chain

1# SPDX-License-Identifier: Apache-2.02# yaml-language-server: $schema=https://nika.sh/spec/v1/workflow.schema.json3#4# TEMPLATE · chain · gather facts → one model step → persist.5#6#   [gather]────▶[think]────▶[persist]7#   nika:read     infer       nika:write8#9# The everyday shape: pull in something real, run exactly ONE model job over10# it, write the result somewhere you can find it again. Most useful workflows11# are this and nothing more — reach for a bigger skeleton only when this one12# genuinely cannot hold the job.13#14# Demonstrates ·15#   - the three-verb spine · invoke → infer → invoke16#   - `with:` as the DAG edge · a task reads its input from a binding, and the17#     binding IS what orders the graph (nobody writes the arrows)18#   - `on_error: recover:` · the skeleton rehearses green in an empty19#     directory, before it is pointed at real data20#21# Needs · nothing. Scaffolds and runs green in an empty directory.22#23# Run · nika run <file> --model mock/echo    # offline rehearsal · zero keys24nika: v125workflow:26  id: chain-template            # SLOT: kebab-case workflow id27  # SLOT: one honest sentence — `nika new` matches intents against these words28  description: "gather → think → persist"29​30# SLOT: provider/model · local · zero key. Measured seat — `ollama/llama3.2:3b`31# answers this prompt in ~50s. `--model mock/echo` needs no seat at all and is32# the path this file guarantees.33model: ollama/llama3.2:3b34​35const:36  source: "./README.md"             # SLOT: your input · README.md exists in most repos37  destination: "./output.md"        # SLOT: where the result lands38​39⛨permits:                            # the blast radius · default-deny once present40  ⛨tools: ["nika:read", "nika:write"]41  # Two literal paths, one each way. `check` can read these (they come from42  # `const:`) and proves them against the boundary before anything runs — keep43  # them in step with the two `const:` entries above.44  ⛨fs:45    ⛨read: ["./README.md"]46    ⛨write: ["./output.md"]47​48tasks:49  gather:50    ◆invoke:                         # SLOT: the fact source · nika:read / nika:fetch / exec51      tool: "nika:read"52      args: { path: "${{ const.source }}" }53    on_error:54      # Offline rehearsal. A freshly scaffolded directory has no README, and a55      # skeleton that dies on its first run teaches nothing — so a not-found56      # recovers into a literal standing in for the real document. `on_codes:`57      # keeps that narrow: ONLY not-found is forgiven, a permission error58      # still fails loudly. Delete this block once the source really exists.59      # In an EMPTY directory check prints one [inputs] hint that this read60      # would fail — the run does not: this recover carries it (measured ·61      # rc=0 · « 1 recovered »). The hint retires once your source exists.62      on_codes: [NIKA-BUILTIN-READ-001]63      recover: "REHEARSAL · no source document here yet."64​65  think:66    with:67      gather: ${{ tasks.gather.output }}68    ◇infer:69      max_tokens: 800               # SLOT: the spend ceiling · sized for the SEAT, not the answer70      # SLOT: the one model job. Keep slot markers OUT of the block below —71      # everything indented under `prompt: |` is prompt TEXT, so a stray72      # `# SLOT:` line is sent to the model verbatim (visible in the mock73      # echo). Comments belong out here, where YAML eats them.74      prompt: |75        Summarize the following in a short paragraph.76​77        ${{ with.gather }}78​79  persist:80    with:81      think: ${{ tasks.think.output }}82    ◆invoke:83      tool: "nika:write"84      args:85        path: "${{ const.destination }}"   # SLOT: destination · same path as permits.fs.write86        content: "${{ with.think }}"       # ALWAYS pass content · a write without it writes nothing87​88outputs:89  result: ${{ tasks.think.output }}  # SLOT: the callable contract90​