diff --git a/internal/app/runtime_provider.go b/internal/app/runtime_provider.go
index 0f822b0..1d61d5d 100644
--- a/internal/app/runtime_provider.go
+++ b/internal/app/runtime_provider.go
@@ -4,8 +4,11 @@ import (
 	"context"
 
 	"github.com/open-cli-collective/codereview-cli/internal/gitprovider"
+	"github.com/open-cli-collective/codereview-cli/internal/outbox"
 )
 
+var _ outbox.LiveProvider = runtimeProvider{}
+
 // runtimeProvider keeps repository reads on the profile git credential while
 // reviewer-authenticated writes and authority checks flow through the posting
 // credential.
diff --git a/internal/gateio/gateio.go b/internal/gateio/gateio.go
index 5efebfd..77d50f6 100644
--- a/internal/gateio/gateio.go
+++ b/internal/gateio/gateio.go
@@ -63,7 +63,7 @@ type AcquireFunc func(string) (Lock, error)
 // Options contains gate IO dependencies.
 type Options struct {
 	Store                   Store
-	Provider                gitprovider.GitProvider
+	Provider                outbox.LiveProvider
 	Limiter                 outbox.Limiter
 	Layout                  statepaths.Layout
 	Acquire                 AcquireFunc
@@ -871,7 +871,7 @@ func summarizeStaleCandidate(opts Options, req Request, run ledger.Run, summary
 	}, nil, nil
 }
 
-func fetchReviewsUnlessApproved(ctx context.Context, provider gitprovider.GitProvider, ref gitprovider.PRRef, reviews []gitprovider.Review, loaded bool, posting gitprovider.Identity) ([]gitprovider.Review, *Result, error) {
+func fetchReviewsUnlessApproved(ctx context.Context, provider outbox.LiveProvider, ref gitprovider.PRRef, reviews []gitprovider.Review, loaded bool, posting gitprovider.Identity) ([]gitprovider.Review, *Result, error) {
 	if !loaded {
 		var err error
 		reviews, err = provider.ListReviews(ctx, ref)
@@ -891,7 +891,7 @@ func fetchReviewsUnlessApproved(ctx context.Context, provider gitprovider.GitPro
 	}, nil
 }
 
-func readGateHostState(ctx context.Context, provider gitprovider.GitProvider, ref gitprovider.PRRef) (gateHostState, error) {
+func readGateHostState(ctx context.Context, provider outbox.LiveProvider, ref gitprovider.PRRef) (gateHostState, error) {
 	reviews, err := provider.ListReviews(ctx, ref)
 	if err != nil {
 		return gateHostState{}, err
@@ -899,7 +899,7 @@ func readGateHostState(ctx context.Context, provider gitprovider.GitProvider, re
 	return readGateHostStateWithReviews(ctx, provider, ref, reviews)
 }
 
-func readGateHostStateWithReviews(ctx context.Context, provider gitprovider.GitProvider, ref gitprovider.PRRef, reviews []gitprovider.Review) (gateHostState, error) {
+func readGateHostStateWithReviews(ctx context.Context, provider outbox.LiveProvider, ref gitprovider.PRRef, reviews []gitprovider.Review) (gateHostState, error) {
 	comments, err := provider.ListIssueComments(ctx, ref)
 	if err != nil {
 		return gateHostState{}, err
diff --git a/internal/gitprovider/github/client_test.go b/internal/gitprovider/github/client_test.go
index e1650c4..30efc9e 100644
--- a/internal/gitprovider/github/client_test.go
+++ b/internal/gitprovider/github/client_test.go
@@ -13,12 +13,14 @@ import (
 	"github.com/open-cli-collective/codereview-cli/internal/config"
 	"github.com/open-cli-collective/codereview-cli/internal/credentials"
 	"github.com/open-cli-collective/codereview-cli/internal/gitprovider"
+	"github.com/open-cli-collective/codereview-cli/internal/outbox"
 )
 
 var errTokenNotFound = errors.New("token not found")
 
 func TestClientImplementsGitProvider(_ *testing.T) {
 	var _ gitprovider.GitProvider = (*Client)(nil)
+	var _ outbox.Provider = (*Client)(nil)
 }
 
 func TestCapabilities(t *testing.T) {
diff --git a/internal/outbox/outbox.go b/internal/outbox/outbox.go
index d0faa5d..732ba74 100644
--- a/internal/outbox/outbox.go
+++ b/internal/outbox/outbox.go
@@ -36,10 +36,29 @@ type Limiter interface {
 	Wait(context.Context, string) error
 }
 
+// Provider is the git-provider behavior required by the post phase.
+type Provider interface {
+	ListInlineThreads(context.Context, gitprovider.PRRef) ([]gitprovider.InlineThread, error)
+	ListReviews(context.Context, gitprovider.PRRef) ([]gitprovider.Review, error)
+	ListIssueComments(context.Context, gitprovider.PRRef) ([]gitprovider.IssueComment, error)
+	PostInlineComment(context.Context, gitprovider.PRRef, gitprovider.InlineComment) (gitprovider.CommentID, error)
+	ReplyToThread(context.Context, gitprovider.PRRef, gitprovider.ThreadID, string) (gitprovider.CommentID, error)
+	ResolveThread(context.Context, gitprovider.PRRef, gitprovider.ThreadID) error
+	PostIssueComment(context.Context, gitprovider.PRRef, string) (gitprovider.CommentID, error)
+	SubmitReview(context.Context, gitprovider.PRRef, gitprovider.ReviewRequest) (gitprovider.ReviewID, error)
+	Capabilities() gitprovider.ProviderCaps
+}
+
+// LiveProvider adds the pull-request read required by live orchestration.
+type LiveProvider interface {
+	Provider
+	GetPR(context.Context, gitprovider.PRRef) (gitprovider.PR, error)
+}
+
 // Options contains post-phase dependencies.
 type Options struct {
 	Store    Store
-	Provider gitprovider.GitProvider
+	Provider Provider
 	Limiter  Limiter
 	Now      func() time.Time
 }
@@ -324,7 +343,7 @@ func validDesiredOutcome(outcome ledger.Outcome) bool {
 		outcome == ledger.OutcomeNothingToReview
 }
 
-func readHostState(ctx context.Context, provider gitprovider.GitProvider, ref gitprovider.PRRef) (hostState, error) {
+func readHostState(ctx context.Context, provider Provider, ref gitprovider.PRRef) (hostState, error) {
 	threads, err := provider.ListInlineThreads(ctx, ref)
 	if err != nil {
 		return hostState{}, err
@@ -487,7 +506,7 @@ func actionMarkerMatches(req Request, action ledger.PlannedAction, kind string,
 	return false
 }
 
-func buildActionPlan(provider gitprovider.GitProvider, req Request, actions []ledger.PlannedAction, action ledger.PlannedAction) (actionPlan, map[string]bool, error) {
+func buildActionPlan(provider Provider, req Request, actions []ledger.PlannedAction, action ledger.PlannedAction) (actionPlan, map[string]bool, error) {
 	bundledInlineIDs := map[string]bool{}
 	switch action.Kind {
 	case ledger.PlannedActionInlineComment:
@@ -684,7 +703,7 @@ func bodyWithThreadSummaryMarker(req Request, action ledger.PlannedAction, body
 	return rendered + "\n\n" + marker.SanitizeModelContent(body), nil
 }
 
-func dispatch(ctx context.Context, provider gitprovider.GitProvider, ref gitprovider.PRRef, plan actionPlan) (string, error) {
+func dispatch(ctx context.Context, provider Provider, ref gitprovider.PRRef, plan actionPlan) (string, error) {
 	switch plan.action.Kind {
 	case ledger.PlannedActionInlineComment:
 		id, err := provider.PostInlineComment(ctx, ref, *plan.inlineComment)
diff --git a/internal/outbox/outbox_test.go b/internal/outbox/outbox_test.go
index c5688b0..9fa430b 100644
--- a/internal/outbox/outbox_test.go
+++ b/internal/outbox/outbox_test.go
@@ -16,6 +16,64 @@ import (
 	"github.com/open-cli-collective/codereview-cli/internal/review"
 )
 
+var (
+	_ Provider = (*gitprovider.Fake)(nil)
+	_ Provider = (*minimalProvider)(nil)
+)
+
+type minimalProvider struct {
+	posted string
+}
+
+func (*minimalProvider) ListInlineThreads(context.Context, gitprovider.PRRef) ([]gitprovider.InlineThread, error) {
+	return nil, nil
+}
+
+func (*minimalProvider) ListReviews(context.Context, gitprovider.PRRef) ([]gitprovider.Review, error) {
+	return nil, nil
+}
+
+func (*minimalProvider) ListIssueComments(context.Context, gitprovider.PRRef) ([]gitprovider.IssueComment, error) {
+	return nil, nil
+}
+
+func (*minimalProvider) PostInlineComment(context.Context, gitprovider.PRRef, gitprovider.InlineComment) (gitprovider.CommentID, error) {
+	return "inline", nil
+}
+
+func (*minimalProvider) ReplyToThread(context.Context, gitprovider.PRRef, gitprovider.ThreadID, string) (gitprovider.CommentID, error) {
+	return "reply", nil
+}
+
+func (*minimalProvider) ResolveThread(context.Context, gitprovider.PRRef, gitprovider.ThreadID) error {
+	return nil
+}
+
+func (p *minimalProvider) PostIssueComment(_ context.Context, _ gitprovider.PRRef, body string) (gitprovider.CommentID, error) {
+	p.posted = body
+	return "issue", nil
+}
+
+func (*minimalProvider) SubmitReview(context.Context, gitprovider.PRRef, gitprovider.ReviewRequest) (gitprovider.ReviewID, error) {
+	return "review", nil
+}
+
+func (*minimalProvider) Capabilities() gitprovider.ProviderCaps { return gitprovider.ProviderCaps{} }
+
+func TestPostAcceptsProviderPortWithoutUnrelatedMethods(t *testing.T) {
+	store := openStore(t)
+	run := allocateRun(t, store, ledger.PostModeLive)
+	provider := &minimalProvider{}
+	insertAction(t, store, plannedAction(run.RunID, "rollup-1", ledger.PlannedActionRollupComment, true, "", RollupCommentPayload{Body: "rollup"}))
+
+	if _, err := Post(context.Background(), Options{Store: store, Provider: provider, Limiter: noopLimiter{}, Now: fixedClock()}, testRequest(run)); err != nil {
+		t.Fatalf("Post: %v", err)
+	}
+	if !strings.Contains(provider.posted, "rollup") {
+		t.Fatalf("posted body = %q, want rollup", provider.posted)
+	}
+}
+
 func TestPostEmbedsMarkersAndPostsInCanonicalOrder(t *testing.T) {
 	store := openStore(t)
 	run := allocateRun(t, store, ledger.PostModeLive)
diff --git a/internal/reviewrun/reviewrun.go b/internal/reviewrun/reviewrun.go
index 456b54c..57bd8ea 100644
--- a/internal/reviewrun/reviewrun.go
+++ b/internal/reviewrun/reviewrun.go
@@ -54,7 +54,7 @@ type Planner interface {
 // Options contains live review dependencies.
 type Options struct {
 	Store                   Store
-	Provider                gitprovider.GitProvider
+	Provider                outbox.LiveProvider
 	Planner                 Planner
 	Limiter                 outbox.Limiter
 	Layout                  statepaths.Layout
diff --git a/internal/threadrespond/threadrespond.go b/internal/threadrespond/threadrespond.go
index c8a8004..a215012 100644
--- a/internal/threadrespond/threadrespond.go
+++ b/internal/threadrespond/threadrespond.go
@@ -64,7 +64,7 @@ type AcquireFunc func(string) (Lock, error)
 // Options contains response-run dependencies.
 type Options struct {
 	Store        Store
-	Provider     gitprovider.GitProvider
+	Provider     outbox.LiveProvider
 	Adapter      llm.Adapter
 	Limiter      outbox.Limiter
 	Layout       statepaths.Layout