{"version":"2.1.302","anchor":"tool-server-launch-env-applied-before-settings-env","canonical_anchor":"tool-server-launch-env-applied-before-settings-env","heading":"Variables from a tool server's launch now apply before your settings","tier":"internal","area":"MCP","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.302\/e\/tool-server-launch-env-applied-before-settings-env","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.302","markdown":"### Variables from a tool server's launch now apply before your settings\n\nClaude Code now applies environment variables taken from a tool server's launch first, then the ones from your settings\n\n**Unclear.** Which variables come from a tool server's launch, and when there are any, is not clear.\n\n**What**\n\nAn environment variable is a named value passed to a program from outside it. Claude Code can set environment variables from your settings. Before it does so, it now first copies in a set of variables taken from the launch of a tool server. Your settings are applied after them, so a setting with the same name takes the place of the value that came from the launch.\n\n**Why**\n\nThe order in which variables are applied has changed for tool-server launches, which decides which value wins when two sources set the same variable.\n\n- Area: MCP\n- Tier: Under the hood\n- Useful: 2\/5\n- Signal: 3\/5\n- Scope: individual\n- Heads-up: no"}