diff --git a/package.json b/package.json
index fa2b9af..1dc02f5 100644
--- a/package.json
+++ b/package.json
@@ -45,6 +45,7 @@
     "schema:generate": "npm run db:generate && npm run schema:contract",
     "test:schema:unit": "vitest run --root . src/server/db/schemaContract.test.ts src/server/db/schemaArtifactGenerator.test.ts src/server/db/schemaIntrospection.test.ts src/server/db/schemaParity.test.ts",
     "test:schema:parity": "vitest run --root . src/server/db/schemaParity.live.test.ts",
+    "test:schema:upgrade": "vitest run --root . src/server/db/schemaUpgrade.live.test.ts",
     "smoke:db": "tsx scripts/dev/db-smoke.ts",
     "smoke:db:sqlite": "tsx scripts/dev/db-smoke.ts --db-type sqlite",
     "smoke:db:mysql": "tsx scripts/dev/db-smoke.ts --db-type mysql",
diff --git a/scripts/dev/generate-upgrade-fixture.ts b/scripts/dev/generate-upgrade-fixture.ts
new file mode 100644
index 0000000..8dabcbf
--- /dev/null
+++ b/scripts/dev/generate-upgrade-fixture.ts
@@ -0,0 +1,113 @@
+import { execFileSync } from 'node:child_process';
+import { mkdirSync, readFileSync, writeFileSync } from 'node:fs';
+import { dirname, resolve } from 'node:path';
+import {
+  resolveGeneratedSchemaContractPath,
+  type SchemaContract,
+} from '../../src/server/db/schemaContract.js';
+
+interface FixtureScriptOptions {
+  fromRef?: string;
+  outputPath: string;
+  dropTables: string[];
+  dropColumns: string[];
+}
+
+function parseArgs(argv: string[]): FixtureScriptOptions {
+  const options: FixtureScriptOptions = {
+    outputPath: 'src/server/db/generated/fixtures/2026-03-14-baseline.schemaContract.json',
+    dropTables: [],
+    dropColumns: [],
+  };
+
+  for (let index = 0; index < argv.length; index += 1) {
+    const argument = argv[index];
+    if (argument === '--from-ref') {
+      options.fromRef = argv[index + 1];
+      index += 1;
+      continue;
+    }
+    if (argument === '--output') {
+      options.outputPath = argv[index + 1];
+      index += 1;
+      continue;
+    }
+    if (argument === '--drop-table') {
+      options.dropTables.push(argv[index + 1]);
+      index += 1;
+      continue;
+    }
+    if (argument === '--drop-column') {
+      options.dropColumns.push(argv[index + 1]);
+      index += 1;
+    }
+  }
+
+  return options;
+}
+
+function pruneContract(contract: SchemaContract, options: FixtureScriptOptions): SchemaContract {
+  const droppedTables = new Set(options.dropTables);
+  const droppedColumns = new Map<string, Set<string>>();
+
+  for (const entry of options.dropColumns) {
+    const [tableName, columnName] = entry.split('.', 2);
+    if (!tableName || !columnName) {
+      throw new Error(`invalid --drop-column value: ${entry}`);
+    }
+    const tableColumns = droppedColumns.get(tableName) ?? new Set<string>();
+    tableColumns.add(columnName);
+    droppedColumns.set(tableName, tableColumns);
+  }
+
+  const tables = Object.fromEntries(
+    Object.entries(contract.tables)
+      .filter(([tableName]) => !droppedTables.has(tableName))
+      .map(([tableName, table]) => {
+        const removedColumns = droppedColumns.get(tableName) ?? new Set<string>();
+        const columns = Object.fromEntries(
+          Object.entries(table.columns).filter(([columnName]) => !removedColumns.has(columnName)),
+        );
+        return [tableName, { columns }];
+      }),
+  );
+
+  const hasColumn = (tableName: string, columnName: string): boolean =>
+    !!tables[tableName]?.columns[columnName];
+
+  return {
+    tables,
+    indexes: contract.indexes.filter((index) =>
+      !!tables[index.table] && index.columns.every((columnName) => hasColumn(index.table, columnName))),
+    uniques: contract.uniques.filter((unique) =>
+      !!tables[unique.table] && unique.columns.every((columnName) => hasColumn(unique.table, columnName))),
+    foreignKeys: contract.foreignKeys.filter((foreignKey) =>
+      !!tables[foreignKey.table]
+      && !!tables[foreignKey.referencedTable]
+      && foreignKey.columns.every((columnName) => hasColumn(foreignKey.table, columnName))
+      && foreignKey.referencedColumns.every((columnName) => hasColumn(foreignKey.referencedTable, columnName))),
+  };
+}
+
+function readContractFromRef(fromRef: string): SchemaContract {
+  const contractJson = execFileSync(
+    'git',
+    ['-c', 'safe.directory=.', 'show', `${fromRef}:src/server/db/generated/schemaContract.json`],
+    { encoding: 'utf8' },
+  );
+  return JSON.parse(contractJson) as SchemaContract;
+}
+
+function readCurrentContract(): SchemaContract {
+  return JSON.parse(readFileSync(resolveGeneratedSchemaContractPath(), 'utf8')) as SchemaContract;
+}
+
+const options = parseArgs(process.argv.slice(2));
+const sourceContract = options.fromRef ? readContractFromRef(options.fromRef) : readCurrentContract();
+const contract = pruneContract(sourceContract, options);
+const outputPath = resolve(process.cwd(), options.outputPath);
+
+mkdirSync(dirname(outputPath), { recursive: true });
+writeFileSync(outputPath, `${JSON.stringify(contract, null, 2)}\n`, 'utf8');
+
+console.log(`[schema:upgrade-fixture] wrote ${outputPath}`);
diff --git a/src/server/db/generated/fixtures/2026-03-14-baseline.schemaContract.json b/src/server/db/generated/fixtures/2026-03-14-baseline.schemaContract.json
new file mode 100644
index 0000000..648bf4b
--- /dev/null
+++ b/src/server/db/generated/fixtures/2026-03-14-baseline.schemaContract.json
@@ -0,0 +1,1120 @@
+{
+  "tables": {
+    "account_tokens": {
+      "columns": {
+        "id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": true
+        },
+        "account_id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "name": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "token": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "source": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": "'manual'",
+          "primaryKey": false
+        },
+        "enabled": {
+          "logicalType": "boolean",
+          "notNull": false,
+          "defaultValue": "true",
+          "primaryKey": false
+        },
+        "is_default": {
+          "logicalType": "boolean",
+          "notNull": false,
+          "defaultValue": "false",
+          "primaryKey": false
+        },
+        "created_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": "datetime('now')",
+          "primaryKey": false
+        },
+        "updated_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": "datetime('now')",
+          "primaryKey": false
+        },
+        "token_group": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        }
+      }
+    },
+    "accounts": {
+      "columns": {
+        "id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": true
+        },
+        "site_id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "username": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "access_token": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "api_token": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "balance": {
+          "logicalType": "real",
+          "notNull": false,
+          "defaultValue": "0",
+          "primaryKey": false
+        },
+        "balance_used": {
+          "logicalType": "real",
+          "notNull": false,
+          "defaultValue": "0",
+          "primaryKey": false
+        },
+        "quota": {
+          "logicalType": "real",
+          "notNull": false,
+          "defaultValue": "0",
+          "primaryKey": false
+        },
+        "unit_cost": {
+          "logicalType": "real",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "value_score": {
+          "logicalType": "real",
+          "notNull": false,
+          "defaultValue": "0",
+          "primaryKey": false
+        },
+        "status": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": "'active'",
+          "primaryKey": false
+        },
+        "checkin_enabled": {
+          "logicalType": "boolean",
+          "notNull": false,
+          "defaultValue": "true",
+          "primaryKey": false
+        },
+        "last_checkin_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "last_balance_refresh": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "extra_config": {
+          "logicalType": "json",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "created_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": "datetime('now')",
+          "primaryKey": false
+        },
+        "updated_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": "datetime('now')",
+          "primaryKey": false
+        },
+        "is_pinned": {
+          "logicalType": "boolean",
+          "notNull": false,
+          "defaultValue": "false",
+          "primaryKey": false
+        },
+        "sort_order": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": "0",
+          "primaryKey": false
+        }
+      }
+    },
+    "checkin_logs": {
+      "columns": {
+        "id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": true
+        },
+        "account_id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "status": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "message": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "reward": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "created_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": "datetime('now')",
+          "primaryKey": false
+        }
+      }
+    },
+    "events": {
+      "columns": {
+        "id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": true
+        },
+        "type": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "title": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "message": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "level": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": "'info'",
+          "primaryKey": false
+        },
+        "read": {
+          "logicalType": "boolean",
+          "notNull": false,
+          "defaultValue": "false",
+          "primaryKey": false
+        },
+        "related_id": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "related_type": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "created_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": "datetime('now')",
+          "primaryKey": false
+        }
+      }
+    },
+    "model_availability": {
+      "columns": {
+        "id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": true
+        },
+        "account_id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "model_name": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "available": {
+          "logicalType": "boolean",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "latency_ms": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "checked_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": "datetime('now')",
+          "primaryKey": false
+        }
+      }
+    },
+    "proxy_logs": {
+      "columns": {
+        "id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": true
+        },
+        "route_id": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "channel_id": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "account_id": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "model_requested": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "model_actual": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "status": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "http_status": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "latency_ms": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "prompt_tokens": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "completion_tokens": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "total_tokens": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "estimated_cost": {
+          "logicalType": "real",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "error_message": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "retry_count": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": "0",
+          "primaryKey": false
+        },
+        "created_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": "datetime('now')",
+          "primaryKey": false
+        },
+        "billing_details": {
+          "logicalType": "json",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        }
+      }
+    },
+    "route_channels": {
+      "columns": {
+        "id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": true
+        },
+        "route_id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "account_id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "token_id": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "priority": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": "0",
+          "primaryKey": false
+        },
+        "weight": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": "10",
+          "primaryKey": false
+        },
+        "enabled": {
+          "logicalType": "boolean",
+          "notNull": false,
+          "defaultValue": "true",
+          "primaryKey": false
+        },
+        "manual_override": {
+          "logicalType": "boolean",
+          "notNull": false,
+          "defaultValue": "false",
+          "primaryKey": false
+        },
+        "success_count": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": "0",
+          "primaryKey": false
+        },
+        "fail_count": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": "0",
+          "primaryKey": false
+        },
+        "total_latency_ms": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": "0",
+          "primaryKey": false
+        },
+        "total_cost": {
+          "logicalType": "real",
+          "notNull": false,
+          "defaultValue": "0",
+          "primaryKey": false
+        },
+        "last_used_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "last_fail_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "cooldown_until": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        }
+      }
+    },
+    "settings": {
+      "columns": {
+        "key": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": true
+        },
+        "value": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        }
+      }
+    },
+    "site_disabled_models": {
+      "columns": {
+        "id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": true
+        },
+        "site_id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "model_name": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "created_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": "datetime('now')",
+          "primaryKey": false
+        }
+      }
+    },
+    "sites": {
+      "columns": {
+        "id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": true
+        },
+        "name": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "url": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "platform": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "status": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": "'active'",
+          "primaryKey": false
+        },
+        "api_key": {
+          "logicalType": "text",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "created_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": "datetime('now')",
+          "primaryKey": false
+        },
+        "updated_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": "datetime('now')",
+          "primaryKey": false
+        },
+        "is_pinned": {
+          "logicalType": "boolean",
+          "notNull": false,
+          "defaultValue": "false",
+          "primaryKey": false
+        },
+        "sort_order": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": "0",
+          "primaryKey": false
+        }
+      }
+    },
+    "token_model_availability": {
+      "columns": {
+        "id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": true
+        },
+        "token_id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "model_name": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "available": {
+          "logicalType": "boolean",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "latency_ms": {
+          "logicalType": "integer",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "checked_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": "datetime('now')",
+          "primaryKey": false
+        }
+      }
+    },
+    "token_routes": {
+      "columns": {
+        "id": {
+          "logicalType": "integer",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": true
+        },
+        "model_pattern": {
+          "logicalType": "text",
+          "notNull": true,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "model_mapping": {
+          "logicalType": "json",
+          "notNull": false,
+          "defaultValue": null,
+          "primaryKey": false
+        },
+        "enabled": {
+          "logicalType": "boolean",
+          "notNull": false,
+          "defaultValue": "true",
+          "primaryKey": false
+        },
+        "created_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": "datetime('now')",
+          "primaryKey": false
+        },
+        "updated_at": {
+          "logicalType": "datetime",
+          "notNull": false,
+          "defaultValue": "datetime('now')",
+          "primaryKey": false
+        }
+      }
+    }
+  },
+  "indexes": [
+    {
+      "name": "account_tokens_account_enabled_idx",
+      "table": "account_tokens",
+      "columns": [
+        "account_id",
+        "enabled"
+      ],
+      "unique": false
+    },
+    {
+      "name": "account_tokens_account_id_idx",
+      "table": "account_tokens",
+      "columns": [
+        "account_id"
+      ],
+      "unique": false
+    },
+    {
+      "name": "account_tokens_enabled_idx",
+      "table": "account_tokens",
+      "columns": [
+        "enabled"
+      ],
+      "unique": false
+    },
+    {
+      "name": "accounts_site_id_idx",
+      "table": "accounts",
+      "columns": [
+        "site_id"
+      ],
+      "unique": false
+    },
+    {
+      "name": "accounts_site_status_idx",
+      "table": "accounts",
+      "columns": [
+        "site_id",
+        "status"
+      ],
+      "unique": false
+    },
+    {
+      "name": "accounts_status_idx",
+      "table": "accounts",
+      "columns": [
+        "status"
+      ],
+      "unique": false
+    },
+    {
+      "name": "checkin_logs_account_created_at_idx",
+      "table": "checkin_logs",
+      "columns": [
+        "account_id",
+        "created_at"
+      ],
+      "unique": false
+    },
+    {
+      "name": "checkin_logs_created_at_idx",
+      "table": "checkin_logs",
+      "columns": [
+        "created_at"
+      ],
+      "unique": false
+    },
+    {
+      "name": "checkin_logs_status_idx",
+      "table": "checkin_logs",
+      "columns": [
+        "status"
+      ],
+      "unique": false
+    },
+    {
+      "name": "events_created_at_idx",
+      "table": "events",
+      "columns": [
+        "created_at"
+      ],
+      "unique": false
+    },
+    {
+      "name": "events_read_created_at_idx",
+      "table": "events",
+      "columns": [
+        "read",
+        "created_at"
+      ],
+      "unique": false
+    },
+    {
+      "name": "events_type_created_at_idx",
+      "table": "events",
+      "columns": [
+        "type",
+        "created_at"
+      ],
+      "unique": false
+    },
+    {
+      "name": "model_availability_account_available_idx",
+      "table": "model_availability",
+      "columns": [
+        "account_id",
+        "available"
+      ],
+      "unique": false
+    },
+    {
+      "name": "model_availability_account_model_unique",
+      "table": "model_availability",
+      "columns": [
+        "account_id",
+        "model_name"
+      ],
+      "unique": true
+    },
+    {
+      "name": "model_availability_model_name_idx",
+      "table": "model_availability",
+      "columns": [
+        "model_name"
+      ],
+      "unique": false
+    },
+    {
+      "name": "proxy_logs_account_created_at_idx",
+      "table": "proxy_logs",
+      "columns": [
+        "account_id",
+        "created_at"
+      ],
+      "unique": false
+    },
+    {
+      "name": "proxy_logs_created_at_idx",
+      "table": "proxy_logs",
+      "columns": [
+        "created_at"
+      ],
+      "unique": false
+    },
+    {
+      "name": "proxy_logs_model_actual_created_at_idx",
+      "table": "proxy_logs",
+      "columns": [
+        "model_actual",
+        "created_at"
+      ],
+      "unique": false
+    },
+    {
+      "name": "proxy_logs_status_created_at_idx",
+      "table": "proxy_logs",
+      "columns": [
+        "status",
+        "created_at"
+      ],
+      "unique": false
+    },
+    {
+      "name": "route_channels_account_id_idx",
+      "table": "route_channels",
+      "columns": [
+        "account_id"
+      ],
+      "unique": false
+    },
+    {
+      "name": "route_channels_route_enabled_idx",
+      "table": "route_channels",
+      "columns": [
+        "route_id",
+        "enabled"
+      ],
+      "unique": false
+    },
+    {
+      "name": "route_channels_route_id_idx",
+      "table": "route_channels",
+      "columns": [
+        "route_id"
+      ],
+      "unique": false
+    },
+    {
+      "name": "route_channels_route_token_idx",
+      "table": "route_channels",
+      "columns": [
+        "route_id",
+        "token_id"
+      ],
+      "unique": false
+    },
+    {
+      "name": "route_channels_token_id_idx",
+      "table": "route_channels",
+      "columns": [
+        "token_id"
+      ],
+      "unique": false
+    },
+    {
+      "name": "site_disabled_models_site_id_idx",
+      "table": "site_disabled_models",
+      "columns": [
+        "site_id"
+      ],
+      "unique": false
+    },
+    {
+      "name": "site_disabled_models_site_model_unique",
+      "table": "site_disabled_models",
+      "columns": [
+        "site_id",
+        "model_name"
+      ],
+      "unique": true
+    },
+    {
+      "name": "sites_status_idx",
+      "table": "sites",
+      "columns": [
+        "status"
+      ],
+      "unique": false
+    },
+    {
+      "name": "token_model_availability_available_idx",
+      "table": "token_model_availability",
+      "columns": [
+        "available"
+      ],
+      "unique": false
+    },
+    {
+      "name": "token_model_availability_model_name_idx",
+      "table": "token_model_availability",
+      "columns": [
+        "model_name"
+      ],
+      "unique": false
+    },
+    {
+      "name": "token_model_availability_token_available_idx",
+      "table": "token_model_availability",
+      "columns": [
+        "token_id",
+        "available"
+      ],
+      "unique": false
+    },
+    {
+      "name": "token_model_availability_token_model_unique",
+      "table": "token_model_availability",
+      "columns": [
+        "token_id",
+        "model_name"
+      ],
+      "unique": true
+    },
+    {
+      "name": "token_routes_enabled_idx",
+      "table": "token_routes",
+      "columns": [
+        "enabled"
+      ],
+      "unique": false
+    },
+    {
+      "name": "token_routes_model_pattern_idx",
+      "table": "token_routes",
+      "columns": [
+        "model_pattern"
+      ],
+      "unique": false
+    }
+  ],
+  "uniques": [
+    {
+      "name": "model_availability_account_model_unique",
+      "table": "model_availability",
+      "columns": [
+        "account_id",
+        "model_name"
+      ]
+    },
+    {
+      "name": "site_disabled_models_site_model_unique",
+      "table": "site_disabled_models",
+      "columns": [
+        "site_id",
+        "model_name"
+      ]
+    },
+    {
+      "name": "token_model_availability_token_model_unique",
+      "table": "token_model_availability",
+      "columns": [
+        "token_id",
+        "model_name"
+      ]
+    }
+  ],
+  "foreignKeys": [
+    {
+      "table": "account_tokens",
+      "columns": [
+        "account_id"
+      ],
+      "referencedTable": "accounts",
+      "referencedColumns": [
+        "id"
+      ],
+      "onDelete": "CASCADE"
+    },
+    {
+      "table": "accounts",
+      "columns": [
+        "site_id"
+      ],
+      "referencedTable": "sites",
+      "referencedColumns": [
+        "id"
+      ],
+      "onDelete": "CASCADE"
+    },
+    {
+      "table": "checkin_logs",
+      "columns": [
+        "account_id"
+      ],
+      "referencedTable": "accounts",
+      "referencedColumns": [
+        "id"
+      ],
+      "onDelete": "CASCADE"
+    },
+    {
+      "table": "model_availability",
+      "columns": [
+        "account_id"
+      ],
+      "referencedTable": "accounts",
+      "referencedColumns": [
+        "id"
+      ],
+      "onDelete": "CASCADE"
+    },
+    {
+      "table": "route_channels",
+      "columns": [
+        "account_id"
+      ],
+      "referencedTable": "accounts",
+      "referencedColumns": [
+        "id"
+      ],
+      "onDelete": "CASCADE"
+    },
+    {
+      "table": "route_channels",
+      "columns": [
+        "route_id"
+      ],
+      "referencedTable": "token_routes",
+      "referencedColumns": [
+        "id"
+      ],
+      "onDelete": "CASCADE"
+    },
+    {
+      "table": "route_channels",
+      "columns": [
+        "token_id"
+      ],
+      "referencedTable": "account_tokens",
+      "referencedColumns": [
+        "id"
+      ],
+      "onDelete": "SET NULL"
+    },
+    {
+      "table": "site_disabled_models",
+      "columns": [
+        "site_id"
+      ],
+      "referencedTable": "sites",
+      "referencedColumns": [
+        "id"
+      ],
+      "onDelete": "CASCADE"
+    },
+    {
+      "table": "token_model_availability",
+      "columns": [
+        "token_id"
+      ],
+      "referencedTable": "account_tokens",
+      "referencedColumns": [
+        "id"
+      ],
+      "onDelete": "CASCADE"
+    }
+  ]
+}
diff --git a/src/server/db/schemaArtifactGenerator.test.ts b/src/server/db/schemaArtifactGenerator.test.ts
index 1afccad..8ecff80 100644
--- a/src/server/db/schemaArtifactGenerator.test.ts
+++ b/src/server/db/schemaArtifactGenerator.test.ts
@@ -106,4 +106,13 @@ describe('schema artifact generator', () => {
     expect(artifacts.mysqlBootstrap).toContain('`created_at` DATETIME DEFAULT CURRENT_TIMESTAMP');
     expect(artifacts.postgresBootstrap).toContain('"created_at" TIMESTAMP DEFAULT CURRENT_TIMESTAMP');
   });
+
+  it('rejects destructive diffs when generating additive upgrades', () => {
+    const current = readSchemaContract();
+    const previous = structuredClone(current);
+
+    delete current.tables.sites.columns.status;
+
+    expect(() => generateDialectArtifacts(current, previous)).toThrow(/non-additive schema diff/i);
+  });
 });
diff --git a/src/server/db/schemaArtifactGenerator.ts b/src/server/db/schemaArtifactGenerator.ts
index 7cd8d03..fa4ba10 100644
--- a/src/server/db/schemaArtifactGenerator.ts
+++ b/src/server/db/schemaArtifactGenerator.ts
@@ -18,6 +18,7 @@ export interface GeneratedDialectArtifacts {
 }
 
 type Dialect = 'mysql' | 'postgres';
+type SqlDialect = 'sqlite' | Dialect;
 
 function resolveDbDir(): string {
   return dirname(fileURLToPath(import.meta.url));
@@ -27,7 +28,7 @@ export function resolveGeneratedArtifactPath(filename: string): string {
   return resolve(resolveDbDir(), 'generated', filename);
 }
 
-function quoteIdentifier(dialect: Dialect, identifier: string): string {
+function quoteIdentifier(dialect: SqlDialect, identifier: string): string {
   return dialect === 'mysql' ? `\`${identifier}\`` : `"${identifier}"`;
 }
 
@@ -35,7 +36,22 @@ function escapeMysqlTextPrefix(columnType: LogicalColumnType): string {
   return columnType === 'text' || columnType === 'datetime' || columnType === 'json' ? '(191)' : '';
 }
 
-function mapColumnType(dialect: Dialect, columnName: string, column: SchemaContractColumn): string {
+function mapColumnType(dialect: SqlDialect, columnName: string, column: SchemaContractColumn): string {
+  if (dialect === 'sqlite') {
+    switch (column.logicalType) {
+      case 'boolean':
+      case 'integer':
+        return 'INTEGER';
+      case 'real':
+        return 'REAL';
+      case 'datetime':
+      case 'json':
+      case 'text':
+      default:
+        return 'TEXT';
+    }
+  }
+
   if (dialect === 'mysql') {
     switch (column.logicalType) {
       case 'boolean':
@@ -72,12 +88,15 @@ function mapColumnType(dialect: Dialect, columnName: string, column: SchemaContr
   }
 }
 
-function formatDefaultValue(column: SchemaContractColumn): string {
+function formatDefaultValue(dialect: SqlDialect, column: SchemaContractColumn): string {
   if (column.defaultValue == null || column.primaryKey) {
     return '';
   }
 
   if (column.logicalType === 'datetime') {
+    if (dialect === 'sqlite') {
+      return " DEFAULT (datetime('now'))";
+    }
     return ' DEFAULT CURRENT_TIMESTAMP';
   }
 
@@ -89,18 +108,18 @@ function formatDefaultValue(column: SchemaContractColumn): string {
 }
 
 function buildColumnDefinition(
-  dialect: Dialect,
+  dialect: SqlDialect,
   columnName: string,
   column: SchemaContractColumn,
 ): string {
   const sqlType = mapColumnType(dialect, columnName, column);
   const notNull = column.notNull ? ' NOT NULL' : '';
-  const defaultValue = formatDefaultValue(column);
+  const defaultValue = formatDefaultValue(dialect, column);
   const primaryKey = column.primaryKey ? ' PRIMARY KEY' : '';
   return `${quoteIdentifier(dialect, columnName)} ${sqlType}${notNull}${defaultValue}${primaryKey}`;
 }
 
-function buildForeignKeyClause(dialect: Dialect, foreignKey: SchemaContractForeignKey): string {
+function buildForeignKeyClause(dialect: SqlDialect, foreignKey: SchemaContractForeignKey): string {
   const sourceColumns = foreignKey.columns.map((column) => quoteIdentifier(dialect, column)).join(', ');
   const targetColumns = foreignKey.referencedColumns.map((column) => quoteIdentifier(dialect, column)).join(', ');
   const onDelete = foreignKey.onDelete ? ` ON DELETE ${foreignKey.onDelete.toUpperCase()}` : '';
@@ -144,7 +163,7 @@ function sortTableNamesForCreation(contract: SchemaContract): string[] {
 }
 
 function buildCreateTableStatement(
-  dialect: Dialect,
+  dialect: SqlDialect,
   tableName: string,
   contract: SchemaContract,
 ): string {
@@ -158,7 +177,7 @@ function buildCreateTableStatement(
   return `CREATE TABLE IF NOT EXISTS ${quoteIdentifier(dialect, tableName)} (${parts.join(', ')})`;
 }
 
-function buildUniqueIndexStatement(dialect: Dialect, uniqueIndex: SchemaContractUnique, contract: SchemaContract): string {
+function buildUniqueIndexStatement(dialect: SqlDialect, uniqueIndex: SchemaContractUnique, contract: SchemaContract): string {
   const columns = uniqueIndex.columns
     .map((columnName) => {
       const column = contract.tables[uniqueIndex.table]?.columns[columnName];
@@ -169,7 +188,7 @@ function buildUniqueIndexStatement(dialect: Dialect, uniqueIndex: SchemaContract
   return `CREATE UNIQUE INDEX ${quoteIdentifier(dialect, uniqueIndex.name)} ON ${quoteIdentifier(dialect, uniqueIndex.table)} (${columns})`;
 }
 
-function buildIndexStatement(dialect: Dialect, index: SchemaContractIndex, contract: SchemaContract): string {
+function buildIndexStatement(dialect: SqlDialect, index: SchemaContractIndex, contract: SchemaContract): string {
   const columns = index.columns
     .map((columnName) => {
       const column = contract.tables[index.table]?.columns[columnName];
@@ -180,7 +199,93 @@ function buildIndexStatement(dialect: Dialect, index: SchemaContractIndex, contr
   return `CREATE INDEX ${quoteIdentifier(dialect, index.name)} ON ${quoteIdentifier(dialect, index.table)} (${columns})`;
 }
 
-function buildBootstrapSql(dialect: Dialect, contract: SchemaContract): string {
+function serializeColumn(column: SchemaContractColumn): string {
+  return [
+    column.logicalType,
+    column.notNull ? 'not-null' : 'nullable',
+    column.defaultValue ?? 'default:null',
+    column.primaryKey ? 'pk' : 'non-pk',
+  ].join('|');
+}
+
+function serializeIndex(index: SchemaContractIndex): string {
+  return [index.table, index.columns.join(','), index.unique ? 'unique' : 'non-unique'].join('|');
+}
+
+function serializeUnique(unique: SchemaContractUnique): string {
+  return [unique.table, unique.columns.join(',')].join('|');
+}
+
+function serializeForeignKey(foreignKey: SchemaContractForeignKey): string {
+  return [
+    foreignKey.table,
+    foreignKey.columns.join(','),
+    foreignKey.referencedTable,
+    foreignKey.referencedColumns.join(','),
+    foreignKey.onDelete ?? 'null',
+  ].join('|');
+}
+
+function assertAdditiveSchemaDiff(currentContract: SchemaContract, previousContract: SchemaContract): void {
+  const violations: string[] = [];
+
+  for (const [tableName, previousTable] of Object.entries(previousContract.tables)) {
+    const currentTable = currentContract.tables[tableName];
+    if (!currentTable) {
+      violations.push(`removed table ${tableName}`);
+      continue;
+    }
+
+    for (const [columnName, previousColumn] of Object.entries(previousTable.columns)) {
+      const currentColumn = currentTable.columns[columnName];
+      if (!currentColumn) {
+        violations.push(`removed column ${tableName}.${columnName}`);
+        continue;
+      }
+
+      if (serializeColumn(currentColumn) !== serializeColumn(previousColumn)) {
+        violations.push(`changed column ${tableName}.${columnName}`);
+      }
+    }
+  }
+
+  const currentIndexes = new Map(currentContract.indexes.map((index) => [index.name, index]));
+  for (const previousIndex of previousContract.indexes) {
+    const currentIndex = currentIndexes.get(previousIndex.name);
+    if (!currentIndex) {
+      violations.push(`removed index ${previousIndex.name}`);
+      continue;
+    }
+    if (serializeIndex(currentIndex) !== serializeIndex(previousIndex)) {
+      violations.push(`changed index ${previousIndex.name}`);
+    }
+  }
+
+  const currentUniques = new Map(currentContract.uniques.map((unique) => [unique.name, unique]));
+  for (const previousUnique of previousContract.uniques) {
+    const currentUnique = currentUniques.get(previousUnique.name);
+    if (!currentUnique) {
+      violations.push(`removed unique ${previousUnique.name}`);
+      continue;
+    }
+    if (serializeUnique(currentUnique) !== serializeUnique(previousUnique)) {
+      violations.push(`changed unique ${previousUnique.name}`);
+    }
+  }
+
+  const currentForeignKeys = new Set(currentContract.foreignKeys.map(serializeForeignKey));
+  for (const previousForeignKey of previousContract.foreignKeys) {
+    if (!currentForeignKeys.has(serializeForeignKey(previousForeignKey))) {
+      violations.push(`removed foreign key ${previousForeignKey.table}(${previousForeignKey.columns.join(',')})`);
+    }
+  }
+
+  if (violations.length > 0) {
+    throw new Error(`Non-additive schema diff detected:\n- ${violations.join('\n- ')}`);
+  }
+}
+
+export function generateBootstrapSql(dialect: SqlDialect, contract: SchemaContract): string {
   const tableStatements = sortTableNamesForCreation(contract)
     .map((tableName) => buildCreateTableStatement(dialect, tableName, contract));
 
@@ -200,7 +305,7 @@ function buildBootstrapSql(dialect: Dialect, contract: SchemaContract): string {
 }
 
 function buildAddColumnStatement(
-  dialect: Dialect,
+  dialect: SqlDialect,
   tableName: string,
   columnName: string,
   column: SchemaContractColumn,
@@ -208,8 +313,8 @@ function buildAddColumnStatement(
   return `ALTER TABLE ${quoteIdentifier(dialect, tableName)} ADD COLUMN ${buildColumnDefinition(dialect, columnName, column)}`;
 }
 
-function buildUpgradeSql(
-  dialect: Dialect,
+export function generateUpgradeSql(
+  dialect: SqlDialect,
   currentContract: SchemaContract,
   previousContract?: SchemaContract | null,
 ): string {
@@ -217,6 +322,8 @@ function buildUpgradeSql(
     return `-- no previous schema contract available for ${dialect} additive upgrade generation\n`;
   }
 
+  assertAdditiveSchemaDiff(currentContract, previousContract);
+
   const previousTableNames = new Set(Object.keys(previousContract.tables));
   const currentTableNames = Object.keys(currentContract.tables).sort((left, right) => left.localeCompare(right, 'en'));
   const addedTableNames = currentTableNames.filter((tableName) => !previousTableNames.has(tableName));
@@ -274,10 +381,10 @@ export function generateDialectArtifacts(
   previousContract?: SchemaContract | null,
 ): GeneratedDialectArtifacts {
   return {
-    mysqlBootstrap: buildBootstrapSql('mysql', contract),
-    postgresBootstrap: buildBootstrapSql('postgres', contract),
-    mysqlUpgrade: buildUpgradeSql('mysql', contract, previousContract),
-    postgresUpgrade: buildUpgradeSql('postgres', contract, previousContract),
+    mysqlBootstrap: generateBootstrapSql('mysql', contract),
+    postgresBootstrap: generateBootstrapSql('postgres', contract),
+    mysqlUpgrade: generateUpgradeSql('mysql', contract, previousContract),
+    postgresUpgrade: generateUpgradeSql('postgres', contract, previousContract),
   };
 }
 
diff --git a/src/server/db/schemaIntrospection.ts b/src/server/db/schemaIntrospection.ts
index 185d9a3..a3a97e3 100644
--- a/src/server/db/schemaIntrospection.ts
+++ b/src/server/db/schemaIntrospection.ts
@@ -5,7 +5,11 @@ import { tmpdir } from 'node:os';
 import pg from 'pg';
 import { join, resolve } from 'node:path';
 import { randomUUID } from 'node:crypto';
-import { resolveGeneratedArtifactPath } from './schemaArtifactGenerator.js';
+import {
+  generateBootstrapSql,
+  generateUpgradeSql,
+  resolveGeneratedArtifactPath,
+} from './schemaArtifactGenerator.js';
 import type {
   LogicalColumnType,
   SchemaContract,
@@ -30,6 +34,8 @@ export interface MaterializeFreshSchemaOptions {
   ssl?: boolean;
 }
 
+export interface ApplyContractFixtureThenUpgradeOptions extends MaterializeFreshSchemaOptions {}
+
 type SqliteTableInfoRow = {
   name: string;
   type: string;
@@ -124,7 +130,12 @@ function splitMigrationStatements(sqlText: string): string[] {
 }
 
 function splitSqlStatements(sqlText: string): string[] {
-  return sqlText
+  const withoutCommentLines = sqlText
+    .split(/\r?\n/g)
+    .filter((line) => !line.trim().startsWith('--'))
+    .join('\n');
+
+  return withoutCommentLines
     .split(/;\s*(?:\r?\n|$)/g)
     .map((statement) => statement.trim())
     .filter((statement) => statement.length > 0);
@@ -762,13 +773,76 @@ function applySqliteMigrations(sqlite: Database.Database): void {
   }
 }
 
+function createTemporarySqlitePath(): string {
+  const tempDir = mkdtempSync(join(tmpdir(), 'metapi-schema-parity-'));
+  return resolve(tempDir, `${randomUUID()}.db`);
+}
+
+function applySqliteStatements(sqlitePath: string, statements: string[]): void {
+  const sqlite = new Database(sqlitePath);
+  sqlite.pragma('foreign_keys = ON');
+  try {
+    for (const statement of statements) {
+      sqlite.exec(statement);
+    }
+  } finally {
+    sqlite.close();
+  }
+}
+
+async function applyMySqlStatements(
+  connectionString: string,
+  ssl: boolean | undefined,
+  statements: string[],
+  resetSchema = false,
+): Promise<void> {
+  const connectionOptions: mysql.ConnectionOptions = { uri: connectionString };
+  if (ssl) {
+    connectionOptions.ssl = { rejectUnauthorized: false };
+  }
+  const connection = await mysql.createConnection(connectionOptions);
+  try {
+    if (resetSchema) {
+      await resetMySqlSchema(connection);
+    }
+    for (const statement of statements) {
+      await connection.query(statement);
+    }
+  } finally {
+    await connection.end();
+  }
+}
+
+async function applyPostgresStatements(
+  connectionString: string,
+  ssl: boolean | undefined,
+  statements: string[],
+  resetSchema = false,
+): Promise<void> {
+  const clientOptions: pg.ClientConfig = { connectionString };
+  if (ssl) {
+    clientOptions.ssl = { rejectUnauthorized: false };
+  }
+  const client = new pg.Client(clientOptions);
+  await client.connect();
+  try {
+    if (resetSchema) {
+      await resetPostgresSchema(client);
+    }
+    for (const statement of statements) {
+      await client.query(statement);
+    }
+  } finally {
+    await client.end();
+  }
+}
+
 export async function materializeFreshSchema(
   dialect: SchemaIntrospectionDialect,
   options: MaterializeFreshSchemaOptions = {},
 ): Promise<string> {
   if (dialect === 'sqlite') {
-    const tempDir = mkdtempSync(join(tmpdir(), 'metapi-schema-parity-'));
-    const sqlitePath = resolve(tempDir, `${randomUUID()}.db`);
+    const sqlitePath = createTemporarySqlitePath();
     const sqlite = new Database(sqlitePath);
     sqlite.pragma('foreign_keys = ON');
     try {
@@ -785,35 +859,47 @@ export async function materializeFreshSchema(
 
   const bootstrapStatements = splitSqlStatements(readBootstrapSql(dialect));
   if (dialect === 'mysql') {
-    const connectionOptions: mysql.ConnectionOptions = { uri: options.connectionString };
-    if (options.ssl) {
-      connectionOptions.ssl = { rejectUnauthorized: false };
+    await applyMySqlStatements(options.connectionString, options.ssl, bootstrapStatements, true);
+    return options.connectionString;
+  }
+
+  await applyPostgresStatements(options.connectionString, options.ssl, bootstrapStatements, true);
+  return options.connectionString;
+}
+
+export async function applyContractFixtureThenUpgrade(
+  dialect: SchemaIntrospectionDialect,
+  baselineContract: SchemaContract,
+  currentContract: SchemaContract,
+  options: ApplyContractFixtureThenUpgradeOptions = {},
+): Promise<string> {
+  const bootstrapStatements = splitSqlStatements(generateBootstrapSql(dialect, baselineContract));
+  const upgradeStatements = splitSqlStatements(generateUpgradeSql(dialect, currentContract, baselineContract));
+
+  if (dialect === 'sqlite') {
+    const sqlitePath = createTemporarySqlitePath();
+    applySqliteStatements(sqlitePath, bootstrapStatements);
+    if (upgradeStatements.length > 0) {
+      applySqliteStatements(sqlitePath, upgradeStatements);
     }
-    const connection = await mysql.createConnection(connectionOptions);
-    try {
-      await resetMySqlSchema(connection);
-      for (const statement of bootstrapStatements) {
-        await connection.query(statement);
-      }
-    } finally {
-      await connection.end();
+    return sqlitePath;
+  }
+
+  if (!options.connectionString) {
+    throw new Error(`connectionString is required to upgrade ${dialect} parity schema`);
+  }
+
+  if (dialect === 'mysql') {
+    await applyMySqlStatements(options.connectionString, options.ssl, bootstrapStatements, true);
+    if (upgradeStatements.length > 0) {
+      await applyMySqlStatements(options.connectionString, options.ssl, upgradeStatements, false);
     }
     return options.connectionString;
   }
 
-  const clientOptions: pg.ClientConfig = { connectionString: options.connectionString };
-  if (options.ssl) {
-    clientOptions.ssl = { rejectUnauthorized: false };
-  }
-  const client = new pg.Client(clientOptions);
-  await client.connect();
-  try {
-    await resetPostgresSchema(client);
-    for (const statement of bootstrapStatements) {
-      await client.query(statement);
-    }
-  } finally {
-    await client.end();
+  await applyPostgresStatements(options.connectionString, options.ssl, bootstrapStatements, true);
+  if (upgradeStatements.length > 0) {
+    await applyPostgresStatements(options.connectionString, options.ssl, upgradeStatements, false);
   }
   return options.connectionString;
 }
diff --git a/src/server/db/schemaUpgrade.live.test.ts b/src/server/db/schemaUpgrade.live.test.ts
new file mode 100644
index 0000000..f58378a
--- /dev/null
+++ b/src/server/db/schemaUpgrade.live.test.ts
@@ -0,0 +1,31 @@
+import baselineContract from './generated/fixtures/2026-03-14-baseline.schemaContract.json' with { type: 'json' };
+import currentContract from './generated/schemaContract.json' with { type: 'json' };
+import { applyContractFixtureThenUpgrade, introspectLiveSchema } from './schemaIntrospection.js';
+import { describe, expect, it } from 'vitest';
+
+const mysqlUpgrade = process.env.DB_PARITY_MYSQL_URL ? it : it.skip;
+const postgresUpgrade = process.env.DB_PARITY_POSTGRES_URL ? it : it.skip;
+
+describe('schema upgrade parity', () => {
+  it('upgrades sqlite to the current contract', async () => {
+    const sqliteUrl = await applyContractFixtureThenUpgrade('sqlite', baselineContract, currentContract);
+    const live = await introspectLiveSchema({ dialect: 'sqlite', connectionString: sqliteUrl });
+    expect(live).toEqual(currentContract);
+  });
+
+  mysqlUpgrade('upgrades mysql to the current contract', async () => {
+    const mysqlUrl = await applyContractFixtureThenUpgrade('mysql', baselineContract, currentContract, {
+      connectionString: process.env.DB_PARITY_MYSQL_URL!,
+    });
+    const live = await introspectLiveSchema({ dialect: 'mysql', connectionString: mysqlUrl });
+    expect(live).toEqual(currentContract);
+  });
+
+  postgresUpgrade('upgrades postgres to the current contract', async () => {
+    const postgresUrl = await applyContractFixtureThenUpgrade('postgres', baselineContract, currentContract, {
+      connectionString: process.env.DB_PARITY_POSTGRES_URL!,
+    });
+    const live = await introspectLiveSchema({ dialect: 'postgres', connectionString: postgresUrl });
+    expect(live).toEqual(currentContract);
+  });
+});