bytebase/bytebase · error

database is required

Error message

database is required

What it means

The MCP change tool (handleChange) validates its input in step 1: database, sql, and title are all mandatory. An empty input.Database cannot identify the target database for the schema-change pipeline, so it throws this error first.

Source

Thrown at backend/api/mcp/tool_change.go:167

**Notes:**
- v1 supports single database targets only. For batch changes across multiple databases, use get_skill("database-change").
- Plan checks run automatically; results included in response when available.
- Requires bb.sheets.create, bb.plans.create, bb.issues.create permissions.
- If createRollout=true but policy gates aren't satisfied, returns success with rolloutCreated=false and a reason.
- Masked data: a masked column reads back as "******". That is a placeholder, not a value anything holds. Any change containing it is refused, because writing it back would overwrite the real value. Ask a human to make the change in the Bytebase console instead.
`

func (s *Server) registerChangeTool() {
	mcp.AddTool(s.mcpServer, &mcp.Tool{
		Name:        "propose_database_change",
		Description: proposeChangeDescription,
	}, s.handleChange)
}

func (s *Server) handleChange(ctx context.Context, req *mcp.CallToolRequest, input ChangeInput) (*mcp.CallToolResult, any, error) {
	// Step 1: Validate input.
	if input.Database == "" {
		return nil, nil, errors.New("database is required")
	}
	if input.SQL == "" {
		return nil, nil, errors.New("sql is required")
	}
	if input.Title == "" {
		return nil, nil, errors.New("title is required")
	}

	changeType := input.ChangeType
	if changeType == "" {
		changeType = changeTypeMigrate
	}
	if changeType != changeTypeMigrate && changeType != changeTypeSDL {
		return formatToolError(&toolError{
			Code:       "INVALID_ARGUMENT",
			Message:    fmt.Sprintf("invalid changeType %q", changeType),
			Suggestion: "allowed values: MIGRATE, SDL",
		}), nil, nil

View on GitHub (pinned to 1870550677)

Solutions

1. Provide the database resource name (e.g. instances/{instance}/databases/{db}) in the change tool input.
2. List available databases first (search/list tool) and pick a valid database name before calling change.
3. Verify the MCP client serializes the database field with the exact expected key.
4. Client-side: validate required fields (database, sql, title) before dispatching the tool call.

Example fix

// before
await callTool('change', { sql: 'CREATE TABLE t(id INT)', title: 'add t' });
// after
await callTool('change', { database: 'instances/prod/databases/appdb', sql: 'CREATE TABLE t(id INT)', title: 'add t' });

for (const field of ['database', 'sql', 'title'] as const) {
  if (!input[field]) throw new Error(`${field} is required`);
}

function isCompleteChangeInput(i: ChangeInput): boolean {
  return i.database !== '' && i.sql !== '' && i.title !== '';
}

try {
  return await callTool('change', input);
} catch (e) {
  if (String(e).includes('database is required')) {
    const dbs = await callTool('search_database', {});
    return await callTool('change', { ...input, database: dbs[0].name });
  }
  throw e;
}

When it happens

Trigger: Invoking the change tool with input.database empty — omitted field in the tool call, an LLM agent that filled only sql/title, or a client binding that maps the database argument to the wrong key.

Common situations: AI agent constructs a change request without resolving which database to target; manual tool invocation in tests missing the database argument; renamed/renumbered input fields breaking argument deserialization so Database defaults to "".

Understand the failure class

Background: "missing required argument" and "the following required arguments were not provided": what required-argument errors mean and how to fix them — this error's family across 20 libraries.

Related errors

• operationId is required
• sql is required
• title is required
• database is required
• statement is required

AI-assisted analysis of bytebase/bytebase@1870550677 (2026-09-06). Data as JSON: /api/errors/65efd0e4a505d259. Report an issue: GitHub.