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Tutorial Add a gRPC plugin to your API

API settings

To add a gRPC plugin to your API, you must specify the bundle name using the custom_middleware_bundle field:

  "name": "Tyk Test API",
  "api_id": "1",
  "org_id": "default",
  "definition": {
    "location": "header",
    "key": "version"
  "auth": {
      "auth_header_name": "authorization"
  "use_keyless": true,
  "version_data": {
    "not_versioned": true,
    "versions": {
      "Default": {
        "name": "Default",
        "expires": "3000-01-02 15:04",
        "use_extended_paths": true,
        "extended_paths": {
          "ignored": [],
          "white_list": [],
          "black_list": []
  "proxy": {
    "listen_path": "/quickstart/",
    "target_url": "http://httpbin.org",
    "strip_listen_path": true
  "custom_middleware_bundle": "test-bundle"

Global settings

To enable gRPC plugins you need to add the following block to tyk.conf:

"coprocess_options": {
  "enable_coprocess": true,
  "coprocess_grpc_server": "tcp://",
  "grpc_recv_max_size": 100000000,
  "grpc_send_max_size": 100000000
"enable_bundle_downloader": true,
"bundle_base_url": "http://my-bundle-server.com/bundles/",
"public_key_path": "/path/to/my/pubkey",

enable_coprocess enables the rich plugins feature.

coprocess_grpc_server specifies the gRPC server URL, in this example we’re using TCP. Tyk will attempt a connection on startup and keep reconnecting in case of failure.

coprocess_options.grpc_recv_max_size coprocess_options.grpc_send_max_size

When using gRPC plugins, Tyk acts as a gRPC client and dispatches requests to your gRPC server. gRPC libraries usually set a default maximum size, for example the official gRPC Java library establishes a 4 MB message size https://jbrandhorst.com/post/grpc-binary-blob-stream/. We’ve added flags for establishing a message size in both directions (send and receive). For most use cases and especially if you’re dealing with multiple hooks, where the same request object is passed through them, it’s recommended to set both values to the same size."

enable_bundle_downloader enables the bundle downloader.

bundle_base_url is a base URL that will be used to download the bundle, in this example we have “test-bundle” specified in the API settings, Tyk will fetch the following URL: http://my-bundle-server.com/bundles/test-bundle.

public_key_path sets a public key, this is used for verifying signed bundles, you may omit this if unsigned bundles are used.


From version 1.3.6, you can now override response code, headers and body using ReturnOverrides. See the Extend ReturnOverides sample for details.