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Builtins catalog / nika:jq

Data

Tool family from the canonical registry.

invoke

Call this builtin through the invoke verb.

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Read this contract

This reference preserves the specification at the revision linked below. Source examples are fragments: their surrounding tasks, inputs and permissions are not supplied here. Consult engine status and nika catalog --tools --json for the installed implementation; a registry declaration is not a runtime qualification.

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Usage and behavior

illustration
Run a jq expression. The single data-transform-and-extraction language: map · filter · select · group_by · reshape · string-interpolation "\(.x)" · @base64/@base64d encoders (the embedded jaq has NO @csv/@tsv — use nika:convert to: csv) · array flatten · leaf_paths/getpath/setpath. The same jq used in extract: bindings (see 04-variables.md). jq is also the law after an extract: the model emits facts (infer.schema: as type: integer for numeric enums); this builtin (or nika:decide) names the level. Do not pay a second infer: to score. Teaching shape · examples/13-extract-then-law.nika.yaml. After . as $c, write ($c | map(...)) — a bare map( maps the current value (hint jq-as-map). input is any JSON value: a single ref (input: "${{ tasks.X.output }}") OR a constructed array for multi-input ops. Recursive merge of two objects (this is exactly why json_merge is NOT a builtin · jaq’s * does it) ·
illustration
Same shape combines / zips N inputs · build the array, index inside jq. The arg is expression:, exactly that name (not query: · not expr: · one name everywhere · the conformance oracle gates it). Throws · NIKA-BUILTIN-JQ-001 (program error at runtime · tool_error). Compile errors are caught statically (NIKA-VAR-005). Implementation · reference engine uses jaq (Rust jq).

Arguments

Pass the values required by the tool contract.

Permissions

Understand authority before granting effects.

Errors and recovery

Read diagnostics and choose a recovery policy.

Workflow templates

Put the fragment inside a complete workflow.

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Contract provenance

Read the pinned specification · Canonical registry. Tool identity: nika:jq. Specification revision: f8c5df2127c7. The Lab language identity is language:tool:jq; the registry view is ecosystem:tool/nika:jq. They refer to this contract without merging their graph identities.