The drawing controls lived in a strip above the chart while the lines they
created were listed in the sidebar — two places for one concern, and the strip
cost vertical space the chart wanted.
The sidebar now carries a tool per object, each with its own parameters. A tool
head arms the tool; the gesture happens on the chart:
- Price level: press anywhere, drag to fine-tune, release. A tag follows the
cursor showing the price snapped to the 0.25 tick, and that snapped value is
exactly what gets committed.
- Trendline: press at one end, drag, release at the other. One gesture where it
used to be two separate clicks and a "place first point / place second point"
prompt.
Dragging from the palette itself was the other candidate and was rejected: a
price level is a one-point object and drops cleanly, but a trendline needs two
points, so it would still have wanted a second click afterwards and the two
tools would have behaved differently for no visible reason.
Panning and scaling are suspended while a tool is armed, or the drag that draws
a line also drags the chart out from under it. Arming survives exactly one
placement, so a stray drag afterwards cannot create a second object.
Typing an exact price stays, next to the drag: "somewhere around here" and
"exactly 7800" are different intents and both are cheap to support.
Verified by driving headless Chrome over CDP rather than by reading: arming sets
the class, the live tag reads 7770.75 mid-drag, the committed level is 7770.75
with zero slope, the trendline rubber-bands and saves with a real slope, and
both tools disarm afterwards.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
There was no way to say "tell me when ES reaches 7800". The only user-settable
alert was a drawn trendline, placed by clicking two points on a canvas — so you
could not hit an exact price, and making the line flat was fiddly.
A price alert is a manual line with zero slope. Reusing that rather than
building a parallel concept means it inherits JSON persistence, renaming,
recolouring, deletion, clustering, and the rule that a hand-placed level alerts
whatever its confluence score. The only genuinely new code is the input, an
endpoint that takes a price instead of two anchors, and the decision to render
zero-slope manual lines as price lines — which spans the chart and labels the
axis, instead of drawing a stubby two-point segment.
Zero-slope lines also skip drag handles, hit-testing and the "end line here"
menu: a price line has no endpoints to grab. They are managed from the sidebar.
Unlabelled alerts are named by their price, since "1d resistance" does not say
which alert fired.
Verified live: a level typed 25 points above price clusters as resistance at
that price and stays quiet, as it should until price arrives.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The confluence engine had nothing to work with. Daily moving averages were the
only level source, and they sat 163 to 697 points from price, so every cluster
had exactly one member and no alert could ever fire.
Two new sources, chosen for having a real following — the engine is a bet that
many participants watch the same price, which is what makes a level hold:
- Prior day high/low/close, from the last *closed* daily bar so mid-session the
levels do not silently switch to today's own developing range. Full daily
weight rather than the 0.75 average discount: a traded high is structure, not
a derived average.
- Session VWAP, anchored to the 18:00 ET open like the daily bars. Institutional
execution is benchmarked against it, and zero-volume overnight minutes are
skipped rather than dividing by zero.
Both are stamped 1d, so they get their own colours to stay distinguishable from
the daily averages. Prior-day levels draw as price lines, which span the chart
and label the axis instead of relying on bar-index interpolation.
VWAP re-prices every minute while a daily average carries hundreds of points and
changes once a session, so broadcasting the whole level set on the VWAP cadence
would have pushed the entire history every minute. Levels now go out as a delta
that clients merge by id.
Adding the levels then exposed two defects that had been invisible while nothing
could cluster:
- Cluster identity was sha1(side + round(center / tolerance)), and tolerance
derives from ATR, so it changed every bar. The same zone was continually
issued a new id, never matched the cooldown table, and the cooldown did
nothing. Identity is now the set of converging levels.
- Alert suppression keyed on that identity, so a level drifting in or out of a
group read as a new zone. It now suppresses by proximity: two zones within an
ATR are the same zone, and the strongest is the one reported.
Over six replayed sessions at threshold 28 that is 247 alerts, then 54, then 40;
raising the cooldown to 4h — which only affects repeats of the same area, never
a genuinely new zone — gives 17 total with a worst session of 9.
calibrate_alerts.py now sweeps threshold and cooldown together in one pass,
since the threshold turns out to be quantised and nearly useless as a control.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Five defects found by exercising the running app rather than reading it:
- Backspace inside the sidebar rename field deleted the trendline instead of
a character. The window keydown handler never checked what was focused, so
correcting a typo in a line's name destroyed the line.
- playAlert() built a new AudioContext per alert and never closed it. Browsers
cap a document at roughly six, after which alerts stop making any sound.
One shared context now, with nodes released on end and a resume() for the
autoplay policy.
- Stored layer preferences were used verbatim, so any key added to
defaultPrefs later would be missing for existing visitors. A missing
enabled.ma is a crash rather than a cosmetic gap. They are now deep-merged
onto the defaults, and unparseable state falls back instead of throwing.
- The alert log keyed rows on a second-resolution timestamp, so two alerts in
the same second collided.
- Clusters embedded whole Level objects, including a moving average's entire
point history — hundreds of entries reaching back years. Because clusters
are re-sent on every closed 1m bar, this shipped the whole levels payload
once a minute. Members are now compact summaries and the client joins on
id; Cluster.to_dict() also stops round-tripping through asdict(), which was
deep-copying those arrays before discarding them.
/api/confluence drops from 61,838 to 1,245 bytes with five clusters live.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
