toml
file.
Query for historical state using REST
Querying for historical state is done using the HTTP header x-cosmos-block-height
. For example, a curl command would look like:
Assuming the state at that block has not yet been pruned by the node, this query should return a non-empty response.
Cross-Origin Resource Sharing (CORS)
CORS policies are not enabled by default to help with security. If you would like to use the rest-server in a public environment we recommend you provide a reverse proxy, this can be done with nginx. For testing and development purposes, there is an enabled-unsafe-cors
field inside app.toml
.
Sending Transactions
Sending transactions using gRPC and REST requires some additional steps: generating the transaction, signing it, and finally broadcasting it.
You can learn more in Transactions.
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