Skip to content

Handle nullable arrays in tool inputSchemas #895

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 2 commits into from
Oct 31, 2025
Merged

Handle nullable arrays in tool inputSchemas #895

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
37acee9
Handle nullable arrays in tool inputSchemas
cliffhall Oct 29, 2025
54484e7
Merge branch 'main' into fix-default-null-array-input
cliffhall Oct 30, 2025
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
8 changes: 4 additions & 4 deletions client/src/components/DynamicJsonForm.tsx
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -113,8 +113,8 @@ const DynamicJsonForm = forwardRef<DynamicJsonFormRef, DynamicJsonFormProps>(
setJsonError(errorMessage);

// Reset to default for clearly invalid JSON (not just incomplete typing)
const trimmed = jsonString.trim();
if (trimmed.length > 5 && !trimmed.match(/^[\s[{]/)) {
const trimmed = jsonString?.trim();
if (trimmed && trimmed.length > 5 && !trimmed.match(/^[\s[{]/)) {
onChange(generateDefaultValue(schema));
}
}
Expand Down Expand Up @@ -155,7 +155,7 @@ const DynamicJsonForm = forwardRef<DynamicJsonFormRef, DynamicJsonFormProps>(

const formatJson = () => {
try {
const jsonStr = rawJsonValue.trim();
const jsonStr = rawJsonValue?.trim();
if (!jsonStr) {
return;
}
Expand All @@ -171,7 +171,7 @@ const DynamicJsonForm = forwardRef<DynamicJsonFormRef, DynamicJsonFormProps>(
const validateJson = () => {
if (!isJsonMode) return { isValid: true, error: null };
try {
const jsonStr = rawJsonValue.trim();
const jsonStr = rawJsonValue?.trim();
if (!jsonStr) return { isValid: true, error: null };
const parsed = JSON.parse(jsonStr);
// Clear any pending debounced update and immediately update parent
Expand Down
22 changes: 12 additions & 10 deletions client/src/components/ToolsTab.tsx
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -194,16 +194,18 @@ const ToolsTab = ({
...params,
[key]: checked
? null
: prop.default !== null
? prop.default
: prop.type === "boolean"
? false
: prop.type === "string"
? ""
: prop.type === "number" ||
prop.type === "integer"
? undefined
: undefined,
: prop.type === "array"
? undefined
: prop.default !== null
? prop.default
: prop.type === "boolean"
? false
: prop.type === "string"
? ""
: prop.type === "number" ||
prop.type === "integer"
? undefined
: undefined,
})
}
/>
Expand Down
3 changes: 2 additions & 1 deletion client/src/utils/jsonUtils.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -85,8 +85,9 @@ export function tryParseJson(str: string): {
success: boolean;
data: JsonValue;
} {
const trimmed = str.trim();
const trimmed = str?.trim();
if (
trimmed &&
!(trimmed.startsWith("{") && trimmed.endsWith("}")) &&
!(trimmed.startsWith("[") && trimmed.endsWith("]"))
) {
Expand Down
10 changes: 10 additions & 0 deletions client/src/utils/schemaUtils.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -235,6 +235,16 @@ export function normalizeUnionType(schema: JsonSchemaType): JsonSchemaType {
return { ...schema, type: "integer", anyOf: undefined, nullable: true };
}

// Handle anyOf with exactly array and null (FastMCP pattern)
if (
schema.anyOf &&
schema.anyOf.length === 2 &&
schema.anyOf.some((t) => (t as JsonSchemaType).type === "array") &&
schema.anyOf.some((t) => (t as JsonSchemaType).type === "null")
) {
return { ...schema, type: "array", anyOf: undefined, nullable: true };
}

// Handle array type with exactly string and null
if (
Array.isArray(schema.type) &&
Expand Down