Ephemeris — the morning brief
Today the software builds the software.
A desktop agent you run on your own keys. An SDK that ships a production backend on command. And the report where Anthropic says Claude now writes most of Claude.
A desktop agent you actually own.
Open Cowork is a free, open-source agent that runs natively on Windows and macOS, drives your files and apps, and never phones home to a vendor. You bring the keys — Claude, GPT, or a local model through Ollama — so the data and the bill stay yours. At v3.3.1 it has 1.6k stars and a one-click installer.
- 01One-click install. Claude Code, MCP tools and Skills wired up out of the box — no terminal archaeology.
- 02VM-level sandbox. The agent runs inside WSL2 / Lima isolation, so a bad step can't touch your real machine.
- 03Your model, your key. Anthropic, OpenAI, or fully local via Ollama — nothing leaves the box if you don't want it to.
- 04Skills that make files. Generate PPTX, DOCX, PDF and XLSX, and drive it remotely from Slack or Feishu.
Tell the agent to ship the backend.
Rayfin, Microsoft's new open-source SDK and CLI, lets a coding agent define a whole application backend in code — SQL database, Entra ID auth, a schema-driven GraphQL API, static hosting — then deploy it without anyone touching infrastructure. It runs on Fabric, lands data in OneLake, and shipped in public preview at Build alongside a Replit partnership.
schema.ts → tables, relations, row policies
logic.ts → business rules + access control
auth → Microsoft Entra ID, built in
api → schema-driven GraphQL, generated
$ rayfin deploy # db + auth + api + hosting, live on Fabric
Describe the diagram; get the file.
The draw.io skill for Claude Code turns a sentence into a real, editable draw.io diagram — not a screenshot. It reads your codebase to draw what's actually there, ships six diagram presets, pulls from 10,000+ official shapes plus a few hundred AI brand logos, and exports to PNG, SVG, PDF or JPG. Latest release v1.14.0.
Claude now writes most of Claude.
In a new report, Anthropic puts numbers on the loop: more than 80% of code merged into production is now authored by Claude, up from single digits before February 2025. Engineers merge roughly 8× more code per quarter than in 2024, and the length of task the model can complete unaided keeps doubling — the early signs, the authors argue, of AI helping design its own successor.
Everyone is in build mode now.
PostHog's argument: shipping is no longer the engineers' job alone. With agents and MCP, marketers, PMs and support staff are opening draft PRs and changing the product themselves — and the company is reorganising around that fact.
The shift is measurable inside one mid-size company: millions of MCP calls and more than 400,000 conversations with its in-house AI happen every month, much of it from people who don't call themselves engineers.
The risk is obvious — more hands on the codebase means more ways to break it — so the bet is on guardrails, review and observability rather than gatekeeping who gets to write a line.
The takeaway for a founder: "build mode" is a staffing and tooling decision before it is a culture slogan. Decide who can ship, and what catches them when they do.
That's today.
Five picks on a single thread — the tools that let agents write, ship and visualise software, and what happens when most of the code is already theirs.