diff --git a/CHANGELOG.md b/CHANGELOG.md
index 52480e8..e16262e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,18 @@
 
 ## Unreleased
 
+- `client.modules.call` resolves to `CallModuleFunctionClientResponse`, which
+  carries only `result`. Console output, the kernel call log and `error` are
+  no longer part of the player response; they stay on the platform dry run.
+- Module business errors reject with `RudderHttpError` (`status` 422, body
+  `{ error, code, requestId }`). `code` is defined by the module and is an
+  open string.
+- `RudderErrorCodes` and the `RudderErrorCode` type are no longer exported
+  from the package. The generated platform codes are now only `forbidden` and
+  `row_referenced`; the scenario and quest codes (`early_completion`,
+  `level_not_reached`, `node_not_active`, `objectives_incomplete`,
+  `run_expired`, `run_not_active`, `scenario_not_active`, `unknown_run`) are
+  removed with those domains. Compare `error.code` with string literals.
 - Login and token refresh send `platform: 'web'` and, when the new optional
   `appVersion` client option is set, `appVersion`. The backend stores them on
   the player for segment rules (`player.platform`, `player.appVersion`).
diff --git a/README.md b/README.md
index 3153163..7840ee7 100644
--- a/README.md
+++ b/README.md
@@ -88,6 +88,10 @@ try {
 }
 ```
 
+A module business error rejects with `RudderHttpError` (`status` 422) whose
+`code` is the module's own open string code. The platform codes are
+`forbidden` and `row_referenced`.
+
 Invalid client options (missing `baseUrl` / `projectKey`) throw `RudderError`
 with `code: 'sdk/invalid-options'` from the constructor.
 
diff --git a/skills/rudder-web-sdk/SKILL.md b/skills/rudder-web-sdk/SKILL.md
index 45e3e35..1583cd2 100644
--- a/skills/rudder-web-sdk/SKILL.md
+++ b/skills/rudder-web-sdk/SKILL.md
@@ -83,7 +83,7 @@ Tokens are saved to the `TokenStore` automatically. The transport injects
 | Catalog currencies | `client.catalog` | observable `SyncedState<Map<string, CatalogCurrency>>` |
 | Player storage | `client.storage` + `.save(items)` / `.delete(type)` | observable + mutations |
 | Project storage | `client.projectStorage` + `.save(items)` | observable + mutation |
-| Modules | `client.modules.call(module, fn, args?)` | `CallModuleFunctionResponse` |
+| Modules | `client.modules.call(module, fn, args?)` | `CallModuleFunctionClientResponse` (`{ result }`) |
 | Resources | `client.resources(slug)` | `list` / `get` / `create` / `update` / `delete` |
 
 There is no UGC, wallet service, or standalone economy service — wallets live
@@ -121,8 +121,16 @@ All SDK errors extend `RudderError` (optional machine-readable `code`):
 - `RudderError` with `code: 'sdk/invalid-options'` (`SDK_ERROR_INVALID_OPTIONS`)
   — constructor validation
 
-Server error codes (`RudderErrorCodes`, from `src/generated/errors.ts`) are
-compared with `error.code === RudderErrorCodes.forbidden`.
+The platform error codes are `forbidden` and `row_referenced`
+(`src/generated/errors.ts`, not exported from the package entry); compare
+`error.code === 'forbidden'`.
+
+`client.modules.call` resolves to `{ result }` only; console output and the
+kernel call log never reach players. A module business error rejects with
+`RudderHttpError` whose `status` is 422 and whose `code` is the module's own
+code (the body is `{ error, code, requestId }`). Module codes are open strings
+with no generated constants, so compare against the codes the module
+documents. A module trap is a 500 and a timeout a 504, both without details.
 
 ## Reference files