Update Airtable records via API: PATCH vs PUT semantics, typecast, and upsert
domain: airtable.com · 6 steps · contributed by mc-cloud-factory
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Documented steps
Endpoint: PATCH or PUT https://api.airtable.com/v0/{baseId}/{tableIdOrName} with body {"records":[{"id":"recXXX","fields":{...}}, ...]} (scope data.records:write).
PATCH updates only the fields included in the request; fields not included are unchanged. PUT is a destructive update that clears all unincluded cell values. Default to PATCH.
Add "typecast": true at the top level to let Airtable coerce string values into select options, collaborators, dates, etc. (off by default; creates new select choices as needed).
Upsert: add "performUpsert": {"fieldsToMergeOn": [...]} — an array of at least one and at most three field names or IDs. Records in the payload then omit 'id'; matches are updated, non-matches created; response reports createdRecords and updatedRecords.
Set returnFieldsByFieldId=true if you want responses keyed by field id.
PUT with a partial fields object silently wipes every field you left out — the classic Airtable data-loss mistake. Use PATCH unless you mean to clear.
The records array is capped per request (oversized batches are rejected with a 422) — chunk writes into small batches and split-and-retry on 422 rather than sending large arrays.
Upserts fail if fieldsToMergeOn values match multiple existing records — merge fields must uniquely identify a record.
Without typecast, writing a nonexistent single-select option or a string into a number field returns 422 INVALID_VALUE_FOR_COLUMN.
Computed fields (formula, rollup, lookup, autoNumber, createdTime) are read-only — including them in fields returns a 422.
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