Put Claude Fable 5.1 and Gemini 3.8 Flash on the same team
Long-form article published on **September 14, 2026** on the X account **@GoogleCloudTech** (~2,000 words, four steps, six blocks of commands and configuration), signed by **Alan Blount**, Technical Solutions Consultant at Google. Starting point: a trivial question, handed to a research agent, billed at **$38**. The article proposes running **Claude Fable 5.1** and **Gemini 3.8 Flash** side by side behind the same **Gemini Enterprise Agent Platform** API (formerly Vertex AI). **(1) Configuration**: access to Fable is subject to Google Cloud's *Advanced AI Safety Addendum*, which requires a `setPublisherModelConfig` call with prompt-response sharing enabled for Anthropic, on pain of a 403; Flash works as soon as it is enabled. **(2) In-house benchmark** with promptfoo driving opencode on two tasks: on a git branch state, Flash answers in **1.1 s** for under a tenth of a cent while Fable costs **23 times more**; on a Postgres-to-Spanner migration, Fable produces in **12 s** a formal DAG with clock-drift risks and a rollback gate, whereas Flash delivers a linear sequence in 3 s. **(3) Usage**: *« asymmetric coordination »* — the fast model as first-line coordinator, the deep planner at checkpoints, an `ask_for_help` tool for escalation, and a warning against dynamic routers: *« Keep it boring »*. **(4) Token ROI**: the value of human time, shipped features, and incidents avoided, minus the cost of tokens and the team's ramp-up. The same task-boundary routing move as [[mazmanov-portal-spotify-shunt-claude-code-tokens-2026-09-03]], within the FinOps framework set out by [[rafal-wenvision-tokenomics-foundation-finops-ia-2026-06-04]].
Alan Blount (Technical Solutions Consultant, Google Cloud, @zeroasterisk) · publié sur le compte X @GoogleCloudTech.