Configurable extra CLI args for native agent session resume

[Chibionos]

Problem

Native agent session restore hardcodes resume argv:

• Claude: claude --resume <id>
• Codex: codex resume <id>

Users who start agents with flags such as Claude --dangerously-skip-permissions / --permission-mode bypassPermissions or Codex --yolo / --dangerously-bypass-approvals-and-sandbox lose those flags when Herdr restores after a server restart. Workarounds today are PATH wrappers or agent-global config defaults.

Proposal

Add optional per-agent extra args in config.toml:

[session]
resume_agents_on_restore = true

[session.resume_extra_args]
claude = ["--dangerously-skip-permissions"]
codex = ["--yolo"]

Semantics: insert the list immediately after the executable name, so global flags apply before subcommands:

Base resume	With extra args
claude --resume <id>	claude --dangerously-skip-permissions --resume <id>
codex resume <id>	codex --yolo resume <id>

Why this design

• Keeps the official resume shape; only injects argv, no shell templates (safer; existing shell quoting stays authoritative).
• Per-agent table matches other Herdr config (e.g. ui.sidebar.agents.rows_by_agent).
• Keys are strict canonical agent ids (claude, codex, …), rejected at load time if unknown.
• Arg validation: non-empty, max 32 args, max 512 chars each, no control characters.
• Applies on the next restore after server restart; does not re-spawn already-running agents on config reload (same as other restore settings).
• Out of scope for v1: Settings UI editor for freeform arg lists (config.toml is the right surface), and agent start default args (can be a follow-up).

Implementation status

A ready branch on a fork implements this with unit tests and next-release docs:

• Branch: https://github.com/Chibionos/herdr/tree/feat/session-resume-extra-args
• Touches: SessionConfig, agent_resume::plan_with_extra_args, restore plumbing, docs/next config/session-state/config-reference, default-config comments.

Happy to open/adjust a PR once this direction is accepted (per CONTRIBUTING, feature work needs maintainer alignment first).

Alternatives considered

1. PATH wrappers for claude/codex — works today, but global and outside Herdr.
2. Agent-native defaults (Codex approval_policy / sandbox) — does not fully cover Claude bypass flags.
3. Full resume command template — more flexible, more footguns and shell injection risk.
4. Hardcode yolo flags for everyone — wrong default; dangerous and not universal.

Ask

Does this fit Herdr’s product direction for session restore? If yes, happy to open the PR (or have a maintainer take the branch) under whatever title/scope override you prefer.

[Chibionos]

Thanks for considering this.

Local need: when Herdr restores Claude/Codex after a server restart it runs bare claude --resume <id> / codex resume <id>, so flags we always launch with (--dangerously-skip-permissions, --yolo) are lost. PATH wrappers work as a stopgap, but a first-class [session.resume_extra_args] keeps resume behavior in config.

Ready branch (with CI clippy fix): https://github.com/Chibionos/herdr/tree/feat/session-resume-extra-args
Closed PR (gate): #2105 — closed by the non-maintainer feature gate as expected.

@ogulcancelik — if this direction is OK, could you convert this discussion into an accepted issue (or reopen PR #2105 with a scope override)? Happy to iterate on naming/validation if you prefer a different config shape.