replace_member

[refactoring]

Replaces one C# member selected by its exact symbolKey.

Available in Glider 13.0.0. Check that the installed server advertises replace_member.

Before you use this tool

Writes files by default. An authorized, unambiguous edit with a clear scope can apply directly. Set applyChanges: false for a preview without file writes. Preview when the user requests inspection only, the scope is unclear, or a broad refactor needs inspection.

Try it locally in the Glider playground

Parameters

Name	Type	Required	Description
symbolKey	string	Yes	Exact member key from symbol discovery. Names and fuzzy matches are unsupported.
expectedText	string	Yes	Exact current declaration without outer trivia. Read replacementSpans from get_symbol_info, then get_file_contents.
memberCode	string	Yes	One complete declaration of the same member category. Exclude outer comments and directives.
filePath	string	No	Exact declaration file for a partial member. Absolute or loaded-root-relative.
applyChanges	boolean	No	Apply to disk by default. Set false to preview. Default: `true`
failOnErrors	boolean	No	Refuse a write when the replacement has compiler errors or incomplete linked-target coverage. Default: `false`
includeDiff	boolean	No	Include the unified diff. Set false for compact output; diagnostics, errors, and application state remain available. Default: `true`
maxDiffChars	number	No	Maximum diff characters. Use 0 for unlimited. Default: `50000`
pathStyle	string	No	Path style: absolute or relative to the loaded root. Default: `"absolute"`
responseDetail	string	No	compact returns results and actionable state. full adds diagnostic metadata under responseDiagnostics. Default: `"compact"`

Examples

Replace sample paths and symbol keys with values from your workspace.

Preview an exact member replacement

Arguments 
{
  "symbolKey": "<member key from find_code>",
  "expectedText": "public int Total() => 1;",
  "memberCode": "public int Total() => 2;",
  "applyChanges": false
}

Full MCP request

Full MCP request 
{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "replace_member",
    "arguments": {
      "symbolKey": "<member key from find_code>",
      "expectedText": "public int Total() => 1;",
      "memberCode": "public int Total() => 2;",
      "applyChanges": false
    }
  }
}

Illustrative response 
{
  "success": true,
  "status": "preview",
  "preview": true,
  "applied": false,
  "diskWriteAttempted": false,
  "filesChanged": 0,
  "wouldChange": true,
  "filePath": "/project/OrderService.cs",
  "workspaceUpdate": "unchanged",
  "diagnostics": {
    "errorCount": 0,
    "warningCount": 0,
    "items": []
  },
  "uncheckedProjects": [],
  "unifiedDiff": "..."
}

Response Notes

Supply its current declaration as expectedText and one replacement declaration as memberCode. Surrounding code and outer comments remain unchanged. Use applyChanges=false for a preview.

Returns status, the original span, replacementSymbolKey, diagnostics, and a bounded diff. Span lines and UTF-16 columns are one-based, with exclusive ends; start/length are zero-based UTF-16 offsets. A conflict requires a fresh read. Compiler checks cover only the replacement; callers remain unchanged. uncheckedProjects reports incomplete coverage. Apply awaits sync across all linked targets without a full reload. A failed sync returns success=false and applied=true. If workspaceUpdate is failed, sync the file instead of repeating the write. Internal directives and multi-variable declarations are unsupported. Supported encodings are UTF-8 and UTF-16 with a BOM. Concurrent writer exclusion covers Windows and cooperating .NET clients on Unix. Results use top-level fields with success. Compact is the default; full adds responseDiagnostics. Both modes retain errors, coverage, partial state, and recovery advice.

For a failed symbol-key request, success=false includes errorCode, parameter, error, and suggestions in compact, full, and batch operation results. Batch keeps a bounded summary outside the requested detail budget. If the hard server limit omits details, failureDetailsOmitted or writeStateOmitted identifies the omission. errorCode is invalid_symbol_key, symbol_not_found, ambiguous_symbol_key, wrong_symbol_kind, source_unavailable, unsupported_symbol, or invalid_arguments. Follow the suggestions for the specific failure. Correct the named selector for invalid_arguments. For symbol_not_found, repeat discovery in the selected workspace and pass a returned key unchanged. An absent identity does not prove that a key is stale.