Skill: TraceMem Reading Data (Data Products)

Purpose

This skill teaches how to safely and correctly read data using TraceMem Data Products. Direct database selection or API calls are prohibited; all data access must be mediated by TraceMem.

When to Use

• •When you need to retrieve information (database rows, API results, resource state).
• •When you need to search or query for specific records.

When NOT to Use

• •Do not use for writing data (use decision_write / insert product).
• •Do not try to use standard SQL libraries or HTTP clients for governed data.

Core Rules

• •Data Products Only: You must access data via a named "Data Product".
• •Operation Specificity: A Data Product usually supports only ONE operation. Use a "read" product (e.g., customers_read) for reading.
• •Purpose is Mandatory: You must declare a purpose string for every read. This purpose must be in the product's allowed_purposes list.
• •Least Privilege: Only request the data you strictly need.

Correct Usage Pattern

1. •

   Identify the Product: Use products_list to find the correct Data Product for your need (e.g., orders_read_v1). Check its schema and allowed_purposes.

2. •

   Execute Read: Call decision_read with:

   • •decision_id: Your current open decision.
   • •product: The name of the data product.
   • •purpose: A valid purpose string (e.g., verification).
   • •query: The key-value filter (e.g., {"user_id": "123"}).
3. •

   Handle Results: The response contains records (list) and summary.

   Example:

   json

   {
     "records": [{"id": 1, "status": "active"}],
     "summary": {"rows": 1}
   }
   

Common Mistakes

• •Implicit Purpose: Failing to provide a purpose or guessing one not in the allowed list.
• •Wrong Product: Trying to read from a product designed for insert.
• •Unbounded Queries: Querying without filters (TraceMem may limit result sets by default).

Safety Notes

• •Audit Trails: Your query parameters and the summary of what you read are recorded in the immutable trace.
• •Sensitive Data: Avoid putting PII in the query parameters if possible, unless the Data Product is explicitly designed for PII lookups.
• •Read-Before-Write: Always read the current state of an object before attempting to modify it, to ensure your decision is based on fresh data.