Idmp Attribute

attribute

Read ../idmp-shared/SKILL.md first.

Before any write: Follow the 🛑 Destructive op confirmation protocol. Read-only commands stay read-only here, but delete / write / patch flows still require the shared yes-gate.

Recommended shortcuts

Recommended references

• references/idmp-attribute-evaluate-expression.md

Product-style workflow

1. Read definitions with attributes.
2. Read current values with data-get or data-post only when needed.
3. Run new-name without --ack-risk before creating an attribute.
4. Run attribute evaluate-expression create before saving a formula or expression.
5. Use write-data only when you need controlled test input on a metric-backed attribute.

Missing context to resolve first

Constrained live behaviors

• attribute attributes new-name only needs the owner scope, but attributes-post must use the final reserved name and a real valueType.
• The expression-preview command family is attribute evaluate-expression create, and the schema path is attribute.evaluate-expression.create; the older guessed attribute.attributes.evaluate-expression path is wrong.
• Older checks may still mention the guessed attribute.attributes.evaluate-expression path; use idmp-cli attribute evaluate-expression create --dry-run --ack-risk --params for the real request.
• attribute evaluate-expression create needs a request body with at least dataReferenceType and expression. The live-safe starter is {"dataReferenceType":"Formula","expression":"..."}; attributeId and uomId are optional context helpers, not substitutes for the formula text.
• A newly created generic attribute is not automatically a TDengine metric reference. attribute write-data create can fail with etda390037 unless the target attribute is backed by writable metric storage.
• In strict live validation, attribute historydata list should use explicit start and end bounds instead of relying on ambient defaults.
• Attribute create is not complete until attributes reread shows the new definition.
• Template-derived attributes are not generic scratch objects. If an attribute still has attrTempId, the generic attribute elements attributes-delete path is expected to reject the delete while the backing template exists.
• Temporary probe attributes should be deleted after the workflow, even when write-data validation used a different existing metric-backed attribute.

Evidence of completion

• A create is only complete when attribute elements attributes --params rereads the new definition under the same owner.
• A value probe is only complete when data-get, data-post, or bounded historydata list returns the intended attribute data.
• A write probe is only complete when the target is known to be metric-backed and the reread reflects the inserted row, not just the CLI success line.

Key commands

idmp-cli schema attribute.elements.attributes
idmp-cli attribute elements attributes --params '{"elementId":1}'

idmp-cli schema attribute.attributes.new-name
# new-name is read-only (reserves a name); no --ack-risk required
idmp-cli attribute attributes new-name --params '{"elementId":1}'

idmp-cli schema attribute.elements.attributes-post
idmp-cli attribute elements attributes-post --ack-risk --params '{"elementId":1}' --data '{"name":"probe-attribute","valueType":"Double"}'

idmp-cli schema attribute.evaluate-expression.create
idmp-cli attribute evaluate-expression create --params '{"elementId":1}' --data '{...}' --dry-run --ack-risk

idmp-cli schema attribute.attributes.data-get
idmp-cli attribute attributes data-get --params '{"elementId":1,"attributeId":2}'

idmp-cli schema attribute.historydata.list
idmp-cli attribute historydata list --params '{"elementId":1,"attributeId":2,"current":1,"size":20,"start":1704067200000,"end":1704153600000}'

Exception and failure handling

• If an attribute is not returned by attributes, do not guess the ID from older notes or scripts.
• If the definition exists but the current value is empty, check history before treating it as a product failure.
• If new-name returns a different candidate, use the reserved value instead of forcing the original name.
• If expression evaluation fails, fix the formula before create or update; do not save a broken expression first.
• If test writes are rejected with errors such as etda390037, switch to a known metric-backed attribute; do not assume the newly created attribute is writable.
• If delete fails because the attribute came from an attribute template, treat that as a scope boundary; do not keep retrying the generic element-attribute delete path.
• If the preview differs from the intended payload, stay read-only until the schema and permissions are correct.

Validation scenarios

1. Read attribute definitions with idmp-cli schema attribute.elements.attributes and idmp-cli attribute elements attributes --params '{"elementId":1}'.
2. Reserve a create-safe name with idmp-cli attribute attributes new-name --params '{"elementId":1}'.
3. Read one live value with idmp-cli attribute attributes data-get --params '{"elementId":1,"attributeId":2}'.
4. Create a probe attribute only after idmp-cli attribute attributes new-name --params '{"elementId":1}', then verify the create path with idmp-cli attribute elements attributes-post --ack-risk --params '{"elementId":1}' --data '{"name":"probe-attribute","valueType":"Double"}'.
5. Check history paging with idmp-cli attribute historydata list --params '{"elementId":1,"attributeId":2,"current":1,"size":20,"start":1704067200000,"end":1704153600000}', then use idmp-cli attribute write-data create --dry-run --ack-risk --params '{"elementId":1}' --data '{"probe":"example"}' only after confirming the target attribute is a writable metric reference and idmp-cli attribute evaluate-expression create --params '{"elementId":1}' --data '{"dataReferenceType":"Formula","expression":"AVG(${attributes['"'"'Current'"'"']})"}' --dry-run --ack-risk already succeeded.