diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -6,6 +6,21 @@
 
 ## [Unreleased]
 
+## 0.9.0.0 — 2026-08-02
+
+### Breaking Changes
+
+- Requires `keiki >=0.8 && <0.9` and `keiki-codec-json >=0.8 && <0.9`,
+  replacing the previous `>=0.7 && <0.8` bounds. Consumers must solve for the
+  same Keiki major; verification results and rendering may differ from the 0.7
+  line.
+
+### New Features
+
+- `Keiro.Inbox.Types` re-exports `RetryDelay` from `Shibuya.Core.Ack`, so
+  generated inbox dispositions carrying retry delays need only the `keiro`
+  import.
+
 ## 0.8.0.0 — 2026-08-01
 
 No changes this release. Version moves with the package set.
diff --git a/keiro.cabal b/keiro.cabal
--- a/keiro.cabal
+++ b/keiro.cabal
@@ -1,6 +1,6 @@
 cabal-version:   3.0
 name:            keiro
-version:         0.8.0.0
+version:         0.9.0.0
 synopsis:        Event sourcing framework and workflow engine
 description:
   A library that composes kiroku, keiki, and shibuya into an
@@ -33,6 +33,7 @@
   default-extensions:
     DeriveAnyClass
     DuplicateRecordFields
+    ImportQualifiedPost
     MultilineStrings
     OverloadedLabels
     OverloadedStrings
@@ -120,9 +121,9 @@
     , hs-opentelemetry-api                   >=1.0      && <1.1
     , hs-opentelemetry-propagator-w3c        >=1.0      && <1.1
     , hs-opentelemetry-semantic-conventions  >=1.40     && <2
-    , keiki                                  >=0.7      && <0.8
-    , keiki-codec-json                       >=0.7      && <0.8
-    , keiro-core                             ^>=0.8.0.0
+    , keiki                                  >=0.8      && <0.9
+    , keiki-codec-json                       >=0.8      && <0.9
+    , keiro-core                             ^>=0.9.0.0
     , kiroku-store                           >=0.3      && <0.4
     , lens                                   >=5.2      && <5.4
     , mmzk-typeid                            >=0.7      && <0.8
@@ -190,7 +191,7 @@
     , hs-opentelemetry-api  >=1.0      && <1.1
     , hs-opentelemetry-sdk  >=1.0      && <1.1
     , keiro
-    , keiro-core            ^>=0.8.0.0
+    , keiro-core            ^>=0.9.0.0
     , keiro-test-support
     , kiroku-store          >=0.3      && <0.4
     , tasty-bench           >=0.4
diff --git a/src/Keiro/Inbox/Types.hs b/src/Keiro/Inbox/Types.hs
--- a/src/Keiro/Inbox/Types.hs
+++ b/src/Keiro/Inbox/Types.hs
@@ -7,7 +7,8 @@
 -- producer republish) become observable as duplicates instead of
 -- re-running the handler.
 module Keiro.Inbox.Types
-  ( InboxDedupePolicy (..),
+  ( RetryDelay (..),
+    InboxDedupePolicy (..),
     InboxPersistence (..),
     InboxStatus (..),
     InboxResult (..),
@@ -25,6 +26,7 @@
 import Keiro.Integration.Event (IntegrationEvent)
 import Keiro.Prelude
 import Kiroku.Store.Types (EventId (..), GlobalPosition (..))
+import Shibuya.Core.Ack (RetryDelay (..))
 
 -- | Which identity is used as the inbox primary key for an
 -- 'IntegrationEvent'.