{"version":"2.1.315","anchor":"mcp-redial-after-sandbox-proxy-policy-refusal-can-be-suppres","canonical_anchor":"mcp-redial-after-sandbox-proxy-policy-refusal-can-be-suppres","heading":"Opt-in setting stops retrying MCP servers the sandbox proxy blocked","tier":"use","area":"MCP","scope":"individual","heads_up":false,"url":"https:\/\/changelogs.core-directive.com\/v\/2.1.315\/e\/mcp-redial-after-sandbox-proxy-policy-refusal-can-be-suppres","release_url":"https:\/\/changelogs.core-directive.com\/v\/2.1.315","markdown":"### Opt-in setting stops retrying MCP servers the sandbox proxy blocked\n\nWith `CLAUDE_CODE_MCP_NO_REDIAL_AFTER_POLICY_REFUSAL` set, Claude Code can stop redialing MCP servers that the sandbox network policy refused\n\n**Unclear.** The second condition is not identified, so setting the variable may not be enough on its own.\n\n**What**\n\nMCP servers are outside tools and services that Claude Code connects to. Some of them are reached over the web, using HTTP or SSE (a kind of streaming web connection). In a sandbox, which is a restricted environment that limits what Claude Code can reach, web traffic passes through a proxy that applies a network policy.\n\nWhen the proxy refuses a connection, it answers with a 403 status (the web's \"forbidden\" code) and a message starting \"request blocked\" that says no rule or allowlist entry allows the host, or that the request was blocked by policy. Claude Code can now remember the host and port in that answer. When an MCP server reached over HTTP or SSE then fails with such a refusal, Claude Code skips retrying it if its address is https and uses a remembered host and port.\n\nThis only happens when both of these hold:\n\n- `CLAUDE_CODE_MCP_NO_REDIAL_AFTER_POLICY_REFUSAL` is set to true\n\n- a second internal condition is also met\n\n**Why**\n\nIt stops sandboxed sessions from reconnecting again and again to MCP servers that the network policy has already blocked. Without the variable, Claude Code keeps retrying as before.\n\n- Area: MCP\n- Tier: Use it now\n- Useful: 5\/5\n- Signal: 2\/5\n- Scope: individual\n- Heads-up: no"}