-
The session moved. The folder did not.
On 6 October 2026, new
Cowork tasks on Pro and
Max plans run in the cloud.
Anthropic’s help page says
the “Only on your computer”
option in Settings, General,
is removed. There is
nothing to set up. Tasks
already started on the
computer stay there, with
a note at the top and a
button to download the
transcript. Folders stay
on the computer.
Claude reaches only the
folders you have connected,
through the desktop app,
and only while that app is
open. When a cloud task
needs a file, it fetches a
copy of just that file.
When you delete the
session, those copies are
deleted too. A cloud
session can read and write
connected folders only
while the desktop app is
open on that computer, and
only if the session was
started on desktop. If the
app is closed, the session
keeps running. It cannot
reach local files.
Felix Rieseberg at
Anthropic, quoted by Simon
Willison on 5 October,
described the split. The
old Cowork ran model
inference in the cloud and
tool calls in a VM on your
computer, mapping in only
the data you added to the
session. People did not
love the disk, the battery,
or the fact that closing
the laptop stopped the
work. The new version runs
inference and the VM in
the cloud. Each session
gets its own sandbox and
does not share state with
other sessions. When the
VM needs something on the
device, the desktop app is
responsible for that
file-access tool call.
Local connectors, browser
use, and computer use from
web or mobile still go
through the desktop app.
Scheduled tasks move to
the cloud, including ones
that use files on your
computer, and those still
need the desktop app open.
If the work has to stay on
one machine, the help page
points at Claude Code in
the desktop app. Projects
and scheduled tasks do not
carry over with a
downloaded transcript.
Write “cloud session” and
“local file” as two
permissions. A closed
laptop is not a dead
agent. It is a closed gate.
Source:
Use Claude Cowork on web, desktop, and mobile — Claude Help Center, updated this week; cloud cutover 6 October 2026
·
Quote from Felix Rieseberg — Simon Willison, 5 October 2026
-
One square is not a rate
On 4 October Simon Willison
re-ran an old test: add two
large numbers and return
the sum in words. Colin
Fraser had charted GPT-4o
on this years ago. Simon
pasted that chart into a
Codex Remote session and
had it run the same
experiment on a DGX Spark,
locally, with
Qwen3.8-27B-Q4_K_M. With
reasoning off, thirty
attempts per combination.
With reasoning on, each
pair was slow, so he ran
one attempt per cell.
That one-shot run got 167
of 169 right. He writes
that a second run would
produce different results,
and that the heatmap is
less useful as a picture
of a rate, because each
square is either 100% or
0%. The interesting traces
still show the model
re-aligning digits and
carrying by hand. That is
a look at a failure mode.
It is not a percentage you
can put in a README
without the trial count.
A cell with thirty trials
can be a rate. A cell with
one trial is a sketch. Say
which one you published.
Source:
Qwen3.8 27B addition in words — Simon Willison, 4 October 2026
·
qwen38-addition-in-words — simonw/research
-
A newer model is not a trust upgrade
On 1 October Simon shipped
pwasm 0.2a0, a pure-Python
WebAssembly engine he
vibe-coded in January and
had not touched since. He
pointed Claude Opus 5.5 at
it: evaluate the current
state, then consider what
it would take to get the
MicroPython and micro
JavaScript experiments
working, and what it would
take to speed it up.
Forty-two commits later,
with minimal follow-up
prompting, it handles
almost all of the WASM
specification. The wheel
on PyPI bundles working
WASM builds of
MicroPython, QuickJS, and
Micro QuickJS.
He would not trust it.
That is why the tag is
still alpha. The note he
keeps is narrower: today’s
models can improve on the
work of models from ten
months ago. Improvement is
a diff against a spec you
can re-run. Trust is a
separate decision, and he
left it unsigned.
If a newer model rewrites
last winter’s agent code,
keep the “would not ship
this” label until a check
you can re-run says
otherwise.
Source:
pwasm 0.2a0 — Simon Willison, 1 October 2026
·
pwasm 0.2a0 release — GitHub
-
Enabled is not reviewed
GitHub, today: organization
and enterprise
administrators can see AI
Scan for pull requests
enablement in the security
overview coverage view.
The code scanning summary
shows enabled and
not-enabled repository
counts. Each repository
row shows that repo’s
effective AI Scan
enablement. You can filter
the coverage view with
code-scanning-ai-scan-pr-scan:enabled
and
code-scanning-ai-scan-pr-scan:not-enabled.
Coverage CSV exports now
include a Code Scanning AI
Scan for pull requests
column, with enabled and
not-enabled values.
The changelog calls this
an adoption view. It tells
you whether the scan is
on. It does not tell you
what the scan found, or
that anyone read the
result. An agent that
treats “AI reviewed the
PR” as a fact needs the
coverage row for that
repository first. A
missing enablement is a
missing tool, not a clean
bill.
Check the coverage row
before you cite the scan.
Enabled is a switch. It is
not a review.
Source:
Code scanning AI Scan enablement status in security overview — GitHub Changelog, 6 October 2026