What people got done with Codex.https://agenticfeats.com/enhttps://agenticfeats.com/c/parallel-feature-shipping-in-codex/https://agenticfeats.com/c/parallel-feature-shipping-in-codex/Keith Rumjahn used the OpenAI Codex desktop app with git worktrees and parallel threads to build four features for their Mac app at once. Result: Four features finished in about 2 hours instead of 3-5 days each, and the daily view took 40 minutes. Evidence: Shown. Source: https://rumjahn.substack.com/p/the-complete-guide-to-openai-codexTue, 13 Oct 2026 15:29:03 GMTCodexCodinghttps://agenticfeats.com/c/s-corp-taxes-with-two-agents-claude-code/https://agenticfeats.com/c/s-corp-taxes-with-two-agents-claude-code/Claude Code wrote Python scripts that compute the author's S-Corp tax forms from QuickBooks and bank data, while Codex reviewed the code. Result: Codex caught real errors, including a wrong Schedule L field mapping, and the author found their own 2025 mistakes. Evidence: Claim. Source: https://common-sense.com/insights/doing-taxes-with-ai-coding-agentsTue, 13 Oct 2026 15:29:03 GMTClaude CodeCodexFinance and Adminhttps://agenticfeats.com/c/codex-agent-as-company-employee/https://agenticfeats.com/c/codex-agent-as-company-employee/The author built an autonomous agent from Codex, ChatGPT Plus, systemd, and UNIX email and user accounts, and uses it like an employee. Result: The agent handles all kinds of tasks for their company, and the author reports no memory problems so far. Evidence: Claim. Source: https://news.ycombinator.com/item?id=47730086Tue, 13 Oct 2026 15:29:03 GMTCodexBusinesshttps://agenticfeats.com/c/amazon-subscription-refund-codex/https://agenticfeats.com/c/amazon-subscription-refund-codex/Codex running GPT-5.5 cancelled an Amazon subscription, opened the live chat with an associate, and argued for an immediate refund. Result: The associate confirmed the refund and the author got $15 back within about five minutes, while the author watched it happen. Evidence: Shown. Source: https://x.com/chrisgpt/status/2049341524958151000Tue, 13 Oct 2026 15:29:03 GMTCodexPersonal and Familyhttps://agenticfeats.com/c/codex-email-audit-and-trip-site/https://agenticfeats.com/c/codex-email-audit-and-trip-site/Codex, driven by two authors, audited a month of missed emails, built a vacation planning site from a phone, and shopped for a dishwasher. Result: Codex returned a complete, classified list of missed email threads where Claude missed many; it also deployed a vacation site researched from hotel availability. Evidence: Shown. Source: https://technicallycurious.substack.com/p/codex-is-excellentTue, 13 Oct 2026 15:29:03 GMTCodexPersonal and Familyhttps://agenticfeats.com/c/client-notes-to-belmond-shortlist-codex/https://agenticfeats.com/c/client-notes-to-belmond-shortlist-codex/Codex Desktop read a client notes Word doc, checked Belmond's live booking site, and built a three-option comparison matching the client's past trip preferences. Result: Codex returned a ranked comparison of three Belmond properties with availability and nightly rate ranges for a sample window, plus a more detailed Word doc. Evidence: Numbers. Source: https://worldviatravelnetwork.com/blog/ai-tip-use-codex-desktop-to-connect-your-files-chatgpt-and-the-webTue, 13 Oct 2026 15:29:03 GMTCodexResearchhttps://agenticfeats.com/c/research-workflow-automation-with-codex/https://agenticfeats.com/c/research-workflow-automation-with-codex/Codex runs a weekly arXiv search, triages new papers, feeds a Zotero library, and turns hypotheses into cheap experiment tests for an AI safety researcher. Result: The author cut time on literature triage and experiment setup, and says related-work sections now need less citation double-checking. No numbers are given. Evidence: Claim. Source: https://aisagroup.substack.com/p/how-i-use-codex-to-automate-partsTue, 13 Oct 2026 15:29:03 GMTCodexResearchhttps://agenticfeats.com/c/comms-tasks-with-codex/https://agenticfeats.com/c/comms-tasks-with-codex/The author used OpenAI's Codex to build a PR coverage dashboard, sort a messy work folder, and filter a recipe site for picky kids. Result: Codex sorted 240 dinner recipes down to 62 family-fit picks, rated them, and produced an index, a spreadsheet, and a Google Drive folder. Evidence: Numbers. Source: https://youbetabelieveit.substack.com/p/oh-holy-codex-the-ai-coworker-hasTue, 13 Oct 2026 15:29:03 GMTCodexPersonal and Familyhttps://agenticfeats.com/c/slack-issue-triage-to-codex-fix/https://agenticfeats.com/c/slack-issue-triage-to-codex-fix/An internal ops agent triaged a Slack issue, passed it to a Codex agent, and then verified the fix back in Slack. Result: The Codex agent resolved the issue in 40 minutes, and the ops agent confirmed the fix in Slack. Evidence: Numbers. Source: https://x.com/wesleymagness/status/2080314934601433570Tue, 13 Oct 2026 15:29:03 GMTCodexCustom agentOps and IThttps://agenticfeats.com/c/self-hosted-agentic-software-factory-hermes-agent/https://agenticfeats.com/c/self-hosted-agentic-software-factory-hermes-agent/The author built a sandboxed home server stack where Hermes with Codex takes one prompt and runs the whole software lifecycle, from repo to deployment. Result: From one prompt it created a repo, wrote the app and tests, got CI green, provisioned Postgres and deployed behind HTTPS with no further messages. Evidence: Shown. Source: https://blog.jakesaunders.dev/building-an-almost-fully-self-hosted-sandboxed-agentic-software-factoryTue, 13 Oct 2026 15:29:03 GMTCodexHermes AgentCodinghttps://agenticfeats.com/c/vnc-client-build-attempts-claude-code/https://agenticfeats.com/c/vnc-client-build-attempts-claude-code/The author asked Claude, then ChatGPT 5.6 Sol, to build a bare-bones VNC viewer for Windows 10 that avoids dropped keystrokes. Result: Claude gave failed builds for a week and used up the 20x Max weekly limit. Sol had worked 20+ hours without success. Evidence: Shown. Source: https://news.ycombinator.com/item?id=49244479Tue, 13 Oct 2026 15:29:03 GMTClaude CodeCodexCodinghttps://agenticfeats.com/c/find-why-a-process-dies-codex/https://agenticfeats.com/c/find-why-a-process-dies-codex/Codex CLI, run on the author's Mac, connected to their Ubuntu server over SSH and checked kernel logs to find why Claude Code kept dying. Result: Codex traced the kills to the Linux OOM killer on a 2 GB droplet with no swap, and listed fixes without changing anything. Evidence: Claim. Source: https://flaviocopes.com/server-process-killedTue, 13 Oct 2026 15:29:03 GMTCodexOps and IThttps://agenticfeats.com/c/ai-bookkeeping-for-swedish-companies-claude-code/https://agenticfeats.com/c/ai-bookkeeping-for-swedish-companies-claude-code/Claude Code and Codex kept the books for several Swedish limited companies over ten weeks, handling receipts, VAT, bank matching and posting. Result: About 1,570 entries posted in Claude Code alone, and Codex caught a VAT return error days before filing. Evidence: Numbers. Source: https://igdrasil.se/en/resources/guides/can-ai-do-your-bookkeepingTue, 13 Oct 2026 15:29:03 GMTClaude CodeCodexFinance and Adminhttps://agenticfeats.com/c/substack-stats-report-in-codex/https://agenticfeats.com/c/substack-stats-report-in-codex/Codex used Computer Use to open the author's Substack dashboard and pull figures for every published post into a newsletter report. Result: The author uses Codex daily for reports, editable designs, video editing and this newsletter, which still needed plenty of corrections. Evidence: Shown. Source: https://charliehills.substack.com/p/codex-beginner-advancedTue, 13 Oct 2026 15:29:03 GMTCodexMarketing and Contenthttps://agenticfeats.com/c/faster-rust-ml-code-via-benchmarks-codex/https://agenticfeats.com/c/faster-rust-ml-code-via-benchmarks-codex/Coding agents wrote Rust ML algorithms like UMAP from scratch, then iteratively optimized them against criterion benchmarks. Result: Each model pass added about 1.5x to 2.0x speedup, reaching roughly 7.5x to 32x over baseline; one implementation beat xgboost on speed. Evidence: Shown. Source: https://minimaxir.com/2026/09/agentic-iterationTue, 13 Oct 2026 15:29:03 GMTCodexOtherCodinghttps://agenticfeats.com/c/ableton-live-mcp-for-codex/https://agenticfeats.com/c/ableton-live-mcp-for-codex/The author built an MCP server so Codex can control Ableton Live, including running Python inside Live. Result: Codex built a full EDM track and a piano duet from scratch in minutes in Ableton, shown in two demo videos with the prompts listed. Evidence: Shown. Source: https://github.com/bschoepke/ableton-live-mcpTue, 13 Oct 2026 15:29:03 GMTCodexCreativehttps://agenticfeats.com/c/three-agents-build-multiplayer-counter-strike-codex/https://agenticfeats.com/c/three-agents-build-multiplayer-counter-strike-codex/The Instant team gave Codex, Claude Opus 4.5 and Gemini 3 Pro the same prompts to build a 3D multiplayer Counter Strike clone. Result: All three produced a playable multiplayer game with a map list and saved rooms; Opus won on visuals, Gemini on backend, Codex landed in between. Evidence: Shown. Source: https://instantdb.com/essays/agents_building_counterstrikeTue, 13 Oct 2026 15:29:03 GMTClaude CodeCodexGemini agentCodinghttps://agenticfeats.com/c/claude-code-plays-rollercoaster-tycoon/https://agenticfeats.com/c/claude-code-plays-rollercoaster-tycoon/Ramp Labs forked OpenRCT2, built a kubectl-style CLI, and let Claude Code manage a theme park through it. Result: Claude handled analytics, pricing, staffing and simple stall placement well, but failed at pathways, large coasters, and vertical terrain. The mod took about 40 hours. Evidence: Shown. Source: https://labs.ramp.com/rctTue, 13 Oct 2026 15:29:03 GMTClaude CodeCodexCodinghttps://agenticfeats.com/c/sqlite-like-engine-in-rust-claude-code/https://agenticfeats.com/c/sqlite-like-engine-in-rust-claude-code/Claude, Codex, and Gemini workers, two of each, built a SQLite-style database engine in Rust by claiming tasks through git lock files. Result: About 19k lines of Rust across 154 commits in three days. The engine passes 64 SQLLogicTest queries and 282 AI-written unit tests. Evidence: Shown. Source: https://kiankyars.github.io/machine_learning/2026/02/12/sqlite.htmlTue, 13 Oct 2026 15:29:03 GMTClaude CodeCodexOtherCodinghttps://agenticfeats.com/c/first-personal-dinner-planning-app-codex/https://agenticfeats.com/c/first-personal-dinner-planning-app-codex/A non-programmer used Codex to build a local web app that suggests dinners from pantry, garden, dietary rules, appliances and weather. Result: Built a working What's for Dinner app with pantry, garden, recipe and restaurant pages plus a suggestions engine, in under a week. Evidence: Shown. Source: https://beginningwithi.com/2026/03/03/retirement-hobby-built-my-first-app-in-under-a-weekTue, 13 Oct 2026 15:29:03 GMTCodexPersonal and Familyhttps://agenticfeats.com/c/personal-site-redesign-with-codex/https://agenticfeats.com/c/personal-site-redesign-with-codex/Codex CLI redesigned the author's personal site after reading a design prompt copied from Anthropic's frontend-design plugin into a local markdown file. Result: The author shipped a redesigned personal site, nearly right in one shot, after a few more iterations. Evidence: Shown. Source: https://wilbertliu.com/blog/how-i-designed-my-personal-site-using-codex-cliTue, 13 Oct 2026 15:29:03 GMTCodexCodinghttps://agenticfeats.com/c/stolen-package-refund-via-computer-use-codex/https://agenticfeats.com/c/stolen-package-refund-via-computer-use-codex/Codex with Computer Use waited in Amazon's support queue, polling on a schedule, then pursued a refund for a stolen package. Result: The author showered while Codex waited in the queue and negotiated. The refund was done when they returned. Evidence: Claim. Source: https://jxnl.co/writing/2026/06/16/three-ways-codex-can-use-a-computerTue, 13 Oct 2026 15:29:03 GMTCodexPersonal and Familyhttps://agenticfeats.com/c/ai-chat-app-on-nokia-110-codex/https://agenticfeats.com/c/ai-chat-app-on-nokia-110-codex/Codex helped the author reverse-engineer a Nokia 110 4G's firmware and build a native AI chat app with a custom agent. Result: A working prototype runs on the handset over mobile data: typed chat via DeepSeek, battery check, torch, calls and alarms, tested on the phone. Evidence: Shown. Source: https://github.com/anupray95/AI-Agent-on-a-NOKIATue, 13 Oct 2026 15:29:03 GMTCodexCustom agentCoding