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gh Oct 31, 2025

MCP client for `X` failed to start: handshaking with MCP server failed: connection closed: initialize response · Issue #6020 · openai/codex · GitHub

What version of Codex is running? codex-cli 0.53.0 What subscription do you have? Pro Which model were you using? GPT-5 What platform is your computer? Darwin 24.6.0 arm64 arm What issue are you seeing? All servers fail at once MCP clien...

by kirso github.com 205 words
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### What version of Codex is running? codex-cli 0.53.0 ### What subscription do you have? Pro ### Which model were you using? GPT-5 ### What platform is your computer? Darwin 24.6.0 arm64 arm ### What issue are you seeing? All servers fail at once MCP client for `X` failed to start: handshaking with MCP server failed: connection closed: initialize response ### What steps can reproduce the bug? Uploaded thread: 019a38db-7497-7b12-bbaa-75edef1f4150 ### What is the expected behavior? MCP servers load ### Additional information model = “gpt-5”
model_reasoning_effort = “high” \[features\]
rmcp_client=true
web_search_request=true \[mcp_servers.svelte\]
command = “npx”
args = \[“-y”, “@sveltejs/mcp”\] \[mcp_servers.sentry\]
command = “npx”
args = \[“-y”, “mcp-remote@latest”, “[https://mcp.sentry.dev/mcp\]()”\] \[mcp_servers.posthog\]
command = “npx”
args = \[ “-y”, “mcp-remote@latest”, “[https://mcp.posthog.com/sse\]()”, “—header”, “Authorization: Bearer {KEY}”\] \[mcp_servers.context7\]
command = “npx”
args = \[“-y”, “@upstash/context7-mcp”, “—api-key”, “{KEY}”\] \[mcp_servers.linear\]
command = “npx”
args = \[“-y”, “mcp-remote”, “[https://mcp.linear.app/sse\]()”\] \[mcp_servers.stripe\]
command = “npx”
args = \[ “mcp-remote”, “[https://mcp.stripe.com/\]()” \] #\[mcp_servers.dataforseo\]
#command = “npx”
#args = \[ “-y”, “dataforseo-mcp-server”\] #\[mcp_servers.dataforseo.env\]
#DATAFORSEO_USERNAME = “{email}“
#DATAFORSEO_PASSWORD = “{KEY}” \[mcp_servers.supabase\]
command = “npx”
args = \[“-y”, “@supabase/mcp-server-supabase@latest”\] \[mcp_servers.supabase.env\]
SUPABASE_ACCESS_TOKEN = “{KEY}” \[mcp_servers.vercel\]
command = “npx”
args = \[ “mcp-remote”, “[https://mcp.vercel.com\]()” \] \[mcp_servers.trigger\]
command = “npx”
args = \[ “trigger.dev@latest”, “mcp”, “—dev-only” \]