[Bug]: Intersection operator not working

[craigchurch]

What happened?

The comma is the intersection operator for selection syntax. AI is running the get lineage tool, but failing to understand the comma (intersection operator)

Steps to Reproduce

{
"direction": "both",
"model_id": "inq_missionary_init+,+inq_missionary_dim",
"recursive": false
}

Error executing tool get_model_lineage_dev: Model name 'inq_missionary_init+,+inq_missionary_dim' not found in manifest.

Deployment

Remote MCP server

Environment

Windows 11
VSCode

Relevant log output

[jairus-m]

Hey @craigchurch , what is the prompt that you are running? The first thing I'm thinking of is that get_model_lineage_dev is meant for passing and understanding the lineage of a single model and not passing multiple potential inputs such as what you'd get with that selector syntax "inq_missionary_init+,+inq_missionary_dim"

[VDFaller]

I was able to query what I think you're asking by just doing.

can you tell me the lineage of ALL models given by `dbt ls -s stg_orders+,+orders --resource-type model`

It first runs the ls tool, THEN it runs the get_lineage_dev tool once for each returned model.

[craigchurch]

My project DAG is very large with many interdependencies. I'm wanting to see what tables are directly between two models, preferrably in graphical format like what you see in the dbt fusion lineage tab. This lets me focus on transformations. I actually want the column lineage, but I recognize that is harder, and I don't see a column lineage MCP tool yet. The selection syntax ""inq_missionary_init+,+inq_missionary_dim" is exactly what I want - as it appears dbt docs graph selection and in dbt fusion lineage. Basically, this removes models that branch off the first model without directly contributing to the second model. inq_missionary+ (parents) would show me way too many models. +inq_missionary_dim (childeren) would show me way too many models. Here is a screenshot example. Notice how every model in the middle is on a direct line between the beginning model and the end model.

And actually, I see that I overlooked the tool get_column_lineage, which would also be super helpful. But that is returning
{
"error": "LSP error: No result from LSP"
}

Does get_column_lineage work locally, or does it require connection to dbt platform (cloud).
Thanks!

[jairus-m]

Hi @craigchurch , for get_column_lineage there was a fix that was just released in dbt-mcp==1.9.0 that should address what you're seeing. You do not need a dbt Platform account for that tool! As long as you have fusion working locally with the dbt VSCE (which should run the dbt LSP), you should be good to go (this also works with a platform account btw).

As for the original issue, totally hear you on wanting to use selector syntax in order to limit the amount of models represented in your DAG of interest. Currently, the model lineage tools only take a single node/model and do not accept the selector syntax. I'll ask the team on their thoughts here.

But in the meantime, can you try asking the LLM to:

"Use the dbt MCP list tool to return the models using this selection: inq_missionary_init+,+inq_missionary_dim. Given the output of the list tool, use get_lineage_dev (or get_lineage) to understand what models are between these two models".

And just to be clear, the MCP outputs data to an LLM that gets returned to use as text, not a visual graph like you shared above.

[VDFaller]

@craigchurch also in case you just want the visuals and didn't know about it in VSCE. You can just right click on a model in the lineage tab and select Show column lineage.