AWS1 input → 2 outputs

DynamoDB Update

Updates specific attributes of an existing DynamoDB item without overwriting the entire record. Perfect for refreshing OAuth tokens or incrementing counters.

Inputs

payload.key object: Full primary key override, e.g. { id: "epic-A", sk: "token" }. Overrides config key fields.
payload.updateExpression string: Raw DynamoDB UpdateExpression — overrides both Simple and Advanced modes entirely.
payload.expressionAttributeNames object: Attribute name aliases (#name → actual attribute name). Used with runtime updateExpression.
payload.expressionAttributeValues object: Attribute value aliases (:value → actual value). Used with runtime updateExpression.
payload.conditionExpression string: Update only if this condition is true. If false, output 2 fires with Condition Failed error.
payload.returnValues string: Override the Return Values setting. One of: ALL_NEW, ALL_OLD, UPDATED_NEW, UPDATED_OLD, NONE.

Outputs

Output 1 — Success

payload.success boolean: true on successful update.
payload.attributes object: The item after the update (shape depends on the Return Values setting).
payload.tableName string: The table that was updated.

Output 2 — Error

payload.errorType string: Human-readable error category (e.g. Condition Failed, Table Not Found).
payload.solution string: Suggested fix for the error.

How to Use

Select an AWS config node and enter the Table Name.
Set the Partition Key (and Sort Key if your table has one).
Choose Simple Mode to use the visual field builder, or Advanced Mode for raw DynamoDB expressions.
In Simple Mode, click Add Field and choose the action: SET, REMOVE, ADD, DELETE.
Set Return Values to ALL_NEW to get the full updated item on output 1.

Update Actions (Simple Mode)

SET action: Sets an attribute to the given value. Creates the attribute if it does not exist.
REMOVE action: Removes an attribute from the item entirely. Leave the value blank.
ADD action: Atomically increments a Number attribute by the given value. Safe for counters — no race conditions.
DELETE action: Removes elements from a Number Set or String Set attribute.

Examples

Refresh an OAuth access token for an Epic integration — atomically update the token and increment a refresh counter:

// Simple Mode: add these rows:
// Field: accessToken  | Action: SET | Value: eyJhbGci...
// Field: expiresAt    | Action: SET | Value: 1714000000
// Field: refreshCount | Action: ADD | Value: 1

// Or use runtime override:
msg.payload = {
  key: { id: "epic-hospital-A", sk: "oauth_token" },
  updateExpression: "SET #at = :token, #exp = :expires ADD #rc :one",
  expressionAttributeNames: {
    "#at": "accessToken", "#exp": "expiresAt", "#rc": "refreshCount"
  },
  expressionAttributeValues: {
    ":token": "eyJhbGci...", ":expires": 1714000000, ":one": 1
  },
  returnValues: "ALL_NEW"
};

Best Practices

Use ADD for counters and numeric increments — it is atomic and safe for concurrent updates.
Set Return Values to ALL_NEW for token updates so you can verify the new value was saved.
Use conditionExpression with attribute_exists(id) to ensure you only update items that actually exist.
Prefer Update over Put for partial changes — Put overwrites the entire item and can delete attributes you didn't intend to change.

// Simple Mode: add these rows: // Field: accessToken | Action: SET | Value: eyJhbGci... // Field: expiresAt | Action: SET | Value: 1714000000 // Field: refreshCount | Action: ADD | Value: 1 // Or use runtime override: msg.payload = { key: { id: "epic-hospital-A", sk: "oauth_token" }, updateExpression: "SET #at = :token, #exp = :expires ADD #rc :one", expressionAttributeNames: { "#at": "accessToken", "#exp": "expiresAt", "#rc": "refreshCount" }, expressionAttributeValues: { ":token": "eyJhbGci...", ":expires": 1714000000, ":one": 1 }, returnValues: "ALL_NEW" };