Graphs, deployments, and revisions
Six nouns hold this domain up: graph, deployment, revision, assistant, thread, run. This lesson takes the first three. They are the "what did I ship" half. The next lesson takes the other three, which are the "what is it doing right now" half.
Graph
A graph is your code. The thing you built in the rest of your LangGraph life: nodes, edges, state schema, compiled. Nothing about deployment changes what a graph is.
The only new fact is that a graph does not stand alone once deployed. It gets declared in your config file and it gets served by something.
Deployment
A deployment is the served instance. It is the box the graphs run inside, with an API in front of them and a database underneath them.
The bit worth burning in: a deployment holds one or more graphs. Not exactly one. You declare them in the graphs key of langgraph.json, and you can declare several. So "one deployment per agent" is a habit people fall into, not a rule the platform enforces.
Revision
A revision is a version of the deployment.
Not a version of a graph. Not a version of a config. A version of the whole deployed unit, and specifically of two things bundled together: the code and the secrets.
Why the pairing matters
There are two versioning concepts in this domain and they operate on different objects. Revisions version the deployment. Assistant versions version the assistant, which is configuration, and you meet those next lesson.
Almost every question that looks like it is testing versioning is really testing whether you know which object each one applies to. When you see "version" in a stem, your first move is not to recall what versioning does, it is to ask version of what.
The sketch to hold
Deployment at the top. One or more graphs inside it. Revisions running down the side as successive snapshots of that whole box, each snapshot including both the code and the secrets that were live when it was cut.
Keep that picture. Next lesson hangs assistants, threads, and runs off it, and the picture only stays legible if the containment is already solid.
Try it yourself
What a revision versions
This is one half of a pair, and the pair is the most confusable thing in the whole domain.
A revision is a version of what, exactly, and what two kinds of change produce a new one?
How many graphs fit in a deployment
Sketch the containment relationship before you answer. Which of these matches it?
The containment sketch
Draw the containment, top down, without looking. Deployment, graph, revision.
Your sketch shows a deployment containing one or more graphs, with revisions as versions of the deployment as a whole (code plus secrets) rather than as versions of any individual graph. Nothing in the sketch suggests a revision versions a graph, and nothing suggests a one-to-one graph-to-deployment rule.