Add MCP server with debug tools and WebSocket bridge

cmd/cmd_mcp.go

@@ -0,0 +1,49 @@
+package cmd
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	mcpserver "github.com/actionforge/actrun-cli/mcp"
+	"github.com/spf13/cobra"
+)
+
+// buildMCPInstructions generates the MCP server instructions from the
+// actual flags registered on cmdRoot so they stay in sync automatically.
+func buildMCPInstructions() string {
+	var b strings.Builder
+
+	b.WriteString("This MCP server provides tools for debugging and running ActionForge graph (.act) files interactively. ")
+	b.WriteString("Use the debug_* tools to step through graph execution node by node, set breakpoints, and inspect state.\n\n")
+
+	b.WriteString("If you just need to run a graph without debugging, use the actrun CLI directly instead of this MCP server:\n\n")
+	fmt.Fprintf(&b, "  %s\n\n", cmdRoot.Use)
+
+	b.WriteString("Available flags:\n")
+	// Include both persistent and local flags from the root command.
+	b.WriteString(cmdRoot.PersistentFlags().FlagUsages())
+	b.WriteString(cmdRoot.LocalNonPersistentFlags().FlagUsages())
+
+	b.WriteString("\nTo pass arguments to the graph itself, append them after the file: actrun file.act arg1 arg2\n")
+	b.WriteString("Use '--' to separate actrun flags from graph arguments: actrun --env-file .env file.act -- --graph-flag")
+
+	return b.String()
+}
+
+var cmdMcp = &cobra.Command{
+	Use:   "mcp",
+	Short: "Start the MCP server (stdio transport).",
+	Long:  `Starts an MCP server over stdio that exposes debug tools for bridging between an AI agent and an actrun local debug session (WebSocket). Configure this as an MCP server in your AI tool with: {"command": "actrun", "args": ["mcp"]}`,
+	Args:  cobra.NoArgs,
+	Run: func(cmd *cobra.Command, args []string) {
+		if err := mcpserver.RunMCPServer(buildMCPInstructions()); err != nil {
+			fmt.Fprintf(os.Stderr, "MCP server error: %v\n", err)
+			os.Exit(1)
+		}
+	},
+}
+
+func init() {
+	cmdRoot.AddCommand(cmdMcp)
+}

examples/mcp-debug-example.act

@@ -0,0 +1,144 @@
+editor:
+  version:
+    created: v1.34.0
+entry: start
+type: generic
+nodes:
+  - id: start
+    type: core/start@v1
+    position:
+      x: -200
+      y: 0
+  - id: greeting-text
+    type: core/const-string@v1
+    position:
+      x: -200
+      y: 200
+    inputs:
+      value: "Hello from MCP debug session!"
+  - id: print-greeting
+    type: core/print@v1
+    position:
+      x: 200
+      y: 0
+    inputs:
+      values[0]: null
+      color: fg_green
+  # Group node: contains two inner print steps to demonstrate step-into / step-out
+  - id: my-group
+    type: core/group@v1
+    position:
+      x: 500
+      y: 0
+    graph:
+      entry: group-inputs
+      type: group
+      nodes:
+        - id: group-inputs
+          type: core/group-inputs@v1
+          position:
+            x: 10
+            y: 60
+        - id: group-outputs
+          type: core/group-outputs@v1
+          position:
+            x: 600
+            y: 60
+        - id: inner-text
+          type: core/const-string@v1
+          position:
+            x: 200
+            y: 200
+          inputs:
+            value: "Inside the group!"
+        - id: inner-print
+          type: core/print@v1
+          position:
+            x: 400
+            y: 60
+          inputs:
+            values[0]: null
+            color: fg_cyan
+      connections:
+        - src:
+            node: inner-text
+            port: result
+          dst:
+            node: inner-print
+            port: values[0]
+      executions:
+        - src:
+            node: group-inputs
+            port: exec-in
+          dst:
+            node: inner-print
+            port: exec
+        - src:
+            node: inner-print
+            port: exec
+          dst:
+            node: group-outputs
+            port: exec-out
+      inputs:
+        exec-in:
+          type: ''
+          index: 0
+          exec: true
+      outputs:
+        exec-out:
+          name: ''
+          type: ''
+          index: 0
+          exec: true
+  - id: done-text
+    type: core/const-string@v1
+    position:
+      x: 800
+      y: 200
+    inputs:
+      value: "Done! Debug session complete."
+  - id: print-done
+    type: core/print@v1
+    position:
+      x: 1000
+      y: 0
+    inputs:
+      values[0]: null
+      color: fg_yellow
+connections:
+  - src:
+      node: greeting-text
+      port: result
+    dst:
+      node: print-greeting
+      port: values[0]
+    isLoop: false
+  - src:
+      node: done-text
+      port: result
+    dst:
+      node: print-done
+      port: values[0]
+    isLoop: false
+executions:
+  - src:
+      node: start
+      port: exec
+    dst:
+      node: print-greeting
+      port: exec
+    isLoop: false
+  - src:
+      node: print-greeting
+      port: exec
+    dst:
+      node: my-group
+      port: exec-in
+    isLoop: false
+  - src:
+      node: my-group
+      port: exec-out
+    dst:
+      node: print-done
+      port: exec
+    isLoop: false

go.mod

@@ -19,6 +19,7 @@ require (
 	github.com/gorilla/websocket v1.5.3
 	github.com/inconshreveable/mousetrap v1.1.0
 	github.com/joho/godotenv v1.5.1
+	github.com/mark3labs/mcp-go v0.44.0
 	github.com/pkg/errors v0.9.1
 	github.com/rhysd/actionlint v1.7.10
 	github.com/rossmacarthur/cases v0.3.0
@@ -66,7 +67,9 @@ require (
 	github.com/aws/aws-sdk-go-v2/service/ssooidc v1.35.12 // indirect
 	github.com/aws/aws-sdk-go-v2/service/sts v1.41.5 // indirect
 	github.com/aws/smithy-go v1.24.0 // indirect
+	github.com/bahlo/generic-list-go v0.2.0 // indirect
 	github.com/bmatcuk/doublestar/v4 v4.9.1 // indirect
+	github.com/buger/jsonparser v1.1.1 // indirect
 	github.com/cespare/xxhash/v2 v2.3.0 // indirect
 	github.com/clipperhouse/stringish v0.1.1 // indirect
 	github.com/clipperhouse/uax29/v2 v2.3.0 // indirect
@@ -91,10 +94,12 @@ require (
 	github.com/google/s2a-go v0.1.9 // indirect
 	github.com/googleapis/enterprise-certificate-proxy v0.3.7 // indirect
 	github.com/googleapis/gax-go/v2 v2.16.0 // indirect
+	github.com/invopop/jsonschema v0.13.0 // indirect
 	github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 // indirect
 	github.com/kevinburke/ssh_config v1.4.0 // indirect
 	github.com/klauspost/compress v1.18.2 // indirect
 	github.com/klauspost/cpuid/v2 v2.3.0 // indirect
+	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/mattn/go-colorable v0.1.14 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect
 	github.com/mattn/go-runewidth v0.0.19 // indirect
@@ -110,10 +115,13 @@ require (
 	github.com/robfig/cron/v3 v3.0.1 // indirect
 	github.com/sergi/go-diff v1.4.0 // indirect
 	github.com/skeema/knownhosts v1.3.2 // indirect
+	github.com/spf13/cast v1.7.1 // indirect
+	github.com/wk8/go-ordered-map/v2 v2.1.8 // indirect
 	github.com/xanzy/ssh-agent v0.3.3 // indirect
 	github.com/xdg-go/pbkdf2 v1.0.0 // indirect
 	github.com/xdg-go/scram v1.2.0 // indirect
 	github.com/xdg-go/stringprep v1.0.4 // indirect
+	github.com/yosida95/uritemplate/v3 v3.0.2 // indirect
 	github.com/youmark/pkcs8 v0.0.0-20240726163527-a2c0da244d78 // indirect
 	go.opentelemetry.io/auto/sdk v1.2.1 // indirect
 	go.opentelemetry.io/contrib/instrumentation/google.golang.org/grpc/otelgrpc v0.64.0 // indirect

go.sum

@@ -73,8 +73,12 @@ github.com/aws/aws-sdk-go-v2/service/sts v1.41.5 h1:SciGFVNZ4mHdm7gpD1dgZYnCuVdX
 github.com/aws/aws-sdk-go-v2/service/sts v1.41.5/go.mod h1:iW40X4QBmUxdP+fZNOpfmkdMZqsovezbAeO+Ubiv2pk=
 github.com/aws/smithy-go v1.24.0 h1:LpilSUItNPFr1eY85RYgTIg5eIEPtvFbskaFcmmIUnk=
 github.com/aws/smithy-go v1.24.0/go.mod h1:LEj2LM3rBRQJxPZTB4KuzZkaZYnZPnvgIhb4pu07mx0=
+github.com/bahlo/generic-list-go v0.2.0 h1:5sz/EEAK+ls5wF+NeqDpk5+iNdMDXrh3z3nPnH1Wvgk=
+github.com/bahlo/generic-list-go v0.2.0/go.mod h1:2KvAjgMlE5NNynlg/5iLrrCCZ2+5xWbdbCW3pNTGyYg=
 github.com/bmatcuk/doublestar/v4 v4.9.1 h1:X8jg9rRZmJd4yRy7ZeNDRnM+T3ZfHv15JiBJ/avrEXE=
 github.com/bmatcuk/doublestar/v4 v4.9.1/go.mod h1:xBQ8jztBU6kakFMg+8WGxn0c6z1fTSPVIjEY1Wr7jzc=
+github.com/buger/jsonparser v1.1.1 h1:2PnMjfWD7wBILjqQbt530v576A/cAbQvEW9gGIpYMUs=
+github.com/buger/jsonparser v1.1.1/go.mod h1:6RYKKt7H4d4+iWqouImQ9R2FZql3VbhNgx27UK13J/0=
 github.com/cenkalti/backoff v2.2.1+incompatible h1:tNowT99t7UNflLxfYYSlKYsBpXdEet03Pg2g16Swow4=
 github.com/cenkalti/backoff/v5 v5.0.3 h1:ZN+IMa753KfX5hd8vVaMixjnqRZ3y8CuJKRKj1xcsSM=
 github.com/cenkalti/backoff/v5 v5.0.3/go.mod h1:rkhZdG3JZukswDf7f0cwqPNk4K0sa+F97BxZthm/crw=
@@ -124,6 +128,8 @@ github.com/fatih/color v1.18.0 h1:S8gINlzdQ840/4pfAwic/ZE0djQEH3wM94VfqLTZcOM=
 github.com/fatih/color v1.18.0/go.mod h1:4FelSpRwEGDpQ12mAdzqdOukCy4u8WUtOY6lkT/6HfU=
 github.com/felixge/httpsnoop v1.0.4 h1:NFTV2Zj1bL4mc9sqWACXbQFVBBg2W3GPvqp8/ESS2Wg=
 github.com/felixge/httpsnoop v1.0.4/go.mod h1:m8KPJKqk1gH5J9DgRY2ASl2lWCfGKXixSwevea8zH2U=
+github.com/frankban/quicktest v1.14.6 h1:7Xjx+VpznH+oBnejlPUj8oUpdxnVs4f8XU8WnHkI4W8=
+github.com/frankban/quicktest v1.14.6/go.mod h1:4ptaffx2x8+WTWXmUCuVU6aPUX1/Mz7zb5vbUoiM6w0=
 github.com/gage-technologies/mistral-go v1.1.0 h1:POv1wM9jA/9OBXGV2YdPi9Y/h09+MjCbUF+9hRYlVUI=
 github.com/gage-technologies/mistral-go v1.1.0/go.mod h1:tF++Xt7U975GcLlzhrjSQb8l/x+PrriO9QEdsgm9l28=
 github.com/gliderlabs/ssh v0.3.8 h1:a4YXD1V7xMF9g5nTkdfnja3Sxy1PVDCj1Zg4Wb8vY6c=
@@ -168,10 +174,13 @@ github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.3 h1:NmZ1PKzSTQbuGHw9DGPFomqkkLW
 github.com/grpc-ecosystem/grpc-gateway/v2 v2.27.3/go.mod h1:zQrxl1YP88HQlA6i9c63DSVPFklWpGX4OWAc9bFuaH4=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
+github.com/invopop/jsonschema v0.13.0 h1:KvpoAJWEjR3uD9Kbm2HWJmqsEaHt8lBUpd0qHcIi21E=
+github.com/invopop/jsonschema v0.13.0/go.mod h1:ffZ5Km5SWWRAIN6wbDXItl95euhFz2uON45H2qjYt+0=
 github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 h1:BQSFePA1RWJOlocH6Fxy8MmwDt+yVQYULKfN0RoTN8A=
 github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99/go.mod h1:1lJo3i6rXxKeerYnT8Nvf0QmHCRC1n8sfWVwXF2Frvo=
 github.com/joho/godotenv v1.5.1 h1:7eLL/+HRGLY0ldzfGMeQkb7vMd0as4CfYvUVzLqw0N0=
 github.com/joho/godotenv v1.5.1/go.mod h1:f4LDr5Voq0i2e/R5DDNOoa2zzDfwtkZa6DnEwAbqwq4=
+github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
 github.com/kevinburke/ssh_config v1.4.0 h1:6xxtP5bZ2E4NF5tuQulISpTO2z8XbtH8cg1PWkxoFkQ=
 github.com/kevinburke/ssh_config v1.4.0/go.mod h1:q2RIzfka+BXARoNexmF9gkxEX7DmvbW9P4hIVx2Kg4M=
 github.com/klauspost/compress v1.18.2 h1:iiPHWW0YrcFgpBYhsA6D1+fqHssJscY/Tm/y2Uqnapk=
@@ -185,6 +194,10 @@ github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/mailru/easyjson v0.7.7 h1:UGYAvKxe3sBsEDzO8ZeWOSlIQfWFlxbzLZe7hwFURr0=
+github.com/mailru/easyjson v0.7.7/go.mod h1:xzfreul335JAWq5oZzymOObrkdz5UnU4kGfJJLY9Nlc=
+github.com/mark3labs/mcp-go v0.44.0 h1:OlYfcVviAnwNN40QZUrrzU0QZjq3En7rCU5X09a/B7I=
+github.com/mark3labs/mcp-go v0.44.0/go.mod h1:YnJfOL382MIWDx1kMY+2zsRHU/q78dBg9aFb8W6Thdw=
 github.com/mattn/go-colorable v0.1.14 h1:9A9LHSqF/7dyVVX6g0U9cwm9pG3kP9gSzcuIPHPsaIE=
 github.com/mattn/go-colorable v0.1.14/go.mod h1:6LmQG8QLFO4G5z1gPvYEzlUgJ2wF+stgPZH1UqBm1s8=
 github.com/mattn/go-isatty v0.0.20 h1:xfD0iDuEKnDkl03q4limB+vH+GxLEtL/jb4xVJSWWEY=
@@ -240,6 +253,8 @@ github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ
 github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
 github.com/skeema/knownhosts v1.3.2 h1:EDL9mgf4NzwMXCTfaxSD/o/a5fxDw/xL9nkU28JjdBg=
 github.com/skeema/knownhosts v1.3.2/go.mod h1:bEg3iQAuw+jyiw+484wwFJoKSLwcfd7fqRy+N0QTiow=
+github.com/spf13/cast v1.7.1 h1:cuNEagBQEHWN1FnbGEjCXL2szYEXqfJPbP2HNUaca9Y=
+github.com/spf13/cast v1.7.1/go.mod h1:ancEpBxwJDODSW/UG4rDrAqiKolqNNh2DX3mk86cAdo=
 github.com/spf13/cobra v1.10.2 h1:DMTTonx5m65Ic0GOoRY2c16WCbHxOOw6xxezuLaBpcU=
 github.com/spf13/cobra v1.10.2/go.mod h1:7C1pvHqHw5A4vrJfjNwvOdzYu0Gml16OCs2GRiTUUS4=
 github.com/spf13/pflag v1.0.9/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
@@ -255,6 +270,8 @@ github.com/stretchr/testify v1.11.1 h1:7s2iGBzp5EwR7/aIZr8ao5+dra3wiQyKjjFuvgVKu
 github.com/stretchr/testify v1.11.1/go.mod h1:wZwfW3scLgRK+23gO65QZefKpKQRnfz6sD981Nm4B6U=
 github.com/tmc/langchaingo v0.1.14 h1:o1qWBPigAIuFvrG6cjTFo0cZPFEZ47ZqpOYMjM15yZc=
 github.com/tmc/langchaingo v0.1.14/go.mod h1:aKKYXYoqhIDEv7WKdpnnCLRaqXic69cX9MnDUk72378=
+github.com/wk8/go-ordered-map/v2 v2.1.8 h1:5h/BUHu93oj4gIdvHHHGsScSTMijfx5PeYkE/fJgbpc=
+github.com/wk8/go-ordered-map/v2 v2.1.8/go.mod h1:5nJHM5DyteebpVlHnWMV0rPz6Zp7+xBAnxjb1X5vnTw=
 github.com/xanzy/ssh-agent v0.3.3 h1:+/15pJfg/RsTxqYcX6fHqOXZwwMP+2VyYWJeWM2qQFM=
 github.com/xanzy/ssh-agent v0.3.3/go.mod h1:6dzNDKs0J9rVPHPhaGCukekBHKqfl+L3KghI1Bc68Uw=
 github.com/xdg-go/pbkdf2 v1.0.0 h1:Su7DPu48wXMwC3bs7MCNG+z4FhcyEuz5dlvchbq0B0c=
@@ -263,6 +280,8 @@ github.com/xdg-go/scram v1.2.0 h1:bYKF2AEwG5rqd1BumT4gAnvwU/M9nBp2pTSxeZw7Wvs=
 github.com/xdg-go/scram v1.2.0/go.mod h1:3dlrS0iBaWKYVt2ZfA4cj48umJZ+cAEbR6/SjLA88I8=
 github.com/xdg-go/stringprep v1.0.4 h1:XLI/Ng3O1Atzq0oBs3TWm+5ZVgkq2aqdlvP9JtoZ6c8=
 github.com/xdg-go/stringprep v1.0.4/go.mod h1:mPGuuIYwz7CmR2bT9j4GbQqutWS1zV24gijq1dTyGkM=
+github.com/yosida95/uritemplate/v3 v3.0.2 h1:Ed3Oyj9yrmi9087+NczuL5BwkIc4wvTb5zIM+UJPGz4=
+github.com/yosida95/uritemplate/v3 v3.0.2/go.mod h1:ILOh0sOhIJR3+L/8afwt/kE++YT040gmv5BQTMR2HP4=
 github.com/youmark/pkcs8 v0.0.0-20240726163527-a2c0da244d78 h1:ilQV1hzziu+LLM3zUTJ0trRztfwgjqKnBWNtSRkbmwM=
 github.com/youmark/pkcs8 v0.0.0-20240726163527-a2c0da244d78/go.mod h1:aL8wCCfTfSfmXjznFBSZNN13rSJjlIOI1fUNAtF7rmI=
 github.com/yuin/goldmark v1.4.13/go.mod h1:6yULJ656Px+3vBD8DxQVa3kxgyrAnzto9xy5taEt/CY=