AGPL-3.0-or-later · forever.

the language

tool

Tool reference · nika:<path> (closed v0.1 builtin set) OR mcp:<server>/<tool> (requires the slash). The namespace set is CLOSED at v1 (spec/02-verbs.md) — an x-<vendor>: prefix is RESERVED, not valid (engine-specific tools route through mcp: · spec/06-stdlib-contract.md §Namespace ownership). One of 59 words the served contract declares, projected from workflow.schema.json, the same file your editor validates against.

  • 1surfaceinvoke
  • optionaleverywherea choice, never a miss
  • stringtypethe declared shape
  • 10skeletonscarry this key

the contract

1 declaration

Descriptions are the schema's own; the deeper invariants (value languages and regexes) ride the same projection. A miss is a nika check finding before anything runs.

invoke
stringTool reference · nika:<path> (closed v0.1 builtin set) OR mcp:<server>/<tool> (requires the slash). The namespace set is CLOSED at v1 (spec/02-verbs.md) — an x-<vendor>: prefix is RESERVED, not valid (engine-specific tools route through mcp: · spec/06-stdlib-contract.md §Namespace ownership).inside invoke:^mcp:[a-z][a-z0-9-]*/[A-Za-z0-9_/-]+$

in a real file

from the chain skeleton
chain.nika.yaml
  gather:    invoke:                         # SLOT: the fact source · nika:read / nika:fetch / exec      tool: "nika:read"      args: { path: "${{ const.source }}" }

a verbatim slice, real line numbers from chain.nika.yaml, conformance-gated upstream on every spec push. open the full skeleton →

cross-references

accepted by

defined by

the block it lives in

invoke: inside invoke:

The whole grammar in one place: the four verbs · the standard library · the spec. Try it in the playground. Read the reference →