Two lint rules + render-time validation built on top of the existing
data-composition-variables schema.
Lint rules (packages/core/src/lint/rules/composition.ts):
- invalid_variable_values_json — host's data-variable-values must parse as
a JSON object. Today the runtime swallows parse failures silently and
falls back to declared defaults, masking typos.
- invalid_composition_variables_declaration — root <html>'s
data-composition-variables must parse as an array of objects with
`id` (string), `type` (one of string/number/color/boolean/enum), `label`
(string), and `default`. Per-entry findings report which fields are
missing or invalid.
Both rules read attributes via a new `readJsonAttr` helper in lint/utils.ts.
The existing `readAttr` regex `["']([^"']+)["']` truncates JSON-in-attribute
values at the first internal quote (e.g. `data-variable-values='{"x":"y"}'`
captures only `{`); `readJsonAttr` alternates double-vs-single-quoted
branches with quote-specific char classes so JSON values round-trip cleanly.
A second helper `findHtmlTag` returns the actual <html> open tag (where
data-composition-variables lives) — distinct from `findRootTag` which
returns the first in-body composition element.
Render-time validation (packages/core/src/runtime/validateVariables.ts):
- validateVariables(values, declarations) returns a structured array of
issues: undeclared keys, type mismatches, enum-out-of-range values.
Pure / sync; works in any environment.
- formatVariableValidationIssue(issue) renders a one-line user-facing
string for CLI output.
- Both exported from @hyperframes/core for studio/tooling reuse.
CLI integration (packages/cli/src/commands/render.ts):
- New --strict-variables flag. Default behavior: print warnings and
continue. With --strict-variables: print warnings then exit 1.
- New `validateVariablesAgainstProject(indexPath, values)` helper:
reads the project's index.html, runs extractCompositionMetadata to
pull the declared schema, validates the CLI's --variables payload
against it. ensureDOMParser polyfill for Node-side parsing (same
pattern as compositions.ts).
Tests:
- 11 new validateVariables unit tests covering happy path, undeclared
keys, type mismatches (string/number/boolean/color/enum), enum range,
multiple-issue aggregation, and formatter output.
- 11 new composition.test.ts cases for both lint rules: parse errors,
shape errors, per-entry validation, unknown types, missing fields,
positive cases.
- 5 new render.test.ts cases for validateVariablesAgainstProject:
no-declarations, happy path, undeclared, type-mismatch, missing-file.
- All 646 core tests + 213 cli tests still green.
Docs:
- docs/packages/cli.mdx — added --strict-variables flag row.
This is PR 3 of a 4-PR stack. PR 4 ships skill/scaffold distribution.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
hyperframes
CLI for creating, previewing, and rendering HTML video compositions.
Install
npm install -g hyperframes
Or use directly with npx:
npx hyperframes <command>
Requirements: Node.js >= 22, FFmpeg
Commands
init
Scaffold a new Hyperframes project from a template:
npx hyperframes init my-video
cd my-video
preview
Start the live preview studio in your browser:
npx hyperframes preview
# Studio running at http://localhost:3002
npx hyperframes preview --port 4567
render
Render a composition to MP4:
npx hyperframes render ./my-composition.html -o output.mp4
lint
Validate your Hyperframes HTML:
npx hyperframes lint ./my-composition
npx hyperframes lint ./my-composition --json # JSON output for CI/tooling
npx hyperframes lint ./my-composition --verbose # Include info-level findings
By default only errors and warnings are shown. Use --verbose to also display informational findings (e.g., external script dependency notices). Use --json for machine-readable output with errorCount, warningCount, infoCount, and a findings array.
compositions
List compositions found in the current project:
npx hyperframes compositions
benchmark
Run rendering benchmarks:
npx hyperframes benchmark ./my-composition.html
doctor
Check your environment for required dependencies (Chrome, FFmpeg, Node.js):
npx hyperframes doctor
browser
Manage the bundled Chrome/Chromium installation:
npx hyperframes browser
info
Print version and environment info:
npx hyperframes info
docs
Open the documentation in your browser:
npx hyperframes docs
upgrade
Check for updates and show upgrade instructions:
npx hyperframes upgrade
npx hyperframes upgrade --check --json # machine-readable for agents
Documentation
Full documentation: hyperframes.heygen.com/packages/cli
Related packages
@hyperframes/core— types, parsers, frame adapters@hyperframes/engine— rendering engine@hyperframes/producer— render pipeline@hyperframes/studio— composition editor UI