WEEK OF AUG 23 – 29, 2025

Grok 2.5's weights went public, a 405B Hermes landed, and Musk sued the App Store

xAI published its best 2024 model as a 500 GB download on Saturday and sued Apple and OpenAI on Monday; Anthropic disclosed an 11.2% prompt-injection failure rate for its new browser agent; and OpenAI put MCP servers and telephony inside the Realtime API.

Five days, one theme: who holds the weights and who holds the distribution. xAI pushed a roughly 500 GB checkpoint of Grok 2.5 to Hugging Face on Saturday; by Monday its lawyers were in a Texas federal court arguing that Apple and OpenAI had rigged the App Store. Nous Research, meanwhile, put 70B and 405B hybrid reasoners on the same platform.

Agent harnesses were the second thread, and the disclosures were unusually specific. Anthropic shipped a browser agent to 1,000 users and published its own prompt-injection failure rate: 11.2%, with mitigations running. OpenAI took the Realtime API out of beta and wired remote MCP servers, image input and SIP telephony into it. Brave's Comet prompt-injection finding from the week before turned out to be chapter one rather than an isolated bug.

Licensing and pricing moved in opposite directions. xAI's custom Grok 2 Community License drew anti-competitive-terms criticism while the weights went out free, and OpenAI cut gpt-realtime audio pricing by 20%. The legal pile also grew: xAI's antitrust filing follows Musk's August 12 threat against Apple.

THU · Aug 28, 2025agent infrastructuremcpvoicepricing

OpenAI graduates the Realtime API and bolts on remote MCP servers and SIP telephony

OpenAI took the Realtime API out of beta on Thursday with a new gpt-realtime speech-to-speech model and three additions that matter for plumbing: remote MCP server support, meaning you pass an MCP server URL into the session config and the API handles tool calls itself; image input; and Session Initiation Protocol support for phones, PBXs and desk endpoints. Function calling on the ComplexFuncBench audio eval rose to 66.5% from 49.7% on the December 2024 model, instruction following on MultiChallenge audio to 30.5% from 20.6%, and two API-only voices, Cedar and Marin, shipped alongside.

Pricing fell 20% against gpt-4o-realtime-preview to $32 per million audio input tokens — $0.40 when cached — and $64 per million audio output tokens. Sessions also gained token limits and multi-turn truncation controls, and long-running function calls no longer disrupt a live conversation.

OpenAI graduates the Realtime API and bolts on remote MCP servers and SIP telephony
developers.openai.com

WHY IT MATTERS

MCP over a telephony transport is the milestone: a phone number can now be an agent endpoint that discovers tools from a remote MCP server without you hand-wiring integrations, which collapses telephony, tool routing and model into one session. At $64 per million audio output tokens, verbosity is a pricing decision as much as a UX one — cache-friendly input at $0.40 and hard token limits are now the levers that keep a talkative agent affordable.

TUE · Aug 26, 2025agentsbrowsersecurityprompt injection

Anthropic puts Claude inside Chrome and publishes the attack numbers: 11.2% prompt-injection success with defenses on

Anthropic opened a research preview of Claude for Chrome on Tuesday to 1,000 Max-plan subscribers, who pay $100-$200 a month, with a waitlist behind them. The extension lives in a sidecar window with context on the page in view and can act on it — clicking, filling forms, moving between tabs using the logins already in your session.

Unusually, the company shipped its own adversary numbers alongside the product: unmitigated browser use fell to prompt injection in 23.6% of tests, reduced to 11.2% with its defenses in place. Financial-services, adult and piracy sites are blocked by default, and publishing, purchasing or sharing personal data requires explicit user permission. It follows Brave's finding that Perplexity's Comet agent was vulnerable to indirect prompt injection, making this the second consecutive week that browser agents have been the story.

Anthropic puts Claude inside Chrome and publishes the attack numbers: 11.2% prompt-injection success with…
cdn.prod.website-files.com

WHY IT MATTERS

Design around 11.2%: roughly one in nine adversarial attempts still succeeds with the vendor's own mitigations running, so if you build a browser agent, scope its credentials separately from the user's main session, allowlist destinations, and gate irreversible actions behind human confirmation at your layer rather than relying on model judgment. An agent with access to your authenticated browser session is an agent holding your session cookies — that is the threat model to write down before you ship.

MON · Aug 25, 2025open weightsreasoningfine-tuneevals

Nous Research ships Hermes 4 at 70B and 405B: hybrid reasoning, open weights, 96.3% on MATH-500

Nous Research published Hermes 4 on Monday — hybrid reasoners at 70B and 405B built on Llama-3.1 bases, with the technical report covering a 14B Qwen3-based variant. Reasoning toggles with a think tag, so one checkpoint serves both fast answers and extended deliberation, and post-training scaled from roughly 1M samples and 1.2B tokens in Hermes 3 to about 5M samples and 60B tokens. Licenses are inherited from the bases: the Llama 3 Community License for the 70B and 405B, which carry Llama-3.1's 128K context windows.

The numbers are competitive with closed systems in reasoning mode: 96.3% on MATH-500 and 81.9% on AIME 2024 for the 405B, plus 57.1% on RefusalBench — the benchmark Nous wrote to measure willingness to answer — against 17.7% for GPT-4o and 17.0% for Claude Sonnet 4. For a 405B checkpoint the license inheritance is the real story: the weights are free to run, but Meta's Llama 3 Community License, not Nous Research, sets the commercial terms.

WHY IT MATTERS

A 405B hybrid reasoner under a community license is the strongest open-weight argument yet that you can run frontier-class math and coding behind your own firewall instead of metering tokens to an API — if you can afford the footprint. Treat the 70B as the deployable tier and the 405B as the eval ceiling, verify the base-model license obligations before you ship either in a product, and benchmark it on your own workload rather than the published scores.

MON · Aug 25, 2025litigationantitrustdistributionapple

xAI and X sue Apple and OpenAI in Texas, alleging an App Store scheme to lock out Grok

On Monday xAI and X Corp. filed suit against Apple and OpenAI in the U.S. District Court for the Northern District of Texas, alleging violations of Sections 1 and 2 of the Sherman Act and the Texas Free Enterprise and Antitrust Act. The complaint claims Apple and OpenAI colluded to maintain monopolies in smartphones and generative AI, and that Apple deprioritizes super apps and chatbot rivals such as Grok in App Store rankings while favoring OpenAI — the company it integrated ChatGPT with across iPhone, iPad and Mac in 2024.

OpenAI's response was a single line: the filing is consistent with Mr. Musk's ongoing pattern of harassment. Apple has said its App Store is designed to be fair and free of bias. The suit lands three weeks after Musk publicly threatened Apple with immediate legal action on 12 August, and it arrives with the judge in Google's separate search case still weighing a Chrome divestiture — the other live lever on who controls assistant distribution.

WHY IT MATTERS

This is the continuing arc that matters to anyone shipping a product that competes with a platform owner's assistant: ranking algorithms, default integrations and app-review discretion are now being litigated, so the rules for reaching users may be set by discovery and consent decrees rather than documentation. Track the filings, not the press releases — if Apple's ranking signals or the OpenAI integration terms come into evidence, they define the distribution constraints your roadmap has been guessing at.

SAT · Aug 23, 2025open weightsxailicensingmoe

xAI open-sources Grok 2.5: 500 GB of FP8 weights under a custom license

At 15:16 PT on Saturday Musk posted that the xAI Grok 2.5 model, which was its best model last year, is now open source; the weights appeared on Hugging Face as xai-org/grok-2. The repository ships 42 files totalling approximately 500 GB in FP8, and its own card states the checkpoint is tensor-parallel 8 — eight GPUs with more than 40 GB of memory each to serve it. It is a 2024-era mixture-of-experts model, and Musk added that Grok 3 will follow in about six months.

The model is not the story; the license is. Grok 2.5 is released under xAI's custom Grok 2 Community License, which engineer Tim Kellogg described to TechCrunch as custom with some anti-competitive terms. What xAI gave away is a one-generation-old system, well behind Grok 4 and the current open frontier set by GLM-4.5 and OpenAI's gpt-oss — so the practical effect is a very large downloadable artefact under non-standard terms rather than a competitive release.

WHY IT MATTERS

Read the license before you build on it: the Grok 2 Community License is not OSI-style permissive, and a 500 GB FP8 checkpoint at tensor-parallel 8 means eight 40 GB-class GPUs is the entry price for self-hosting before a single token is generated. The bigger signal for architects is precedent — a frontier-adjacent lab has demonstrated it can dump a half-terabyte checkpoint on Hugging Face whenever it wants leverage, which changes the baseline you should expect from vendors you depend on.