nika: v1
workflow:
  id: bookmark-triage
  description: "URL list → per-page metadata fan-out (dead links survive) → one markdown triage table"

vars:
  bookmarks:
    type: array
    default:
      - "https://example.com"
      - "https://github.com/supernovae-st/nika"
      - "https://this-domain-does-not-exist-0000.invalid" # the dead one · the recover path IS the demo
    description: "The saved-links pile to triage"

permits:
  exec: false
  net:
    http: ["example.com", "github.com", "this-domain-does-not-exist-0000.invalid"]
  fs:
    write: ["out/**"]
  tools: ["nika:fetch", "nika:jq", "nika:write"]

tasks:
  # The fan-out · one metadata fetch per URL · a dead link recovers to a
  # marker object (the batch NEVER dies at bookmark 14).
  pages:
    for_each: ${{ vars.bookmarks }}
    max_parallel: 3
    fail_fast: false
    retry: { max_attempts: 2, backoff_ms: 500 } # a transient blip retries BEFORE the dead verdict
    on_error:
      recover: { dead: true } # a YAML value, not a JSON string — the marker row
    invoke:
      tool: "nika:fetch"
      args:
        url: "${{ item }}"
        mode: metadata

  # The fan-in · zip results back to their URLs · split live from dead.
  table:
    with:
      pages: ${{ tasks.pages.output }}
    invoke:
      tool: "nika:jq"
      args:
        input:
          urls: ${{ vars.bookmarks }}
          pages: ${{ with.pages }}
        expression: >-
          def esc: tostring | gsub("\\|"; "\\|") | gsub("\n"; " ");
          ([.urls, .pages] | transpose | map({ url: .[0], page: .[1] })) as $rows |
          {
            live: ([$rows[] | select(.page.dead != true) |
              "| \(.url) | \(.page.title // "—" | esc) | \((.page.description // "—" | esc) | .[0:80]) |"] | join("\n")),
            dead: ([$rows[] | select(.page.dead == true) | "| \(.url) | DEAD | link rot |"] | join("\n"))
          }

  report:
    with:
      table_live: ${{ tasks.table.output.live }}
      table_dead: ${{ tasks.table.output.dead }}
    invoke:
      tool: "nika:write"
      args:
        path: out/bookmarks.md
        create_dirs: true
        content: |
          # Bookmark triage

          | url | title | description |
          | --- | --- | --- |
          ${{ with.table_live }}
          ${{ with.table_dead }}

          *Generated by [nika](https://nika.sh) — dead links survived the batch (`on_error: recover:`).*

outputs:
  table:
    value: ${{ tasks.table.output }}
    description: "Live rows + dead rows · the triage split"

{"a":{"graph_format":2,"workflow":"bookmark-triage","nodes":[{"id":"pages","verb":"invoke","tool":"nika:fetch","fan_out":{"kind":"expression"},"permits":["tool: nika:fetch"]},{"id":"table","verb":"invoke","tool":"nika:jq","permits":["tool: nika:jq"]},{"id":"report","verb":"invoke","tool":"nika:write","permits":["fs.write: out/bookmarks.md","tool: nika:write"]}],"edges":[{"from":"pages","to":"table","kind":"value"},{"from":"table","to":"report","kind":"value"},{"from":"table","to":"report","kind":"value"}]},"engine":"0.105.0"}

showcase · tier 2 · research

Bookmark triage

One metadata fetch per URL (retry for blips, recover for dead links), then jq renders the triage table.

The pile becomes a sortable table. Dead links say dead instead of killing the batch. · conformance-gated in nika-spec ↗ · re-proven at every push

The whole file

3 tasks · 3 waves · the plan falls out of the bindings, nothing is scheduled by hand.

t2-bookmark-triage.nika.yamlsource

1nika: v12workflow:3  id: bookmark-triage4  description: "URL list → per-page metadata fan-out (dead links survive) → one markdown triage table"56vars:7  bookmarks:8    type: array9    default:10      - "https://example.com"11      - "https://github.com/supernovae-st/nika"12      - "https://this-domain-does-not-exist-0000.invalid" # the dead one · the recover path IS the demo13    description: "The saved-links pile to triage"1415permits:16  ▷exec: false17  net:18    http: ["example.com", "github.com", "this-domain-does-not-exist-0000.invalid"]19  fs:20    write: ["out/**"]21  tools: ["nika:fetch", "nika:jq", "nika:write"]2223tasks:24  # The fan-out · one metadata fetch per URL · a dead link recovers to a25  # marker object (the batch NEVER dies at bookmark 14).26  pages:27    for_each: ${{ vars.bookmarks }}28    max_parallel: 329    fail_fast: false30    retry: { max_attempts: 2, backoff_ms: 500 } # a transient blip retries BEFORE the dead verdict31    on_error:32      recover: { dead: true } # a YAML value, not a JSON string — the marker row33    ◆invoke:34      tool: "nika:fetch"35      args:36        url: "${{ item }}"37        mode: metadata3839  # The fan-in · zip results back to their URLs · split live from dead.40  table:41    with:42      pages: ${{ tasks.pages.output }}43    ◆invoke:44      tool: "nika:jq"45      args:46        input:47          urls: ${{ vars.bookmarks }}48          pages: ${{ with.pages }}49        expression: >-50          def esc: tostring | gsub("\\|"; "\\|") | gsub("\n"; " ");51          ([.urls, .pages] | transpose | map({ url: .[0], page: .[1] })) as $rows |52          {53            live: ([$rows[] | select(.page.dead != true) |54              "| \(.url) | \(.page.title // "—" | esc) | \((.page.description // "—" | esc) | .[0:80]) |"] | join("\n")),55            dead: ([$rows[] | select(.page.dead == true) | "| \(.url) | DEAD | link rot |"] | join("\n"))56          }5758  report:59    with:60      table_live: ${{ tasks.table.output.live }}61      table_dead: ${{ tasks.table.output.dead }}62    ◆invoke:63      tool: "nika:write"64      args:65        path: out/bookmarks.md66        create_dirs: true67        content: |68          # Bookmark triage6970          | url | title | description |71          | --- | --- | --- |72          ${{ with.table_live }}73          ${{ with.table_dead }}7475          *Generated by [nika](https://nika.sh) — dead links survived the batch (`on_error: recover:`).*7677outputs:78  table:79    value: ${{ tasks.table.output }}80    description: "Live rows + dead rows · the triage split"81

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

3 declared edges · 3 waves · the plan falls out of the bindings

try itopen in the playground guidethe walkthrough · docs verbinvoke toolnika:fetch toolnika:jq toolnika:write