lookup
Configure lookup parameters, input/output bindings and lineage.
Enrich the primary input with fields from a reference input using key-based matching.
Install
Install the Transforms bundle, then select the lookup capability on a pipeline transform node. Runtime entrypoint: transforms/lookup.ts. The installed capability must be enabled and pass preflight.
Configure
Execution: deterministic. Declared runtime support: supported.
Parameters
| Field | Type | Required | Details |
|---|---|---|---|
primaryKey | string | No | Join key on the primary input. |
referenceKey | string | No | Join key on the reference input. |
joinType | string | No | How unmatched primary rows should be handled. Default: "left". Allowed: left, inner. |
onMissing | string | No | How to handle a missing reference match for a primary row. Default: "null". Allowed: null, drop, error. |
fields | array | No | Reference fields to copy onto the primary row. Items: object. |
View the complete contract for nested parameter shapes, defaults, named bindings and lineage.
Bindings
- Input
primary: Primary input (required) - Input
reference: Reference input (required) - Output
out: Output
Verify the result
Create a small input with known values that exercise lookup and supply the required parameters above. Validate, save and run the pipeline. Inspect the output records and compare row counts and changed fields with the input. Check the run’s errors and evidence before accepting a conversational summary.
Include empty inputs, missing values and relevant duplicate or multi-match cases so the intended behavior is clear.
Lineage and changes
Lineage mode: explicit. This operation can change row membership or combine records. Its explicit lineage must map output records to their contributing inputs; check those links after the run.
Changing parameters changes the computation. Review the saved pipeline revision before rerunning it. Publishing a new plugin version and editing node parameters are different changes.
FAQ
Why does validation fail?
Check required parameters, the installed capability version, runtime support and the named input/output bindings. A missing nested field may be visible only in the full contract.
Is this a standalone MCP tool?
It is a plugin capability used by a pipeline, not a new top-level MCP tool with this operation name. An assistant can inspect, validate and execute the pipeline through the MCP reference.