Lint and error codes

Every lint rule id and runtime error code Chartnaut reports for scripts, with its severity and the fix. Look up the id shown in the builder's Problems list or in an agent's tool result, fix the line, and lint again.

How to read this page

error blocks the save, the preview or the run. warn is advisory: the script runs, but the result is worse or will surprise someone.
Where says which script type the rule checks: I indicator, D definition, S study. Some rules have a different severity per type; the table says so.
The indicator lint runs in the builder and in the agents' lint_indicator tool, so a person and an agent see the same findings. A definition is linted by the same rule set on save and by the Definition authoring agent.
A few problems throw without a rule id. The common ones are listed in the last section of this page.

Sandbox

Id	Severity	Where	Fix
`caps/forbidden-dsl`	error	D	Remove the blocked call: `document.`, `window.`, `eval()`, `new Function()`, `phenomena.find()`, `ICT.`, `composition.`, or an inline function inside `dialog({ settingsValidator })` (use `validatorId`).
`caps/no-async`	error	D, S	Scripts are synchronous. Remove `await`, `async function`, `setTimeout`, `setInterval`, `requestAnimationFrame`, `queueMicrotask` and `new Promise`.
`caps/no-network`	error	D, S	Remove `fetch`, `XMLHttpRequest`, `WebSocket` and `navigator.sendBeacon`. Read data through declared dependencies.
`caps/non-deterministic`	error	D, S	Replace `Date.now()`, `new Date()`, `performance.now()` and `crypto.randomUUID` with the bar's own time (`ctx.time`, or the event time in a study).
`caps/no-imports`	error	D	Replace `require()` with a relative ESM `import` from another file in the same definition.
`caps/unbounded-loop`	warn	I	`while (true)` or `for (;;)` needs an explicit `break`. Prefer a bounded loop.

Files, modules and entry

Id	Severity	Where	Fix
`bundle/no-files`	error	D, S	Add a file.
`bundle/no-entry`	error	D	Mark one file as the entry (`role: "main"`) and check its path.
`bundle/multiple-main`	error	D	Keep exactly one `role: "main"` file.
`bundle/no-entry-meta`	error	D, S	Put `meta({...})` in the entry file.
`bundle/duplicate-path`	error	D	Two files share a path. Rename one.
`bundle/multi-file`	error	S	Studies are one file. Merge helpers into `study.js`.
`bundle/no-on-event`	error	S	Declare `export function onEvent(ctx, scope)`. Without it the run produces no rows or results.
`bundle/scope-duplicate`	error	S	The study exports `scope()` more than once. Export it once.
`bundle/scope-and-scope-event`	error	S	The study exports `scope()` and also calls `ctx.scopeEvent()`. `scope()` returns the event's scope tuple, so remove the `ctx.scopeEvent` call.
`bundle/scope-in-trade-study`	error	S	Trade studies group by trade and never export `scope()`. Group trades in `onPosition` and `onFinish`.
`bundle/empty`	error	S	The study bundled to nothing. Check the file has code.
`meta/entry-only`	error	D	Move `meta()` into the entry file.
`runtime/onbar-required`	error	D	The entry file must declare `export function onBar(ctx)`.
`runtime/onbar-entry-only`	error	D	Only the entry file exports `onBar`. Export helpers as plain functions and call them from it.
`runtime/onbar-multiple`	error	D	More than one file exports `onBar`. Keep the entry's.
`runtime/no-onbar`	warn	D	No file exports `onBar`, so the preview runs and emits nothing.
`modules/bare-import`	error	D	Package imports are not supported. Use a relative path such as `./levels.js`.
`modules/missing-extension`	error	D	Write the extension: `./levels.js`, not `./levels`.
`modules/cjs-extension`	error	D	`.cjs` files are not supported. Use `.js` or `.mjs`.
`modules/path-escape`	error	D	The path leaves the definition's folder. Keep imports inside it.
`modules/unresolved-import`	error	D	The imported file does not exist. Fix the path or add the file.
`modules/import-cycle`	error	D	Two files import each other. Move the shared code into a third file.
`modules/parse-error`	error	D	Syntax error in a module. The message names the file and position.
`modules/unsupported-export`	error	D	Export with `export const` or `export function`. Default exports and live bindings are not supported.
`modules/top-level-await`	error	D	Remove `await` at module scope.
`modules/dynamic-import`	error	D	Replace `import()` with a static relative import.
`modules/unreachable-file`	warn	D	Nothing imports this file from the entry, so it never runs. Import it or delete it.
`derive/no-meta`	error	D, S	Add a `meta({...})` call.
`derive/multiple-meta`	error	D, S	Keep one `meta({...})`. Only the first is used.
`derive/eval`	error	D, S	The script threw while its declarations were read. The message is the thrown error.
`derive/compile`	error	D, S	The script did not compile. Fix the syntax error in the message.
`derive/settings-dialog`	error	D, S	The settings declarations are invalid. The message names the input.
`derive/flows-missing`	error	S	`flows.declare(...)` is in the source but no flow was derived. Usually a syntax error above it.
`derive/timeframes`	error	D	Saving could not work out the definition's timeframes. Fix the `tf/*` errors first.
`derive/deps`	error	D	A declared dependency cannot be read by your account. Pick one you own or one that is public.
`settings/dialog-required`	error	D	The definition declares inputs but no `dialog(...)`, so the inputs reach nothing. Add `dialog({ title })`.

Meta, settings and data source

Id	Severity	Where	Fix
`meta/missing-name`	warn	D	Give `meta({ name })` or `shortName`.
`meta/kind-mismatch`	error	D	`meta({ kind })` must match the definition's kind. Use `kind: "flow"`.
`meta/window-is-run-window`	warn	D	`meta({ window })` describes which bars to compute over. That option is `runWindow`; `window` takes `{ on }`.
`meta/timeframe-deprecated`	warn	D	Replace `window: { timeframe }` with timeframe handles.
`meta/timeframes-deprecated`	warn	D	Drop `window: { timeframes }`. Timeframes are inferred from `timeframe(...)` handles.
`meta/timeframes-empty`	error	D	The legacy `timeframes` list is empty. Remove it.
`meta/timeframes-unknown`	error	D	The legacy `timeframes` list has an unknown timeframe. Remove it.
`meta/timeframes-not-multiples`	warn	D	A higher timeframe is not a whole multiple of the lowest. Buckets will misalign.
`meta/run-on-empty`	error on I, warn on D	I, D	`runOn: []` allows nothing. Omit `runOn` or list at least one timeframe.
`meta/run-on-unknown-tf`	error	I, D	`runOn` lists a timeframe Chartnaut does not know. Use `1m`, `5m`, `15m`, `30m`, `1h`, `2h`, `4h`, `1d` or `1w`.
`meta/data-source-invalid`	error	I, D	`dataSource.type` must be `"candles"` or `"volume-candles"`; `purgeStrategy` must be `"floor-aware"`, `"max-bars"` or `"session-daily"`.
`meta/volume-candles-purge-required`	error	I, D	`dataSource: { type: "volume-candles" }` needs `settings: { purgeStrategy: "floor-aware" }`. The string form `dataSource: "volume_candles"` needs no settings.
`runtime/price-levels-without-volume-datasource`	warn	I, D	`ctx.volumePriceLevels` needs `meta({ dataSource: { type: "volume-candles", ... } })`. Without it the tape is always `[]`.
`params/unknown-type`	error	D, S	Use a known param type: `number`, `string`, `boolean`, `color`, `timeframe`, `multiSelect`, `range` or `array`. `colour` is spelled `color`.
`params/color-default-invalid`	error	D, S	The color default is not a valid color.
`params/color-alpha-disallowed`	error	D, S	The default has alpha but the param does not set `allowAlpha`.
`params/string-looks-like-color`	warn	D, S	A string param has a color default. Use `type: "color"` to get a picker.
`outputs/color-from-undeclared`	error	D	`colorFrom` names a setting that `meta.params` does not declare.
`outputs/color-from-not-color`	error, or warn for a string param	D	`colorFrom` must name a `color` param.
`settings-validator/unknown-id`	warn	I	`dialog({ settingsValidator: { validatorId } })` names no registered validator. The message lists the known ids.
`settings-validator/unknown-gate`	warn	I	Use a known gate: `instrument`, `timeframe`, `chartType`, `assetClass`, `priceRange` or `trigger`.

Timeframes and summaries

Id	Severity	Where	Fix
`tf/security-removed`	error	I, D	`ctx.security(...)` and `ctx.tf(...)` in `onBar` were removed. Declare `const h = timeframe("1d")` at module scope and read `h.last`, `h.forming`, `h.bars(n)` or `h.state`. The message carries the rewrite.
`tf/handle-not-module-scope`	error	I, D	Call `timeframe(...)` and `.onBar(...)` at module scope, next to your inputs, not inside a function.
`tf/no-ctx-at-module-scope`	error	I, D	Pass the `input.timeframe` handle itself to `timeframe()`, not `ctx.params.<id>`.
`tf/missing-source`	error	I, D	`timeframe(...)` needs a literal (`"1d"`), `"chart"`, or an `input.timeframe` handle.
`tf/untyped-source`	error	I, D	The argument is not timeframe-typed (a template string, a free variable). Use a literal, `"chart"` or an `input.timeframe` handle.
`tf/use-input-timeframe`	warn on I, error on D	I, D	An `input.select` whose options are all timeframes. Use `input.timeframe({ id, label, default, options })`.
`tf/invalid-input-timeframe`	error	I, D	`input.timeframe(...)` needs an object literal with literal `id` and `default`.
`tf/unknown-option`	error	I, D	The only option is `reads`: `timeframe(tf, { reads: [handle] })`.
`tf/reads-not-a-handle`	error	I, D	`reads` must be an array literal of handles declared above this one.
`tf/reads-forward-reference`	error	I, D	`reads` names a handle declared below. Reorder, or split the state into a third handle.
`tf/undeclared-read`	error	I, D	Inside a handler, `ctx.tf(x)` must pass a handle object that is listed in that handle's `reads`.
`tf/duplicate-handler`	error	I, D	One `onBar` per handle. Merge the two handlers.
`tf/parse-error`	error	I, D	The timeframe analyser could not parse the source. Fix the syntax error first.
`timeframe/no-output-in-handler`	error	I, D	`ctx.plot`, `emit`, `hline`, `range` or `mark` inside a timeframe handler. Keep the value with `ctx.accum` and paint from the chart `onBar`. Also raised at run time.
`timeframe/undeclared-read`	error	I, D	Run-time form of `tf/undeclared-read`.
`timeframe/unknown-option`	error	I, D	Run-time form of `tf/unknown-option`.
`timeframe/reads-not-a-handle`	error	I, D	Run-time form of `tf/reads-not-a-handle`.
`timeframe/reads-unused`	warn	I	A handle lists a read its handler never calls. Drop it or read it.
`flow/unknown-timeframe`	error	D	`timeframe("X")` where X is not a known timeframe or `"chart"`.
`summary/missing-window`	error	I, D	`ctx.summary(tf)` needs a window, e.g. `{ since: "52w" }`.
`summary/untyped-window`	error	I, D	Write the window as an object literal, not a variable or spread. The runtime sizes history from it.
`summary/invalid-window`	error	I, D	Keys are `{ since }` or `{ period, back }`. `since` is `"all"`, a duration, a date or a period name; `back` is a whole number of zero or more.

History window and state

Id	Severity	Where	Fix
`window/warmup-required`	error	I, D	The script keeps state but declares no warmup, so its values would depend on where the run began. Call `warmup(...)` after your inputs: `w.window(length)` for a lookback, `w.ema(length)` or `w.wilder(length)` for smoothing, `w.day()` or `w.span("7d")` for state that resets on a session or calendar boundary, `w.forever()` for state that never forgets (a sum, a count, an all-time high).
`window/warmup-inert`	error	I, D	A warmup is declared and handles exist, but no handle registers an `onBar` handler, so nothing walks it.
`window/declare-with-call`	error	D	A `warmup` or `retain` key inside `meta({ window })`. `window` takes `{ on }`. Declare history with the `warmup(...)` or `retain(...)` call the message names, after your inputs.
`state/never-forgets`	error on I, warn on D	I, D	A running sum, count or high declared with a count means "since the cell began". Declare `warmup((w) => w.forever())`, or reset it on a boundary and declare the span between resets, such as `w.day()`.
`window/forever-on-decaying`	warn	I, D	`w.forever()` on state that only decays fetches the whole cap for nothing. Declare `w.ema(length)` or `w.wilder(length)`.
`window/reset-wants-span`	warn	I, D	The script resets on `ctx.session.isStart` but declares a typed count, which is a different stretch of time on every timeframe. Declare `w.day()`, or `w.span("7d")` for a weekly reset.
`window/decay-under-factor`	warn	I, D	An EMA or Wilder average whose length the lint can read is declared under 30x (EMA) or 50x (Wilder) that length. Declare `w.ema(length)` or `w.wilder(length)`.
`window/clamped-to-cap`	warn	I, D	The declared warmup or retain exceeds your plan's indicator memory on a timeframe and was clamped. The message gives the effective `warmup` and `retain`. Read a higher timeframe or use `ctx.summary` for a longer span.

The state/never-forgets warning on definitions will become an error once the number of existing definitions it would refuse has been measured.

Events and emits

Id	Severity	Where	Fix
`events/missing-id`	error	D	Give `events.declare` an `id`.
`events/missing-intent`	error	D	Give `events.declare` an `intent`, e.g. `"signal"`.
`events/duplicate-id`	error	D	An event id is declared twice across files.
`events/bad-payload-type`	error	D	A payload field type must be `string`, `number`, `boolean`, `object`, `array` or `{ enum: [...] }`.
`events/payload-missing-description`	error	D	Every payload field needs `{ type, description }`. Study agents read the description.
`events/reserved-payload-key`	error	D	Remove `_displayLabel` or `_displaySubtitle` from the payload and pass `label` and `subtitle` in the `ctx.emit` options. Remove `_firedBarTime`: Chartnaut records the bar each event fired on under that key.
`events/unknown-paint`	warn	D	Use `none`, `pin`, `highlight_event_bar`, `highlight_price` or `highlight_event_bar_and_price`.
`events/hidden-paint-explicit`	warn	D	`paint: "none"` hides every emit on the chart. Use `"pin"` unless you want data-only events.
`events/paint-needs-price`	warn	D	Price paints need a numeric `payload.price` or `ctx.emit(..., { price })`.
`events/emit-missing-label`	warn	D	Pass a non-empty `label` in the `ctx.emit` options. At run time an emit without a label is dropped.
`marker/duplicate-paint`	warn	D	The same event is painted by `ctx.emit` and `ctx.mark`. Keep one channel.
`snapshot/schema-mismatch`	error	D	A snapshot schema field has an invalid type.
`snapshots/duplicate-id`	error	D	A snapshot id is declared twice.

Outputs and lifecycle

Definitions use outputs.declare and the outputs/* rules. Indicators use output.* and the output/* rules.

Id	Severity	Where	Fix
`outputs/unknown-id`	error	D	`ctx.<verb>("id")` names an output that `outputs.declare` does not declare.
`outputs/kind-mismatch`	error	D	The paint verb does not match the declared kind, e.g. `ctx.hline` on a `line` output.
`outputs/declared-unused`	warn	D	An output is declared but never painted.
`outputs/hline-missing-time1`	error	D	`ctx.hline(id, price, { time1 })` needs an anchor time: `time1: ctx.time`, or the event's anchor time.
`outputs/invalidate-needs-time1`	error	D	Invalidating hlines need `time1` on every emission.
`outputs/all-needs-distinct-time1`	warn	D	`mode: "all"` with a literal `time1` collapses every emission onto one anchor. Use a per-bar time.
`outputs/invalid-mode`	error	D	`mode` applies to `hline`, `range` and `trendline` only, and must be one that kind allows.
`outputs/missing-mode`	warn	D	Set `mode` explicitly on `hline`, `range` and `trendline`.
`outputs/invalidate-needs-policy`	error	D	`mode: "invalidateOnCustomFunction"` needs `invalidateWhen`. There is no default.
`outputs/invalidate-without-mode`	warn	D	`invalidateWhen` is ignored unless `mode` is `"invalidateOnCustomFunction"`.
`outputs/unknown-invalidate-preset`	warn	D	The preset name is not known for this kind. Use a listed preset or a predicate function.
`outputs/trendline-no-presets`	error	D	Trendlines take a predicate function, never a preset name.
`outputs/event-needs-binding`	error	D	`mode: "invalidateOnEvent"` needs `invalidateOnEvent: "<event id>"`.
`outputs/event-without-mode`	warn	D	`invalidateOnEvent` is ignored unless `mode` is `"invalidateOnEvent"`.
`outputs/unknown-event-binding`	error	D	`invalidateOnEvent` names an event that `events.declare` does not declare.
`outputs/label-mode-invalid`	error	D	`labelMode` is `always`, `onHover`, `onLastBar` or `none`.
`outputs/zindex-not-finite`	error	D	`zIndex` must be a finite number.
`outputs/note-missing-price`	error	D	`ctx.note` needs a numeric `price`.
`outputs/mark-missing-text`	warn	D	Pass `text` to `ctx.mark` when `labelMode` is `always` or `onHover`.
`outputs/range-missing-label`	warn	D	Pass `label` to `ctx.range` when `labelMode` is `always`.
`outputs/trendline-missing-coords`	error	D	`ctx.trendline` needs `time1`, `price1`, `time2` and `price2`.
`output/range-invalidate-needs-policy`	error	I	Same as `outputs/invalidate-needs-policy`, for `output.range`.
`output/range-invalidate-without-mode`	warn	I	Same as `outputs/invalidate-without-mode`, for `output.range`.
`output/range-unknown-preset`	warn	I	Unknown `invalidateWhen` preset on `output.range`.
`output/hline-invalidate-needs-policy`	error	I	Same, for `output.hline`.
`output/hline-invalidate-without-mode`	warn	I	Same, for `output.hline`.
`output/hline-unknown-preset`	warn	I	Unknown `invalidateWhen` preset on `output.hline`.
`output/hline-event-without-mode`	error	I	`invalidateOnEvent` on `output.hline` is ignored unless `mode` is `"invalidateOnEvent"`.
`output/trendline-invalidate-needs-policy`	error	I	`output.trendline` with `invalidateOnCustomFunction` needs a predicate.
`output/trendline-invalidate-without-mode`	error	I	`invalidateWhen` on `output.trendline` is ignored without the mode.
`output/trendline-preset-unsupported`	error	I	Trendlines have no presets. Pass an inline predicate.
`output/trendline-event-without-mode`	error	I	`invalidateOnEvent` on `output.trendline` is ignored without the mode.
`output/expires-required`	error	I	An invalidating output needs `expires`, e.g. `expires: "5d"`, or `"max"` for no expiry.
`output/expires-without-mode`	warn	I	`expires` has no effect unless `mode` is `"invalidateOnCustomFunction"` or `"invalidateOnEvent"`.
`output/invalidate-per-emit-fn`	error	I	`invalidateWhen: fn` on a `ctx.hline`, `ctx.range` or `ctx.trendline` emission cannot be re-checked past the cell that emitted it. Declare the rule on the output and pass per-level numbers through `meta`.
`output/invalidate-predicate-shape`	error	I, D	The predicate reads the wrong shape. It receives `{ bar, entry, history }`, e.g. `({ bar, entry }) => bar.low <= entry.top && bar.high >= entry.bottom`.
`output/invalidate-predicate-ctx-name`	warn	I, D	Rename the predicate argument from `ctx`. Destructure `({ bar, entry, history })`.

On indicators, only the rules the builder classes as advisory are warnings. The trendline and hline-event-without-mode rules are not on that list, so they block.

Layers

Id	Severity	Where	Fix
`layer/no-write-in-renderer`	error	I, D	No `upsert`, `patch`, `seal`, `remove` or `ctx` inside `layout`, `paint`, `paintGL`, `hit`, `autoscale` or `legend`. Write rows from `onBar`, `onRun` or a gesture.
`layer/no-write-in-timeframe-handler`	error	I, D	Write layer rows from the chart `onBar`, not inside a `timeframe(...)` handler.
`layer/upsert-never-called`	error	I, D	Nothing writes to the layer. Call `upsert()` or `patch()` from `onBar` or `onRun`, or add a gesture.
`layer/expires-required`	error	I	A layer that seals rows (`sealWhen` or `sealOn`) needs `expires`.
`layer/rows-in-bar-hook`	warn	I, D	`.rows()` in `onBar` scans every row on every bar. Use `get(key)`, `last()` or `range(t1, t2)`.
`layer/renderer-not-registered`	warn	I, D	The layer has neither `paint` nor `paintGL`, so nothing draws. Fine for a data-only layer.
`layer/escape-hatch`	warn	I, D	`p.all()`, `p.bitmap`, `g.raw` or `g.program` bypasses culling. Budget it.
`outputs/layer-use-output-layer`	warn	I, D	`outputs.declare({ kind: "layer" })` returns no handle. Use `const rows = output.layer({ id, row, derived })`.

Dependencies

Id	Severity	Where	Fix
`indicators/missing-slug`	error	D	`indicators.declare` needs `slug`.
`indicators/missing-as`	error	D	`indicators.declare` needs `as`, the local alias.
`indicators/duplicate-as`	error	D	Each `as` must be unique.
`indicators/legacy-shape`	error	D	Replace `{ id, symbol, args }` with `{ slug, as, version, settings }` and read `ctx.indicators.<as>`.
`indicators/missing-version`	error	D, S	Pin `version` (a positive integer; natives use `1`).
`indicators/unknown-slug`	error	D	No native, scripted indicator or definition has this slug.
`indicators/version-not-found`	error	D	The pinned version does not exist. The message lists the ones that do.
`indicators/cycle`	error	D	The dependency graph loops back to this script.
`indicators/container-series-read`	error	D	Read series by output key: `ctx.indicators.<as>.<outputKey>.value`, never `ctx.indicators.<as>.value`. The message lists the keys.
`flows/missing-version`	error	S	Pin `version` on `flows.declare`.
`study/indicator-missing-version`	warn	S	Server form of the same check: an unpinned indicator floats to the latest version.
`study/flow-missing-version`	warn	S	Server form: an unpinned definition floats to the latest version.
`imports/missing-flow-id`	error	D	`imports.use` needs `flowId`.
`imports/missing-alias`	error	D	`imports.use` needs `alias`.
`imports/duplicate-alias`	error	D	Each import alias must be unique.
`flow/upstream-lifecycle-reimplementation`	error	D	The definition rebuilds zone invalidation that its dependency already has. Read `ctx.indicators.<as>.lifecycle()` instead.
`indicator/native-version-mismatch`	error at run time	D, S	A built-in indicator was pinned to a version other than `1`.

Sessions and ctx use

Id	Severity	Where	Fix
`flow/session-legacy-api`	error	D	`ctx.session.window`, `boundsOf` and `isStart` are not available. Use `ctx.session({ period, open?, close?, tz? })` and `s.didOpen`, `s.didClose`, `s.isOpen`, `s.prev`.
`flow/session-bar-count-gate`	error	D	`ctx.session` takes no `length` or `tf`. Sessions end by clock: gate on `s.didClose`.
`flow/session-bucket-param`	warn	D	A param looks like a bar-count session knob. Use `ctx.session` instead.
`flow/hand-rolled-session-counter`	warn	D	`Math.floor(t / 86400)` day rollover. Use `ctx.session`.
`flow/ctx-fn-as-value`	error	D	`ctx.accum`, `ctx.plot` and the other ctx functions must be called, not stored. A stored function cannot cross to the chart.

Workload

Id	Severity	Where	Fix
`workload/fine-price-step`	warn	I	A loop steps price by `0.01` or finer. On BTC that is tens of thousands of iterations per bar. Use the instrument tick size or a row-size setting.
`workload/price-step-soft`, `workload/price-step-hard`	warn in the dry run	I, D	The projected rows per bar are high (soft) or excessive (hard). Coarsen the row size.
`workload/tpo-zone-size-soft`, `workload/tpo-zone-size-hard`	warn in the dry run	I, D	The TPO zone spans too many ticks. Check the tick size.

Studies

Id	Severity	Fix
`study/no-emit`	error	`ctx.emit` is definition-only. Use `ctx.collect` and `ctx.publish`.
`study/no-snapshot`	error	`ctx.snapshot` is not available in studies.
`study/no-accum`	error	`ctx.accum` is not available. Use `ctx.collected(...)` in `onEvent` for earlier events.
`study/no-timeframe-handles`	error	`timeframe(...)` is not available. Read declared definitions and indicators.
`study/no-priceLevels`	error	The volume-at-price tape is not available. Read upstream events, visuals or `lifecycle()`.
`study/no-events-declare`, `study/no-snapshots-declare`, `study/no-output`, `study/no-outputs-declare`, `study/no-imports`	error	Definition-only DSL. Studies use `flows.declare`, `results.declare` and `ctx.publish`.
`study/forward-bad-opts`	error	`ctx.candles.forward()` takes `minutes`, `bars`, `untilTime`, `stopAt`, `targetAt`, `firstHit` and `atBar`.
`study/window-as-object`	error	`ctx.candles.window()` returns a flat array. Iterate it; there is no `.bars` or `.candles`.
`study/window-absolute-time`	warn	`before` and `after` are seconds relative to the event time, not timestamps.
`study/session-boundsof-arity`	error	`ctx.session.boundsOf(t)` gives the UTC day only. Use `ctx.temporal.containing(t, { period })`.
`study/session-key-not-numeric`	error	`ctx.session.key(t)` is a `YYYY-MM-DD` string. Use `ctx.temporal.containing(t, { period: "day" }).start` for day arithmetic.
`study/ctx-out-of-scope`	error	`ctx` used in a helper that does not receive it, or at module scope. Pass `ctx` as a parameter.
`study/event-flow-branch-mismatch`	error	`ctx.event.flow` is compared to a name that is not a `flows.declare({ as })` alias.
`study/payload-key-undeclared`	error	`ctx.event.payload.<key>` is not in any declared definition's payload.
`study/payload-shape-mismatch`	warn	A published payload is missing keys its result kind needs.
`study/unsafe-multi-output-indicator-access`	error, or warn for an unguarded read	Read `ctx.indicators.<as>.<outputKey>?.valueAt(t)` and guard with `Number.isFinite`.
`study/ranges-not-lifecycle`	error	Do not treat `ranges()` fields such as `closedAt` as lifecycle. Use `.lifecycle()`.
`study/lifecycle-source-missing`	error	Survival or invalidation measurements need `.lifecycle()` or a secondary event join `events({ after, filter })`.
`study/publish-only-in-onFinish`	error	Call `ctx.publish` only in `onFinish`.
`study/collect-not-in-onFinish`	error	`ctx.collect` writes are not allowed in `onFinish`. Read with `ctx.collected()`.
`study/no-event-cursor-in-onFinish`	error	Event-cursor APIs have no clock in `onFinish` and return empty. Measure in `onEvent` and collect the result.
`study/publish-without-declare`	error	Add `results.declare({ id, kind, title })` for the published id.
`study/declare-without-publish`	warn	A declared result is never published.
`study/result-missing-description`	warn	Add a `description` to the result. Forward Insight popovers show it.
`study/missing-answer-prose`	warn	Add a `kind: "prose"` result published with `role: "answer"`.
`study/readout-missing`	warn	Heavy chart results need a compact `readout__*` metric.
`study/publish-looks-indexed`	warn	Rows carry a dimension but the result has no `indexedBy`.
`study/publish-missing-index-column`	error	Rows (or `popover_layout` cells) must include every `indexedBy` column.
`study/publish-missing-declared-column`	warn	A declared column is not set on published rows.
`study/dimension-declare-fields`	error	`dimensions.declare` needs `id`, `title` and `description`.
`study/dimension-invalid-role`	error	`role` is `"scope"` or `"report"`.
`study/dimension-id-unique`	error	A dimension id is declared twice.
`study/scope-required`	error, or warn on a hand edit of a study that groups with `ctx.scopeEvent`	Export `scope(ctx)`: it returns each event's scope tuple from what was known when the event fired, or `null` to leave the event out. It is an error when the study groups nothing, for a new study, and for every agent edit.
`study/scope-return-keys`	error	`scope()` returns a key that is not a declared dimension, or does not return every scope dimension on every path. A tuple built at run time is checked when the study runs.
`study/scope-report-dimension`	error	`scope()` returns a `role: "report"` dimension. Measure the outcome in `onEvent`, collect it and publish it through `indexedBy`.
`study/scope-no-return`	error	`scope()` never returns, or has a bare `return;`. Return the tuple, or `null` to leave the event out.
`study/scope-forward-read`	error for `ctx.candles.forward`, warn for `events({ after })`	`scope()` sees only what was known when the event fired. Read forward bars and later events in `onEvent`.
`study/scope-side-effect`	error	`scope()` calls something that is not available there: `ctx.collect`, `ctx.collected`, `ctx.state`, `ctx.rand`, `ctx.cluster`, `ctx.scopeEvent`, `ctx.publish`, `ctx.popoverLayout`, `ctx.plot`, `ctx.range`, `ctx.mark`, `ctx.hline`, `ctx.note`, `ctx.groupByScope`, `ctx.emit` or `ctx.snapshot`. Measure and record in `onEvent`; use `ctx.previous()` for earlier events.
`study/scope-reads-module-state`	error	`scope()` reads a module variable that other events change. The chart groups one event on its own and would not see it. Derive the group from the event, its past data or `ctx.previous()`.
`study/record-only-in-onEvent`	error	A study without `scope()` calls `ctx.scopeEvent` outside `onEvent`. Move the grouping into `scope(ctx)`.
`study/record-multiple`	warn	A study without `scope()` calls `ctx.scopeEvent` more than once in `onEvent`. Export `scope(ctx)` returning one tuple.
`study/record-unknown-dimension`	error	A study without `scope()` passes an undeclared dimension to `ctx.scopeEvent`.
`study/record-report-dimension`	error	A study without `scope()` passes a `role: "report"` dimension to `ctx.scopeEvent`. It belongs in `indexedBy`.
`study/record-missing-declared-dimension`	error	A study without `scope()` collects rows but its `ctx.scopeEvent` never sets a declared scope dimension.
`study/record-non-canonical-dimension-value`	error	A scope value is not one of the dimension's declared `values`. Display labels go in blocks.
`study/record-without-publish`	warn	A scope dimension is in no result's `indexedBy`.
`study/report-dimension-unused`	warn	A report dimension is in no result's `indexedBy`.
`study/joint-cell-required`	warn	The scope tuple holds two or more scope dimensions, so publish one result indexed by all of them.
`study/bucket-record-without-bucketed-publish`	warn	A study without `scope()` calls `ctx.scopeEvent({ bucket })` with no bucketed result. Declare dimensions and return them from `scope()`.
`study/bucketed-publish-without-bucket-record`	warn	Bucketed results need declared dimensions returned from `scope()` for Forward Insights to match.
`study/dry-run`	error	The Study authoring agent's proposal failed a real run on a preset market. The faults are listed.

Run-time errors

Indicator and definition budgets

A script that goes over a budget stops with <kind> exceeded: <observed> / <limit> and a remedy. Soft limits warn once; hard limits stop the run.

Kind	Limit	Fix
`run_wall_clock`	warn at 2 s, stop at 30 s per calculation	Use less history or do less per bar.
`handler_wall_clock`	5 s in one handler call	Avoid loops over every price tick on every bar.
`loop_iterations`	350,000 per handler; per run it scales with bars, from 2 million to 50 million	Process each higher-timeframe bucket once; use the tick size.
`ctx_calls`	500,000 per handler	Fewer `ctx.plot`, `emit`, `range` and `accum` calls per bar.
`indicator_points`	warn at 500,000, stop at 2,000,000	Emit on transitions only, or use less history.
`emitted_events`	warn at 25,000, stop at 100,000	Tighten emit conditions or declare `oncePer`.
`accum_slots`	warn at 256, stop at 1,024	Reuse fewer `ctx.accum` ids.
`lifecycle_instances`	warn at 2,500, stop at 10,000	Emit fewer persistent ranges, or use `mode: "replace"`.
`collected_rows`	100,000 per key, 500,000 total	Aggregate before collecting.
`payload_size`		Publish smaller payloads.
`layer_rows`	warn at 5,000, stop at 20,000 rows per layer	Seal and remove old rows, or key one row per session.
`layer_bytes`	warn at 4 MB, stop at 32 MB per layer	Coarsen `bins` or `grid` steps, or remove old rows.
`warmup_replay`	warn at 2.5 s, stop at 10 s	Lower the warmup, or keep running sums in handlers instead of arrays.

Layers also stop with frame hooks are read-only when a renderer writes, and pause with paint exceeded the 4 ms frame budget when painting stays slow for three frames.

Emits dropped at run time

A definition's run counts every emit it drops. These are the reasons:

Reason	Cause	Fix
`missing_label`	`ctx.emit` without `label`.	Pass `{ label }`.
`unknown_event_id`	The id has no `events.declare`.	Declare it.
`dedupe_oncePer`	The event's `oncePer` keys matched an earlier emit.	Expected. Widen the keys if you wanted repeats.
`warmup`	The bar was in the warmup. Warmup bars compute state but record no events.	Expected.

Dependency output

Code	Cause	Fix
`dependency_output_unavailable`	A declared dependency produced no value for the output you read.	See Dependency unavailable.

Study run errors

A failed study run reports one of these kinds with a request ID for support.

Kind	Meaning	Fix
`compile_error`	The study did not compile.	Fix the error in the message.
`runtime_error`	The study threw.	Fix the line in the message.
`script_execution_timeout`	One event took longer than 15 s, or `onFinish` or startup took too long.	Do less per event.
`too_many_event_timeouts`	10 or more events timed out in one run.	Do less per event.
`too_many_event_errors`	Events kept throwing.	Fix the first reported error.
`budget_wall_clock`	The run passed 10 minutes.	Use a shorter range or fewer dependencies.
`memory_limit`	The run ran out of memory.	Use a shorter range.
`budget_call_stack`	Recursion deeper than 1,024 calls.	Remove the recursion.
`budget_total_events`	More than 100,000 events.	Use a shorter range or a more selective definition.
`budget_emitted_events`	The definition produced too many events.	Tighten its conditions.
`budget_indicator_points`	An indicator produced too many points.	Use a shorter range or fewer outputs.
`budget_collected_rows`	Too many collected rows.	Collect fewer values.
`budget_annotations`	More than 10,000 chart annotations.	Annotate less often.
`budget_payload`	Results too large.	Publish fewer or smaller results.
`budget_forward_bars`	A forward scan of more than 5,000 bars.	Shorten the forward window.
`budget_kmeans_iterations`, `budget_bootstrap_samples`, `budget_pca_features`	Statistics helper limits: 200 iterations, 100,000 samples, 128 features.	Reduce the size.
`data_query_timeout`	Market data did not load in time.	Try again.
`dependency_failed`	A definition run the study waited on did not finish.	Retry the definition run.
`unsupported_data_type`	The instrument cannot serve data the study needs, such as the volume tape on an FX CFD.	Pick another instrument.
`security_policy_violation`	The script generates code at run time.	Remove `eval` or `Function`.
`capacity_unavailable`	Study execution is busy.	Try again shortly.
`cancelled`	The run was cancelled.
`internal`	Something failed on Chartnaut's side.	Contact support with the request ID.

Scope errors

A problem with one event's scope() call leaves that event out of the study and the run continues. The run lists each error.

Message	Fix
`scope() returned undefined: return the event's scope tuple, or null to leave the event out of the study`	Return on every path.
`scope() returned <value>: return an object of scope dimensions, or null`	Return an object.
`scope() returned "<key>", which is not a declared dimension`	Declare it, or drop it from the tuple.
`scope() returned "<key>", a report dimension (role: "report")`	Measure it in `onEvent` and publish it through `indexedBy`.
`scope() did not return "<key>": every scope dimension needs a value for every event in the study`	Set every scope dimension in every tuple.
`scope() returned "<key>": <reason>`	The value is outside the dimension's declared `values`. Use a canonical value.
`scope threw: <error>`	Fix the line in the error.
`ctx.candles.window({ after }) reads <time>, after the event fired (<time>): ...`	`scope()` read past the bar the event fired on. Read later data in `onEvent`.

A finished run warns with study/pin-cell-count-mismatch when a pin_cell reports an n that differs from the number of events scope() put in that group. Build cells from ctx.groupByScope(rows) so each n counts exactly the events a marker can land in. See scope.

Errors without a rule id

Message starts with	Where	Fix
`meta(...) is required`	I	Add `meta({ shortName, kind })` at the top.
`dialog(...) is required`	I	Add `dialog({ title })`. Indicators always need one.
`output.<kind>: 'id' is required`	I	Give every output an `id`.
`meta({ mode: "once" }) requires an exported onRun(ctx)`	I	Export `onRun`, or drop `mode: "once"`.
`onRun(ctx) requires meta({ mode: "once" })`	I	Add `mode: "once"`, or rename `onRun` to `onBar`.
`meta: window takes { on }`	I	A `warmup` or `retain` key inside `meta({ window })`. Declare it with its own `warmup(...)` or `retain(...)` call after your inputs.
`window.<key> is not an option`	I	`window` takes `{ on }`. Use `runWindow` for the bars a `mode: "once"` script computes over.

PreviousBudgets and limits NextSubscription and billing