The live socket never made a REST call, so the seven-day refresh
token expired while the chart still looked fine. A deploy then
could not log in. Ping user preferences every six hours, and when
the grant is already dead offer a one-click reconnect that writes
the token on the existing callback.
Trendlines project into the whitespace beyond the newest candle, but the time
axis stopped there, so a converging pair could be seen without knowing when it
converges. Lightweight Charts only labels times present on its scale, so the
chart now carries whitespace points past the last bar: no value, nothing drawn,
but the axis has something to label and timeToCoordinate answers out there.
Future times repeat the most recent bar interval, which is what timeAtIndex
already does for the projections themselves. That drifts across the daily halt
and the weekend; agreeing with the projected line matters more than abstract
accuracy, and session-accurate projection needs server-side session rules the
client does not have.
Two bugs surfaced while measuring it. Padding meant to be five bars measured as
sixty-seven, because the interval came from the gap between the final two bars;
barInterval now takes a median over recent bars and ignores a ragged tail.
And that gap was two seconds on a one-minute chart because Yahoo stamps its
in-progress candle with the time of the request, while the poller emitted
anything newer than the last thing it sent. Every poll therefore appended a new
"1m" bar seconds after the previous one, interleaved with the real ones — live
in production, which is still on Yahoo. Timestamps are bucketed on parse, and
the final candle is emitted unclosed so it revises the current minute rather
than entering the aggregator and adding its volume to every higher timeframe
again on each poll. Verified live: eight consecutive bars, all aligned, all
sixty seconds apart.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Two faults, both introduced by the tick feed, both visible as a huge bar that
flattened the price scale.
A LEVEL_ONE_FUTURES update arrived carrying LAST_PRICE: 0. The parser rejected
None, but 0 is not None, so a minute opened at zero — o=0.0 h=7777.25 l=0.0 —
and provisional_higher carried that low into 5m, 15m, 30m, 1h and the daily bar.
Non-positive prices are treated as absent now, so the last real price carries
forward and the update still counts as the trade it is.
Separately, store.put replaced a bar only when it matched the tail. That was
sufficient while one closed bar arrived per minute, but ticks open the next
minute before CHART_FUTURES delivers the previous one, so the exchange's own bar
stopped matching the tail and was silently dropped — leaving the tick-built
approximation, with its partial volume, in place permanently. put now searches
back a bounded number of buckets for the one it belongs to, and refuses to let a
provisional bar overwrite a settled one.
Tests cover all three invariants: a zero price parses as a trade with no price,
a late closed bar replaces its bucket and keeps the exchange's volume, and a
tick cannot overwrite a settled bar.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Two things kept the chart quieter than the feed.
Higher timeframes only moved once a minute. Tick bars are 1m and the socket
filters bar events by the subscriber's timeframe, so on the hourly chart every
tick was discarded and only a closed minute passing through the aggregator
showed up. They cannot simply be fed to the aggregator — it accumulates with
current.v += incoming.v, so the same forming minute re-sent on each tick would
add its volume to every higher timeframe again and again. provisional_higher
combines the aggregator's committed state with the live minute instead, without
mutating it; the next closed minute goes through normally and replaces the
result, because the store keys on the bucket timestamp. A test pins the
behaviour: five ticks in one minute leave the hour's volume at closed plus live,
counted exactly once.
Trades known only by their volume were skipped. Level 1 resends only changed
fields, so some trades carry a trade stamp and a moved TOTAL_VOLUME with neither
LAST_PRICE nor LAST_SIZE. Those now count, with size left at zero rather than
guessed from the volume delta — CHART_FUTURES replaces the minute's volume with
the exchange's own figure moments later, and two ways of counting the same
trades is how double counting starts. Measured: 66 to 74 updates per 90s.
The tick throttle drops to 0.25s, which no longer binds. Measured in regular
hours the gaps between updates are whole multiples of 1.005s — 2.01, 3.02,
4.03 — which is Schwab conflating LEVEL_ONE_FUTURES to one update per second
per symbol. One per second is the source's ceiling, not ours; the longer gaps
are seconds in which their feed carried no trade.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
The candle still paused for ten to twenty seconds at a time. Instrumenting the
raw Level 1 stream settled why: 87 messages in 90 seconds, only 33 carrying
LAST_PRICE. Most of the remainder is bid and ask movement, correctly ignored,
but a seventh carry LAST_SIZE, TRADE_TIME_MILLIS and TOTAL_VOLUME with no
LAST_PRICE — trades that printed at the price of the one before, so the field
did not change and Level 1 did not resend it.
Requiring LAST_PRICE discarded those trades and their volume with them.
parse_level_one now recognises size-plus-trade-time as a trade and returns a
null price, which stream() fills from the forming bar. A quote carrying neither
a price nor any trade field is still skipped: a bid is not a trade and must not
extend a candle's high or low.
Measured on the live feed: median gap between updates 3.1s to 2.0s, worst gap
21.5s to 8.1s, roughly 9 updates a minute to 22, and bar volume climbs within
the minute instead of standing still.
The pauses that remain are the market rather than the pipe. Thin pre-open tape
goes seconds without a price-changing trade and then moves several ticks at
once, which is what a gap up after a quiet spell is.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
CHART_FUTURES emits a bar only once its minute is over, so the chart stepped
once a minute and sat still in between, which reads as a dead feed.
LEVEL_ONE_FUTURES carries real trades on the same socket and the same login — no
extra REST call, no extra rate limit — and reports delayed: False on this
account. It was verified back in M6 and never subscribed to. It is now, building
a forming bar for the current minute that the authoritative CHART_FUTURES bar
then supersedes.
Three constraints shaped it, each a real bug avoided:
- Tick bars never reach the aggregator. It accumulates with current.v +=
incoming.v, so re-sending the same forming minute would add its volume into
every higher timeframe again on every update. Runtime.on_bar returns early for
an unclosed bar: store, set price, broadcast, stop.
- Emissions are throttled, SCHWAB_TICK_SECONDS default 1.0, because /ES trades
many times a second and each emission is a store write plus a broadcast to
every open socket. Negative drops the Level 1 subscription entirely.
- A tick for a minute CHART_FUTURES has already closed is dropped, or a late
trade would overwrite a settled exchange bar with a partial one.
Bid-only updates are skipped rather than carried forward: a bid is not a trade
and must not extend a candle's high or low. Alerts stay on closed bars — a level
is judged on a settled bar, not a price that may not last the minute — which
needed no change, since on_bar already gated on closed.
Verified against the live socket: 15 forming bars and 2 closed bars in 100
seconds, the closed bar superseding each forming minute. Verified in a browser:
the last candle's high and low visibly extend within the minute, no console
errors. 85 tests pass, four of them new.
The plan gains the cold-restart options asked for: make seeding non-quadratic
first, then persist cooldowns, then persist bars.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Verified against a live account before and after writing it. CHART_FUTURES
delivers one true-OHLCV minute bar per symbol per minute, LEVEL_ONE_FUTURES
reports delayed: false, and consecutive bars arrived sixty seconds apart through
the production code path.
Yahoo stays. Schwab serves no futures history whatever, so seed_source resolves
to Yahoo even when SEED_SOURCE=schwab is asked for — the pairing is the intended
configuration rather than a fallback. The symbols differ, ES=F against /ES, so
Settings.live_symbol picks the live one while seeding always uses Yahoo's.
Three findings worth keeping, each of which cost a round trip:
- get_quote() singular returns the wrong instrument entirely. It puts the symbol
in the URL path, where the leading slash is normalised away, so /ES resolves to
Eversource Energy at $72 and returns HTTP 200 with a populated body. Only
get_quotes() plural, which passes symbols as a query parameter, returns the
future. A 200 is not evidence; assetMainType is.
- Streaming requires the Accounts and Trading product. StreamClient.login() reads
/trader/v1/userPreference for its socket URL, and that path does not exist in
Market Data Production.
- /ES resolves to the active contract on Schwab's side, so the contract roll
handling the plan left open needs no code.
The stream drops the oldest queued message rather than stalling the socket, and
surfaces a dead pump task instead of waiting forever on a queue nothing fills.
schwab-py moves into requirements.txt, imported only when LIVE_SOURCE=schwab.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
