An 83-page paper from Wavestone AI Lab dissects 11 coding harnesses, including Claude Code, Codex CLI, Gemini CLI and OpenClaw. Across roughly 4 million lines of code, none imports a general-purpose agent framework and none retrieves code with vector embeddings. If you are building or choosing an agent, you can follow the paper's 18 recommendations and start from one bash tool and one while loop.
Nine coding agents have taken at least four different paths for long-term memory: Claude Code and Codex use Markdown files (agent-written, human-readable), Antigravity CLI inherits Gemini CLI's approval inbox (agent proposes, human decides), and Copilot uses citations with JIT verification (auto-deleted after 28 days unverified). Cursor removed its Memories feature and fell back to human-written Rules. Hermes Agent, OpenClaw, and Letta Code treat memory as a core harness component, not a plugin. Their choices on write timing, forgetting, and cross-team sharing are completely different — and none has published a controlled experiment on whether their memory system actually helps.
Four coding agent TUIs all follow the same two rules: tools maintain constant height (one-line summary, never jumping from 0 to N lines) and never auto-collapse (only user-initiated expand/collapse). looplane violates both.
Codex 以 Bazel 管理 140+ Rust crate，核心分為 core/tui/exec-server/protocol 四大塊；沙箱用 codex_sandboxing 統一 macOS Seatbelt、Linux Landlock/bwrap、Windows 沙箱三平台介面；exec-server 以 JSON-RPC + Noise Relay 實現遠端執行。
ThreadManager 持有 Arc<ThreadManagerState> 統管所有 thread，spawn_thread() 統一處理新建/恢復/分叉/子代理四種啟動路徑；ForkSnapshot 定義 TruncateBeforeNthUserMessage/Interrupted 兩種語義；AgentControl 透過 Weak<ThreadManagerState> 避免循環引用；agent_graph_store 追蹤 ThreadSpawnEdgeStatus::Open/Closed。
TurnContext 在 turn 初始化時捕獲所有設定（模型、審批、token budget），後續 step 透過 StepContext 讀取快照；StepActivation 驗證設定變更不違反 legacy 安全約束；ContextManager 用 Arc<Vec> + 版本號實現 Copy-on-Write 歷史共享；壓縮觸發條件為 token_remaining < threshold，支援 remote v1/v2、local、model fallback 四條路徑。
looplane now has a Cloudflare Durable Object run resource with async creation, status/cancel/artifacts, live NDJSON, and Last-Event-ID SSE; remote approvals use a separate short-lived capability. Python also provides an attach client and a stateful conversation WebSocket. Production deployment, cross-runtime parity, and full multi-tenant hardening remain unverified.
Looplane now grades effects as read/modify/modify_execute/execute and fails closed on unclassified tools. Native MCP tools default to execute unless trusted read-only metadata lowers them. Approval events still land in events.jsonl first and grants can scope to one change set or backend; general command rules and universal sandbox coupling remain unfinished.
looplane now ships a bounded tool-program DSL: read-only programs support list/read/search/diff, repeat, and if_contains; modify/check transactions receive whole-transaction approval and roll back touched paths on failure. This is not arbitrary JavaScript/Python code mode, and transaction execution is not parallel.
Mature-agent compaction must handle triggers, complete-turn cut points, and recovery. looplane now has an 85% high-watermark, automatic compaction, a deterministic native-loop fallback summary, persisted checkpoints, and workspace-context reinjection. Cross-runtime fallback, model-quality summaries, and live-provider long-session validation remain open.
All five projects combine allow/ask/deny decisions, compound-command inspection, and fail-closed behavior. looplane now has a deny-first classifier, critical floor, shell segmentation, timeout-deny, configured allow/deny rules, and visible policy reasons. Broader syntax coverage and live interactive validation remain open.
Hooks govern control flow, skills inject knowledge, and plugins package both. looplane now has opt-in deny-only project hooks, a bounded SKILL.md loader, exact enabled_skills selection, plugin manifests/install/list, and external-runtime projection. Input rewriting, full lifecycle coverage, remote registries, and a mature marketplace remain open.
looplane now has static ModelRole/ModelRoute candidates, opt-in aliases such as --model @cheap, cross-provider fallback, and a no-tool reviewer lane that runs after verification. Role inheritance/override rules and automatic summarizer, parser, or scout routing remain open.
looplane now connects events.jsonl to a deterministic reducer, CLI timeline, canonical JSON, SDK replay, and safe event-point forks. Forking never replays prior tools or model calls; provider/live-runtime validation, redaction, and richer replay hooks remain open.
The local products post (order 6) of the Sandbox Series. How OpenCode, Codex CLI, Cursor and other CLI agents and IDEs set up local sandboxes, where the isolation boundary lies, common pitfalls, and security best practices.
Mature coding-agent CLIs have converged on the same conventions: positional prompt, -p means print, exec is headless, resume is a first-class command, -C changes directory; looplane inherits this vocabulary directly, driving learning cost close to zero.
Every mature coding agent ships a machine interface: codex has `exec --json` plus a full app-server JSON-RPC protocol, claude-code has `-p` with stream-json, and pi/opencode/omp each expose a JSON event stream. Wrapping these CLIs as your backend is the fastest path to subscription-backed coding — but they own their agent loop, their login, and their permission model. looplane's answer: let the external CLI fully own its loop while looplane holds only three things — an isolated working copy, patch audit, and final verification. One runtime never impersonates another.
The biggest problem when an agent enters CI is approval: no TTY, nobody to click approve. The five reference projects converge on two strategies — delegate permission decisions to the calling program (claude-code's control protocol), or replace approval semantics entirely (codex defaults to Never plus sandboxing, opencode auto-rejects). looplane keeps one AgentRunner loop and injects a different ApprovalPolicy: headless uses HeadlessApprovalPolicy, which never reads stdin so it cannot hang the pipeline, and denies EXECUTE by default — fail closed.
A blank config file drives people away; a bad credential discovered too late drives them away faster. All five mature agents treat setup as a first-class state, and looplane adds the step most of them skip: verify the key right after saving it.
An agent's two dependencies — the LLM and external CLIs — are both non-deterministic, but mature projects separate 'the moving parts' from 'the shape of the boundary': codex fakes the Responses API with wiremock plus a scripted SSE server and pins its TUI with insta snapshots; opencode built a VCR-style http-recorder package; pi splits model-backed evals from unit tests into two vitest configs; omp wraps its edit benchmark itself in unit tests. looplane stacks four layers against external CLIs: unit tests, fake-CLI contract tests, recorded-stream integration proofs, and Textual pilot TUI tests. The methodology in one line: record real non-deterministic output, then make deterministic assertions about it.
Mature coding agent TUIs never print the event stream directly — they build a typed projection layer first and update it in place. looplane took three steps (full-screen composition, runtime-first dual modes, removing the Ask/Agent split) before two old constraints — non-streaming output and resume-without-replay — were truly lifted.
A Claude Code- or Codex-style TUI depends on long-lived sessions, typed transcripts, and approval at tool boundaries—not a screen full of color.
`hermes claw migrate` imports persona, memory, skills from four locations, model and provider config, platform tokens, and the approval allowlist — but secrets are never imported silently, and even `--preset full` requires an explicit `--migrate-secrets`. What can't move (cron jobs, plugins, hooks, the multi-agent list, deep channel config) isn't discarded but parked in `~/.hermes/migration/openclaw/<timestamp>/archive/` for manual work. Coming from Claude Code or Codex is a different command: `hermes import-agent`.
A VS Code extension open-sourced by Microsoft employees that reads your local Claude Code / Codex / OpenCode session logs. The real payload is 45 Markdown rules: prompts under 30 characters, sending the next message within 15 seconds of receiving 20 lines of AI code, instruction files over 4,000 bytes — turning 'context engineering' into numbers you can argue with.
In May 2026, OpenAI published its internal Codex deployment practices: sandboxes define technical boundaries, approval policies determine when to pause, Auto-review delegates approval decisions to a sub-agent instead of a human, and Managed configuration lets enterprise admins enforce policies top-down. The core philosophy: zero friction for low-risk actions, mandatory review for high-risk ones.
Spin up a local OpenAI-compatible endpoint at localhost:20128 that automatically routes requests from Claude Code / Cursor / Cline / Codex / Copilot through a Subscription → Cheap → Free 3-tier fallback to 40+ providers. Built-in RTK compresses tool_result (saving 20–40% input tokens), Caveman mode compresses output, OAuth auto-refresh, multi-account round-robin — install with npm install -g 9router and two commands.
Three vendors originally took three routes: Anthropic built an extension, OpenAI built its own browser, Google welded AI into Chrome. By August 2026 there are only two — OpenAI's Atlas stopped working on 9 August, with its capabilities folded back into the ChatGPT desktop app and Codex. The remaining split is 'live alongside Chrome' versus 'be Chrome'.
On 2026/4/22 OpenAI launched Workspace Agents — powered by Codex, capable of long-running cloud execution, and integrating with Slack/Salesforce/Google Drive. They are the enterprise successor to Custom GPTs.
A detailed look at OpenAI's Codex agent loop design: how prompts are constructed, how multi-turn conversations are managed, how prompt caching prevents cost explosions, and how context window auto-compaction works.
OpenAI wrapped the Codex harness as a JSON-RPC over stdio App Server, enabling VS Code, JetBrains, Web, and desktop apps to share a single agent loop. Three core primitives: Item, Turn, and Thread.
An OpenAI internal team spent 5 months with 3 people and 0 lines of hand-written code, delivering a complete product using Codex. This article distills their core lessons on AGENTS.md design, repo-local knowledge bases, architecture enforcement, and entropy management.
Claude Code only reads CLAUDE.md; Codex only reads AGENTS.md. Teams using both end up maintaining two identical files. Fix: make CLAUDE.md a symlink pointing to AGENTS.md — one source of truth.
A comparison of six agent CLI subscriptions (Claude Code, Cursor CLI, Codex, Kiro, Antigravity/Gemini CLI, OpenCode) plus the multi-model routing pattern — cheap models for simple work, strong models for hard work. Nearly every one of these changed its billing in the first half of 2026; this version was re-verified on 8/18.
Skill paths are almost always runtime-specific. AGENTS.md is the reliable way to share rules across agents. Put personal reusable capabilities in each agent's supported global directory; put project workflows inside the repo.
Codex CLI is OpenAI's open source terminal coding agent (Rust, Apache-2.0, ~106.6k stars) with MCP, subagents, image input, code review, and Skills. The model line is now GPT-5.6 Sol / Terra / Luna, and the desktop app, CLI, and IDE extension share one config.toml.