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.

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, 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

@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 below.
• Refer to the detailed package comparison 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.max_connection_age_ms
• grpc.max_connection_age_grace_ms
• grpc.max_connection_idle_ms
• 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
• grpc-node.retry_max_attempts_limit
• grpc-node.flow_control_window
• 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.