The Atlan MCP Cookbook

Check the master list before you add a new value

Before adding a new value to a field, pull the existing values so a new entry doesn't duplicate one under a different name and fragment the master list.

All recipes

On the menu

Use case
Govern & keep trusted
Action
Look up
Persona
Data/Business User, Data/BI Analyst, Data Governance Lead
Effort
Quick
Runs in
any AI tool

The task

Scenario. Someone's about to add a new category to a field, say a new `product_category` value, but the field already has a governed set of values. If the new one duplicates an existing value under a slightly different name, "Eco" vs "Eco-Friendly" vs "Green", it fragments the master list and quietly breaks every report that groups by it. Before adding, they check what's already there.

The ask

  • The current set of distinct values already on the field
  • Whether the value you're about to add already exists under another name
  • A clear reuse-or-add decision, instead of a silent duplicate

Hero prompt

Hero prompt

Before I add `Eco-Friendly` to `product_category`, show me the existing distinct values so I can tell if it already exists under another name.

Step by step

  1. Pull the current value set.

    Step 1

    List the existing distinct values in <product_category>, so I can see the master list I'd be adding to.

  2. Check the proposed value against it.

    Step 2

    Does <Eco-Friendly> already exist in that list, exactly or as a near-variant like <Eco> or <Green>? Flag the closest matches.

  3. Decide: reuse or add.

    Step 3

    Recommend whether to reuse an existing value or add a genuinely new one, and if new, whether <Eco-Friendly> fits the naming pattern of the rest.

What you'll give it

Required context

  • The field you're adding a value to
  • The value you're proposing to add
  • Read access to the connected source through Atlan, with query permission

Optional context

  • The naming convention for the field, if one exists, so a new value can be checked against it
  • Any governed term or documentation that defines the allowed set

What Atlan creates

Outputs

  • The current distinct values in the field, the effective master list
  • The closest existing matches to your proposed value, exact or near-variant
  • A reuse-or-add recommendation, with a naming-fit check if it's genuinely new

Summary. You add a value that fits the governed set instead of a near-duplicate that fragments it, so reports that group by the field keep reconciling.

Read-only

Read-only in Atlan. It checks the existing values so you can decide; the value itself is added in the source system, not here.

Follow-up prompts

Keep going once the first answer lands.

Check the whole load

Check the whole load

Run this check across every field I'm about to add values to in this load, not just one.

Find near-duplicates

Find near-duplicates

Show me values that already look like near-duplicates of each other, so I can flag the mess that's already there.

Define it properly

Define it properly

If we add it, draft a one-line definition so the next person knows when to use it.

Tips & troubleshooting

Cook's note

The expensive mistake isn't a typo, it's a synonym. "Eco" and "Eco-Friendly" both look fine until a report splits one category into two.

  • Match the client to the work.** Use a client that shows the full existing value list, so you're judging against everything, not just the top few.
  • Automate or chain it.** Run this ahead of any bulk load that introduces new category values, so variants get caught before they land, not after.
  • Ask what it found.** Have it list the near-variants it matched against, so the reuse-or-add call is on the record.
THE ATLAN MCP COOKBOOK

Point your AI at the Atlan MCP.
Run your first recipe.

[Website env: production]