nika: v1
workflow:
  id: csv-chart-report
  description: "CSV → aggregate → rendered bar chart + markdown report · offline · deterministic"

vars:
  sales_csv: "./data/sales.csv" # columns · region,revenue (revenue a plain number)

permits:
  exec: false
  fs:
    read: ["data/**"]
    write: ["out/**"]
  tools: ["nika:read", "nika:convert", "nika:jq", "nika:chart", "nika:write"]

tasks:
  raw:
    invoke:
      tool: "nika:read"
      args: { path: "${{ vars.sales_csv }}" }

  rows:
    with:
      raw: ${{ tasks.raw.output }}
    invoke:
      tool: "nika:convert"
      args:
        input: "${{ with.raw }}"
        from: csv
        to: json
        has_header: true

  # Sum revenue per region · a deterministic reduce, no model.
  by_region:
    with:
      rows: ${{ tasks.rows.output }}
    invoke:
      tool: "nika:jq"
      args:
        input: "${{ with.rows }}"
        expression: 'group_by(.region) | map({ region: .[0].region, revenue: (map(.revenue | tonumber) | add) })'

  # The picture · one SVG, its sha lands in the trace.
  chart:
    with:
      by_region: ${{ tasks.by_region.output }}
    invoke:
      tool: "nika:chart"
      args:
        data: "${{ with.by_region }}"
        semantics: { region: category, revenue: usd }
        chart: { type: bar, x: region, y: revenue, title: "Revenue by region" }
        out: out/revenue-by-region.svg

  # The rows as MARKDOWN · a report renders lines, never a JSON blob
  # (region names are user data — the esc guards a `|` in them).
  rows_md:
    with:
      by_region: ${{ tasks.by_region.output }}
    invoke:
      tool: "nika:jq"
      args:
        input: "${{ with.by_region }}"
        expression: >-
          def esc: tostring | gsub("\\|"; "\\|") | gsub("\n"; " ");
          map("| \(.region | esc) | \(.revenue) |") | join("\n")

  # The page · the report references the picture beside it.
  report:
    with:
      rows_md: ${{ tasks.rows_md.output }}
    after:
      chart: succeeded
    invoke:
      tool: "nika:write"
      args:
        path: out/revenue-report.md
        content: |
          # Revenue by region

          ![Revenue by region](revenue-by-region.svg)

          | region | revenue |
          | --- | --- |
          ${{ with.rows_md }}

          *Generated offline by [nika](https://nika.sh) · the chart's sha is in the run trace (`nika trace verify`).*

outputs:
  by_region:
    value: ${{ tasks.by_region.output }}
    description: "Per-region revenue totals · the chart + report render from this"

{"a":{"graph_format":2,"workflow":"csv-chart-report","nodes":[{"id":"raw","verb":"invoke","tool":"nika:read","permits":["tool: nika:read"]},{"id":"rows","verb":"invoke","tool":"nika:convert","permits":["tool: nika:convert"]},{"id":"by_region","verb":"invoke","tool":"nika:jq","permits":["tool: nika:jq"]},{"id":"chart","verb":"invoke","tool":"nika:chart","permits":["fs.write: out/revenue-by-region.svg","tool: nika:chart"]},{"id":"rows_md","verb":"invoke","tool":"nika:jq","permits":["tool: nika:jq"]},{"id":"report","verb":"invoke","tool":"nika:write","permits":["fs.write: out/revenue-report.md","tool: nika:write"]}],"edges":[{"from":"by_region","to":"chart","kind":"value"},{"from":"by_region","to":"rows_md","kind":"value"},{"from":"chart","to":"report","kind":"control"},{"from":"raw","to":"rows","kind":"value"},{"from":"rows","to":"by_region","kind":"value"},{"from":"rows_md","to":"report","kind":"value"}]},"engine":"0.105.0"}

showcase · tier 2 · business

CSV chart report

convert types the spreadsheet, jq aggregates, chart renders a real image, write assembles the report. Zero model calls.

Paste the export, get the slide: same data, same bytes, works on a plane. · conformance-gated in nika-spec ↗ · re-proven at every push

The whole file

6 tasks · 5 waves · the plan falls out of the bindings, nothing is scheduled by hand.

t2-csv-chart-report.nika.yamlsource

1nika: v12workflow:3  id: csv-chart-report4  description: "CSV → aggregate → rendered bar chart + markdown report · offline · deterministic"56vars:7  sales_csv: "./data/sales.csv" # columns · region,revenue (revenue a plain number)89permits:10  ▷exec: false11  fs:12    read: ["data/**"]13    write: ["out/**"]14  tools: ["nika:read", "nika:convert", "nika:jq", "nika:chart", "nika:write"]1516tasks:17  raw:18    ◆invoke:19      tool: "nika:read"20      args: { path: "${{ vars.sales_csv }}" }2122  rows:23    with:24      raw: ${{ tasks.raw.output }}25    ◆invoke:26      tool: "nika:convert"27      args:28        input: "${{ with.raw }}"29        from: csv30        to: json31        has_header: true3233  # Sum revenue per region · a deterministic reduce, no model.34  by_region:35    with:36      rows: ${{ tasks.rows.output }}37    ◆invoke:38      tool: "nika:jq"39      args:40        input: "${{ with.rows }}"41        expression: 'group_by(.region) | map({ region: .[0].region, revenue: (map(.revenue | tonumber) | add) })'4243  # The picture · one SVG, its sha lands in the trace.44  chart:45    with:46      by_region: ${{ tasks.by_region.output }}47    ◆invoke:48      tool: "nika:chart"49      args:50        data: "${{ with.by_region }}"51        semantics: { region: category, revenue: usd }52        chart: { type: bar, x: region, y: revenue, title: "Revenue by region" }53        out: out/revenue-by-region.svg5455  # The rows as MARKDOWN · a report renders lines, never a JSON blob56  # (region names are user data — the esc guards a `|` in them).57  rows_md:58    with:59      by_region: ${{ tasks.by_region.output }}60    ◆invoke:61      tool: "nika:jq"62      args:63        input: "${{ with.by_region }}"64        expression: >-65          def esc: tostring | gsub("\\|"; "\\|") | gsub("\n"; " ");66          map("| \(.region | esc) | \(.revenue) |") | join("\n")6768  # The page · the report references the picture beside it.69  report:70    with:71      rows_md: ${{ tasks.rows_md.output }}72    after:73      chart: succeeded74    ◆invoke:75      tool: "nika:write"76      args:77        path: out/revenue-report.md78        content: |79          # Revenue by region8081          ![Revenue by region](revenue-by-region.svg)8283          | region | revenue |84          | --- | --- |85          ${{ with.rows_md }}8687          *Generated offline by [nika](https://nika.sh) · the chart's sha is in the run trace (`nika trace verify`).*8889outputs:90  by_region:91    value: ${{ tasks.by_region.output }}92    description: "Per-region revenue totals · the chart + report render from this"93

nika inspect · engine 0.105.0 · vendored graph, never re-derived

6 declared edges · 5 waves · the plan falls out of the bindings

try itopen in the playground guidethe walkthrough · docs verbinvoke toolnika:read toolnika:convert toolnika:jq toolnika:chart toolnika:write