feat: sentinel-mcp — MCP sidecar for governance telemetry

.github/workflows/release.yml

@@ -0,0 +1,72 @@
+name: Release
+
+on:
+  release:
+    types: [published]
+  workflow_dispatch:
+    inputs:
+      tag:
+        description: "Release tag (e.g., v0.1.0)"
+        required: true
+
+permissions:
+  contents: write
+
+jobs:
+  build:
+    strategy:
+      matrix:
+        include:
+          - os: linux
+            arch: amd64
+            runner: ubuntu-latest
+          - os: linux
+            arch: arm64
+            runner: ubuntu-latest
+          - os: darwin
+            arch: amd64
+            runner: macos-latest
+          - os: darwin
+            arch: arm64
+            runner: macos-latest
+
+    runs-on: ${{ matrix.runner }}
+
+    env:
+      RELEASE_TAG: ${{ github.event.release.tag_name || github.event.inputs.tag }}
+      BUILD_OS: ${{ matrix.os }}
+      BUILD_ARCH: ${{ matrix.arch }}
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "1.22"
+
+      - name: Build sentinel CLI
+        env:
+          GOOS: ${{ matrix.os }}
+          GOARCH: ${{ matrix.arch }}
+          CGO_ENABLED: "0"
+        run: |
+          go build -ldflags="-s -w" \
+            -o "sentinel-${BUILD_OS}-${BUILD_ARCH}" \
+            ./cmd/sentinel/
+
+      - name: Build sentinel-mcp
+        env:
+          GOOS: ${{ matrix.os }}
+          GOARCH: ${{ matrix.arch }}
+          CGO_ENABLED: "0"
+        run: |
+          go build -ldflags="-s -w" \
+            -o "sentinel-mcp-${BUILD_OS}-${BUILD_ARCH}" \
+            ./cmd/sentinel-mcp/
+
+      - name: Upload release assets
+        uses: softprops/action-gh-release@v2
+        with:
+          files: |
+            sentinel-*
+          tag_name: ${{ github.event.release.tag_name || github.event.inputs.tag }}

cmd/sentinel-mcp/main.go

@@ -0,0 +1,51 @@
+package main
+
+import (
+	"context"
+	"fmt"
+	"os"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+
+	"github.com/AgentGuardHQ/sentinel/internal/mcp"
+)
+
+func main() {
+	// Database URL — from env or passed by the MCP client config
+	dbURL := os.Getenv("NEON_DATABASE_URL")
+	if dbURL == "" {
+		fmt.Fprintln(os.Stderr, "sentinel-mcp: NEON_DATABASE_URL is required")
+		os.Exit(1)
+	}
+
+	// Tenant ID — identifies whose events these are
+	tenantID := os.Getenv("SENTINEL_TENANT_ID")
+	if tenantID == "" {
+		tenantID = "00000000-0000-0000-0000-000000000000" // default single-tenant
+	}
+
+	// Connect to Neon
+	pool, err := pgxpool.New(context.Background(), dbURL)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "sentinel-mcp: database connection failed: %v\n", err)
+		os.Exit(1)
+	}
+	defer pool.Close()
+
+	if err := pool.Ping(context.Background()); err != nil {
+		fmt.Fprintf(os.Stderr, "sentinel-mcp: database ping failed: %v\n", err)
+		os.Exit(1)
+	}
+
+	// Build MCP server
+	server := mcp.New()
+	mcp.RegisterTools(server, pool, tenantID)
+
+	fmt.Fprintln(os.Stderr, "sentinel-mcp: ready (stdio)")
+
+	// Run the stdio JSON-RPC loop
+	if err := server.Run(); err != nil {
+		fmt.Fprintf(os.Stderr, "sentinel-mcp: %v\n", err)
+		os.Exit(1)
+	}
+}

go.mod

@@ -1,6 +1,6 @@
 module github.com/AgentGuardHQ/sentinel
 
-go 1.24.0
+go 1.21
 
 require (
 	github.com/jackc/pgx/v5 v5.7.4

internal/mcp/ingest.go

@@ -0,0 +1,101 @@
+package mcp
+
+import (
+	"bufio"
+	"context"
+	"encoding/json"
+	"fmt"
+	"os"
+	"strings"
+
+	"github.com/jackc/pgx/v5/pgxpool"
+)
+
+// ChitinEvent matches the JSONL format emitted by chitin's hook/emit.go.
+type ChitinEvent struct {
+	Timestamp string `json:"ts"`
+	SessionID string `json:"sid"`
+	Agent     string `json:"agent"`
+	Tool      string `json:"tool"`
+	Action    string `json:"action"`
+	Path      string `json:"path,omitempty"`
+	Command   string `json:"command,omitempty"`
+	Outcome   string `json:"outcome"`
+	Reason    string `json:"reason,omitempty"`
+	Source    string `json:"source,omitempty"`
+	LatencyUs int64  `json:"latency_us"`
+}
+
+// IngestFile reads a JSONL file and inserts events into governance_events.
+// Returns the number of events ingested.
+func IngestFile(pool *pgxpool.Pool, path string, tenantID string) (int, error) {
+	f, err := os.Open(path)
+	if err != nil {
+		return 0, fmt.Errorf("open events file: %w", err)
+	}
+	defer f.Close()
+
+	ctx := context.Background()
+	count := 0
+	scanner := bufio.NewScanner(f)
+
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" {
+			continue
+		}
+
+		var ev ChitinEvent
+		if err := json.Unmarshal([]byte(line), &ev); err != nil {
+			continue // skip malformed lines
+		}
+
+		metadata, _ := json.Marshal(map[string]any{
+			"command":    ev.Command,
+			"source":     ev.Source,
+			"latency_us": ev.LatencyUs,
+			"reason":     ev.Reason,
+		})
+
+		riskLevel := "low"
+		if ev.Outcome == "deny" {
+			riskLevel = "medium"
+			if ev.Source == "invariant" {
+				riskLevel = "high"
+			}
+		}
+
+		_, err := pool.Exec(ctx, `
+			INSERT INTO governance_events
+				(tenant_id, session_id, agent_id, event_type, action, resource, outcome, risk_level, event_source, driver_type, metadata, timestamp)
+			VALUES
+				($1, $2, $3, 'tool_call', $4, $5, $6, $7, 'agent', $8, $9::jsonb, $10::timestamptz)
+		`,
+			tenantID,
+			ev.SessionID,
+			ev.Agent,
+			ev.Tool,
+			coalesce(ev.Path, ev.Command),
+			ev.Outcome,
+			riskLevel,
+			ev.Agent,
+			string(metadata),
+			ev.Timestamp,
+		)
+		if err != nil {
+			return count, fmt.Errorf("insert event: %w", err)
+		}
+		count++
+	}
+
+	return count, scanner.Err()
+}
+
+func coalesce(values ...string) string {
+	for _, v := range values {
+		if v != "" {
+			return v
+		}
+	}
+	return ""
+}