fix(mcp): support NODE_EXTRA_CA_CERTS for enterprise MITM proxies#2271
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fahreddinozcan merged 2 commits intoupstash:masterfrom Mar 19, 2026
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When NODE_EXTRA_CA_CERTS is set, reads the CA certificate file and injects it into undici's global dispatcher. This fixes fetch failures behind enterprise transparent SSL intercept proxies (Zscaler, etc.) where the default TLS context does not trust the corporate CA. The CA certs are also passed through when an explicit HTTPS_PROXY is configured, so both proxy modes work with custom certificates. Fixes upstash#2268 This contribution was developed with AI assistance (Claude Code). Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
fahreddinozcan
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Mar 19, 2026
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Thanks for the quick review and merge on both PRs. |
This was referenced Apr 9, 2026
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Summary
NODE_EXTRA_CA_CERTSand injects them into undici's global dispatcher at runtimesetGlobalDispatcher+undicipattern already used for HTTP proxy supportProblem
Behind enterprise MITM proxies (Zscaler, corporate VPNs), Node's default
fetch()TLS context does not trust the corporate CA certificate. Even whenNODE_EXTRA_CA_CERTSis set, many MCP client launchers (npx, background daemons) strip or inject the env var too late for Node to pick it up at startup, causingUNABLE_TO_VERIFY_LEAF_SIGNATUREerrors.Solution
Explicitly read the CA cert file at module load time and pass it to undici's
AgentorProxyAgentvia theconnect.caoption. This bypasses Node's frozen TLS context and works regardless of when the env var was set.Three cases are handled:
ProxyAgentgets both the proxy URI and the CA certAgentwith the CA cert is set as the global dispatcherFixes #2268
This contribution was developed with AI assistance (Claude Code).