fix: remove shell-style string interpolation from MCP config#29
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fix: remove shell-style string interpolation from MCP config#29
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Cursor (and automations like Lovable) don't support `${VAR:-default}`
syntax in MCP configs. This caused the MCP URL to be passed as a
literal string instead of resolving to the actual endpoint.
Self-hosted users can still override via POSTHOG_MCP_URL in their
local MCP config per the README instructions.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
rafaeelaudibert
approved these changes
Apr 16, 2026
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Problem
Cursor and automations built on Cursor (like Lovable) don't support shell-style
${VAR:-default}string interpolation in MCP configs. Cursor only supports${env:NAME},${userHome},${workspaceFolder}, etc.Our
mcp.jsonused${POSTHOG_MCP_URL:-https://mcp.posthog.com/mcp}, which meant the URL was passed as a literal string instead of resolving tohttps://mcp.posthog.com/mcp. This broke the MCP connection for anyone installing from the Cursor marketplace.Reported by Lovable via shared Slack channel, flagged by Georgiy.
Changes
https://mcp.posthog.com/mcpinmcp.jsonand.mcp.json(removes the${POSTHOG_MCP_URL:-...}wrapper).cursor-plugin/plugin.jsonversion from1.0.4→1.1.2to match the Claude pluginPOSTHOG_MCP_URLin their local MCP config per the READMEHow did you test this?
${VAR:-default}is not a supported interpolation syntaxFollow-up
After merging, we need to reach out to Cursor to update the marketplace listing (original setup was via email/form).
🤖 Generated with Claude Code