Ephemeris. Issue 021 · Saturday 09 May 2026 · Zürich
Ephemeris · Issue 021 01 / 07 · OpenAI
Dev tools · Security

Codex inside a box with the door bolted shut.

OpenAI publishes how it actually runs Codex internally: sandboxed file roots, an approvals layer for risky ops, locked-down network policy, and telemetry on every shell call. The doc reads like a checklist any team shipping autonomous coding agents should steal.

Default sandbox · what Codex can / can't touch

  • read & write under workdir
  • run scoped shell commands with approval prompts
  • emit structured telemetry on every action
  • arbitrary outbound network egress
  • writes outside the agent root
  • long-lived credentials in env
Ephemeris · Issue 021 02 / 07 · PostHog
AI tools · MCP

A short list of MCP servers that actually pay rent.

PostHog's team waded through tens of thousands of MCP servers and surfaced the ones a startup engineer can plug in this afternoon — debugging in production, sprint planning, customer behaviour, and a few that quietly replace whole SaaS subscriptions.

posthog
Query product data & errors from the editor.
linear
File and triage issues in the same chat.
github
PR review, search, and ship from CLI.
sentry
Trace through to the failing request.
notion
Pull specs and write back decisions.
stripe
Inspect customers, charges, refunds.
Ephemeris · Issue 021 03 / 07 · PostHog
Agents · Operations

4,063 errors closed before anyone opened the dashboard.

PostHog ran a month with agents triaging the error inbox: thousands of issues quietly resolved, noise suppressed, the rest routed to the team that owns the code. The interesting bit isn't the headline number — it's the column showing how many were the same flaky thing repeated.

ActionCountShareNotes
Closed (resolved)4,06366%verified fix or intended behaviour
Suppressed (noise)1,75128%repeated patterns, third-party flakes
Routed to humans3105%tagged owner, posted in channel
Escalated (severity)521%paged on-call
Total handled6,176100%one month, zero humans opening it first
Ephemeris · Issue 021 04 / 07 · Sentry
[ DEV TOOLS · OBSERVABILITY ]

RE: stop monkey-patching every JS library you ship.

Sentry is upstreaming TracingChannel support into 44 JavaScript libraries so observability emits from the source instead of a brittle wrapper. The end of a fifteen-year hack — and a clean blueprint for any vendor still injecting at runtime.

From
Sentry Engineering
To
The JavaScript ecosystem
Subject
Native telemetry via diagnostics_channel
Status
Patches landing in 44 libraries · Node, Bun, Deno
Action
Drop your monkey-patch shims; subscribe to channels.
approved · 2026-05-07
Ephemeris · Issue 021 05 / 07 · Sentry
Agents · Observability

When agents orchestrate agents, who is watching?

A planner spawns a researcher who spawns a coder who calls another planner. Sentry's piece argues the failure mode that bites you isn't any single agent — it's the silence between two of them. Concrete patterns for tracing the gaps.

plannerdecompose("ship invoice export")
plannerspawn(researcher) · spawn(coder)
researcherfound 3 schemas, returns shape
coderawaits researcher · timeout 90s
coderno parent span · trace orphaned
plannerretries silently · cost doubles
Ephemeris · Issue 021 06 / 07 · The Batch
The week in research

Seedance makes a splash, Nvidia lets a model design its own chips, robots learn not to forget.

DeepLearning's weekly digest on a fat issue: a generative-video model that closes the gap on Sora-class incumbents, AI in the silicon-design loop at Nvidia, and continual learning landing in real robots.

Seedance's open release lands close enough to closed-source video models that the practical question — which one is cheapest per acceptable second — finally has a real answer.

Nvidia's chip team describes a workflow where AI proposes layouts and floorplans the humans then pick from, shaving wall-clock weeks off the back end of a tape-out.

Continual-learning research reports robots that retain skills across tasks instead of catastrophically forgetting them between deployments — a quiet but load-bearing result.

Ephemeris · Issue 021 07 / 07 · Don't Worry About the Vase
Dev tools · Reading

Eight months of agentic coding, and the honeymoon is over.

Zvi's eighth round-up reads less like "look what's new" and more like a state-of-the-craft: where Claude Code and Codex genuinely move the needle, where they create new failure modes, and which workflows the steady users have actually settled into.

#8in series

Skim the table of contents first — Zvi's pieces reward jumping to the section that matches your current pain.

End of issue 021 Back to top ↑

That's today.

Issue 021 · 09 May 2026 Today drew on OpenAI, PostHog, Sentry, The Batch, and Don't Worry About the Vase. Picks favour AI tools you can adopt this week, agentic-coding craft, and observability over the rest. Zürich · daily