diff --git a/pkg/agentic/commands.go b/pkg/agentic/commands.go
index 97aaa18..b566060 100644
--- a/pkg/agentic/commands.go
+++ b/pkg/agentic/commands.go
@@ -85,6 +85,7 @@ func (s *PrepSubsystem) registerCommands(ctx context.Context) {
 	s.registerPlanCommands()
 	s.registerCommitCommands()
 	s.registerSessionCommands()
+	s.registerPhaseCommands()
 	s.registerTaskCommands()
 	s.registerSprintCommands()
 	s.registerStateCommands()
diff --git a/pkg/agentic/commands_phase.go b/pkg/agentic/commands_phase.go
new file mode 100644
index 0000000..c97f749
--- /dev/null
+++ b/pkg/agentic/commands_phase.go
@@ -0,0 +1,133 @@
+// SPDX-License-Identifier: EUPL-1.2
+
+package agentic
+
+import (
+	core "dappco.re/go/core"
+)
+
+func (s *PrepSubsystem) registerPhaseCommands() {
+	c := s.Core()
+	c.Command("phase", core.Command{Description: "Manage plan phases", Action: s.cmdPhase})
+	c.Command("agentic:phase", core.Command{Description: "Manage plan phases", Action: s.cmdPhase})
+	c.Command("phase/get", core.Command{Description: "Read a plan phase by slug and order", Action: s.cmdPhaseGet})
+	c.Command("agentic:phase/get", core.Command{Description: "Read a plan phase by slug and order", Action: s.cmdPhaseGet})
+	c.Command("phase/update_status", core.Command{Description: "Update a plan phase status by slug and order", Action: s.cmdPhaseUpdateStatus})
+	c.Command("agentic:phase/update_status", core.Command{Description: "Update a plan phase status by slug and order", Action: s.cmdPhaseUpdateStatus})
+	c.Command("phase/update-status", core.Command{Description: "Update a plan phase status by slug and order", Action: s.cmdPhaseUpdateStatus})
+	c.Command("agentic:phase/update-status", core.Command{Description: "Update a plan phase status by slug and order", Action: s.cmdPhaseUpdateStatus})
+	c.Command("phase/add_checkpoint", core.Command{Description: "Append a checkpoint note to a plan phase", Action: s.cmdPhaseAddCheckpoint})
+	c.Command("agentic:phase/add_checkpoint", core.Command{Description: "Append a checkpoint note to a plan phase", Action: s.cmdPhaseAddCheckpoint})
+	c.Command("phase/add-checkpoint", core.Command{Description: "Append a checkpoint note to a plan phase", Action: s.cmdPhaseAddCheckpoint})
+	c.Command("agentic:phase/add-checkpoint", core.Command{Description: "Append a checkpoint note to a plan phase", Action: s.cmdPhaseAddCheckpoint})
+}
+
+func (s *PrepSubsystem) cmdPhase(options core.Options) core.Result {
+	switch action := optionStringValue(options, "action"); action {
+	case "get":
+		return s.cmdPhaseGet(options)
+	case "update_status", "update-status", "update":
+		return s.cmdPhaseUpdateStatus(options)
+	case "add_checkpoint", "add-checkpoint", "checkpoint":
+		return s.cmdPhaseAddCheckpoint(options)
+	case "":
+		core.Print(nil, "usage: core-agent phase get <plan> --phase=1")
+		core.Print(nil, "       core-agent phase update-status <plan> --phase=1 --status=completed [--reason=\"...\"]")
+		core.Print(nil, "       core-agent phase add-checkpoint <plan> --phase=1 --note=\"Build passes\" [--context='{\"build\":\"ok\"}']")
+		return core.Result{OK: true}
+	default:
+		core.Print(nil, "usage: core-agent phase get <plan> --phase=1")
+		core.Print(nil, "       core-agent phase update-status <plan> --phase=1 --status=completed [--reason=\"...\"]")
+		core.Print(nil, "       core-agent phase add-checkpoint <plan> --phase=1 --note=\"Build passes\" [--context='{\"build\":\"ok\"}']")
+		return core.Result{Value: core.E("agentic.cmdPhase", core.Concat("unknown phase command: ", action), nil), OK: false}
+	}
+}
+
+func (s *PrepSubsystem) cmdPhaseGet(options core.Options) core.Result {
+	result := s.handlePhaseGet(s.commandContext(), core.NewOptions(
+		core.Option{Key: "plan_slug", Value: optionStringValue(options, "plan_slug", "plan", "slug", "_arg")},
+		core.Option{Key: "phase_order", Value: optionIntValue(options, "phase_order", "phase")},
+	))
+	if !result.OK {
+		err := commandResultError("agentic.cmdPhaseGet", result)
+		core.Print(nil, "error: %v", err)
+		return core.Result{Value: err, OK: false}
+	}
+
+	output, ok := result.Value.(PhaseOutput)
+	if !ok {
+		err := core.E("agentic.cmdPhaseGet", "invalid phase get output", nil)
+		core.Print(nil, "error: %v", err)
+		return core.Result{Value: err, OK: false}
+	}
+
+	core.Print(nil, "phase:  %d", output.Phase.Number)
+	core.Print(nil, "name:   %s", output.Phase.Name)
+	core.Print(nil, "status: %s", output.Phase.Status)
+	if output.Phase.Description != "" {
+		core.Print(nil, "desc:   %s", output.Phase.Description)
+	}
+	if output.Phase.Notes != "" {
+		core.Print(nil, "notes:  %s", output.Phase.Notes)
+	}
+	if len(output.Phase.Tasks) > 0 {
+		core.Print(nil, "tasks:  %d", len(output.Phase.Tasks))
+	}
+	if len(output.Phase.Checkpoints) > 0 {
+		core.Print(nil, "checkpoints: %d", len(output.Phase.Checkpoints))
+	}
+	return core.Result{Value: output, OK: true}
+}
+
+func (s *PrepSubsystem) cmdPhaseUpdateStatus(options core.Options) core.Result {
+	result := s.handlePhaseUpdateStatus(s.commandContext(), core.NewOptions(
+		core.Option{Key: "plan_slug", Value: optionStringValue(options, "plan_slug", "plan", "slug", "_arg")},
+		core.Option{Key: "phase_order", Value: optionIntValue(options, "phase_order", "phase")},
+		core.Option{Key: "status", Value: optionStringValue(options, "status")},
+		core.Option{Key: "reason", Value: optionStringValue(options, "reason")},
+	))
+	if !result.OK {
+		err := commandResultError("agentic.cmdPhaseUpdateStatus", result)
+		core.Print(nil, "error: %v", err)
+		return core.Result{Value: err, OK: false}
+	}
+
+	output, ok := result.Value.(PhaseOutput)
+	if !ok {
+		err := core.E("agentic.cmdPhaseUpdateStatus", "invalid phase update output", nil)
+		core.Print(nil, "error: %v", err)
+		return core.Result{Value: err, OK: false}
+	}
+
+	core.Print(nil, "phase:  %d", output.Phase.Number)
+	core.Print(nil, "name:   %s", output.Phase.Name)
+	core.Print(nil, "status: %s", output.Phase.Status)
+	return core.Result{Value: output, OK: true}
+}
+
+func (s *PrepSubsystem) cmdPhaseAddCheckpoint(options core.Options) core.Result {
+	result := s.handlePhaseAddCheckpoint(s.commandContext(), core.NewOptions(
+		core.Option{Key: "plan_slug", Value: optionStringValue(options, "plan_slug", "plan", "slug", "_arg")},
+		core.Option{Key: "phase_order", Value: optionIntValue(options, "phase_order", "phase")},
+		core.Option{Key: "note", Value: optionStringValue(options, "note")},
+		core.Option{Key: "context", Value: optionAnyMapValue(options, "context")},
+	))
+	if !result.OK {
+		err := commandResultError("agentic.cmdPhaseAddCheckpoint", result)
+		core.Print(nil, "error: %v", err)
+		return core.Result{Value: err, OK: false}
+	}
+
+	output, ok := result.Value.(PhaseOutput)
+	if !ok {
+		err := core.E("agentic.cmdPhaseAddCheckpoint", "invalid phase checkpoint output", nil)
+		core.Print(nil, "error: %v", err)
+		return core.Result{Value: err, OK: false}
+	}
+
+	core.Print(nil, "phase:  %d", output.Phase.Number)
+	core.Print(nil, "name:   %s", output.Phase.Name)
+	core.Print(nil, "status: %s", output.Phase.Status)
+	core.Print(nil, "checkpoints: %d", len(output.Phase.Checkpoints))
+	return core.Result{Value: output, OK: true}
+}
diff --git a/pkg/agentic/commands_phase_test.go b/pkg/agentic/commands_phase_test.go
new file mode 100644
index 0000000..0651f92
--- /dev/null
+++ b/pkg/agentic/commands_phase_test.go
@@ -0,0 +1,94 @@
+// SPDX-License-Identifier: EUPL-1.2
+
+package agentic
+
+import (
+	"context"
+	"testing"
+
+	core "dappco.re/go/core"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestCommandsPhase_RegisterPhaseCommands_Good_AllRegistered(t *testing.T) {
+	s, c := testPrepWithCore(t, nil)
+	s.registerPhaseCommands()
+
+	cmds := c.Commands()
+	assert.Contains(t, cmds, "phase")
+	assert.Contains(t, cmds, "agentic:phase")
+	assert.Contains(t, cmds, "phase/get")
+	assert.Contains(t, cmds, "agentic:phase/get")
+	assert.Contains(t, cmds, "phase/update_status")
+	assert.Contains(t, cmds, "agentic:phase/update_status")
+	assert.Contains(t, cmds, "phase/update-status")
+	assert.Contains(t, cmds, "agentic:phase/update-status")
+	assert.Contains(t, cmds, "phase/add_checkpoint")
+	assert.Contains(t, cmds, "agentic:phase/add_checkpoint")
+	assert.Contains(t, cmds, "phase/add-checkpoint")
+	assert.Contains(t, cmds, "agentic:phase/add-checkpoint")
+}
+
+func TestCommandsPhase_CmdPhase_Good_GetUpdateCheckpoint(t *testing.T) {
+	s, _ := testPrepWithCore(t, nil)
+	_, _, err := s.planCreate(context.Background(), nil, PlanCreateInput{
+		Title:     "Phase command plan",
+		Slug:      "phase-command-plan",
+		Objective: "Exercise phase commands",
+		Phases: []Phase{
+			{Number: 1, Name: "Setup", Status: "pending"},
+		},
+	})
+	require.NoError(t, err)
+
+	output := captureStdout(t, func() {
+		r := s.cmdPhase(core.NewOptions(
+			core.Option{Key: "action", Value: "get"},
+			core.Option{Key: "_arg", Value: "phase-command-plan"},
+			core.Option{Key: "phase", Value: 1},
+		))
+		assert.True(t, r.OK)
+	})
+	assert.Contains(t, output, "phase:  1")
+	assert.Contains(t, output, "name:   Setup")
+	assert.Contains(t, output, "status: pending")
+
+	output = captureStdout(t, func() {
+		r := s.cmdPhase(core.NewOptions(
+			core.Option{Key: "action", Value: "update-status"},
+			core.Option{Key: "_arg", Value: "phase-command-plan"},
+			core.Option{Key: "phase", Value: 1},
+			core.Option{Key: "status", Value: "completed"},
+		))
+		assert.True(t, r.OK)
+	})
+	assert.Contains(t, output, "status: completed")
+
+	output = captureStdout(t, func() {
+		r := s.cmdPhase(core.NewOptions(
+			core.Option{Key: "action", Value: "add-checkpoint"},
+			core.Option{Key: "_arg", Value: "phase-command-plan"},
+			core.Option{Key: "phase", Value: 1},
+			core.Option{Key: "note", Value: "Build passes"},
+		))
+		assert.True(t, r.OK)
+	})
+	assert.Contains(t, output, "checkpoints: 1")
+}
+
+func TestCommandsPhase_CmdPhase_Bad_MissingActionStillShowsUsage(t *testing.T) {
+	s, _ := testPrepWithCore(t, nil)
+	output := captureStdout(t, func() {
+		r := s.cmdPhase(core.NewOptions())
+		assert.True(t, r.OK)
+	})
+	assert.Contains(t, output, "core-agent phase get")
+}
+
+func TestCommandsPhase_CmdPhase_Ugly_UnknownAction(t *testing.T) {
+	s, _ := testPrepWithCore(t, nil)
+	r := s.cmdPhase(core.NewOptions(core.Option{Key: "action", Value: "explode"}))
+	require.False(t, r.OK)
+	assert.Contains(t, r.Value.(error).Error(), "unknown phase command")
+}
diff --git a/pkg/agentic/commands_test.go b/pkg/agentic/commands_test.go
index 088fde6..07dae10 100644
--- a/pkg/agentic/commands_test.go
+++ b/pkg/agentic/commands_test.go
@@ -1614,6 +1614,14 @@ func TestCommands_RegisterCommands_Good_AllRegistered(t *testing.T) {
 	assert.Contains(t, cmds, "review-queue")
 	assert.Contains(t, cmds, "agentic:review-queue")
 	assert.Contains(t, cmds, "task")
+	assert.Contains(t, cmds, "phase")
+	assert.Contains(t, cmds, "agentic:phase")
+	assert.Contains(t, cmds, "phase/get")
+	assert.Contains(t, cmds, "agentic:phase/get")
+	assert.Contains(t, cmds, "phase/update_status")
+	assert.Contains(t, cmds, "agentic:phase/update_status")
+	assert.Contains(t, cmds, "phase/add_checkpoint")
+	assert.Contains(t, cmds, "agentic:phase/add_checkpoint")
 	assert.Contains(t, cmds, "task/update")
 	assert.Contains(t, cmds, "task/toggle")
 	assert.Contains(t, cmds, "sprint")
diff --git a/pkg/agentic/prep_test.go b/pkg/agentic/prep_test.go
index 71eafae..68437a0 100644
--- a/pkg/agentic/prep_test.go
+++ b/pkg/agentic/prep_test.go
@@ -754,6 +754,14 @@ func TestPrep_OnStartup_Good_RegistersGenerateCommand(t *testing.T) {
 	assert.Contains(t, c.Commands(), "task/create")
 	assert.Contains(t, c.Commands(), "task/update")
 	assert.Contains(t, c.Commands(), "task/toggle")
+	assert.Contains(t, c.Commands(), "phase")
+	assert.Contains(t, c.Commands(), "agentic:phase")
+	assert.Contains(t, c.Commands(), "phase/get")
+	assert.Contains(t, c.Commands(), "agentic:phase/get")
+	assert.Contains(t, c.Commands(), "phase/update_status")
+	assert.Contains(t, c.Commands(), "agentic:phase/update_status")
+	assert.Contains(t, c.Commands(), "phase/add_checkpoint")
+	assert.Contains(t, c.Commands(), "agentic:phase/add_checkpoint")
 	assert.Contains(t, c.Commands(), "state")
 	assert.Contains(t, c.Commands(), "state/set")
 	assert.Contains(t, c.Commands(), "state/get")