The AI Wire ●

OpenAI announced via its @ChatGPT account on September 15 that GPT-5.5 will be retired from ChatGPT, ChatGPT Work, and Codex across all plans on October 14, 2026. Everyday users will be moved to the new default automatically, but builders and Codex users who hardcoded the model need to migrate to GPT-5.6 Sol or GPT-6 Astra before the cutoff.

The retirement does not affect the API: API-key-authenticated calls keep working. GPT-5.5 only launched April 23, 2026, giving it a short six-month run in the main product surfaces.

On September 13, Elon Musk announced on X that xAI's next model will be Grok 4.8: 2.5 trillion parameters on an in-house C++ software stack rebuilt from scratch, moving straight into reinforcement learning once the main training run completes. The announcement effectively supersedes Grok 4.7 (2.1T), which missed multiple release windows and was publicly downgraded by Musk to 'roughly comparable to Anthropic's Opus 5.0'.

No model card, benchmark table, pricing, API identifier, or release date has been published; every figure attached to Grok 4.8 is a founder claim, not a shipped specification.

OpenAI temporarily paused new sign-ups for its $200-per-month ChatGPT Pro tier on September 10, saying demand for GPT-6 Astra was putting unprecedented strain on its infrastructure. Product leader Thibault (Tibo) Sottiaux announced the move on X, calling the Pro tier the heaviest load on the company's systems and framing the pause as 'the smallest step that allows us to continue giving the broadest access possible.'

Plus, Go and API access remain open. A day earlier he had warned that demand was 'really unprecedented' and that a pause might be needed to protect service quality for existing subscribers. OpenAI gave no reopen date. (Filed September 21 as backfill.)

Same underlying model as Fable 5.1 but with reduced safeguards, available only through trusted-access programs for cybersecurity and life-sciences work. Not generally available.

OpenAI expanded its Daybreak cybersecurity initiative into two access tiers for vetted defenders. Daybreak Blue opens general-purpose models, including GPT-5.6 Sol, to approved defenders for everyday security work — vulnerability discovery, secure code review, malware analysis, incident response, and patch validation — with the system-level cyber guardrails recalibrated rather than removed.

Daybreak Red sits behind tighter vetting and gates the new purpose-trained GPT-5.6-Cyber model, built for vulnerability research, exploit validation, and authorized security testing. On OpenAI's internal Advanced Cybersecurity Completion Rate benchmark, GPT-5.6-Cyber completed 95% of offensive-security tasks, up from 57.3% for GPT-5.5-Cyber and just 1.5% for general-purpose GPT-5.6 Sol. OpenAI says it used the model to find two previously unknown vulnerabilities in Chrome's V8 engine.

Access requires identity verification, monitoring, and legal attestations — and from September 1, hardware security keys became mandatory for individual Daybreak accounts. The models also landed on Amazon Bedrock on August 11, with a partner program covering 16 security providers including IBM, CrowdStrike, Accenture, Cisco, and Cloudflare.

After CEO Dario Amodei refused the Department of War's demand to drop safeguards barring Claude's use for mass surveillance of Americans or fully autonomous weapons — a $200M contract clause the Pentagon wanted rewritten to permit "any lawful use" — President Trump posted on Truth Social ordering every federal agency to stop using Anthropic technology, with a six-month phaseout, and warned he would use "the Full Power of the Presidency to make them comply, with major civil and criminal consequences to follow." Defense Secretary Hegseth separately designated Anthropic a "supply chain risk," a label never before applied to an American company.

Amodei called the threats retaliatory and said Anthropic would challenge the designation in court; a judge later blocked the ban as illegal First Amendment retaliation.