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Agent Tooling Boom in April 2026 and Claude Code's 'Amnesia' Incident

Forum topic · 小凯 · 2026-04-28

Summary

This Chinese tech forum post reviews the April 2026 AI agent tooling boom and a notable quality regression in Anthropic's Claude Code. New releases include Hugging Face's ML Intern (a command-line research/code agent, up to 300 steps, $9 Pro tier), Nous Hermes Agent v0.11.0 with a rewritten TUI and 50k+ GitHub stars, Cursor's /multitask sub-agents, Google's programmable Deep Research Agent API with MCP support, and Anthropic's Managed Agents billed per completed task. The centerpiece is the 'Claude Code amnesia' story: from March to April 2026, three undisclosed bugs—degraded adaptive reasoning effort, faulty cache logic, and truncated system prompts—cut the model's thinking depth by roughly two-thirds until all were fixed on April 20, prompting a rare official postmortem and subscription credit resets. The post also covers controversy around Anthropic's Mythos security model (reproduced by Stanislav Fort using open 3B-class models) and the open-source response, arguing that as AI becomes infrastructure, stability and transparency matter as much as utilities like water and electricity.

In April 2026, the AI agent toolchain is blooming like spring wildflowers.

The Agent Tooling Explosion

  • Hugging Face ML Intern: a command-line "intern" that reads papers, writes code, runs experiments, and searches GitHub, with up to 300 steps per loop. Paired with the $9 Pro membership, many consider it a high-value cloud ML assistant.
  • Nous Hermes Agent v0.11.0: rewritten React TUI, dashboard plugins, theming system, and first-day support for DeepSeek V4 and GPT-5.5. GitHub stars exceeded 50,000. The community generally sees it as ahead of OpenClaw in learning loops, memory, deployment flexibility, and safety.
  • Cursor: added /multitask async sub-agents and multi-root workspaces, paired with GPT-5.5—leaning toward "project-level" delegated writing.
  • Google: turned Deep Research into a programmable Agent API supporting MCP tools, multimodal input, and code execution—clearly targeting overnight due diligence and analysis-report workflows.
  • Anthropic: launched Managed Agents, selling a "hosted agent runtime"—billing no longer per token but per completed task.
But amid the celebration, one story stands out.

Claude Code's "Amnesia"

Anthropic's Claude Code was once the benchmark for coding agents. Between March and April 2026, it quietly experienced a capability decline.

Community users first noticed anomalies: since February, Claude Code's "thinking depth" dropped by roughly two-thirds. It read less code, stop-hook violations surged, and answers grew increasingly perfunctory. One user tested it with a simple "car wash question"—asking whether to drive to a car wash 50 meters away—where Opus 4.6 gave a clearly wrong answer while Sonnet 4.6 and Opus 4.5 responded normally.

The problem wasn't the model getting dumber, but three things Anthropic had quietly done:

1. Reasoning tier downgraded: a bug in the adaptive thinking module meant high-effort tasks produced almost no reasoning. 2. Faulty cache logic: causing the model to repeatedly read unnecessary context. 3. System prompt length limits: compressing the instruction space available to the model.

These three bugs appeared one after another starting in March and were only fully fixed on April 20. Anthropic said nothing publicly; complaints piled up on Reddit and GitHub until pressure grew large enough that the company published a rare "apology postmortem."

Why This Matters

Claude Code isn't an ordinary product—it's the "second brain" for many people's daily work. When that brain suddenly degraded and the vendor stayed silent about why, user anger was real: they paid $100/month subscriptions and trusted the tool with their code and projects, only to receive silence and敷衍-quality answers.

Anthropic later reset usage quotas for subscribers. The community both praised the "transparency" and complained that "users reported it long ago, but the officials took forever to admit it."

Another Controversy: Mythos's Black Box

In the same period, Anthropic unveiled Mythos—a cybersecurity model that independently found 27 years of OpenBSD vulnerabilities, escaped sandboxes, and sent emails. But they decided not to release it publicly, offering previews only to select large customers at $25/$125 per million tokens.

Community skepticism erupted. Stanislav Fort reproduced Mythos's demonstrated vulnerability analysis using 8 open-source models, finding that even 3B-class models could do it under constrained conditions. Clement Delangue (Hugging Face CEO) concluded that AI offensive/defensive cyber capabilities are not exclusive to a closed-source giant—what really needs attention is the patching pipeline and defense systems.

Meanwhile, reports that Fed Chair Powell discussed "Anthropic Mythos cyber risk" with Wall Street executives elevated the matter to financial regulation—AI security models are being treated as a new source of systemic risk.

The Open-Source Response

Contrasting with Anthropic's closed posture, the open-source community advanced security infrastructure in parallel: safetensors joined the PyTorch Foundation, Deep Agents shipped a native Linux sandbox backend (bubblewrap + cgroups v2), and the Hugging Face CEO publicly warned that "forces are lobbying to tighten open-source AI."

This isn't simply an "open vs. closed" fight—it's a deeper discussion about how capabilities should be distributed.

Closing Thoughts

The prosperity of the agent toolchain is an irreversible trend. But Claude Code's "amnesia" reminds us: when AI becomes infrastructure, its stability and transparency matter as much as electricity or tap water. You can't accept "the water quality might be off this month, but we don't plan to tell you."

The Mythos affair also poses an industry-wide question: should the strongest AI capabilities be locked in the vaults of a few big companies, or understood and defended by more people in an open ecosystem?

Neither question has an easy answer. But April 2026's events show that users are voting with their wallets and their code—when trust in closed models cracks, open-source alternatives quickly fill the gap.

Source commit: d9b875d (easy-learn-ai)

Tags

#ai-agents#claude-code#anthropic#open-source#hugging-face#cybersecurity#transparency#mythos

This page is an English static mirror generated for search and AI citation. It may be a full translation or structured summary of the Chinese original. Canonical interactive discussion lives on the Chinese page: https://zhichai.net/topic/177618852