An agentic lakehouse is an architecture, not a product: open storage and tables at the bottom, a catalog and engines in the middle, and a semantic layer and agent interface on top, so AI agents get governed answers instead of raw access. The diagram shows each layer, what flows between them, and where governance applies.

Agentic lakehouse reference architecture A stack of seven numbered layers, top (7) to bottom (1): agents; agent interface such as MCP; semantic layer; query engine; catalog; table format such as Apache Iceberg; and object storage. Agents call typed tools over MCP, the interface sends metric requests to the semantic layer, which compiles governed SQL for the query engine. The engine reads table metadata from the catalog, snapshots and manifests from the table format, and Parquet data files from object storage. A governance rail runs beside the agent interface, semantic layer, query engine, and catalog: agent identity, row and column policies, query guardrails, cost caps, audit log, and catalog access control. Diagram by Alex Merced, CC BY 4.0, agenticlakehouse.com. Agentic lakehouse reference architecture How AI agents reach open lakehouse data through governed, typed interfaces 7 Agents Ask questions and act for people and teams Workflows Coding agents Assistants tool calls over MCP 6 Agent interface (MCP) Typed tools the agent can discover and call OAuth identity Tool schemas MCP servers metric requests, never raw SQL 5 Semantic layer Business definitions and agent-safe views Governed views Dimensions Metrics governed SQL 4 Query engine Plans and runs SQL, enforces grants DuckDB Spark Trino Dremio table metadata and credentials 3 Catalog Names tables and tracks their metadata Nessie Iceberg REST Apache Polaris snapshots and manifests 2 Table format Files become tables with ACID snapshots Time travel Snapshots Apache Iceberg Parquet data files 1 Object storage Holds every byte once, in open formats MinIO Google GCS Azure ADLS Amazon S3 Governance Applies to layers 3 to 6 Agent identity Row and column policies Query guardrails Cost caps Audit log Catalog access control Diagram: Alex Merced, agenticlakehouse.com. License: CC BY 4.0 (creativecommons.org/licenses/by/4.0). Examples are illustrative, not endorsements.
Seven layers from object storage to agents, with governance applied across the agent interface, semantic layer, query engine, and catalog. Examples in each layer are illustrative.

Download the diagram

License: CC BY 4.0. Use it in slides, docs, and posts, and adapt it. Credit “Alex Merced, agenticlakehouse.com”.

The layers, bottom to top

Read the diagram from the bottom. Each layer does one job and exposes it through an open interface to the layer above, which is what lets you replace one part without rebuilding the rest. Agents sit at the top and never skip a layer: they do not read files, they do not call the catalog, and they do not write SQL against raw tables.

1

Object storage

Amazon S3, Azure Data Lake Storage, Google Cloud Storage, or an S3-compatible store such as MinIO. It holds every byte once, as open files (usually Parquet), so no engine or vendor owns the data. See object storage for analytics.

2

Table format

Apache Iceberg turns a folder of files into a table with ACID commits, snapshots, schema evolution, and hidden partitioning. Its manifests record row counts and value ranges per file, which engines, and guardrails, use to skip data before reading it.

3

Catalog

The catalog names tables and points each one at its current metadata. An Iceberg REST catalog such as Apache Polaris lets every engine see the same tables and is the first place access control applies: the agent platform gets its own principal with read access to the namespaces it needs.

4

Query engine

The engine plans and runs SQL over Iceberg tables and enforces grants, row filters, and column masks for the identity running the query. Dremio, Trino, Spark, and DuckDB all read Iceberg; the right one depends on concurrency, latency, and how much governance it enforces natively. See AI query engine.

5

Semantic layer

Metrics, dimensions, and agent-safe governed views: the definitions the business agreed on, compiled to SQL the engine runs. This is what keeps an agent from inventing its own meaning for revenue. See semantic layer.

6

Agent interface (MCP)

An MCP server exposes typed tools such as list_metrics and query_metric, with descriptions the agent reads and errors it can act on. No tool accepts raw SQL. The pattern is built step by step in exposing a semantic layer over MCP.

7

Agents

Assistants, coding agents, and scheduled workflows. They act for a person or a team, so their identity comes from that person, not from the prompt. See autonomous data agents.

G

Governance, across layers 3 to 6

Governance is not a layer you pass through once. Identity flows from the agent's user into the interface, row and column policies apply in views and the engine, query guardrails cap rows, time, and cost, and the catalog controls which tables exist for whom. Every call lands in an audit log.

Build it

The implementation patterns build the middle of this diagram in Python with working code: an MCP server over an Iceberg catalog, a semantic layer exposed over MCP, governed views, policies, and guardrails.

Build This Architecture Today

Architecting an Apache Iceberg Lakehouse

Architecting an Apache Iceberg Lakehouse

Buy on Manning
The AI Lakehouse

The AI Lakehouse

Buy on Amazon

Build with the community