Two OpenAI APIs shipped three weeks apart solve very different problems. A marketer's read on what each one actually does, where each one earns a slot in a real automation stack, and the routing principle that picks between them.
Dots launched at DevDay on Sept 29 2026 as OpenAI's answer to Meta Muse — a persistent, GPT-6 Astra-powered agent with its own cloud computer. Here's the first-week practitioner read: the 5 marketing jobs I'd hand it, the 3 I wouldn't, and where it sits against the Claude/Gemini/Muse agents already in my stack.
Anthropic shipped Sonnet 5.5 on September 28, 2026 — same $2/$10 as Sonnet 5, same 1M context, 30%+ faster, up to 30% cheaper per task, and on GDPval-AA it sits two Elo points under Opus 5.5. Five jobs Sonnet 5.5 already replaced in its first day on real marketing work, three where Opus 5.5 or Sonnet 5 still wins, and the routing principle that matters now that the Sonnet tier can carry real marketing work.
Anthropic shipped Opus 5.5 on September 22, 2026 — same 1M context as [Opus 5](/posts/claude-opus-5-marketers/) and [Fable 5.1](/posts/claude-fable-5-1-marketers/), but $4/$20 instead of $5/$25, cache reads cut 60% to $0.20, and a writing-style fix that actually lands. The number that matters for marketers isn't a benchmark — it's that 60% cache-read cut. Four jobs Opus 5.5 earns from Opus 5 this week, three where Fable 5.1 or Opus 5 still wins, one routing principle that holds, and the four breaking API changes you need to patch before Monday.
Anthropic's Fable 5.1 shipped September 1 with the same $10/$50 sticker as GPT-6 Astra but a 75% cache-read cut and flat pricing across the full 1M window. That changes which agent loops become viable: persistent brand-context documents can stay open across hundreds of turns. Four jobs to give it, two to keep on Opus 5, and three API breaking changes marketers need to patch this week.
Anthropic shipped Opus 5 on July 25, 2026. Here's how it actually performs on the marketing jobs I run daily — long-context research, multi-agent orchestration, complex content — and the three situations where Opus 4.8 is still the smarter spend.
xAI shipped Grok 4.5 on July 9, 2026 at $2/$6 per million tokens, claiming Opus-class quality and roughly half the tokens of comparable models. After running it through a week of marketing pipelines, here's the cost math that actually matters, 5 jobs where I'd reach for it, and 3 where I'd skip it.
Anthropic's first public Mythos-class model is fast, opinionated, and 2× the price of Opus 4.8. After a week of running real marketing jobs through it, here's the actual breakdown — capabilities, costs, the 30-day data retention rule that affects agencies, and the marketer use cases where Fable 5 actually wins.
Palmier Pro is a Y Combinator-backed video editor that puts Claude, Codex, and Cursor directly inside your timeline via MCP, with inline integrations to Kling V3, Seedance 2.0, Veo 3.1, and Grok Imagine. From $29/month, with a free editor-only tier.
Five frontier models, five different superpowers. After running them side by side on real campaigns for six months, here's which one I open for which marketing job — and the brand-safety landmine that makes Grok-Imagine unusable for most brands.
A 3-sub-agent competitive intel pipeline that produces an 8-page PDF brief every Friday at 6am — no human reads a single competitor page in between. The parent Claude agent dispatches a site-watcher, an ad-watcher, and a social-watcher, each returns a strict JSON schema, the parent synthesizes everything into a Markdown brief that Pandoc renders to PDF. The parent prompt, the three JSON contracts, the PDF template, and the failure modes that have actually cost me a brief.
A 0-100 pre-publish scorecard that scores any post on E-E-A-T, Depth, Freshness, and Structure (25 each), with a single Claude prompt that does all four in one pass plus a remediation list. The 75/100 + no-dimension-below-16 publish gate, the batch-of-10 audit workflow, and the hard reason a rubric beats vibes-based editing when you have 200+ posts and staff turnover.
