csf-theme

CSF Workbench theme consumer

This runnable example composes the CSF service in one Go process and exposes its HTTP operations and MCP tools. It reads one operator-owned CSS file from a consumer-selected directory. The filename is always csf.WorkbenchThemeFileName (workbench-theme.css); neither the CSS contents nor a filepath can be supplied as operation input.

From the public archive or repository root containing go.mod, start it with:

go run ./examples/csf-theme \
  -listen 127.0.0.1:8089 \
  -theme-dir ./examples/csf-theme

-listen selects the HTTP address, and -theme-dir selects only the directory that contains workbench-theme.css. The example file in this directory is a small sample. CSF loads the file during startup; a missing or empty file uses the default Workbench appearance. The configured file is limited to 65536 UTF-8 bytes.

The HTTP API reads the current in-memory theme and its resolved host file path:

curl -sS http://127.0.0.1:8089/api/workbench/theme/get \
  -H 'Content-Type: application/json' \
  -d '{}'

GetWorkbenchTheme returns theme.customCss and theme.filePath, the resolved host path to the fixed file.

After editing that file, reload it without restarting the process:

curl -sS http://127.0.0.1:8089/api/workbench/theme/reload \
  -H 'Content-Type: application/json' \
  -d '{}'

Edit the host file directly. The ReloadWorkbenchTheme operation takes {} and rereads only the fixed filename under the configured directory. It updates the active theme on successful validation and returns the theme snapshot. Missing or empty CSS restores the default theme; invalid UTF-8 or CSS larger than 65536 bytes leaves the active theme unchanged. The MCP surface offers the same GetWorkbenchTheme and ReloadWorkbenchTheme capabilities at /mcp; reload takes no CSS or filepath arguments:

curl -sS http://127.0.0.1:8089/mcp \
  -H 'Content-Type: application/json' \
  -H 'Accept: application/json, text/event-stream' \
  -H 'MCP-Protocol-Version: 2025-11-25' \
  -d '{"jsonrpc":"2.0","id":1,"method":"tools/call","params":{"name":"ReloadWorkbenchTheme","arguments":{},"_meta":{"io.modelcontextprotocol/protocolVersion":"2025-11-25"}}}'

The example exposes CSF HTTP and MCP endpoints only. It does not serve or embed the packaged React Workbench. A consumer that wants the browser UI must build and serve that bundle explicitly and configure its CSF API origin to reach this process.

Cleanup and file ownership

Two separate defers provide no extra guarantee over one deferred block that closes a temporary file and then removes it. Go runs separate defers in reverse registration order; grouping related cleanup makes that ordering explicit. For a file writer, checking Close before renaming the temporary file matters: a close failure must prevent publication. A later deferred close/remove is best-effort cleanup and should preserve the original failure.

CSF only reads this stylesheet; the editor owns saving it. Its single deferred close releases the read descriptor, while read and validation errors are returned to the caller. It does not need a file-writing cleanup helper.