Reporter Notes

Notes — 2026-03-22 — Parallel agents need real addresses

Chosen angle

Parallel agents are becoming manageable infrastructure, not just background concurrency. Gemini CLI now gives parallel sessions separate Git worktrees; Codex now gives subagents path-like identities rooted at /root.

Why this is new vs archive

• Not the 2026-03-18 isolation/trust philosophy piece.
• Not the 2026-03-19 scheduling piece.
• Not the 2026-03-20 hook/control-plane piece.
• Not the 2026-03-21 progress-reporting piece.

This story is about agent logistics: locating workers and separating their work.

Evidence highlights

Gemini CLI

• PR #22973: feat(worktree): add Git worktree support for isolated parallel sessions
• Issue #22945 explains the problem: shared directories cause state contention, block spec-driven parallel tracks, and make manual worktree handling too cumbersome.
• WorktreeService.setup() captures base SHA before creating a worktree.
• Worktrees live under .gemini/worktrees/<name>.
• maybeCleanup() only removes the worktree if there are no uncommitted changes and HEAD did not move.
• Docs explain resume flow with cd .gemini/worktrees/<name> then gemini --resume <session_id>.

Codex

• PR #15313: feat: change multi-agent to use path-like system instead of uuids
• New AgentPath type enforces /root absolute paths and validates lowercase child names.
• join() and resolve() support child and relative references.
• spawn_agent now surfaces task_name from new_agent_path when available, only falling back to opaque thread ID if no path exists.

Candidate angles considered

1. Browser safety/approval UX: good, but less distinct from earlier control-plane and observability pieces.

2. Parallel agents with real addresses and separate rooms: chosen.

3. Event plumbing as product strategy: strong, but close to yesterday’s observability piece.

Editorial warning

Do not claim equivalent isolation. Gemini shows concrete filesystem separation via Git worktrees. Codex evidence here is stronger on identity and addressability than on filesystem sandboxing.

Working thesis

Terminal AI agents are growing up from anonymous background threads into workers with real addresses and separate workspaces — because parallelism only becomes usable when each agent is both findable and fenced off.

Sources — 2026-03-22

Archive / state

• daily edition corpus/_state.json
• Prior article titles in daily edition corpus/*/index.html

gsio

• gsio projects scope -p openai/codex -p google-gemini/gemini-cli
• Coverage: 100% for both repos
• Last synced: 2026-03-22 02:00–02:01
• gsio search q "worktree isolated parallel sessions agent path subagent" -p openai/codex -p google-gemini/gemini-cli --output summary
• Top results included Gemini commit 5a3c7154df30 and Codex commit 79ad7b247bb6

Git / GitHub evidence

Gemini CLI

• PR #22973 — https://github.com/google-gemini/gemini-cli/pull/22973
• Issue #22945 — https://github.com/google-gemini/gemini-cli/issues/22945
• Issue #22851 — https://github.com/google-gemini/gemini-cli/issues/22851
• Commit 5a3c7154df30 — feat(worktree): add Git worktree support for isolated parallel sessions
• File: packages/core/src/services/worktreeService.ts
• Doc: docs/cli/git-worktrees.md

Codex

• PR #15313 — https://github.com/openai/codex/pull/15313
• Commit 79ad7b247bb6 — feat: change multi-agent to use path-like system instead of uuids
• File: codex-rs/protocol/src/agent_path.rs
• File: codex-rs/core/src/tools/handlers/multi_agents/spawn.rs

llm editorial synthesis

• llm prompt -m gpt-5.4 run over 3 candidate angles, recent archive, and code facts
• Outcome: chose angle B, with warning not to overstate Codex as equivalent filesystem isolation