todai
Thursday, 23 April
6 min read · 1,066 words

REDDIT SIGNAL

  • KeygraphHQ/shannon — 346★ today (39,405★ total) — autonomous AI pentester: point it at your web app source code and it identifies then exploits injection/XSS/SSRF/auth-bypass vulnerabilities before you ship them; built explicitly for the "Claude Code ships fast, pentest happens once a year" gap | https://github.com/KeygraphHQ/shannon

TODAY'S ITEMS

1. Anthropic Tests Removing Claude Code From Pro — Community Erupts, Reverts Within Hours

  • Anthropic yesterday quietly removed Claude Code from the $20/month Pro pricing page; the community erupted (2,665 upvotes on r/ClaudeAI, covered by Simon Willison and The Register), the Head of Growth tweeted it was a "~2% test on new prosumer signups", and the pricing page reverted within hours — but the underlying A/B test may still be running for a small slice of new sign-ups. Existing Pro and Max subscribers were unaffected.
  • Source: simonwillison.net
  • Source: r/ClaudeAI
  • Why it matters: Anthropic just signalled they are actively considering moving Claude Code above the $20 Pro tier — the test is over but the intent is not; if your workflow depends on Claude Code at Pro, budget for Max ($100/month) or start building a backup harness around Kimi K2.6 via OpenCode.
  • Verified

2. Claude Code April 22: Opus 4.7 Context Window Bug Fixed, Default Effort Bumped

  • Two changes that affect your daily workflow: (1) Opus 4.7 sessions were incorrectly computing context against a 200K window instead of the native 1M — fixed today, so sessions will compact far later and /context percentages are now accurate; (2) default effort for Pro/Max subscribers on Opus 4.6 and Sonnet 4.6 bumped from medium to high. Also shipped: faster MCP concurrent startup, improved model persistence across restarts, and native macOS/Linux builds that replace Glob/Grep with faster embedded bfs and ugrep.
  • Source: GitHub anthropics/claude-code
  • Why it matters: If you've been on Opus 4.7 and sessions were autocompacting early or showing suspiciously high /context usage — update now, you've been working with 80% less context than you should have been; and if you're cost-sensitive, add "effortLevel": "medium" to your .claude/settings.json to reverse the effort bump.
  • Verified

3. Qwen 3.6 27B: Local Flagship-Level Coding in 16.8GB

  • Qwen dropped a 27B dense model today claiming it beats their previous 397B MoE flagship on all major coding benchmarks at a fraction of the size — Simon Willison tested the 16.8GB Q4_K_M Unsloth quantised variant and confirmed solid output quality at ~25 tokens/sec on consumer hardware. Also released: Qwen 3.6 35B-A3B, a MoE model with only 3B active parameters that runs on a single consumer GPU.
  • Source: HuggingFace + simonwillison.net | https://simonwillison.net/2026/Apr/22/qwen36-27b/
  • Why it matters: Best local coding model released this year — brew install llama.cpp then run llama-server with the unsloth/Qwen3.6-27B-GGUF:Q4_K_M variant; gives you near-frontier coding quality for zero ongoing API cost when Claude rate limits are the bottleneck.
  • Verified

4. Claude Mythos Finds 271 Zero-Day Vulnerabilities in Firefox

  • Mozilla used early access to Anthropic's Claude Mythos Preview before the Firefox 150 release and identified 271 security vulnerabilities, all patched before shipping. Mozilla CTO: "So far we've found no category or complexity of vulnerability that humans can find that this model can't" — Mythos remains restricted to a small group of Project Glasswing industry partners (Apple, Amazon, Microsoft, Google, Cisco, et al).
  • Source: Mozilla blog
  • Why it matters: AI-powered security scanning just moved from benchmark to production-scale reality — if you're shipping production software fast with Claude Code, the Shannon AI pentester (GitHub Trending above) is the closest open-source approximation available without Glasswing access.
  • Verified

YOUR STACK — UPDATES

  • Claude Code (April 22): default effort bumped to "high" for Pro/Max on Opus 4.6 and Sonnet 4.6 — smarter sessions but higher token burn; add "effortLevel": "medium" to .claude/settings.json to revert | https://github.com/anthropics/claude-code/releases

NEW TOOL / PRODUCT SPOTLIGHT

  • langfuse — Open-source LLM observability platform: track costs, latency, evals, and prompt versions across all your Claude API calls. Integrates with the Anthropic SDK in two lines. Free cloud tier or self-hostable. | docker compose up -d (self-hosted) or cloud at https://cloud.langfuse.com | https://github.com/langfuse/langfuse

PROMPT OF THE DAY

You are helping me bootstrap a production-grade Claude Code setup
for this project. Do the following in order:

1. Read README.md and package.json (or equivalent config files)
   to understand the stack
2. Identify: language, framework, test runner, build command,
   and any auth/payment/infrastructure components
3. Generate a complete CLAUDE.md with:
   - Stack overview with key dependencies and versions
   - Off-limits paths (auth, migrations, payments — flag these
     as requiring explicit approval before editing)
   - Hard rules: run the test suite before marking anything done,
     max 50 lines per edit, one logical change per commit
   - Verification commands for test, lint, and type-check
   - Recommended MCP servers for this stack

Output the full CLAUDE.md ready to copy-paste.

Drop this in Claude Code at the root of any new project before your first coding session — takes 30 seconds and saves hours of mid-session re-briefing. Inspired by community harness guide https://www.reddit.com/r/ClaudeAI/comments/1spehot/

LANDSCAPE NOTES

  • Anthropic's Pro plan kerfuffle handed OpenAI a clean marketing moment: Codex engineering lead tweeted that Codex stays available on free + Plus plans with a promise of "transparency and trust." Competitive pressure on Claude Code's positioning just increased. https://simonwillison.net/2026/Apr/22/claude-code-confusion/
  • Qwen also released Qwen3.6 35B-A3B (3B active parameters, MoE) — designed for agentic coding, runs on a single consumer GPU; a viable Claude Code backend alternative via OpenCode for teams with local GPU capacity. https://huggingface.co/Qwen/Qwen3.6-35B-A3B