diff --git a/.changeset/pre.json b/.changeset/pre.json
index 61400572f..3a036d4a3 100644
--- a/.changeset/pre.json
+++ b/.changeset/pre.json
@@ -208,6 +208,7 @@
     "infra-sentry-node-dep",
     "invalidation-set-add-shortcut-and-batch",
     "itchy-mangos-find",
+    "jitm-json-store-boundary",
     "khaki-frogs-wave",
     "kind-lizards-bathe",
     "large-pugs-strive",
diff --git a/packages/e2e/CHANGELOG.md b/packages/e2e/CHANGELOG.md
index 69b8d0392..2460ea483 100644
--- a/packages/e2e/CHANGELOG.md
+++ b/packages/e2e/CHANGELOG.md
@@ -1,5 +1,14 @@
 # @effect-app/e2e
 
+## 4.0.0-beta.326
+
+### Patch Changes
+
+- Updated dependencies [2ebf8ae]
+  - effect-app@4.0.0-beta.326
+  - @effect-app/infra@4.0.0-beta.326
+  - @effect-app/vue@4.0.0-beta.326
+
 ## 4.0.0-beta.325
 
 ### Patch Changes
diff --git a/packages/e2e/package.json b/packages/e2e/package.json
index 483aa02f9..e27524697 100644
--- a/packages/e2e/package.json
+++ b/packages/e2e/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@effect-app/e2e",
-  "version": "4.0.0-beta.325",
+  "version": "4.0.0-beta.326",
   "license": "MIT",
   "type": "module",
   "private": true,
diff --git a/packages/effect-app/CHANGELOG.md b/packages/effect-app/CHANGELOG.md
index f7a553a12..89fed7943 100644
--- a/packages/effect-app/CHANGELOG.md
+++ b/packages/effect-app/CHANGELOG.md
@@ -1,5 +1,21 @@
 # @effect-app/prelude
 
+## 4.0.0-beta.326
+
+### Minor Changes
+
+- 2ebf8ae: `jitM` runs at the store boundary as JSON → JSON, before the `toCodecJson(toEncoded(schema))` decode; repositories decode the Encoded shape only.
+
+  `jitM` used to be applied by the repository _after_ the store had already decoded the document, and was typed `(pm: Encoded) => Encoded` - a lie, since jitMs are written against the stored JSON and `Encoded` holds native `Date`/`Map`/`Set` values.
+
+  The read pipeline is now: raw JSON document → merge `defaultValues` (unchanged: they only fill _absent_ keys, so an explicitly stored `null` reaches `jitM`) → `jitM` (JSON → JSON) → decode `Schema.toCodecJson(Schema.toEncoded(schema))` → Encoded. The repository then decodes Encoded → the domain type with `schema` and no longer applies `jitM` at all. Because `jitM` now runs before any schema decode sees the document, it can repair legacy shapes including explicit `null`s.
+
+  - `StoreConfig.jitM?: (json: JsonRecord) => JsonRecord` is new, where `JsonRecord` (exported from `effect-app/Store`) is `{ readonly [key: string]: Schema.Json }`. It is not applied on the write/encode path, and never receives `_etag`.
+  - `RepositoryOptions.jitM` changes type from `(pm: Encoded) => Encoded` to `(json: JsonRecord) => JsonRecord` and is forwarded into the store config.
+  - **Migrating a jitM:** it now receives and must return JSON. A `Date` field arrives as an ISO string (return a string, not a `Date`), a `ReadonlySet` as an array, a `ReadonlyMap` as an array of `[key, value]` pairs. Field access is index-signature based (`json["x"]`) rather than typed property access.
+  - The JSON→Encoded decode stays strict: a document `jitM` does not repair fails at the store boundary instead of being read back half-decoded.
+  - `ValidationError.jitMResult` is deprecated: `validateSample` only ever sees the store's output, so it is identical to `rawData`.
+
 ## 4.0.0-beta.325
 
 ### Patch Changes
diff --git a/packages/effect-app/package.json b/packages/effect-app/package.json
index 60c188c3f..c582e7822 100644
--- a/packages/effect-app/package.json
+++ b/packages/effect-app/package.json
@@ -1,6 +1,6 @@
 {
   "name": "effect-app",
-  "version": "4.0.0-beta.325",
+  "version": "4.0.0-beta.326",
   "license": "MIT",
   "type": "module",
   "repository": {
diff --git a/packages/infra/CHANGELOG.md b/packages/infra/CHANGELOG.md
index 9a306d43e..d56954f0c 100644
--- a/packages/infra/CHANGELOG.md
+++ b/packages/infra/CHANGELOG.md
@@ -1,5 +1,26 @@
 # @effect-app/infra
 
+## 4.0.0-beta.326
+
+### Minor Changes
+
+- 2ebf8ae: `jitM` runs at the store boundary as JSON → JSON, before the `toCodecJson(toEncoded(schema))` decode; repositories decode the Encoded shape only.
+
+  `jitM` used to be applied by the repository _after_ the store had already decoded the document, and was typed `(pm: Encoded) => Encoded` - a lie, since jitMs are written against the stored JSON and `Encoded` holds native `Date`/`Map`/`Set` values.
+
+  The read pipeline is now: raw JSON document → merge `defaultValues` (unchanged: they only fill _absent_ keys, so an explicitly stored `null` reaches `jitM`) → `jitM` (JSON → JSON) → decode `Schema.toCodecJson(Schema.toEncoded(schema))` → Encoded. The repository then decodes Encoded → the domain type with `schema` and no longer applies `jitM` at all. Because `jitM` now runs before any schema decode sees the document, it can repair legacy shapes including explicit `null`s.
+
+  - `StoreConfig.jitM?: (json: JsonRecord) => JsonRecord` is new, where `JsonRecord` (exported from `effect-app/Store`) is `{ readonly [key: string]: Schema.Json }`. It is not applied on the write/encode path, and never receives `_etag`.
+  - `RepositoryOptions.jitM` changes type from `(pm: Encoded) => Encoded` to `(json: JsonRecord) => JsonRecord` and is forwarded into the store config.
+  - **Migrating a jitM:** it now receives and must return JSON. A `Date` field arrives as an ISO string (return a string, not a `Date`), a `ReadonlySet` as an array, a `ReadonlyMap` as an array of `[key, value]` pairs. Field access is index-signature based (`json["x"]`) rather than typed property access.
+  - The JSON→Encoded decode stays strict: a document `jitM` does not repair fails at the store boundary instead of being read back half-decoded.
+  - `ValidationError.jitMResult` is deprecated: `validateSample` only ever sees the store's output, so it is identical to `rawData`.
+
+### Patch Changes
+
+- Updated dependencies [2ebf8ae]
+  - effect-app@4.0.0-beta.326
+
 ## 4.0.0-beta.325
 
 ### Patch Changes
diff --git a/packages/infra/package.json b/packages/infra/package.json
index cfd75f4a6..ddd7b9ab0 100644
--- a/packages/infra/package.json
+++ b/packages/infra/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@effect-app/infra",
-  "version": "4.0.0-beta.325",
+  "version": "4.0.0-beta.326",
   "license": "MIT",
   "type": "module",
   "repository": {
diff --git a/packages/vue-components/CHANGELOG.md b/packages/vue-components/CHANGELOG.md
index e516ab2da..7b05cb05b 100644
--- a/packages/vue-components/CHANGELOG.md
+++ b/packages/vue-components/CHANGELOG.md
@@ -1,5 +1,13 @@
 # @effect-app/vue-components
 
+## 4.0.0-beta.326
+
+### Patch Changes
+
+- Updated dependencies [2ebf8ae]
+  - effect-app@4.0.0-beta.326
+  - @effect-app/vue@4.0.0-beta.326
+
 ## 4.0.0-beta.325
 
 ### Patch Changes
diff --git a/packages/vue-components/package.json b/packages/vue-components/package.json
index 4ebbc6216..8e7d5edaa 100644
--- a/packages/vue-components/package.json
+++ b/packages/vue-components/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@effect-app/vue-components",
-  "version": "4.0.0-beta.325",
+  "version": "4.0.0-beta.326",
   "repository": {
     "type": "git",
     "url": "https://github.com/effect-app/libs.git",
diff --git a/packages/vue/CHANGELOG.md b/packages/vue/CHANGELOG.md
index 8dd16b6d1..1d6776816 100644
--- a/packages/vue/CHANGELOG.md
+++ b/packages/vue/CHANGELOG.md
@@ -1,5 +1,12 @@
 # @effect-app/vue
 
+## 4.0.0-beta.326
+
+### Patch Changes
+
+- Updated dependencies [2ebf8ae]
+  - effect-app@4.0.0-beta.326
+
 ## 4.0.0-beta.325
 
 ### Patch Changes
diff --git a/packages/vue/package.json b/packages/vue/package.json
index 1937c9587..1f412427e 100644
--- a/packages/vue/package.json
+++ b/packages/vue/package.json
@@ -1,6 +1,6 @@
 {
   "name": "@effect-app/vue",
-  "version": "4.0.0-beta.325",
+  "version": "4.0.0-beta.326",
   "license": "MIT",
   "type": "module",
   "repository": {