| # Pure JavaScript gRPC Client | |
| ## Installation | |
| Node 12 is recommended. The exact set of compatible Node versions can be found in the `engines` field of the `package.json` file. | |
| ```sh | |
| npm install @grpc/grpc-js | |
| ``` | |
| ## Documentation | |
| Documentation specifically for the `@grpc/grpc-js` package is currently not available. However, [documentation is available for the `grpc` package](https://grpc.github.io/grpc/node/grpc.html), and the two packages contain mostly the same interface. There are a few notable differences, however, and these differences are noted in the "Migrating from grpc" section below. | |
| ## Features | |
| - Clients | |
| - Automatic reconnection | |
| - Servers | |
| - Streaming | |
| - Metadata | |
| - Partial compression support: clients can compress and decompress messages, and servers can decompress request messages | |
| - Pick first and round robin load balancing policies | |
| - Client Interceptors | |
| - Connection Keepalives | |
| - HTTP Connect support (proxies) | |
| If you need a feature from the `grpc` package that is not provided by the `@grpc/grpc-js`, please file a feature request with that information. | |
| This library does not directly handle `.proto` files. To use `.proto` files with this library we recommend using the `@grpc/proto-loader` package. | |
| ## Migrating from [`grpc`](https://www.npmjs.com/package/grpc) | |
| `@grpc/grpc-js` is almost a drop-in replacement for `grpc`, but you may need to make a few code changes to use it: | |
| - If you are currently loading `.proto` files using `grpc.load`, that function is not available in this library. You should instead load your `.proto` files using `@grpc/proto-loader` and load the resulting package definition objects into `@grpc/grpc-js` using `grpc.loadPackageDefinition`. | |
| - If you are currently loading packages generated by `grpc-tools`, you should instead generate your files using the `generate_package_definition` option in `grpc-tools`, then load the object exported by the generated file into `@grpc/grpc-js` using `grpc.loadPackageDefinition`. | |
| - If you have a server and you are using `Server#bind` to bind ports, you will need to use `Server#bindAsync` instead. | |
| - If you are using any channel options supported in `grpc` but not supported in `@grpc/grpc-js`, you may need to adjust your code to handle the different behavior. Refer to [the list of supported options](#supported-channel-options) below. | |
| - Refer to the [detailed package comparison](https://github.com/grpc/grpc-node/blob/master/PACKAGE-COMPARISON.md) for more details on the differences between `grpc` and `@grpc/grpc-js`. | |
| ## Supported Channel Options | |
| Many channel arguments supported in `grpc` are not supported in `@grpc/grpc-js`. The channel arguments supported by `@grpc/grpc-js` are: | |
| - `grpc.ssl_target_name_override` | |
| - `grpc.primary_user_agent` | |
| - `grpc.secondary_user_agent` | |
| - `grpc.default_authority` | |
| - `grpc.keepalive_time_ms` | |
| - `grpc.keepalive_timeout_ms` | |
| - `grpc.keepalive_permit_without_calls` | |
| - `grpc.service_config` | |
| - `grpc.max_concurrent_streams` | |
| - `grpc.initial_reconnect_backoff_ms` | |
| - `grpc.max_reconnect_backoff_ms` | |
| - `grpc.use_local_subchannel_pool` | |
| - `grpc.max_send_message_length` | |
| - `grpc.max_receive_message_length` | |
| - `grpc.enable_http_proxy` | |
| - `grpc.default_compression_algorithm` | |
| - `grpc.enable_channelz` | |
| - `grpc.dns_min_time_between_resolutions_ms` | |
| - `grpc.enable_retries` | |
| - `grpc.per_rpc_retry_buffer_size` | |
| - `grpc.retry_buffer_size` | |
| - `grpc.service_config_disable_resolution` | |
| - `grpc.client_idle_timeout_ms` | |
| - `grpc-node.max_session_memory` | |
| - `grpc-node.tls_enable_trace` | |
| - `channelOverride` | |
| - `channelFactoryOverride` | |
| ## Some Notes on API Guarantees | |
| The public API of this library follows semantic versioning, with some caveats: | |
| - Some methods are prefixed with an underscore. These methods are internal and should not be considered part of the public API. | |
| - The class `Call` is only exposed due to limitations of TypeScript. It should not be considered part of the public API. | |
| - In general, any API that is exposed by this library but is not exposed by the `grpc` library is likely an error and should not be considered part of the public API. | |
| - The `grpc.experimental` namespace contains APIs that have not stabilized. Any API in that namespace may break in any minor version update. | |