Fabric’s lineage API gives agents a dependency map—but read permission is not impact authority

Microsoft Fabric has added a beta item-relations API that returns an item’s dependency graph in machine-readable form. Fabric’s current feature index positions the preview for impact analysis, catalog work, CI/CD checks and lineage-aware AI agents; the REST reference exposes the concrete contract behind that promise.

What the endpoint returns

A caller can request the upstream relations for a Fabric item and receive three collections: related items, relation edges and referenced workspaces. Microsoft’s sample response connects an item to an “Enterprise Sales Lakehouse” with a typed PushData edge and identifies the workspace that contains the dependency.

That is more useful to an agent than a flat inventory. Before editing a warehouse, notebook or semantic asset, an automated workflow can inspect what the target depends on and identify cross-workspace relationships that deserve review. The companion feature listing says the preview also covers downstream relationships, which is the direction needed for blast-radius checks.

The permission boundary matters

The endpoint requires read permission on the target item and either the delegated Item.Read.All or Item.ReadWrite.All scope. It supports users, service principals and managed identities. Those requirements make the graph available to unattended automation, but they do not make a returned dependency safe to modify.

That distinction should shape agent design. A dependency map is evidence for planning: it can tell an agent which assets may be involved, where they live and how Fabric classifies the edge. It is not an approval to rewrite every connected item, nor proof that the graph captures business ownership, freshness requirements or every downstream consumer.

A practical deployment pattern

Teams can use the API as a preflight gate: fetch upstream and downstream relations, record the graph with the proposed change, and escalate when the response crosses workspaces or includes unfamiliar relation types. Actual edits should still run through the permissions and review process for each affected item.

Microsoft labels the endpoint beta, requires callers to send beta=true, and says it is not recommended for production use. The response schema also warns that additional item and relation types may appear over time. For production-minded teams, that means tolerant parsers, explicit unknown-edge handling and versioned audit records are part of the minimum integration—not optional polish.