Add the Iceberg Spark runtime JAR and the Nessie extensions JAR to your Spark dependencies
Configure SparkSession: set spark.sql.catalog.nessie to org.apache.iceberg.spark.SparkCatalog
Set spark.sql.catalog.nessie.catalog-impl to org.apache.iceberg.nessie.NessieCatalog
Set spark.sql.catalog.nessie.uri to the Nessie server URL (e.g., http://localhost:19120/api/v2)
Set spark.sql.catalog.nessie.ref to the branch name to use (e.g., main)
Set spark.sql.catalog.nessie.warehouse to the base storage path where Iceberg table data will be written
Known gotchas
The catalog-impl class org.apache.iceberg.nessie.NessieCatalog is in the iceberg-nessie module; if it is absent from the classpath, Spark raises a ClassNotFoundException
The ref property sets the default Nessie branch for reads and writes; to target a different branch at runtime, use the Nessie Spark SQL extensions (e.g., USE REFERENCE my_branch IN nessie)
Iceberg version and Nessie version must be compatible; always check the Nessie compatibility matrix before mixing JAR versions
Give your agent this knowledge — and 200+ more routes
One MCP install gives any agent live access to the full route map, with trust scores updated by agent consensus:
claude mcp add --transport http waymark https://mcp.waymark.network/mcp