A node's error cleared the moment it ran again, so a failure that genuinely
fired an alert could leave no trace on the canvas by the time anyone looked.
The engine records it now — on the node's status, so it survives a reload and
every client agrees — and reading the traceback is what clears it. The seam is
the event bus, which is where every failing path already meets: a queued live
run, an explicit run, a preview, and a single triggered node all publish
`node_error`, while the controller's own observer would have seen only one of
them.
That was half the confusion. The other half: clicking a failed neuron on Home
often landed on a flow where everything looked fine. Nodes merge into one
neuron by instance key — every InfluxDB node pointing at the same bucket is one
neuron — and the click went to whichever flow contributed a member first, not
the one that failed. It now goes to the failing member and selects it, and the
canvas marks a failing node rather than leaving it to the dot alone.
The inject node emitted one payload to every port it declared, whatever their
types, so an inject on a bool port carrying the text "true" raised at publish
time. Each port gets its own field now, typed and parsed by that port's dtype,
and remembers what it last sent. A port that is renamed carries its value with
it; one that is removed takes its value with it. An inject written before this
keeps emitting exactly what it did.
The derived-cron chip also appeared on the delay node, where `interval` is a
rate limit and a schedule derived from it means nothing.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Uq8mtNb97A7praJLyeEYgs
The socket belonged to whichever hook instance ran its effect first. Passive
effects run children before parents, so on Home that was the brain graph rather
than the shell: navigating to a sibling route unmounted the graph, which closed
the socket, while the shell kept the reference count above zero. From there the
page was deaf for the rest of its life, with nothing left to reconnect it.
A module-level connection with a real refcount replaces it — connect on the
first subscriber, disconnect on the last — and the hook is a thin subscription
with the same signature, correct under StrictMode's mount/unmount/mount.
A 1008 now reconnects instead of returning silently: the token is read afresh
per attempt, and three consecutive rejections fall through to the caller's auth
handler so a revoked session surfaces rather than spins.
The snapshot's emit counts are read into a store of their own, apart from the
live count, so a graph that connects into a busy engine is drawn as busy without
every neuron claiming it just fired. The neuron and edge pulses now key off a
change seen while they were mounted, so returning to Home no longer replays
every emission of the session.
Home gets a live indicator for the case none of this can fix: quiet while the
socket is up, and named in words when it is down, since HTTP polling keeps the
rest of the page looking current.
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01HTsT1isxUjw5gtkJk8WhuA
The worker script is handed to the interpreter by path, so app/flow was
sys.path[0] for every node: `import queue` got the engine's. It now drops
its own directory before anything else imports, and runs with the
deployment's credentials scrubbed out of its environment.
Also: reload builds off the event loop, the pool wakes what is blocked on
it when it stops, a refused metrics flush is kept for the next one rather
than dropped, and the cascade events are paired through failures.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017MeiWk3Yq12n2pTvnQWYvt
A node type can now say which outside thing its parameters point at, and
nodes sharing one — a broker topic, a URL, a bucket — are drawn as a single
neuron on a new /brain canvas. That makes the wiring which runs between
flows through a broker visible for the first time; no single flow's canvas
can show it. The key is read off stored parameters, so a credential
reference never reaches an id.
Layout is a d3 force simulation settled once and then frozen, lit by the
socket the editor already listens to: a neuron pulses when any node behind
it publishes, and its connections light as values pass.
Fixes the message pulse while here: interpolating the stroke against the
edge's `color-mix()` resting colour went through oklab and left the gamut,
which turned every pulse on both canvases fluorescent yellow.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017MeiWk3Yq12n2pTvnQWYvt
A second bus subscriber folds executions, errors, timings and queue lag
into per-minute rollups, keeps failures with their traceback and an audit
trail of who published what, and records one row per cascade — manual runs
and previews included, under an id of their own that writes no idempotency
markers. Read back through /observability/*, which always answers 200 so a
degraded engine still renders its own health screen.
Also fixes two things found on the way: node-health alerts read `status`
where the engine publishes `health`, so a device dropping never alerted
anyone, and the Redis queue reported `parked: 0` whatever was held.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017MeiWk3Yq12n2pTvnQWYvt
Moving a dashboard slider lit up an edge between two nodes that had done
nothing. The canvas pulsed on the message's timestamp alone, and a message
has no idea who published it — so it credited whichever node happened to
be drawn as a producer.
That was never only about dashboards. Two nodes producing one message
pulsed both their edges whichever fired, and a message produced in another
flow changed with nothing on screen to account for it at all.
Values now carry their cause: a node, a dashboard widget, another flow, an
agent or an API caller. An edge pulses only for the producer that actually
published, and the edge inspector says where a value came from when it did
not come from a node.
What is not a node in this flow is now drawn as one — a label rather than
a card, because a dashboard with twenty tiles would otherwise bury the
logic the canvas exists to show. That covers cross-flow wiring too, which
is the link in/out affordance that has been missing.
They are never part of the document. They join at render, after everything
that reads or writes the canvas nodes, so an autosave, an undo or a delete
cannot reach them — with a Playwright test that drags a node and asserts
the stored flow still holds exactly what it did.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_011LF61rxW1FG5YCD2J9YqjY
Flows can now be taken off the engine and put back. Stopped state lives in a
runtime.json beside the flow, not in the flow document: the canvas autosaves
that document, so a stopped flow would otherwise start itself again on the
next edit. A stopped flow gets no subscriptions, schedules or webhooks, its
nodes are skipped by the scheduler, and running it answers 409. Pausing holds
a flow's nodes while its values keep arriving, so the canvas still shows what
is coming in.
Node code is user code and print is how it says things, so stdout is teed
through a contextvar sink active only during a node execution — one event per
execution, capped, so a chatty node cannot outrun the stream. A node that
fails sends its traceback the same way, trimmed to the author's own frames.
The dock gains a logs panel and a pause control; the dashboard replaces its
placeholder with what is running, stopped or failing; the edge inspector can
send the last message again.
Single-stepping is deferred and noted: the scheduler keeps no progress between
calls, so a step button would re-run the same node rather than advance.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
- One dot per node now carries the whole story: primary while running, sage
after a good run, red when anything is wrong, with the explanation on hover.
The corner badge is gone, along with the second way of saying the same thing.
- A node that publishes something flashes a ring, so a running flow is legible
without reading the edge values. Nodes that consume but publish nothing stay
quiet, which is why the event carries an output count.
- Flow settings open in the same panel its nodes use, from a pencil in the
dock: the title, the name, and deleting the flow. NodePanel and FlowPanel
share the panel chrome rather than each drawing their own.
- Renaming is a server operation, because a flow's name is the namespace of its
messages: the directory moves and every other flow reading `old.message` is
repointed, instead of being left pointing at a flow that no longer exists.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016WzrvW7rjQbynnhF6pxh6i
The browser half of M3. Flows open on a full-bleed canvas with their chrome
floating over it: flow tabs top, dock bottom, node settings in a panel on the
right that leaves the graph visible and running behind it.
- Connections are derived, not stored. A node declares the messages it reads
and publishes; every matching pair draws an edge, so two producers of one
message converge on their consumer. Dragging output to input is shorthand
for pointing that input at the producer's message, and asks before it
replaces an existing one.
- Values land on the edges as they flow, over a websocket that feeds a store
outside React, so a value arriving re-renders its own chip and nothing else.
Clicking an edge shows the last payload and when it arrived.
- Node source is edited in Monaco, loaded only when a panel opens and themed
from the design tokens.
- Edits autosave; identical documents are skipped server-side, so a quiet
canvas writes nothing.
- Validation from the API shows on the node it belongs to and is summarised in
the dock, where each entry pans to its node.
- Works on a phone: touch-connect, 44px dock targets, and the node panel
becomes a full-screen sheet.
Two new tokens (--status-success, --font-mono) are mirrored in the website repo
and recorded in DESIGN-GUIDELINES.md.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_016WzrvW7rjQbynnhF6pxh6i
stroblmeandClaude Opus 5