nika: v1
workflow:
  id: release-train
  description: "parallel gates → human GO → hold until the window → ship · verify · record"

vars:
  version:
    type: string
    required: true
    description: "The version to ship (e.g. 1.4.0)"
  window: "2026-07-28T09:00:00Z"

secrets:
  team_webhook:
    source: env
    key: TEAM_WEBHOOK_URL
    egress:                       # sanction the on_finally ping · the secret IS the URL
      - to: "nika:notify"
        host_from_self: true

tasks:
  t0:
    invoke:
      tool: "nika:date"
      args: { op: now }

  # ── the gate wave · all three run in parallel ──
  tests:
    exec:
      command: ["cargo", "test", "--workspace", "--quiet"]
      capture: structured
    timeout: "15m"

  lint:
    exec:
      command: ["cargo", "clippy", "--workspace", "--all-targets", "--", "-D", "warnings"]
      capture: structured
    timeout: "10m"

  audit:
    exec:
      command: ["cargo", "audit"]
      capture: structured
    timeout: "5m"
    retry:
      max_attempts: 2                  # advisory DB fetch can flake

  gates_green:
    with:
      all_green: ${{ tasks.tests.output.exit_code == 0 && tasks.lint.output.exit_code == 0 && tasks.audit.output.exit_code == 0 }}   # three value edges · one boundary expression
    invoke:
      tool: "nika:assert"
      args:
        condition: "${{ with.all_green }}"
        message: "A release gate is RED: the train does not depart"

  gate_time:
    with:
      t0: ${{ tasks.t0.output }}
    after:
      gates_green: succeeded           # state, no data · the timing is only worth taking on a green board
    invoke:
      tool: "nika:date"
      args:
        op: diff
        start: "${{ with.t0 }}"
        end: "now"
        unit: minutes

  # ── the human signs the departure ──
  conductor:
    with:
      gate_time: ${{ tasks.gate_time.output }}
    invoke:
      tool: "nika:prompt"
      args:
        message: "Gates GREEN in ${{ with.gate_time }} min. Ship ${{ vars.version }} in the ${{ vars.window }} window?"
        default: false

  approved:
    with:
      signed: ${{ tasks.conductor.output == true }}   # the signature check crosses as ONE boundary expression
    invoke:
      tool: "nika:assert"
      args:
        condition: "${{ with.signed }}"
        message: "Departure not signed: train cancelled"

  # ── hold until the window · absolute time, not a sleep ──
  hold:
    after:
      approved: succeeded
    invoke:
      tool: "nika:wait"
      args:
        until: "${{ vars.window }}"
        timeout: "48h"

  ship:
    after:
      hold: succeeded
    exec:
      command: ["./scripts/release.sh", "${{ vars.version }}"]   # argv: the interpolation cannot break out
      capture: structured
    timeout: "30m"

  verify:
    after:
      ship: succeeded
    invoke:
      tool: "nika:fetch"
      args:
        url: "https://api.example.com/v1/version"
        mode: jq
        jq: ".version"
    retry:
      max_attempts: 5
      backoff_strategy: exponential
      backoff_ms: 5000

  live:
    with:
      version_live: ${{ tasks.verify.output == vars.version }}   # the whole check crosses as ONE boundary expression
    invoke:
      tool: "nika:assert"
      args:
        condition: "${{ with.version_live }}"
        message: "Prod does not report the shipped version: investigate before announcing"

  # the always-pattern · `after: {live: terminal}` admits every settled
  # state · this task runs whether `live` succeeded, failed, or was
  # cancelled by an upstream abort · a record that must land on EVERY
  # outcome is a terminal task, not a cleanup hook (03 §on_finally).
  record:
    after:
      live: terminal
    with:
      outcome: ${{ tasks.live.status }}   # observe the departure verdict · same pass-set as the after edge
    invoke:
      tool: "nika:emit"
      args:
        event_type: "release.train.departed"
        payload:
          version: "${{ vars.version }}"
          status: "${{ with.outcome }}"
    on_finally:
      - invoke:
          tool: "nika:notify"
          args:
            channel: webhook
            target: "${{ secrets.team_webhook }}"
            message: "Release train ${{ vars.version }} · ${{ with.outcome }}"
            severity: info

outputs:
  shipped: ${{ tasks.verify.output }}

{"a":{"graph_format":2,"workflow":"release-train","nodes":[{"id":"t0","verb":"invoke","tool":"nika:date","permits":["tool: nika:date"]},{"id":"tests","verb":"exec","permits":["exec: cargo"]},{"id":"lint","verb":"exec","permits":["exec: cargo"]},{"id":"audit","verb":"exec","permits":["exec: cargo"]},{"id":"gates_green","verb":"invoke","tool":"nika:assert","permits":["tool: nika:assert"]},{"id":"gate_time","verb":"invoke","tool":"nika:date","permits":["tool: nika:date"]},{"id":"conductor","verb":"invoke","tool":"nika:prompt","permits":["tool: nika:prompt"]},{"id":"approved","verb":"invoke","tool":"nika:assert","permits":["tool: nika:assert"]},{"id":"hold","verb":"invoke","tool":"nika:wait","permits":["tool: nika:wait"]},{"id":"ship","verb":"exec","permits":["exec: ./scripts/release.sh"]},{"id":"verify","verb":"invoke","tool":"nika:fetch","permits":["net.http: api.example.com","tool: nika:fetch"]},{"id":"live","verb":"invoke","tool":"nika:assert","permits":["tool: nika:assert"]},{"id":"record","verb":"invoke","tool":"nika:emit","permits":["tool: nika:emit","tool: nika:notify"]}],"edges":[{"from":"approved","to":"hold","kind":"control"},{"from":"audit","to":"gates_green","kind":"value"},{"from":"conductor","to":"approved","kind":"value"},{"from":"gate_time","to":"conductor","kind":"value"},{"from":"gates_green","to":"gate_time","kind":"control"},{"from":"hold","to":"ship","kind":"control"},{"from":"lint","to":"gates_green","kind":"value"},{"from":"live","to":"record","kind":"control"},{"from":"live","to":"record","kind":"terminal-observation"},{"from":"ship","to":"verify","kind":"control"},{"from":"t0","to":"gate_time","kind":"value"},{"from":"tests","to":"gates_green","kind":"value"},{"from":"verify","to":"live","kind":"value"}]},"engine":"0.105.0"}

showcase · tier 4 · research

Release train

Tests, lint and audit run in parallel. Only if all three are green does a human sign the GO; then it holds for the window, ships, and verifies prod reports the new version.

No green gates, no departure. No human GO, no departure. It ships on time or not at all, and the journal records which. · conformance-gated in nika-spec ↗ · re-proven at every push

The whole file

13 tasks · 10 waves · the plan falls out of the bindings, nothing is scheduled by hand.

t4-release-train.nika.yamlsource

1nika: v12workflow:3  id: release-train4  description: "parallel gates → human GO → hold until the window → ship · verify · record"56vars:7  version:8    type: string9    required: true10    description: "The version to ship (e.g. 1.4.0)"11  window: "2026-07-28T09:00:00Z"1213secrets:14  team_webhook:15    source: env16    key: TEAM_WEBHOOK_URL17    egress:                       # sanction the on_finally ping · the secret IS the URL18      - to: "nika:notify"19        host_from_self: true2021tasks:22  t0:23    ◆invoke:24      tool: "nika:date"25      args: { op: now }2627  # ── the gate wave · all three run in parallel ──28  tests:29    ▷exec:30      command: ["cargo", "test", "--workspace", "--quiet"]31      capture: structured32    timeout: "15m"3334  lint:35    ▷exec:36      command: ["cargo", "clippy", "--workspace", "--all-targets", "--", "-D", "warnings"]37      capture: structured38    timeout: "10m"3940  audit:41    ▷exec:42      command: ["cargo", "audit"]43      capture: structured44    timeout: "5m"45    retry:46      max_attempts: 2                  # advisory DB fetch can flake4748  gates_green:49    with:50      all_green: ${{ tasks.tests.output.exit_code == 0 && tasks.lint.output.exit_code == 0 && tasks.audit.output.exit_code == 0 }}   # three value edges · one boundary expression51    ◆invoke:52      tool: "nika:assert"53      args:54        condition: "${{ with.all_green }}"55        message: "A release gate is RED: the train does not depart"5657  gate_time:58    with:59      t0: ${{ tasks.t0.output }}60    after:61      gates_green: succeeded           # state, no data · the timing is only worth taking on a green board62    ◆invoke:63      tool: "nika:date"64      args:65        op: diff66        start: "${{ with.t0 }}"67        end: "now"68        unit: minutes6970  # ── the human signs the departure ──71  conductor:72    with:73      gate_time: ${{ tasks.gate_time.output }}74    ◆invoke:75      tool: "nika:prompt"76      args:77        message: "Gates GREEN in ${{ with.gate_time }} min. Ship ${{ vars.version }} in the ${{ vars.window }} window?"78        default: false7980  approved:81    with:82      signed: ${{ tasks.conductor.output == true }}   # the signature check crosses as ONE boundary expression83    ◆invoke:84      tool: "nika:assert"85      args:86        condition: "${{ with.signed }}"87        message: "Departure not signed: train cancelled"8889  # ── hold until the window · absolute time, not a sleep ──90  hold:91    after:92      approved: succeeded93    ◆invoke:94      tool: "nika:wait"95      args:96        until: "${{ vars.window }}"97        timeout: "48h"9899  ship:100    after:101      hold: succeeded102    ▷exec:103      command: ["./scripts/release.sh", "${{ vars.version }}"]   # argv: the interpolation cannot break out104      capture: structured105    timeout: "30m"106107  verify:108    after:109      ship: succeeded110    ◆invoke:111      tool: "nika:fetch"112      args:113        url: "https://api.example.com/v1/version"114        mode: jq115        jq: ".version"116    retry:117      max_attempts: 5118      backoff_strategy: exponential119      backoff_ms: 5000120121  live:122    with:123      version_live: ${{ tasks.verify.output == vars.version }}   # the whole check crosses as ONE boundary expression124    ◆invoke:125      tool: "nika:assert"126      args:127        condition: "${{ with.version_live }}"128        message: "Prod does not report the shipped version: investigate before announcing"129130  # the always-pattern · `after: {live: terminal}` admits every settled131  # state · this task runs whether `live` succeeded, failed, or was132  # cancelled by an upstream abort · a record that must land on EVERY133  # outcome is a terminal task, not a cleanup hook (03 §on_finally).134  record:135    after:136      live: terminal137    with:138      outcome: ${{ tasks.live.status }}   # observe the departure verdict · same pass-set as the after edge139    ◆invoke:140      tool: "nika:emit"141      args:142        event_type: "release.train.departed"143        payload:144          version: "${{ vars.version }}"145          status: "${{ with.outcome }}"146    on_finally:147      - ◆invoke:148          tool: "nika:notify"149          args:150            channel: webhook151            target: "${{ secrets.team_webhook }}"152            message: "Release train ${{ vars.version }} · ${{ with.outcome }}"153            severity: info154155outputs:156  shipped: ${{ tasks.verify.output }}157

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

13 declared edges · 10 waves · the plan falls out of the bindings

try itopen in the playground guidethe walkthrough · docs verbinvoke verbexec toolnika:date toolnika:assert toolnika:prompt toolnika:wait toolnika:fetch toolnika:emit