Description

The expandEnvVarsInRecord function in packages/providers/src/claude/provider.ts (line 222) uses a regex that only matches $VAR syntax but not the more explicit ${VAR} brace syntax.

Current regex:

val.replace(/\$([A-Z_][A-Z0-9_]*)/g, ...)

Problem: MCP config files commonly use ${VAR} notation (standard in shell, Docker, and most templating systems). When users write:

{
  "my-server": {
    "env": {
      "API_KEY": "${MY_API_KEY}"
    }
  }
}

The braces are left in the expanded value, producing {actual_value} instead of actual_value.

Proposed Fix

Update the regex to handle both forms:

val.replace(/\$(?:\{([A-Z_][A-Z0-9_]*)\}|([A-Z_][A-Z0-9_]*))/g, (_, braced, bare) => {
  const varName = braced ?? bare;
  const envVal = process.env[varName];
  if (envVal === undefined) {
    missingVars.push(varName);
  }
  return envVal ?? '';
});

Environment

• OS: Windows 11
• Archon: v0.3.10 (dev branch)
• Node: via Bun runtime