What version of Codex is running?
codex-cli 0.144.0 (also reproduced on 0.143.0; pre-5.6 behavior verified on 0.137.0)
What platform is your computer?
macOS (Darwin 25.5.0, arm64)
What steps can reproduce the bug?
With any GPT-5.6 model selected, codex exec -s read-only sessions are provisioned with no tools at all — the model reports it has no shell or file-reading tool and cannot inspect the repo:
$ codex exec -s read-only -m gpt-5.6-sol "Run the shell command \`echo tool-check-ok\` and report its exact output. If you have no shell tool available, say NO-TOOLS."
NO-TOOLS
Reproduction matrix (all from the same machine/auth, same working directory):
| model |
sandbox |
result |
| gpt-5.6-sol |
read-only |
❌ NO-TOOLS |
| gpt-5.6-terra |
read-only |
❌ NO-TOOLS |
| gpt-5.6-sol |
read-only + -c 'sandbox_permissions=["disk-full-read-access"]' |
❌ NO-TOOLS |
| gpt-5.6-sol |
workspace-write |
✅ runs echo, returns output |
| gpt-5.5 |
read-only |
✅ runs echo, returns output |
CLI version is not the variable: identical results on 0.143.0 and 0.144.0. gpt-5.5 + read-only worked on 0.137.0 earlier the same day and still works on 0.144.0.
In interactive sessions the model describes it as: "This session includes the repo path and filesystem permissions in its context, but no terminal or file-reading tool was actually provisioned to me."
What is the expected behavior?
Read-only sandbox sessions should provision the shell/file tools (with read-only enforcement), as they do for gpt-5.5.
What do you see instead?
GPT-5.6 sessions in read-only sandbox receive no tool bundle at all, so any read-only automation (codex exec -s read-only ..., review flows) silently degrades to a no-tool chat.
Additional information
- Auth: ChatGPT login (Plus/Pro plan),
model_provider is the local codex-lb (http://127.0.0.1:2455/backend-api/codex) provided by the ChatGPT desktop app — so this may be backend/rollout-side rather than CLI-side. Filed within hours of the GPT-5.6 GA rollout announcement.
- Workaround: pass
-m gpt-5.5 for read-only runs, or use -s workspace-write.
What version of Codex is running?
codex-cli 0.144.0 (also reproduced on 0.143.0; pre-5.6 behavior verified on 0.137.0)
What platform is your computer?
macOS (Darwin 25.5.0, arm64)
What steps can reproduce the bug?
With any GPT-5.6 model selected,
codex exec -s read-onlysessions are provisioned with no tools at all — the model reports it has no shell or file-reading tool and cannot inspect the repo:Reproduction matrix (all from the same machine/auth, same working directory):
-c 'sandbox_permissions=["disk-full-read-access"]'echo, returns outputecho, returns outputCLI version is not the variable: identical results on 0.143.0 and 0.144.0. gpt-5.5 + read-only worked on 0.137.0 earlier the same day and still works on 0.144.0.
In interactive sessions the model describes it as: "This session includes the repo path and filesystem permissions in its context, but no terminal or file-reading tool was actually provisioned to me."
What is the expected behavior?
Read-only sandbox sessions should provision the shell/file tools (with read-only enforcement), as they do for gpt-5.5.
What do you see instead?
GPT-5.6 sessions in read-only sandbox receive no tool bundle at all, so any read-only automation (
codex exec -s read-only ..., review flows) silently degrades to a no-tool chat.Additional information
model_provideris the local codex-lb (http://127.0.0.1:2455/backend-api/codex) provided by the ChatGPT desktop app — so this may be backend/rollout-side rather than CLI-side. Filed within hours of the GPT-5.6 GA rollout announcement.-m gpt-5.5for read-only runs, or use-s workspace-write.