diff --git a/.claude/skills/agent-integration/researcher.md b/.claude/skills/agent-integration/researcher.md
index 6f4223d43..748ed4840 100644
--- a/.claude/skills/agent-integration/researcher.md
+++ b/.claude/skills/agent-integration/researcher.md
@@ -8,7 +8,7 @@ Assess whether a target AI coding agent's hook/lifecycle model is compatible wit
 
 Read `docs/architecture/agent-guide.md` to understand what Entire expects from agents: EventType names, required interfaces, hook patterns, and lifecycle flow. This gives you the vocabulary to map the target agent's native hooks to Entire's event model.
 
-**Do NOT read other internal Entire source files** (`agent.go`, `event.go`, `hook_registry.go`, `lifecycle.go`, or reference implementations). The implementer handles those.
+You may also reference `cmd/entire/cli/agent/agent.go` and `cmd/entire/cli/agent/event.go` for exact interface signatures and EventType constants. Prefer `agent-guide.md` as the primary source, but the source files are the ground truth if the guide is out of date. Avoid reading other internal files (`hook_registry.go`, `lifecycle.go`, strategy code) — the implementer handles those, and architecture tests enforce this boundary at the code level.
 
 ### Phase 2: Static Capability Checks
 
@@ -158,4 +158,4 @@ If blocked at any point (auth, sandbox, binary not found):
 - **Non-destructive.** All artifacts go under `.entire/tmp/` (gitignored). The one-pager goes in the agent package directory.
 - **Agent-specific scripts.** Adapt based on Phase 2 findings, not a generic template.
 - **Ask, don't assume.** If the hook mechanism is unclear, ask the user.
-- **External focus.** Do not read internal Entire source files beyond `agent-guide.md`. The implementer reads those.
+- **External focus.** Prefer `agent-guide.md` for Entire's expectations. You may reference `agent.go` and `event.go` for exact names, but avoid deeper internals — architecture tests enforce the boundary at the code level.
diff --git a/cmd/entire/cli/agent/architecture_test.go b/cmd/entire/cli/agent/architecture_test.go
new file mode 100644
index 000000000..481cce12b
--- /dev/null
+++ b/cmd/entire/cli/agent/architecture_test.go
@@ -0,0 +1,260 @@
+package agent
+
+import (
+	"go/ast"
+	"go/parser"
+	"go/token"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"testing"
+)
+
+// TestAgentPackages_NoForbiddenImports verifies that agent implementation packages
+// (claudecode, geminicli, opencode, cursor, etc.) only import from allowed packages.
+//
+// This prevents agent implementations from coupling to framework internals
+// (strategy, checkpoint, session, commands, hook_registry, lifecycle) which
+// would create brittle dependencies that break when internals change.
+//
+// Agents should depend only on:
+//   - The agent contract package (agent, agent/types, agent/testutil)
+//   - Utility packages (logging, paths, jsonutil, textutil, transcript, etc.)
+//   - Standard library and external dependencies
+func TestAgentPackages_NoForbiddenImports(t *testing.T) {
+	t.Parallel()
+
+	const repoPrefix = "github.com/entireio/cli/cmd/entire/cli/"
+
+	// Packages that agent implementations must NOT import.
+	// These are framework internals that agents should be decoupled from.
+	forbiddenSuffixes := []string{
+		"strategy",
+		"checkpoint",
+		"session",
+		"commands",
+	}
+
+	// Individual files in the cli package that agents must not depend on.
+	// We check for the cli package import itself since these are all in
+	// the top-level cli package (not sub-packages).
+	forbiddenCLIPackage := repoPrefix[:len(repoPrefix)-1] // "github.com/entireio/cli/cmd/entire/cli"
+
+	// Packages within the repo that agents ARE allowed to import.
+	allowedPrefixes := []string{
+		repoPrefix + "agent",      // agent contract + sub-packages
+		repoPrefix + "logging",    // logging utilities
+		repoPrefix + "paths",      // path utilities
+		repoPrefix + "jsonutil",   // JSON utilities
+		repoPrefix + "textutil",   // text utilities
+		repoPrefix + "transcript", // transcript utilities
+		repoPrefix + "trailers",   // git trailer utilities
+		repoPrefix + "stringutil", // string utilities
+		repoPrefix + "telemetry",  // telemetry
+		repoPrefix + "validation", // validation utilities
+		repoPrefix + "settings",   // settings (read-only access)
+	}
+
+	agentDir := findAgentDir(t)
+	agentPkgs := discoverAgentPackages(t, agentDir)
+
+	if len(agentPkgs) == 0 {
+		t.Fatal("no agent packages found — test setup is broken")
+	}
+
+	for _, pkgDir := range agentPkgs {
+		pkgName := filepath.Base(pkgDir)
+		t.Run(pkgName, func(t *testing.T) {
+			t.Parallel()
+			imports := extractImports(t, pkgDir)
+			for _, imp := range imports {
+				if !strings.HasPrefix(imp, repoPrefix) && imp != forbiddenCLIPackage {
+					continue // external or stdlib — allowed
+				}
+
+				// Check if it's the top-level cli package itself
+				if imp == forbiddenCLIPackage {
+					t.Errorf("forbidden import %q — agent packages must not import the top-level cli package directly", imp)
+					continue
+				}
+
+				// Check forbidden suffixes
+				rel := strings.TrimPrefix(imp, repoPrefix)
+				isForbidden := false
+				for _, forbidden := range forbiddenSuffixes {
+					if rel == forbidden || strings.HasPrefix(rel, forbidden+"/") {
+						t.Errorf("forbidden import %q — agent packages must not import %s internals", imp, forbidden)
+						isForbidden = true
+					}
+				}
+				if isForbidden {
+					continue
+				}
+
+				// Check it's in the allowed list
+				allowed := false
+				for _, prefix := range allowedPrefixes {
+					if imp == prefix || strings.HasPrefix(imp, prefix+"/") {
+						allowed = true
+						break
+					}
+				}
+				if !allowed {
+					t.Errorf("unexpected internal import %q — if this is intentional, add it to allowedPrefixes in architecture_test.go", imp)
+				}
+			}
+		})
+	}
+}
+
+// findAgentDir returns the absolute path to cmd/entire/cli/agent/.
+// Go test runner sets cwd to the package directory, so os.Getwd() gives us
+// the agent dir directly.
+func findAgentDir(t *testing.T) string {
+	t.Helper()
+	wd, err := os.Getwd()
+	if err != nil {
+		t.Fatalf("os.Getwd: %v", err)
+	}
+	return wd
+}
+
+// discoverAgentPackages finds all subdirectories of the agent dir that contain
+// Go files, excluding "types" and "testutil" (those are contract/shared packages).
+func discoverAgentPackages(t *testing.T, agentDir string) []string {
+	t.Helper()
+
+	skipDirs := map[string]bool{
+		"types":    true, // contract types, not an agent implementation
+		"testutil": true, // shared test utilities
+	}
+
+	entries, err := os.ReadDir(agentDir)
+	if err != nil {
+		t.Fatalf("ReadDir(%s): %v", agentDir, err)
+	}
+
+	var pkgs []string
+	for _, e := range entries {
+		if !e.IsDir() || skipDirs[e.Name()] {
+			continue
+		}
+		dir := filepath.Join(agentDir, e.Name())
+		// Only include if it has Go files
+		goFiles, err := filepath.Glob(filepath.Join(dir, "*.go"))
+		if err != nil {
+			t.Fatalf("filepath.Glob(%s): %v", dir, err)
+		}
+		if len(goFiles) > 0 {
+			pkgs = append(pkgs, dir)
+		}
+	}
+	return pkgs
+}
+
+// extractImports parses all Go files in a directory and returns unique import paths.
+// Includes both production and test files — test-only imports should also respect boundaries.
+func extractImports(t *testing.T, dir string) []string {
+	t.Helper()
+
+	fset := token.NewFileSet()
+	//nolint:staticcheck // ParseDir is deprecated in favor of go/packages, but we intentionally
+	// scan all files regardless of build tags to catch forbidden imports in test files too.
+	pkgs, err := parser.ParseDir(fset, dir, nil, parser.ImportsOnly)
+	if err != nil {
+		t.Fatalf("parser.ParseDir(%s): %v", dir, err)
+	}
+
+	seen := make(map[string]bool)
+	for _, pkg := range pkgs {
+		for _, file := range pkg.Files {
+			for _, imp := range file.Imports {
+				path, err := strconv.Unquote(imp.Path.Value)
+				if err != nil {
+					t.Fatalf("strconv.Unquote(%s): %v", imp.Path.Value, err)
+				}
+				seen[path] = true
+			}
+		}
+	}
+
+	imports := make([]string, 0, len(seen))
+	for imp := range seen {
+		imports = append(imports, imp)
+	}
+	return imports
+}
+
+// TestAgentPackages_SelfRegister verifies that each agent package has an init()
+// function that calls agent.Register(). This ensures agents are properly
+// discoverable via the registry.
+func TestAgentPackages_SelfRegister(t *testing.T) {
+	t.Parallel()
+
+	agentDir := findAgentDir(t)
+	agentPkgs := discoverAgentPackages(t, agentDir)
+
+	if len(agentPkgs) == 0 {
+		t.Fatal("no agent packages found — test setup is broken")
+	}
+
+	for _, pkgDir := range agentPkgs {
+		pkgName := filepath.Base(pkgDir)
+		t.Run(pkgName, func(t *testing.T) {
+			t.Parallel()
+			if !hasInitWithRegister(t, pkgDir) {
+				t.Errorf("agent package %q has no init() function calling Register() — agents must self-register", pkgName)
+			}
+		})
+	}
+}
+
+// hasInitWithRegister checks if any Go file in the directory has an init()
+// function that contains a call to Register.
+func hasInitWithRegister(t *testing.T, dir string) bool {
+	t.Helper()
+
+	fset := token.NewFileSet()
+	//nolint:staticcheck // See extractImports for rationale.
+	pkgs, err := parser.ParseDir(fset, dir, func(fi os.FileInfo) bool {
+		return !strings.HasSuffix(fi.Name(), "_test.go")
+	}, 0)
+	if err != nil {
+		t.Fatalf("parser.ParseDir(%s): %v", dir, err)
+	}
+
+	for _, pkg := range pkgs {
+		for _, file := range pkg.Files {
+			for _, decl := range file.Decls {
+				fn, ok := decl.(*ast.FuncDecl)
+				if !ok || fn.Name.Name != "init" || fn.Recv != nil {
+					continue
+				}
+				// Walk the init body looking for a call to Register or agent.Register
+				found := false
+				ast.Inspect(fn.Body, func(n ast.Node) bool {
+					call, ok := n.(*ast.CallExpr)
+					if !ok {
+						return true
+					}
+					switch fun := call.Fun.(type) {
+					case *ast.Ident:
+						if fun.Name == "Register" {
+							found = true
+						}
+					case *ast.SelectorExpr:
+						if fun.Sel.Name == "Register" {
+							found = true
+						}
+					}
+					return !found
+				})
+				if found {
+					return true
+				}
+			}
+		}
+	}
+	return false
+}