Bug Report: OpenCode v2 fails under proxychains (port conflict + socket closed on local service) #54523

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1. opencode-agent commented on Oct 11, 2026

   

   opencode-agentBot

   on Oct 11, 2026 – with OpenCode Agent

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   Thanks for the report. I could reproduce both errors on v2.0.26 (you didn't give a version, so I used the latest release), and they still happen on the latest dev (d21b0790).

   What's happening: proxychains also sends OpenCode's own connections to 127.0.0.1 through your SOCKS proxy. A proxy on another machine can't reach your local 127.0.0.1, so the OpenCode client can never connect to its own server:

   • proxychains opencode: the background service starts, but the client's checks to 127.0.0.1:<port> go through the proxy and fail. On the next launch, the client tries to start a second service on the same port and fails with Managed service port … is already in use by another process. The port is actually in use by OpenCode's own service.
   • proxychains opencode --standalone: the TUI can't reach its in-process server, which gives the ClientError: Transport: … error.

   The script below reproduces this with a small local SOCKS5 proxy that refuses loopback connections, the way a remote proxy would.

   Workaround: tell proxychains not to proxy loopback traffic by adding this line to your proxychains.conf (above [ProxyList]):

   localnet 127.0.0.0/255.0.0.0
   

   With that line, both opencode and opencode --standalone started normally in my test. Another option is to skip proxychains and use HTTPS_PROXY=… NO_PROXY=localhost,127.0.0.1 opencode.

   At the very least, the "already in use" error is misleading here, so I've passed this on to the maintainers.

   Related: #4284 (the same proxychains failure in v1), #52054 and #49796 (local traffic going through an HTTP proxy in v2).

   Reproduction script (repro.sh)

   #!/usr/bin/env bash
   # Reproduces #54523: opencode v2 fails under proxychains when the SOCKS proxy
   # cannot reach the client's own 127.0.0.1 (e.g. a proxy on another host).
   # Needs: proxychains4 (proxychains-ng), node, opencode (or OC_CMD="bun ... index.ts").
   set -u
   # OC_DEV=/path/to/checkout runs the CLI from source instead of `opencode` on PATH.
   if [ -n "${OC_DEV:-}" ]; then
     OC_CMD="bun --conditions=browser --preload=$OC_DEV/packages/tui/node_modules/@opentui/solid/scripts/preload.js $OC_DEV/packages/cli/src/index.ts"
   fi
   OC_CMD=${OC_CMD:-opencode}
   DIR=$(cd "$(dirname "$0")" && pwd)
   WORK=$(mktemp -d); mkdir -p "$WORK/home" "$WORK/proj"
   export HOME="$WORK/home"
   
   # Simulated remote proxy: drops CONNECTs to loopback.
   cat > "$WORK/socks5.mjs" <<'JS'
   // Minimal SOCKS5 proxy (no auth, CONNECT only) on 127.0.0.1:1080.
   // With REMOTE=1 it behaves like a proxy on another machine: the client's
   // "127.0.0.1" is not reachable through it, so loopback CONNECTs are dropped.
   import net from "node:net"
   net.createServer((c) => {
     c.once("data", () => {
       c.write(Buffer.from([5, 0]))
       c.once("data", (d) => {
         let host, i
         if (d[3] === 1) { host = [...d.subarray(4, 8)].join("."); i = 8 }
         else if (d[3] === 3) { host = d.subarray(5, 5 + d[4]).toString(); i = 5 + d[4] }
         else { host = "::1"; i = 20 }
         const port = d.readUInt16BE(i)
         console.log("CONNECT", host, port)
         if (process.env.REMOTE && /^(127\.|localhost$|::1$)/.test(host)) { c.destroy(); return }
         const u = net.connect(port, host, () => {
           c.write(Buffer.from([5, 0, 0, 1, 0, 0, 0, 0, 0, 0])); u.pipe(c); c.pipe(u)
         })
         u.on("error", () => { try { c.end(Buffer.from([5, 5, 0, 1, 0, 0, 0, 0, 0, 0])) } catch {} })
         c.on("error", () => u.destroy())
       })
     })
   }).listen(1080, "127.0.0.1", () => console.log("socks5 on 1080"))
   JS
   REMOTE=1 node "$WORK/socks5.mjs" > "$WORK/socks.log" 2>&1 &
   SOCKS=$!
   trap 'kill $SOCKS 2>/dev/null; pkill -f "serve --service" 2>/dev/null' EXIT
   sleep 1
   
   cat > "$WORK/pc.conf" <<'EOF'
   strict_chain
   proxy_dns
   tcp_read_time_out 15000
   tcp_connect_time_out 8000
   [ProxyList]
   socks5 127.0.0.1 1080
   EOF
   cd "$WORK/proj"
   # From-source runs: child server processes need the opentui preload too.
   [ -n "${OC_DEV:-}" ] && printf 'preload = ["%s/packages/tui/node_modules/@opentui/solid/scripts/preload.js"]\n' "$OC_DEV" > bunfig.toml
   run() { timeout "$1" script -qc "proxychains4 -q -f $WORK/pc.conf $OC_CMD $2" "$WORK/out.txt" >/dev/null 2>&1
     sed 's/\x1b\[[0-9;?]*[a-zA-Z]//g' "$WORK/out.txt" | tr -d '\r' | grep -E 'Error|in use|Starting' | head -6; }
   
   echo "== 1) proxychains opencode (first run starts the service, client cannot reach it)"
   run 40 ""
   echo "== 2) proxychains opencode again (service still running -> port conflict)"
   run 110 ""
   echo "== 3) proxychains opencode --standalone"
   run 60 "--standalone"
   echo "== proxy saw $(grep -c 'CONNECT 127.0.0.1' "$WORK/socks.log") loopback CONNECTs"
   echo "Workaround: add 'localnet 127.0.0.0/255.0.0.0' to proxychains.conf"

   Run it: bash repro.sh
2. opencode-agent

   added

   reproduced

   on Oct 11, 2026