diff --git a/packages/opencode/src/server/routes/instance/httpapi/groups/v2/session.ts b/packages/opencode/src/server/routes/instance/httpapi/groups/v2/session.ts
index 70331c27f0..c1a07957db 100644
--- a/packages/opencode/src/server/routes/instance/httpapi/groups/v2/session.ts
+++ b/packages/opencode/src/server/routes/instance/httpapi/groups/v2/session.ts
@@ -4,7 +4,13 @@ import { Prompt } from "@opencode-ai/core/session-prompt"
 import { SessionV2 } from "@/v2/session"
 import { Schema } from "effect"
 import { HttpApiEndpoint, HttpApiGroup, HttpApiSchema, OpenApi } from "effect/unstable/httpapi"
-import { InvalidCursorError, InvalidRequestError, ServiceUnavailableError, SessionNotFoundError, UnknownError } from "../../errors"
+import {
+  InvalidCursorError,
+  InvalidRequestError,
+  ServiceUnavailableError,
+  SessionNotFoundError,
+  UnknownError,
+} from "../../errors"
 import { V2Authorization } from "../../middleware/authorization"
 import { WorkspaceRoutingQuery, WorkspaceRoutingQueryFields } from "../../middleware/workspace-routing"
 import { QueryBoolean } from "../query"
diff --git a/packages/opencode/src/server/routes/instance/httpapi/handlers/v2/session.ts b/packages/opencode/src/server/routes/instance/httpapi/handlers/v2/session.ts
index 330b6fe1bf..ff4e098fb4 100644
--- a/packages/opencode/src/server/routes/instance/httpapi/handlers/v2/session.ts
+++ b/packages/opencode/src/server/routes/instance/httpapi/handlers/v2/session.ts
@@ -3,7 +3,13 @@ import { SessionV2 } from "@/v2/session"
 import { DateTime, Effect, Option, Schema } from "effect"
 import { HttpApiBuilder, HttpApiSchema } from "effect/unstable/httpapi"
 import { InstanceHttpApi } from "../../api"
-import { InvalidCursorError, InvalidRequestError, ServiceUnavailableError, SessionNotFoundError, UnknownError } from "../../errors"
+import {
+  InvalidCursorError,
+  InvalidRequestError,
+  ServiceUnavailableError,
+  SessionNotFoundError,
+  UnknownError,
+} from "../../errors"
 
 const DefaultSessionsLimit = 50
 
diff --git a/packages/opencode/src/v2/session.ts b/packages/opencode/src/v2/session.ts
index 1b65245ded..dcff1a318a 100644
--- a/packages/opencode/src/v2/session.ts
+++ b/packages/opencode/src/v2/session.ts
@@ -110,7 +110,9 @@ export interface Interface {
       direction: "previous" | "next"
     }
   }) => Effect.Effect<SessionMessage.Message[], NotFoundError | MessageDecodeError>
-  readonly context: (sessionID: SessionID) => Effect.Effect<SessionMessage.Message[], NotFoundError | MessageDecodeError>
+  readonly context: (
+    sessionID: SessionID,
+  ) => Effect.Effect<SessionMessage.Message[], NotFoundError | MessageDecodeError>
   readonly prompt: (input: {
     id?: EventV2.ID
     sessionID: SessionID
diff --git a/packages/sdk/js/src/v2/gen/types.gen.ts b/packages/sdk/js/src/v2/gen/types.gen.ts
index d4bdbbb6e1..c291571b5c 100644
--- a/packages/sdk/js/src/v2/gen/types.gen.ts
+++ b/packages/sdk/js/src/v2/gen/types.gen.ts
@@ -1836,6 +1836,12 @@ export type ServiceUnavailableError = {
   service?: string
 }
 
+export type UnknownError1 = {
+  _tag: "UnknownError"
+  message: string
+  ref?: string
+}
+
 export type V2SessionMessagesResponse = {
   items: Array<SessionMessage>
   cursor: {
@@ -7311,6 +7317,10 @@ export type V2SessionContextErrors = {
    * SessionNotFoundError
    */
   404: SessionNotFoundError
+  /**
+   * UnknownError
+   */
+  500: UnknownError1
 }
 
 export type V2SessionContextError = V2SessionContextErrors[keyof V2SessionContextErrors]
@@ -7355,6 +7365,10 @@ export type V2SessionMessagesErrors = {
    * SessionNotFoundError
    */
   404: SessionNotFoundError
+  /**
+   * UnknownError
+   */
+  500: UnknownError1
 }
 
 export type V2SessionMessagesError = V2SessionMessagesErrors[keyof V2SessionMessagesErrors]
diff --git a/packages/sdk/openapi.json b/packages/sdk/openapi.json
index 8548eeb6d3..1b47efcd08 100644
--- a/packages/sdk/openapi.json
+++ b/packages/sdk/openapi.json
@@ -8517,6 +8517,16 @@
                 }
               }
             }
+          },
+          "500": {
+            "description": "UnknownError",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/UnknownError1"
+                }
+              }
+            }
           }
         },
         "description": "Retrieve the active context messages for a v2 session (all messages after the last compaction).",
@@ -8634,6 +8644,16 @@
                 }
               }
             }
+          },
+          "500": {
+            "description": "UnknownError",
+            "content": {
+              "application/json": {
+                "schema": {
+                  "$ref": "#/components/schemas/UnknownError1"
+                }
+              }
+            }
           }
         },
         "description": "Retrieve projected v2 messages for a session. Items keep the requested order across pages; use cursor.next or cursor.previous to move through the ordered timeline.",
@@ -15735,6 +15755,23 @@
         "required": ["_tag", "message"],
         "additionalProperties": false
       },
+      "UnknownError1": {
+        "type": "object",
+        "properties": {
+          "_tag": {
+            "type": "string",
+            "enum": ["UnknownError"]
+          },
+          "message": {
+            "type": "string"
+          },
+          "ref": {
+            "type": "string"
+          }
+        },
+        "required": ["_tag", "message"],
+        "additionalProperties": false
+      },
       "V2SessionMessagesResponse": {
         "type": "object",
         "properties": {