This week, I learned:

  • “But when an identity based belief was challenged, the brain responded as if under physical attack.” Why Engineers Can’t Be Rational About Programming Languages
  • Notes from How to build a cult, Lulu Cheng, The Knowledge Project podcast
    • Conviction is infectious.
    • Communicate at the INTERSECTION of interests. Learn theirs
    • Begin with “why your story matters to them” (first sentence). That beats “how you tell it” > “where you tell it”.
    • The easiest way to align with an audience is to find your community.
    • Humor, curiosity, awe, any strong emotion is a hook.
    • Culture has momentum. Best way to break it is to show an alternative that works. People will copy that
    • REPEAT messages over and over with complete CONVICTION to convince people who TRUST you. That works, but you need all three.
    • Trust builds from likeability, repeated exposure, common beliefs.
    • An excellent way to defend against online criticism (when it matters) is to just SHOW UP and THANK them for feedback.
    • Serious reputational damage must either be fixed immediately - or you live with it forever.
    • Between a story and statistics, the story will always wins. Never fight a story with a statistic. Dig into your statistics and uncover BETTER stories.
    • ⭐ Prebuttals are a great idea. Start with all possible criticisms yourself and diffuse them. The other person has nothing left to say
    • Sparring keeps you sharp. Spar with LLMs.
    • To defend, show how the attack targets other people, increasing the surface area. Show how the SPECIFIC attack targets a larger group. Create a SPECIFIC cause worth fighting for.
    • Each role has specific objective to optimise for. The leader’s role is to balance across these.
    • Cheerleader effect. People look beautiful next to a cheerleader. Associations taint.
    • Each person has dozens of aspects to their persona. We cannot remember all of them. Each person can make a choice on who they project themselves to be in any group. Shaping their persona.
  • The Rainbow CSV extension may be causing delays (infinite spinner) when pasting Markdown in VS Code. Restarting it seems to fix the issue.
  • ⭐ Claude scientific skills is a collection of skills teaching Claude how to use scientific libraries, databases, and APIs across several domains. This may be a good example of a non-trivial skill library - that is hard for AI coding agents to infer by themselves.
  • Notes from How I use every Claude Code feature
    • Use AGENTS.md as guardrails, not a manual. Document what it gets wrong.
    • Use self-documenting tools/APIs rather than documenting.
    • Docs: Explain why and when to read each doc.
    • Never say “Never.” Explain when to which which alternative.
    • Prefer CLIs for stateless tools, MCPs for stateful, authenticated, or complex (e.g. Playwright).
  • Coding agents work well with version control. Simon Willison
    • Break up uncommitted changes into small commits
    • Rewrite branch history for readability
    • Use gh CLI to fetch line-wise comments from a PR and make requested changes (e.g. renaming, refactoring, adding types, etc.)
  • ⭐ When using MCPs or tools with private data, “color untrusted content in red, unsafe actions in blue, and never mix colors.” Good advice.
  • ⭐ DeepWiki offers a codemaps feature that explains code in an interactive way. It shows a structured explanation on the left. You can click on any note to see the code on the right. It’s an effective way to understand how a library or tool executes a task. Here’s an example of how Mermaid works.
  • Gemini offers RAG with free storage. RAG costs are quite high. This simplifies the process a lot. But I tried running the sample program and after an hour, it still had not completed uploading a single file. Best to wait and watch.
  • OpenRouter supports embedding models using an OpenAI-like API
  • Kimi K2 Thinking seems popular because
    • It’s an open-weights model on par with the top models on Humanity’s Last Exam (text-only) and BrowseComp
    • Can run 200-300 tool calls without human guidance
    • 4x cheaper than GPT-5 with low tokens (32B active on 1T parameters, INT4 quantized)
  • Based on responses to Simon Willison’s question, ChatGPT
    • Fine-tuning helps when:
      • Lower latency, e.g. for type-ahead, at lower cost (37 mentions)
      • Structured extraction, parsing and classifiers, e.g. postal address, detecting secrets (18 mentions)
      • Custom vision models, e.g. check containers (12 mentions)
      • Domain-specific code and stacks (niche languages, stack-specific generation, text→SQL) (11 mentions)
      • … and a long tail.
    • Fine tuning does not help:
      • When A base model plus prompting or RAG does as well or better (15 mentions)
      • When you risk being leapfrogged by a new release (4 mentions)
      • When cost and data do not justify the ROI (3 mentions)
  • The data I can export from my Android phone includes the below. 🟢 indicates it’s tracked. 🟡 might need action, e.g. enabling / coding. #
    • 🟢 GPS/GNSS location (current & history). Turn on device Location. If you want a timeline you can export, enable Google Location History and later export via Google Takeout → Location History (JSON/KML).
    • 🟡 GNSS raw measurements (engineering traces). Android exposes GNSS “raw” logs on many devices; capture with dev tools or logging apps if supported (intended for research). See GNSS Raw Measurements API.
    • 🟢 Wi-Fi scans (nearby SSIDs/BSSIDs). Toggle Location scanning → Wi-Fi scanning in Location settings; apps need location permission to read results.
    • 🟡 Wi-Fi RTT distance to APs (indoor ranging). Apps can use Wi-Fi RTT (802.11mc/az) to measure distance to compatible APs; requires location permission.
    • 🟢 Bluetooth proximity/traffic. For packet-level logs, enable Developer options → Enable Bluetooth HCI snoop log, then pull /sdcard/btsnoop_hci.log (Wireshark).
    • 🟢 Cell towers (IDs, signal strength). Apps can read via TelephonyManager (e.g., getAllCellInfo()), with appropriate telephony permissions.
    • 🟢 Activity recognition (walking, running, in vehicle). Apps must request ACTIVITY_RECOGNITION (runtime) from Android 10+.
    • 🟢 Steps (step counter / detector). Use sensors API; from Android 10+ you must declare ACTIVITY_RECOGNITION to access step counter/step detector.
    • 🟢 Accelerometer / gyroscope / magnetometer streams. Apps read via SensorManager; some high-rate reads require HIGH_SAMPLING_RATE_SENSORS.
    • 🟢 Ambient light / proximity. Read via SensorManager; typically no special permission.
    • 🟢 Google Fit data (steps, workouts, heart rate from wearables, etc.). Manage and export from Google Fit / Google account Download your data.
    • 🟢 Contacts. MIUI → Settings → System apps → Contacts → Import/Export to .vcf (vCard).
    • 🟢 Call history / SMS (device). MIUI local/cloud backup can include call logs & messages; export by creating a local/Cloud backup and downloading. Note: 3P apps can’t read call/SMS logs unless they’re the default dialer/SMS.
    • 🟡 Gmail, Calendar, Contacts (Google). Export via Google Takeout (MBOX/ICS/CSV etc.).
    • 🟡 WhatsApp / Telegram / Signal chats. Use in-app exports: WhatsApp → Export chat, Telegram Desktop → Export, Signal → encrypted backup.
    • 🟢 Advertising ID. View/reset in Settings → Google → Ads (wording varies), per Google help on Ad ID reset.
    • 🟡 Per-app screen time / unlocks / opens. Third-party “usage” apps (e.g., analytics or “digital wellbeing” clones) require Usage Access (PACKAGE_USAGE_STATS). Use Android’s UsageStatsManager or apps that export CSV. Stock Digital Wellbeing does not offer an export.
    • 🟡 Notification history (last 24h). Settings → Notifications → Notification history → On. OEM-optional, but present on most devices. Viewable once enabled.
    • 🟡 Notification content stream (live). Grant an app Notification access to capture/export notifications going forward. (User-granted API via NotificationListenerService.) |
    • 🟢 Per-app data usage (mobile/Wi-Fi). Apps/ADB can query NetworkStatsManager; Settings shows per-app totals. Advanced dumps via adb shell dumpsys netstats.
    • 🟡 Wi-Fi detailed logs. Developer options → Enable Wi-Fi verbose logging for richer diagnostics.
    • 🟡 Bluetooth packet logs. Developer options → Enable Bluetooth HCI snoop log; export file and analyze in Wireshark.
    • 🟢 Per-app storage usage. Apps/ADB can query StorageStatsManager; Settings shows per-app storage.
    • 🟡 Photo/video metadata (EXIF incl. location). Enable “Save location” in Camera app to embed GPS in EXIF; export files normally (EXIF remains). |
    • 🟢 Downloads & file metadata. Use a file manager or connect via USB; metadata is in the files themselves. |
    • 🟢 Battery usage history (per-UID/app), wakelocks, jobs. Generate adb bugreport and analyze with Battery Historian or dumpsys batterystats.
    • 🟡 System/device logs (logcat). You can view via ADB/Android Studio. Android restricts 3rd-party access to system-wide logs for privacy.
    • 🟢 Developer quick tiles (Sensors off). Developer options → Quick settings developer tiles → Sensors off to globally cut Camera/Mic & SensorManager sensors on demand.
    • 🟡 Google Takeout: one-stop export for Location History (Timeline), Gmail (MBOX), Calendar (ICS), Google Photos, Drive, YouTube, Fit, etc.
  • MacroDroid, Automate and Tasker sound like powerful Android workflow automation tools. Some uses I can put it to:
    • Automatically upload recordings to Dropbox
    • Turn off hotspot when I reach office
    • Vibrate if I’m walking slowly
  • Adding <link rel="alternate" type="text/markdown" title="LLM-friendly version" href="/llms.txt"> is an emerging approach for pointing to LLMs.txt. It works. I asked Codex to read the CloudFlare vitest page. It read the file truncating the middle, found the <link rel="alternate" type="text/markdown" href="https://developers.cloudflare.com/workers/testing/vitest-integration/write-your-first-test/index.md"/ link in it, and reasoned “Considering fetching markdown instructions” and fetched the Markdown page. Giles’ Blog
  • toon is a YAML-like format that’s LLM friendly and especially token-efficient (CSV-like) for tables. You can convert back and forth between JSON and toon.
  • Food printing applies 3D printing techniques to create real food items. Given the art that this can create, I expect at least some adoption in niche restaurants.
  • PMTiles lets you store map tiles as a single-file archive that libraries like MapLibre can read. Useful to avoid tile servers.
  • Mirrow is a CLI SVG animation builder that converts a DSL to animated SVGs. However, it may be easier to use an LLM to create the animated SVG directly with SMIL than learning Mirrow (or teaching the LLM Mirrow).
  • ⭐ One approach to giving memory (“episodic memory”) to coding agents is to allow them to search their logs.This gives them access to past discussions about a repo or other repos.
  • To configure Gemini CLI with an AI router, set:
    • "security.auth.selectedType": "gemini-api-key" in ~/.gemini/settings.json
    • export GOOGLE_GEMINI_BASE_URL=https://llmfoundry.straive.com/gemini/ (or your AI router base URL for Gemini)
    • export GEMINI_API_KEY=... (your AI router API key)
  • Passing a HAR export to an LLM to build a scraper is a powerful idea! Lessons from Diagram Chasing
  • Addy Osmani’s Gemini CLI tips are practical guides to using any coding agent, not just Gemini. I learnt about:
    • Run shell commands with !, e.g. !ls -la or even !bash. It’s added to the chat.
    • On-the-fly tool creation: ask it to write code for the task on the fly.
    • Use it for system optimization, e.g. editing dotfiles, system customization, log error analysis, etc.
    • Run GEMINI_SYSTEM_MD=... gemini -p "task" --yolo --format json < input.txt to run Gemini with a different system prompt and feed it input.txt to run in a pipeline. (FYI: Codex does not send a default system prompt, so there’s nothing to override.)
    • There is a Gemini CLI Show and Tell thread with examples. This include Janitor AI, a Gemini CLI session viewer, etc.
    • Hands on with Gemini CLI has several Use cases to try out. Renaming photos and organizing files are clever ones.
    • AGENTS.md can be used like a decision log - rules, styles, or preferences that evolve over time - on a per-repo basis. Gemini’s /memory add feature helps with this.
    • gemini --checkpointing is a useful “undo” feature. /restore rolls you back to a specific checkpoint. The overhead is small.
    • Caching is only available with API key or Vertex AI, not OAuth login as of now
  • OpenAI TTS costs are confusing. But in short
    • TTS-1 costs $15 / MChars (max 4,096 chars per request), which ends up at ~86c / hour
    • GPT-4o Mini TTS costs ~$16 / MChars (max 2K tokens which is ~7,000 chars per request), which ends up at ~88c / hour. Very similar cost, effectively
    • TTS-1 HD is twice TTS-1.
  • OpenAI has a usage API that provides cost as well as usage for completions, images, audio speeches, etc.
    • These require an organization admin key
    • Cost API: curl "https://api.openai.com/v1/organization/costs?start_time=$TIMESTAMP&project_ids=$PROJECT_ID&group_by=line_item"
    • Audio speech usage API: curl "https://api.openai.com/v1/organization/usage/audio_speeches?start_time=$TIMESTAMP&project_ids=$PROJECT_ID&group_by=model"