Echart Skill

EChart Data Analysis Skill

Use this skill to turn structured data into evidence-backed analysis and standalone ECharts deliverables. The invariant is not “an HTML file exists”; it is that the data, metric definition, analysis claim, visual expression, and live browser result all reconcile.

Required pipeline

Follow these stages for every analysis. Read only the references needed for the requested deliverable.

1. Resolve data and business scope
   • Inspect schema with maintained CLIs; do not load large tables into context.
   • Run python scripts/metrics_manager.py effective before defining metrics, filters, governed entity sets, comparison scope, or business terminology.
   • Never invent fields or approximate a governed set with keyword matching.
2. Assess data fitness
   • Check date coverage, incomplete periods, nulls, duplicates, grain, uniqueness, units, currency, timezone, status filters, and known exclusions.
   • Use scripts/data_quality.py or scripts/data_contract.py when relevant.
3. Query through the audited execution path
   • Generate reviewable SQL and execute it with scripts/sql_runner.py, scripts/db_cli.py, or scripts/db_manager.py.
   • Never write temporary database connection code, heredoc Python, duckdb.connect, psycopg.connect, pymysql.connect, create_engine, .cursor(), or cur.execute().
   • Write query results with --out so query hash and lineage metadata exist.
4. Plan the analytical expression
   • Read analysis expression quality.
   • Write an analysis-plan JSON and run python scripts/validate_analysis_plan.py <plan.json>.
   • Use Message → Relation → View. Select views through references/chart_capabilities.json or python scripts/chart_capabilities.py <view-request.json>.
   • Distinguish the hidden audit/source table from a visible analytical companion table.
5. Bind evidence instead of restating it
   • Read workflow_specs/artifact_evidence_contract.md.
   • Create a draft artifact manifest that references actual query result files.
   • Run python scripts/artifact_manifest.py bind <output.html> <draft.json>.
   • The binder computes query-result SHA-256, row count, date coverage, and binds query hashes, metric/scope fingerprints, comparisons, charts, and findings into the HTML.
6. Render from maintained recipes and templates
   • Read references/examples/INDEX.md, then the selected recipe completely.
   • Dashboard: read workflow_specs/dashboard_workflow.md and workflow_specs/dashboard_runtime_quality.md.
   • Report: read workflow_specs/report_workflow.md.
   • Use workflow_specs/html_templates/dashboard_light.html or workflow_specs/html_templates/report_light.html as the relevant shell.
7. Run the complete delivery gate
   • Run python scripts/validate_delivery.py <output.html>.
   • This combines static ECharts/runtime checks, governance checks, manifest reconciliation, and a real Playwright/Chromium render.
   • Any console error, page error, external request, missing ECharts instance, zero-size canvas/SVG, evidence mismatch, or invalid comparison blocks delivery.
   • --allow-static-only is a degraded exception only when browser execution is genuinely unavailable; disclose that reduced assurance.

SQL execution contract

Preferred examples:

python scripts/schema_manager.py show <table>
python scripts/sql_runner.py --db workspace.duckdb --file queries/<task>.sql \
  --output json --out outputs/query_results/<task>.json
python scripts/sql_runner.py --profile <profile> --file queries/<task>.sql \
  --output json --out outputs/query_results/<task>.json

For one-off external connections, pass credentials only through approved environment-backed CLI parameters such as --password-env or --dsn-env. Project queries, connection profiles, outputs, logs, and generated packages are local state and must never be added to the reusable skill release.

Comparison and metric correctness

All YoY, QoQ, MoM, WoW, period, and cohort comparisons must declare:

• current and baseline start/end;
• complete or partial status;
• latest complete period;
• calendar type: calendar, fiscal, retail 4-4-5, or custom;
• alignment rule and comparability;
• visible current/baseline labels;
• evidence query IDs and metric IDs;
• identical current/baseline fingerprints for metric definition, entity scope, filters, unit, currency, and timezone.

YTD-versus-full-year and partial-versus-complete comparisons are blocking failures. Fiscal and retail calendars align governed named periods rather than being forced onto calendar-month boundaries.

An HTML comparison must contain both analysis-comparison-contract and analysis-artifact-manifest. The declared windows must match each other and the actual dates in the bound query result files.

Findings and analytical depth

Every major finding must state What, baseline, Why status, Why, So what, next check, evidence references, and limitations.

• tested: allowed only when the artifact manifest references an executed next check query.
• hypothesis: a plausible explanation that still needs testing.
• unknown: insufficient evidence; state the missing data.

Correlation, ranking, trend, anomaly, and composition detectors produce descriptive candidates, not causal conclusions. Drill down through contribution, segment, volume × rate/price, anomaly/data-quality, and stability/sample-size checks when the data supports them.

Visual and table contract

• Prefer position and length encodings over angle, area, volume, and decorative effects.
• A pie chart is limited to 2–3 positive categories and approximate share.
• Use a visible companion table for exact lookup, high-density comparison, exceptions, risk/action lists, or four-plus measures.
• Every chart still needs a default-hidden 查看数据 source table, chart-level statistical scope, data source, and evidence/query reference.
• Include units, readable labels, semantic colors, responsive sizing, and a text/table fallback. Do not rely on color alone.
• Do not invent a product, brand, industry label, or title that is absent from the request, governed scope, schema, and evidence.
• Mixed bar/line charts with different units or magnitudes require separate y-axes and explicit yAxisIndex: 0 / yAxisIndex: 1 assignment.

Standalone HTML and runtime contract

• Inline ECharts and required local assets; no CDN, runtime loader, fetch() to external URLs, iframe/object/embed, self-navigation, or file:// nesting.
• Load libraries before chart bootstrap. Use literal </script> closing tags.
• Serialize data with json.dumps(..., ensure_ascii=False, default=str); never hand-write large JavaScript data objects or call JSON.parse({...}).
• Use real responsive chart dimensions and resize handling.
• Dashboard runtime rules cover map registration including accidental chinaGeoJSON references, PDF export compatibility including color-mix(), card/grid density, data-table controls, and export/download behavior.

Routing references

When adding a reusable dashboard expert, start from workflow_specs/dashboard_expert_library/DASHBOARD_EXPERT_TEMPLATE.md; never place a project-specific dashboard or query in the skill.

Release hygiene

Run:

bash package.sh
python scripts/validate_release_package.py dist/<package>.zip

The package uses an allowlist. Project SQL, database connection files, outputs, logs, caches, tests, and local indexes are forbidden release content.