# gRPC, REST, and Tendermint Endpoints

### An Overview of All Endpoints <a href="#an-overview-of-all-endpoints" id="an-overview-of-all-endpoints"></a>

Each node exposes the following endpoints for users to interact with a node, each endpoint is served on a different port. Details on how to configure each endpoint is provided in the endpoint's own section.

* the gRPC server (default port: `9090`),
* the REST server (default port: `1317`),
* the Tendermint RPC endpoint (default port: `26657`).

The node also exposes some other endpoints, such as the Tendermint P2P endpoint, or the [Prometheus endpoint (opens new window)](https://docs.tendermint.com/master/nodes/metrics.html#metrics), which are not directly related to the Cosmos SDK. Please refer to the [Tendermint documentation (opens new window)](https://docs.tendermint.com/master/tendermint-core/using-tendermint.html#configuration)for more information about these endpoints.

### [#](https://docs.cosmos.network/master/core/grpc_rest.html#grpc-server)gRPC Server <a href="#grpc-server" id="grpc-server"></a>

In the Cosmos SDK, Protobuf is the main [encoding](https://docs.cosmos.network/master/core/encoding) library. This brings a wide range of Protobuf-based tools that can be plugged into the Cosmos SDK. One such tool is [gRPC (opens new window)](https://grpc.io/), a modern open-source high performance RPC framework that has decent client support in several languages.

Each module exposes a [Protobuf `Query` service](https://docs.cosmos.network/master/building-modules/messages-and-queries.html#queries) that defines state queries. The `Query` services and a transaction service used to broadcast transactions are hooked up to the gRPC server via the following function inside the application:

Copy // RegisterGRPCServer registers gRPC services directly with the gRPC // server. RegisterGRPCServer(grpc.Server)

Note: It is not possible to expose any [Protobuf `Msg` service](https://docs.cosmos.network/master/building-modules/messages-and-queries.html#messages) endpoints via gRPC. Transactions must be generated and signed using the CLI or programmatically before they can be broadcasted using gRPC. See [Generating, Signing, and Broadcasting Transactions](https://docs.cosmos.network/master/run-node/txs.html) for more information.

The `grpc.Server` is a concrete gRPC server, which spawns and serves all gRPC query requests and a broadcast transaction request. This server can be configured inside `~/.simapp/config/app.toml`:

* `grpc.enable = true|false` field defines if the gRPC server should be enabled. Defaults to `true`.
* `grpc.address = {string}` field defines the address (really, the port, since the host should be kept at `0.0.0.0`) the server should bind to. Defaults to `0.0.0.0:9090`.

`~/.simapp` is the directory where the node's configuration and databases are stored. By default, it's set to `~/.{app_name}`.

Once the gRPC server is started, you can send requests to it using a gRPC client. Some examples are given in our [Interact with the Node](https://docs.cosmos.network/master/run-node/interact-node.html#using-grpc) tutorial.

An overview of all available gRPC endpoints shipped with the Cosmos SDK is [Protobuf documentation (opens new window)](https://buf.build/cosmos/cosmos-sdk).

### [#](https://docs.cosmos.network/master/core/grpc_rest.html#rest-server)REST Server <a href="#rest-server" id="rest-server"></a>

Cosmos SDK supports REST routes via gRPC-gateway.

All routes are configured under the following fields in `~/.simapp/config/app.toml`:

* `api.enable = true|false` field defines if the REST server should be enabled. Defaults to `false`.
* `api.address = {string}` field defines the address (really, the port, since the host should be kept at `0.0.0.0`) the server should bind to. Defaults to `tcp://0.0.0.0:1317`.
* some additional API configuration options are defined in `~/.simapp/config/app.toml`, along with comments, please refer to that file directly.

#### [#](https://docs.cosmos.network/master/core/grpc_rest.html#grpc-gateway-rest-routes)gRPC-gateway REST Routes <a href="#grpc-gateway-rest-routes" id="grpc-gateway-rest-routes"></a>

If, for various reasons, you cannot use gRPC (for example, you are building a web application, and browsers don't support HTTP2 on which gRPC is built), then the Cosmos SDK offers REST routes via gRPC-gateway.

[gRPC-gateway (opens new window)](https://grpc-ecosystem.github.io/grpc-gateway/)is a tool to expose gRPC endpoints as REST endpoints. For each gRPC endpoint defined in a Protobuf `Query` service, the Cosmos SDK offers a REST equivalent. For instance, querying a balance could be done via the `/cosmos.bank.v1beta1.QueryAllBalances` gRPC endpoint, or alternatively via the gRPC-gateway `"/cosmos/bank/v1beta1/balances/{address}"` REST endpoint: both will return the same result. For each RPC method defined in a Protobuf `Query` service, the corresponding REST endpoint is defined as an option:

Copy // AllBalances queries the balance of all coins for a single account. rpc AllBalances(QueryAllBalancesRequest) returns (QueryAllBalancesResponse) { option (google.api.http).get = "/cosmos/bank/v1beta1/balances/{address}";

For application developers, gRPC-gateway REST routes needs to be wired up to the REST server, this is done by calling the `RegisterGRPCGatewayRoutes` function on the ModuleManager.

#### [#](https://docs.cosmos.network/master/core/grpc_rest.html#swagger)Swagger <a href="#swagger" id="swagger"></a>

A [Swagger (opens new window)](https://swagger.io/)(or OpenAPIv2) specification file is exposed under the `/swagger` route on the API server. Swagger is an open specification describing the API endpoints a server serves, including description, input arguments, return types and much more about each endpoint.

Enabling the `/swagger` endpoint is configurable inside `~/.simapp/config/app.toml` via the `api.swagger` field, which is set to true by default.

For application developers, you may want to generate your own Swagger definitions based on your custom modules. The Cosmos SDK's [Swagger generation script (opens new window)](https://github.com/cosmos/cosmos-sdk/blob/v0.46.0-rc1/scripts/protoc-swagger-gen.sh)is a good place to start.

### [#](https://docs.cosmos.network/master/core/grpc_rest.html#tendermint-rpc)Tendermint RPC <a href="#tendermint-rpc" id="tendermint-rpc"></a>

Independently from the Cosmos SDK, Tendermint also exposes a RPC server. This RPC server can be configured by tuning parameters under the `rpc` table in the `~/.simapp/config/config.toml`, the default listening address is `tcp://0.0.0.0:26657`. An OpenAPI specification of all Tendermint RPC endpoints is available [here (opens new window)](https://docs.tendermint.com/master/rpc/).

Some Tendermint RPC endpoints are directly related to the Cosmos SDK:

* `/abci_query`: this endpoint will query the application for state. As the `path` parameter, you can send the following strings:
  * any Protobuf fully-qualified service method, such as `/cosmos.bank.v1beta1.QueryAllBalances`. The `data` field should then include the method's request parameter(s) encoded as bytes using Protobuf.
  * `/app/simulate`: this will simulate a transaction, and return some information such as gas used.
  * `/app/version`: this will return the application's version.
  * `/store/{path}`: this will query the store directly.
  * `/p2p/filter/addr/{port}`: this will return a filtered list of the node's P2P peers by address port.
  * `/p2p/filter/id/{id}`: this will return a filtered list of the node's P2P peers by ID.
* `/broadcast_tx_{aync,async,commit}`: these 3 endpoint will broadcast a transaction to other peers. CLI, gRPC and REST expose [a way to broadcast transations](https://docs.cosmos.network/master/core/transactions.html#broadcasting-the-transaction), but they all use these 3 Tendermint RPCs under the hood.

### [#](https://docs.cosmos.network/master/core/grpc_rest.html#comparison-table)Comparison Table <a href="#comparison-table" id="comparison-table"></a>

| Name           | Advantages                                                                                                                                                                   | Disadvantages                                                                                                        |
| -------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------------------- |
| gRPC           | <p>- can use code-generated stubs in various languages<br>- supports streaming and bidirectional communication (HTTP2)<br>- small wire binary sizes, faster transmission</p> | <p>- based on HTTP2, not available in browsers<br>- learning curve (mostly due to Protobuf)</p>                      |
| REST           | <p>- ubiquitous<br>- client libraries in all languages, faster implementation<br></p>                                                                                        | <p>- only supports unary request-response communication (HTTP1.1)<br>- bigger over-the-wire message sizes (JSON)</p> |
| Tendermint RPC | - easy to use                                                                                                                                                                | - bigger over-the-wire message sizes (JSON)                                                                          |