diff --git a/hindsight-api-slim/hindsight_api/api/http.py b/hindsight-api-slim/hindsight_api/api/http.py
index 799cfee7..cda32987 100644
--- a/hindsight-api-slim/hindsight_api/api/http.py
+++ b/hindsight-api-slim/hindsight_api/api/http.py
@@ -2064,6 +2064,26 @@ def create_app(
     # This is required for mounted sub-applications where lifespan may not fire
     app.state.memory = memory
 
+    # ---------------------------------------------------------------------------
+    # Patch OpenAPI schema: align ValidationError with Pydantic v2 error format
+    # ---------------------------------------------------------------------------
+    # FastAPI auto-generates ValidationError with only loc/msg/type, but Pydantic
+    # v2 actually returns additional fields: input (the rejected value), ctx (extra
+    # context dict), and url (link to error docs). Without these in the spec,
+    # generated clients using strict JSON decoding break on real 422 responses.
+    _original_openapi = app.openapi
+
+    def _patched_openapi() -> dict[str, Any]:
+        schema = _original_openapi()
+        ve = schema.get("components", {}).get("schemas", {}).get("ValidationError")
+        if ve and "input" not in ve.get("properties", {}):
+            ve["properties"]["input"] = {"title": "Input"}
+            ve["properties"]["ctx"] = {"title": "Context", "type": "object"}
+            ve["properties"]["url"] = {"title": "URL", "type": "string"}
+        return schema
+
+    app.openapi = _patched_openapi  # type: ignore[assignment]
+
     # Add HTTP metrics middleware
     @app.middleware("http")
     async def http_metrics_middleware(request, call_next):
diff --git a/hindsight-clients/go/api/openapi.yaml b/hindsight-clients/go/api/openapi.yaml
index 3007f8bd..de015606 100644
--- a/hindsight-clients/go/api/openapi.yaml
+++ b/hindsight-clients/go/api/openapi.yaml
@@ -3884,12 +3884,18 @@ components:
           loc:
           - ValidationError_loc_inner
           - ValidationError_loc_inner
+          input: ""
+          ctx: "{}"
           type: type
+          url: url
         - msg: msg
           loc:
           - ValidationError_loc_inner
           - ValidationError_loc_inner
+          input: ""
+          ctx: "{}"
           type: type
+          url: url
       properties:
         detail:
           items:
@@ -5202,7 +5208,10 @@ components:
         loc:
         - ValidationError_loc_inner
         - ValidationError_loc_inner
+        input: ""
+        ctx: "{}"
         type: type
+        url: url
       properties:
         loc:
           items:
@@ -5214,6 +5223,13 @@ components:
         type:
           title: Error Type
           type: string
+        input: {}
+        ctx:
+          title: Context
+          type: object
+        url:
+          title: URL
+          type: string
       required:
       - loc
       - msg
diff --git a/hindsight-clients/go/model_validation_error.go b/hindsight-clients/go/model_validation_error.go
index 50255c64..576f07f3 100644
--- a/hindsight-clients/go/model_validation_error.go
+++ b/hindsight-clients/go/model_validation_error.go
@@ -24,6 +24,9 @@ type ValidationError struct {
 	Loc []ValidationErrorLocInner `json:"loc"`
 	Msg string `json:"msg"`
 	Type string `json:"type"`
+	Input interface{} `json:"input,omitempty"`
+	Ctx map[string]interface{} `json:"ctx,omitempty"`
+	Url *string `json:"url,omitempty"`
 }
 
 type _ValidationError ValidationError
@@ -120,6 +123,103 @@ func (o *ValidationError) SetType(v string) {
 	o.Type = v
 }
 
+// GetInput returns the Input field value if set, zero value otherwise (both if not set or set to explicit null).
+func (o *ValidationError) GetInput() interface{} {
+	if o == nil {
+		var ret interface{}
+		return ret
+	}
+	return o.Input
+}
+
+// GetInputOk returns a tuple with the Input field value if set, nil otherwise
+// and a boolean to check if the value has been set.
+// NOTE: If the value is an explicit nil, `nil, true` will be returned
+func (o *ValidationError) GetInputOk() (*interface{}, bool) {
+	if o == nil || IsNil(o.Input) {
+		return nil, false
+	}
+	return &o.Input, true
+}
+
+// HasInput returns a boolean if a field has been set.
+func (o *ValidationError) HasInput() bool {
+	if o != nil && !IsNil(o.Input) {
+		return true
+	}
+
+	return false
+}
+
+// SetInput gets a reference to the given interface{} and assigns it to the Input field.
+func (o *ValidationError) SetInput(v interface{}) {
+	o.Input = v
+}
+
+// GetCtx returns the Ctx field value if set, zero value otherwise.
+func (o *ValidationError) GetCtx() map[string]interface{} {
+	if o == nil || IsNil(o.Ctx) {
+		var ret map[string]interface{}
+		return ret
+	}
+	return o.Ctx
+}
+
+// GetCtxOk returns a tuple with the Ctx field value if set, nil otherwise
+// and a boolean to check if the value has been set.
+func (o *ValidationError) GetCtxOk() (map[string]interface{}, bool) {
+	if o == nil || IsNil(o.Ctx) {
+		return map[string]interface{}{}, false
+	}
+	return o.Ctx, true
+}
+
+// HasCtx returns a boolean if a field has been set.
+func (o *ValidationError) HasCtx() bool {
+	if o != nil && !IsNil(o.Ctx) {
+		return true
+	}
+
+	return false
+}
+
+// SetCtx gets a reference to the given map[string]interface{} and assigns it to the Ctx field.
+func (o *ValidationError) SetCtx(v map[string]interface{}) {
+	o.Ctx = v
+}
+
+// GetUrl returns the Url field value if set, zero value otherwise.
+func (o *ValidationError) GetUrl() string {
+	if o == nil || IsNil(o.Url) {
+		var ret string
+		return ret
+	}
+	return *o.Url
+}
+
+// GetUrlOk returns a tuple with the Url field value if set, nil otherwise
+// and a boolean to check if the value has been set.
+func (o *ValidationError) GetUrlOk() (*string, bool) {
+	if o == nil || IsNil(o.Url) {
+		return nil, false
+	}
+	return o.Url, true
+}
+
+// HasUrl returns a boolean if a field has been set.
+func (o *ValidationError) HasUrl() bool {
+	if o != nil && !IsNil(o.Url) {
+		return true
+	}
+
+	return false
+}
+
+// SetUrl gets a reference to the given string and assigns it to the Url field.
+func (o *ValidationError) SetUrl(v string) {
+	o.Url = &v
+}
+
 func (o ValidationError) MarshalJSON() ([]byte, error) {
 	toSerialize,err := o.ToMap()
 	if err != nil {
@@ -133,6 +233,15 @@ func (o ValidationError) ToMap() (map[string]interface{}, error) {
 	toSerialize["loc"] = o.Loc
 	toSerialize["msg"] = o.Msg
 	toSerialize["type"] = o.Type
+	if o.Input != nil {
+		toSerialize["input"] = o.Input
+	}
+	if !IsNil(o.Ctx) {
+		toSerialize["ctx"] = o.Ctx
+	}
+	if !IsNil(o.Url) {
+		toSerialize["url"] = o.Url
+	}
 	return toSerialize, nil
 }
 
diff --git a/hindsight-docs/static/openapi.json b/hindsight-docs/static/openapi.json
index 866e5a7d..d5116425 100644
--- a/hindsight-docs/static/openapi.json
+++ b/hindsight-docs/static/openapi.json
@@ -8265,6 +8265,17 @@
           "type": {
             "type": "string",
             "title": "Error Type"
+          },
+          "input": {
+            "title": "Input"
+          },
+          "ctx": {
+            "title": "Context",
+            "type": "object"
+          },
+          "url": {
+            "title": "URL",
+            "type": "string"
           }
         },
         "type": "object",