How to Run GPT-5.6 Sol in Claude Code — Claudex & CLIProxyAPI Setup (July 2026)
Tibo posted OpenAI's official claudex recipe: CLIProxyAPI + alias with CLAUDE_CODE_SUBAGENT_MODEL. Theo started it. Step-by-step, env vars, CC Switch, and mixing Claude + GPT-5.6 Sol in the orange crab harness.
On July 11, 2026, Theo (@theo) posted that gpt-5.6-sol runs meaningfully better in Claude Code than in Codex — including better designs in a side-by-side test. His follow-up gripe: set Sol to ultra and every subagent inherits ultra → massive token burn for work that should run on Terra or Luna.
Tibo (@thsottiaux, OpenAI Codex) first asked Theo to "Share the recipe." Then on July 12 he posted the official OpenAI-endorsed version (933K+ views):
"If you aren't yet bold enough to install the Codex app, you can stay in the presence of your orange crab and point it at GPT 5.6 Sol. Takes 5 minutes. Kudos to Theo."
"If this gets blocked, I owe you a reset."
Theo replied 🫡.
This guide leads with Tibo's 3-step recipe, then covers alternative proxies, what each env var does, and how to mix Claude and GPT without wrecking your default setup.
Connect — OAuth Codex (and Claude if needed) so CC routes through the proxy
3
Add the claudex alias below
Tibo's alias (verbatim)
bash
alias claudex='CLAUDE_CODE_SUBAGENT_MODEL=gpt-5.6-sol \
CLAUDE_CODE_ALWAYS_ENABLE_EFFORT=1 \
CLAUDE_CODE_MAX_TOOL_USE_CONCURRENCY=3 \
ENABLE_TOOL_SEARCH=false \
claude --model gpt-5.6-sol'
Add to ~/.zshrc or ~/.bashrc, then source ~/.zshrc and run claudex.
Note: Tibo's alias assumes Step 2 already wired Claude Code → CLIProxyAPI (proxy listening, auth synced). It does not inline ANTHROPIC_BASE_URL — connection lives in proxy config or CC Switch. If requests still hit Anthropic directly, complete Step 2 first.
What each env var does
Variable
Tibo's value
Purpose
CLAUDE_CODE_SUBAGENT_MODEL
gpt-5.6-sol
Pin subagent model — fixes inherited ultra burn (#31814)
CLAUDE_CODE_ALWAYS_ENABLE_EFFORT
1
Effort controls always on — matches model vs effort guidance
CLAUDE_CODE_MAX_TOOL_USE_CONCURRENCY
3
Cap parallel tool calls — stability over blast radius
ENABLE_TOOL_SEARCH
false
Disable tool-search overhead for leaner sessions
--model gpt-5.6-sol
CLI flag
Parent session on Sol via proxy
Theo's shorter tl;dr (same day): CLIProxyAPI + Codex auth + env alias — "Took like 2 prompts (proxy already set up tbf)."
TL;DR — pick your path
Path
Who endorsed
Upstream
Best for
B — Tibo recipe
OpenAI Codex lead
CLIProxyAPI + ChatGPT OAuth
Most viral thread followers
A — claude-code-proxy
Community
API key or Codex OAuth
Cleaner docs, port 18765
C — CC Switch
@Jason_Young1231
GUI/CLI provider manager
No manual env juggling
D — native Codex
OpenAI app
Codex CLI only
Until #31814 fixed
Theo's claim in one line: weights are OpenAI's; orchestration is Anthropic's — Tibo now ships the bridge officially.
Tibo posted official recipe — "we don't discriminate on the harness"
Artificial Analysis ranks Sol-in-Codex atop its Coding Agent Index — but that's each lab on its own harness, not Sol cross-swapped. The viral claim is controlled comparison: Sol + CC > Sol + Codex for some builders right now.
Prerequisites
Claude Code installed (claude --version)
ChatGPT Plus/Pro with Codex access or billed OpenAI API key with gpt-5.6-sol enabled
Separate terminal session — do not globally overwrite Anthropic settings
Optional: second ChatGPT account if testing OAuth proxy on Path B
Path B — CLIProxyAPI (Tibo's stack) — expanded
Tibo's recipe uses CLIProxyAPI — OAuth against ChatGPT Codex, exposed as an endpoint Claude Code talks to.
Architecture:
snippet
Claude Code → claudex alias → CLIProxyAPI → chatgpt.com/backend-api/codex
Step 1 — Install CLIProxyAPI
Follow upstream README — typically Go binary or Docker. Default listen port is often 8317 (verify your config.yaml).
bash
# Example: clone and build (check repo for current install)
git clone https://github.com/router-for-me/CLIProxyAPI.git
cd CLIProxyAPI
# build + configure per README
cc-switch proxy enable# Claude Code proxy on
cc-switch --app claude proxy config --listen-port 15721
cc-switch proxy serve --takeover claude # foreground debug
Then still use Tibo's claudex alias — CC Switch handles connection; alias handles model + subagent tuning.
Path A — claude-code-proxy (API-first alternative)
raine/claude-code-proxy translates Claude Code's Anthropic Messages API into Codex OAuth or OpenAI API calls. Maintained; supports gpt-5.6-sol, gpt-5.6-terra, gpt-5.6-luna.
Step 1 — Install proxy
bash
# macOS / Linux (Homebrew)
brew install raine/claude-code-proxy/claude-code-proxy
# Or install script
curl -fsSL https://raw.githubusercontent.com/raine/claude-code-proxy/main/scripts/install.sh | bash
Step 2 — Authenticate Codex
bash
claude-code-proxy codex auth login # browser OAuth — ChatGPT account, not API key
claude-code-proxy codex auth status # verify token stored
Step 3 — Start proxy
bash
claude-code-proxy serve
# Listens on http://127.0.0.1:18765
Keep this terminal open. Use --no-monitor if you want plain logs.
Step 4 — Launch Claude Code through proxy (one session)
claude-code-proxy serve & # background proxy
claudex # GPT-5.6 Sol session
claude # normal Anthropic session (unchanged)
Critical: env vars are per-shell — default claude stays on Fable/Sonnet/Opus (the orange crab's native diet).
Path A notes — when to use claude-code-proxy instead
Use Path A if you want billed OpenAI API (no subscription grey area) or Homebrew install without CLIProxyAPI. Tibo's recipe is the social default; Path A is the compliance default.
Model & effort mapping — avoid token burn
Task
Model in proxy
Effort
Orchestration / hard bugs
gpt-5.6-sol[1m]
medium–high
Fast edits
gpt-5.6-terra[1m]
medium
Background / titles
gpt-5.6-luna[1m]
low
UI / taste
Real Fable via claude
default effort
Theo's ultra bug (native Codex): Sol ultra → subagents ultra. Workaround in CC: spawn subagents with explicit cheaper model ids via your proxy's model routing — CC lets you set effort per delegation in ways Codex currently doesn't.
Append -fast to model name for Codex priority tier: gpt-5.6-sol-fast.
Mixing Claude + GPT in one workflow
snippet
┌─────────────────────────────────────────────────┐
│ claude → Anthropic API → Fable / Sonnet │
│ claudex → proxy → GPT-5.6 Sol │
│ codex → OpenAI CLI → native Codex │
└─────────────────────────────────────────────────┘
Patterns that work:
Pattern
Flow
Plan / execute split
Fable plans in claude → Sol grinds bugs in claudex
@hqmank posted a 31s screen recording of Sol inside CC via CLIProxyAPI — useful smoke-test reference.
@madhavajay/alex — multi-subscription router with trace inspection; supports cross-routing Fable ↔ Codex for power users.
Native alternative — Codex inside Claude Code without proxy?
@Jon_Slemp asked: "Why do this when there's already a way to invoke codex via CC?"
Some teams use MCP bridges or OpenAI's official Codex integration paths — check your Claude Code version's /help and Codex vs Claude Code for native invoke. Proxy routing remains the popular Jul 2026 path because it swaps the entire model backend while keeping CC's harness — not just one tool call.
Proxy ports, model ids, and OAuth flows reflect July 2026 community tooling — verify against upstream READMEs before production use. Not affiliated with Anthropic or OpenAI.
