feat: add SLIMRPC transport support

.github/actions/setup/action.yml

@@ -22,5 +22,10 @@ runs:
         path: |
           ~/.cache/go-build
           ~/go/pkg/mod
+          ~/.cgo-cache
         key: ${{ runner.os }}-go-build-${{ hashFiles('**/go.mod', '**/go.sum') }}
         restore-keys: ${{ runner.os }}-go-build-
+
+    - name: Install SLIM bindings native library
+      shell: bash
+      run: go run github.com/agntcy/slim-bindings-go/v2/cmd/slim-bindings-setup

.github/workflows/go.yaml

@@ -32,9 +32,13 @@ jobs:
 
     - name: Build
       run: go build -mod=readonly -v ./...
+      env:
+        CGO_ENABLED: "1"
 
     - name: Test
       run: go test -race -mod=readonly -v -count=1 -shuffle=on ./...
+      env:
+        CGO_ENABLED: "1"
 
   lint:
     runs-on: ubuntu-latest

go.mod

@@ -1,6 +1,6 @@
 module github.com/a2aproject/a2a-cli
 
-go 1.25.0
+go 1.25.2
 
 require (
 	github.com/a2aproject/a2a-go v0.3.15
@@ -13,6 +13,8 @@ require (
 )
 
 require (
+	github.com/agntcy/slim-a2a-go v0.3.0
+	github.com/agntcy/slim-bindings-go/v2 v2.1.1
 	github.com/google/uuid v1.6.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	golang.org/x/mod v0.35.0 // indirect
@@ -24,3 +26,5 @@ require (
 	google.golang.org/genproto/googleapis/rpc v0.0.0-20260427160629-7cedc36a6bc4 // indirect
 	google.golang.org/protobuf v1.36.11 // indirect
 )
+
+replace github.com/agntcy/slim-a2a-go => /Users/sambetts/Work/src/github.com/agntcy/slim-a2a-go

go.sum

@@ -2,6 +2,8 @@ github.com/a2aproject/a2a-go v0.3.15 h1:h5YpCiPq3jxQ5rIns7oDjPag3ivP8u817AzdA4F+
 github.com/a2aproject/a2a-go v0.3.15/go.mod h1:I7Cm+a1oL+UT6zMoP+roaRE5vdfUa1iQGVN8aSOuZ0I=
 github.com/a2aproject/a2a-go/v2 v2.4.1-0.20260817112309-579cff89f7ba h1:4EedjlTSsl92mWP9qAfa8zKHI7mLzOkMpFiSHl9Y8u0=
 github.com/a2aproject/a2a-go/v2 v2.4.1-0.20260817112309-579cff89f7ba/go.mod h1:EghJ/rY9OCC6jme1z+otOBf+1YCVVCpMSPZU31t3hKY=
+github.com/agntcy/slim-bindings-go/v2 v2.1.1 h1:I2Ac5GRH7W+1gp3Vxm2me0wME0TVroPuK1uvkivp9t0=
+github.com/agntcy/slim-bindings-go/v2 v2.1.1/go.mod h1:LfBa89/DfmYRg9EeU9DxkyXhJTBjsJ0OLIpxA1iBuhc=
 github.com/cespare/xxhash/v2 v2.3.0 h1:UL815xU9SqsFlibzuggzjXhog7bL6oX9BbNZnL2UFvs=
 github.com/cespare/xxhash/v2 v2.3.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=

internal/cli/client.go

@@ -66,8 +66,13 @@ func newClientFromEndpoint(ctx context.Context, cfg *globalConfig, ref string, e
 	}
 	cfg.logf("connecting directly to %s via %s (skipping card resolution)", endpointURL, protocol)
 
+	factoryOpts, err := clientFactoryOpts(cfg)
+	if err != nil {
+		return nil, err
+	}
+
 	endpoint := a2a.NewAgentInterface(endpointURL, protocol)
-	client, err := a2aclient.NewFromEndpoints(ctx, []*a2a.AgentInterface{endpoint}, append(clientFactoryOpts(cfg), extraOpts...)...)
+	client, err := a2aclient.NewFromEndpoints(ctx, []*a2a.AgentInterface{endpoint}, append(factoryOpts, extraOpts...)...)
 	return client, hintInsecure(err)
 }
 
@@ -90,7 +95,11 @@ func newClientFromCard(ctx context.Context, cfg *globalConfig, ref string, extra
 		return nil, fmt.Errorf("resolving agent card: %w", err)
 	}
 
-	factoryOpts := append(clientFactoryOpts(cfg), extraOpts...)
+	factoryOpts, err := clientFactoryOpts(cfg)
+	if err != nil {
+		return nil, err
+	}
+	factoryOpts = append(factoryOpts, extraOpts...)
 	if len(protos) > 0 {
 		factoryOpts = append(factoryOpts, a2aclient.WithConfig(a2aclient.Config{PreferredTransports: protos}))
 	}
@@ -107,22 +116,33 @@ func hintInsecure(err error) error {
 	return err
 }
 
-func clientFactoryOpts(cfg *globalConfig) []a2aclient.FactoryOption {
-	factoryOpts := []a2aclient.FactoryOption{
+func clientFactoryOpts(cfg *globalConfig) ([]a2aclient.FactoryOption, error) {
+	opts := []a2aclient.FactoryOption{
 		a2av0.WithRESTTransport(a2av0.RESTTransportConfig{}),
 		a2av0.WithJSONRPCTransport(a2av0.JSONRPCTransportConfig{}),
 	}
 	var grpcOpts []grpc.DialOption
 	if cfg.insecureGRPC {
 		grpcOpts = append(grpcOpts, grpc.WithTransportCredentials(insecure.NewCredentials()))
 	}
-	factoryOpts = append(factoryOpts,
+	opts = append(opts,
 		a2agrpcv0.WithGRPCTransport(grpcOpts...),
 		a2agrpc.WithGRPCTransport(grpcOpts...),
 	)
-	return factoryOpts
+	for _, t := range cfg.transports {
+		if strings.EqualFold(t, "slimrpc") {
+			slimOpt, err := withSLIMRPCTransport(cfg)
+			if err != nil {
+				return nil, err
+			}
+			opts = append(opts, slimOpt)
+			break
+		}
+	}
+	return opts, nil
 }
 
+
 func stripHTTPScheme(raw string) string {
 	u, err := url.Parse(raw)
 	if err != nil || (u.Scheme != "http" && u.Scheme != "https") {

internal/cli/root.go

@@ -56,6 +56,14 @@ type globalConfig struct {
 	insecureGRPC bool
 	configPath   string
 
+	// SLIM RPC transport options (only used when --transport slimrpc)
+	slimEndpoint                        string
+	slimLocalName                       string
+	slimIdentityProviderType            string
+	slimIdentityProviderSharedSecret    string
+	slimIdentityVerifierType            string
+	slimIdentityVerifierSharedSecret    string
+
 	bindings []clicfg.FlagBinding
 
 	*output.Printer
@@ -122,6 +130,12 @@ func newRootCmd(cfg *globalConfig, deps deps) *cobra.Command {
 	pf.BoolVarP(&cfg.verbose, "verbose", "v", false, "Verbose output to stderr")
 	pf.BoolVar(&cfg.insecureGRPC, "insecure", false, "Use insecure (plaintext) gRPC transport credentials")
 	pf.StringVar(&cfg.configPath, "config", "", "Load configuration from an explicit .env file in place of the local .env")
+	pf.StringVar(&cfg.slimEndpoint, "slim-endpoint", "http://127.0.0.1:46357", "SLIM node endpoint (used with --transport slimrpc)")
+	pf.StringVar(&cfg.slimLocalName, "slim-local-name", "agntcy/a2a-cli/client", "Local SLIM identity name org/namespace/app (used with --transport slimrpc)")
+	pf.StringVar(&cfg.slimIdentityProviderType, "slim-identity-provider-type", "", "SLIM identity provider type: sharedSecret (required with --transport slimrpc)")
+	pf.StringVar(&cfg.slimIdentityProviderSharedSecret, "slim-identity-provider-shared-secret", "", "Shared secret for the SLIM identity provider (used when --slim-identity-provider-type=sharedSecret)")
+	pf.StringVar(&cfg.slimIdentityVerifierType, "slim-identity-verifier-type", "", "SLIM identity verifier type: sharedSecret (required with --transport slimrpc)")
+	pf.StringVar(&cfg.slimIdentityVerifierSharedSecret, "slim-identity-verifier-shared-secret", "", "Shared secret for the SLIM identity verifier (used when --slim-identity-verifier-type=sharedSecret)")
 
 	cmd.AddCommand(
 		newCardCmd(cfg),

internal/cli/slim.go

@@ -0,0 +1,85 @@
+//go:build cgo
+
+// Copyright 2026 The A2A Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cli
+
+import (
+	"fmt"
+
+	"github.com/a2aproject/a2a-go/v2/a2aclient"
+	a2aslimrpc "github.com/agntcy/slim-a2a-go/a2aslimrpc/v1"
+	slim_bindings "github.com/agntcy/slim-bindings-go/v2"
+)
+
+func withSLIMRPCTransport(cfg *globalConfig) (a2aclient.FactoryOption, error) {
+	localName, err := slim_bindings.NameFromString(cfg.slimLocalName)
+	if err != nil {
+		return nil, fmt.Errorf("--slim-local-name: %w", err)
+	}
+
+	identityProvider, err := slimIdentityProvider(cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	identityVerifier, err := slimIdentityVerifier(cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	slim_bindings.InitializeWithDefaults()
+	svc := slim_bindings.GetGlobalService()
+
+	app, err := svc.CreateApp(localName, identityProvider, identityVerifier)
+	if err != nil {
+		return nil, fmt.Errorf("slim: create app: %w", err)
+	}
+
+	connID, err := svc.Connect(slim_bindings.NewInsecureClientConfig(cfg.slimEndpoint))
+	if err != nil {
+		return nil, fmt.Errorf("slim: connect to %s: %w", cfg.slimEndpoint, err)
+	}
+
+	if err := app.Subscribe(localName, &connID); err != nil {
+		return nil, fmt.Errorf("slim: subscribe: %w", err)
+	}
+
+	cfg.logf("connected to SLIM node at %s as %s", cfg.slimEndpoint, cfg.slimLocalName)
+
+	return a2aslimrpc.WithSLIMRPCTransport(app, &connID), nil
+}
+
+func slimIdentityProvider(cfg *globalConfig) (slim_bindings.IdentityProviderConfig, error) {
+	switch cfg.slimIdentityProviderType {
+	case "sharedSecret":
+		return slim_bindings.IdentityProviderConfigSharedSecret{Data: cfg.slimIdentityProviderSharedSecret}, nil
+	case "":
+		return nil, fmt.Errorf("--slim-identity-provider-type is required with --transport slimrpc (use sharedSecret)")
+	default:
+		return nil, fmt.Errorf("--slim-identity-provider-type: unknown type %q (use sharedSecret)", cfg.slimIdentityProviderType)
+	}
+}
+
+func slimIdentityVerifier(cfg *globalConfig) (slim_bindings.IdentityVerifierConfig, error) {
+	switch cfg.slimIdentityVerifierType {
+	case "sharedSecret":
+		return slim_bindings.IdentityVerifierConfigSharedSecret{Data: cfg.slimIdentityVerifierSharedSecret}, nil
+	case "":
+		return nil, fmt.Errorf("--slim-identity-verifier-type is required with --transport slimrpc (use sharedSecret)")
+	default:
+		return nil, fmt.Errorf("--slim-identity-verifier-type: unknown type %q (use sharedSecret)", cfg.slimIdentityVerifierType)
+	}
+}

internal/cli/slim_nocgo.go

@@ -0,0 +1,27 @@
+//go:build !cgo
+
+// Copyright 2026 The A2A Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cli
+
+import (
+	"fmt"
+
+	"github.com/a2aproject/a2a-go/v2/a2aclient"
+)
+
+func withSLIMRPCTransport(_ *globalConfig) (a2aclient.FactoryOption, error) {
+	return nil, fmt.Errorf("slimrpc transport requires CGO; rebuild without CGO_ENABLED=0")
+}

internal/flagparse/transports.go

@@ -46,7 +46,7 @@ func SingleTransport(ss []string) (a2a.TransportProtocol, error) {
 		return "", err
 	}
 	if len(protos) != 1 {
-		return "", fmt.Errorf("exactly one --transport is required (rest, jsonrpc, or grpc)")
+		return "", fmt.Errorf("exactly one --transport is required (rest, jsonrpc, grpc, or slimrpc)")
 	}
 	return protos[0], nil
 }
@@ -59,7 +59,9 @@ func parseTransport(s string) (a2a.TransportProtocol, error) {
 		return a2a.TransportProtocolJSONRPC, nil
 	case "grpc":
 		return a2a.TransportProtocolGRPC, nil
+	case "slimrpc":
+		return a2a.TransportProtocol("slimrpc"), nil
 	default:
-		return "", fmt.Errorf("unknown transport %q (use rest, jsonrpc, or grpc)", s)
+		return "", fmt.Errorf("unknown transport %q (use rest, jsonrpc, grpc, or slimrpc)", s)
 	}
 }