ADR-0014: Codex interactive runtime belongs to a pane

Status: Accepted — 2026-09-30.

Context

Codex 0.159 shares a detached daemon between interactive clients. Native hooks snapshot that server environment rather than the current TUI environment. A stale SIGNALTTY_PANE produces hook exit 1; an existing old pane receives wrong state. Disabling daemon_auto_start alone still allows existing daemon reuse.

Decision

At the common PTY execution boundary, direct local interactive Codex sessions use the native --no-daemon option, including resume/fork. Probe support with a bounded read-only --no-daemon --version invocation in a private process group (cleaned up on completion/timeout); unsupported clients retain original argv and get a setup notice. Existing explicit flags are preserved. Utility/exec launches remain unchanged; explicit remote sessions get a notice. Original argv and native resume commands stay persisted unmodified.

Consequences

Each managed interactive pane owns its in-process app-server, preserving pane and socket provenance. Higher per-pane resource usage is accepted. Hook commands, provider config/auth/trust and shared daemons remain untouched. Manually typed shell commands require the same flag; running clients need explicit exit/resume. No guessed cwd attribution, per-pane hook-hash churn, daemon termination, or silent acceptance of invalid pane ids. Upstream client-env forwarding can be reassessed once it has a supported contract.

Evidence

Native flag and daemon exclusion, hook environment snapshot.