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.
Edits autosave to flow.draft.json and nodes.draft/ instead of the files the
engine reads, so the pipeline keeps running the published version until
someone publishes. Every save carries the version it was based on: a second
client editing the same flow is refused with 409 and offered the choice
between their version and its own, rather than silently overwriting.
Draft saves no longer rebuild the pipeline; validation and node status for a
draft come from a throwaway build that never touches live state.
Also fixes a latent bug where an empty state backend is falsy, so Pipeline
quietly built itself a second, private state and left message history empty.
- 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.
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.
Melvin Strobl