diff --git a/cmd/schema_gen.go b/cmd/schema_gen.go
index 37169fd..cc9d688 100644
--- a/cmd/schema_gen.go
+++ b/cmd/schema_gen.go
@@ -146,8 +146,8 @@ func suggestDocsForGraph(graph *fs.Graph) error {
 }
 
 // generateSchemaForModel generates a schema and writes yml for modelName.
-func generateSchemaForModel(ctx context.Context, model *fs.File) error {
-	target, err := model.GetTarget()
+func generateSchemaForModel(ctx context.Context, file *fs.File) error {
+	target, err := file.GetTarget()
 	if err != nil {
 		fmt.Println("could not get target for schema")
 		return err
@@ -155,7 +155,7 @@ func generateSchemaForModel(ctx context.Context, model *fs.File) error {
 	fmt.Println("\n🎯 Target for retrieving schema:", target.ProjectID+"."+target.DataSet)
 
 	// retrieve columns from BigQuery
-	bqColumns, err := getColumnsForModel(ctx, model.Name, target)
+	bqColumns, err := getColumnsForModel(ctx, file.Name, target)
 	if err != nil {
 		fmt.Println("Could not retrieve schema")
 		return err
@@ -163,16 +163,16 @@ func generateSchemaForModel(ctx context.Context, model *fs.File) error {
 	fmt.Println("✅ BQ Schema retrieved. Number of columns in BQ table:", len(bqColumns))
 
 	// create schema file
-	ymlPath, schemaFile := generateEmptySchemaFile(model)
+	ymlPath, schemaFile := generateEmptySchemaFile(file)
 	var schemaModel *properties.Model
 
-	if model.Schema == nil {
-		fmt.Println("\n🔍 " + model.Name + " schema file not found.. 🌱 Generating new schema file")
-		schemaModel = generateNewSchemaModel(model.Name, bqColumns)
+	if file.Schema == nil {
+		fmt.Println("\n🔍 " + file.Name + " schema file not found.. 🌱 Generating new schema file")
+		schemaModel = generateNewSchemaModel(file.Name, bqColumns)
 	} else {
-		fmt.Println("\n🔍 " + model.Name + " schema file found.. 🛠  Updating schema file")
-		// set working schema model to current schema model
-		schemaModel = model.Schema
+		fmt.Println("\n🔍 " + file.Name + " schema file found.. 🛠  Updating schema file")
+		// set working schema file to current schema file
+		schemaModel = file.Schema
 		// add and remove columns in-place
 		addMissingColumnsToSchema(schemaModel, bqColumns)
 		removeOutdatedColumnsFromSchema(schemaModel, bqColumns)
@@ -184,7 +184,7 @@ func generateSchemaForModel(ctx context.Context, model *fs.File) error {
 		fmt.Println("Error writing YML to file in path")
 		return err
 	}
-	fmt.Println("\n✅ " + model.Name + "schema successfully updated at path: " + ymlPath)
+	fmt.Println("\n✅ " + file.Name + "schema successfully updated at path: " + ymlPath)
 
 	return nil
 }
@@ -205,8 +205,8 @@ func getColumnsForModel(ctx context.Context, modelName string, target *config.Ta
 
 // generate an empty schema file which will be populated according to existing yml schemas and the bigquery schema.
 // Returns the local path for the yml file and the yml file struct
-func generateEmptySchemaFile(model *fs.File) (ymlPath string, schemaFile properties.File) {
-	ymlPath = strings.Replace(model.Path, ".sql", ".yml", 1)
+func generateEmptySchemaFile(file *fs.File) (ymlPath string, schemaFile properties.File) {
+	ymlPath = strings.Replace(file.Path, ".sql", ".yml", 1)
 	schemaFile = properties.File{}
 	schemaFile.Version = properties.FileVersion
 	return ymlPath, schemaFile
diff --git a/cmd/test_gen.go b/cmd/test_gen.go
new file mode 100644
index 0000000..c0365e1
--- /dev/null
+++ b/cmd/test_gen.go
@@ -0,0 +1,318 @@
+package cmd
+
+import (
+	"context"
+	"ddbt/bigquery"
+	"ddbt/config"
+	"ddbt/fs"
+	"ddbt/properties"
+	schemaTestMacros "ddbt/schemaTestMacros"
+	"ddbt/utils"
+	"fmt"
+	"os"
+	"strings"
+	"sync"
+
+	"github.com/spf13/cobra"
+)
+
+// TODO:
+// only output suggestions to terminal for new tests
+// Parse macro files
+// Test with value inputs e.g. accepted values
+
+func init() {
+	rootCmd.AddCommand(testGenCmd)
+	addModelsFlag(testGenCmd)
+}
+
+type ColumnTestQuery struct {
+	Column    string
+	TestName  string
+	TestQuery string
+}
+
+type TestSuggestions struct {
+	mu          sync.Mutex
+	suggestions map[string]map[string][]string
+}
+
+func (d *TestSuggestions) SetSuggestion(modelName string, testSuggestions map[string][]string) {
+	d.mu.Lock()
+	d.suggestions[modelName] = testSuggestions
+	d.mu.Unlock()
+}
+
+func (d *TestSuggestions) Init() {
+	d.mu.Lock()
+	d.suggestions = make(map[string]map[string][]string)
+	d.mu.Unlock()
+}
+
+func (d *TestSuggestions) Value() (suggestions map[string]map[string][]string) {
+	d.mu.Lock()
+	suggestions = d.suggestions
+	d.mu.Unlock()
+	return
+}
+
+var testGenCmd = &cobra.Command{
+	Use:               "test-gen [model name]",
+	Short:             "Suggests tests to add to the YML schema file for a given model",
+	Args:              cobra.RangeArgs(0, 1),
+	ValidArgsFunction: completeModelFn,
+	Run: func(cmd *cobra.Command, args []string) {
+		switch {
+		case len(args) == 0 && len(ModelFilters) == 0:
+			fmt.Println("Please specify model with test-gen -m model-name")
+			os.Exit(1)
+		case len(args) == 1 && len(ModelFilters) > 0:
+			fmt.Println("Please specify model with either test-gen model-name or test-gen -m model-name but not both")
+			os.Exit(1)
+		case len(args) == 1:
+			// This will actually allow something weird like
+			// ddbt test-gen +model+
+			ModelFilters = append(ModelFilters, args[0])
+		}
+
+		fmt.Println(`ℹ️  test-gen requires models without sampling to be accurate
+❓  Have you run the provided models with sampling off? (y/N)`)
+		var userPrompt string
+		fmt.Scanln(&userPrompt)
+		if userPrompt != "y" {
+			fmt.Println("❌ Please run your model with sampling and then use test-gen")
+			os.Exit(1)
+		}
+
+		// Build a graph from the given filter.
+		fileSystem, _ := compileAllModels()
+		graph := buildGraph(fileSystem, ModelFilters)
+
+		// Generate schema for every file in the graph concurrently.
+		if err := generateTestsForModelsGraph(graph); err != nil {
+			fmt.Printf("❌ %s\n", err)
+			os.Exit(1)
+		}
+		os.Exit(1)
+	},
+}
+
+func generateTestsForModelsGraph(graph *fs.Graph) error {
+	pb := utils.NewProgressBar("🖨 Generating tests for models in graph", graph.Len())
+
+	ctx, cancel := context.WithCancel(context.Background())
+	var testSugs TestSuggestions
+	testSugs.Init()
+
+	err := graph.Execute(func(file *fs.File) error {
+		if file.Type == fs.ModelFile {
+			testSuggestions, err := generateTestsForModel(ctx, file)
+			if err != nil {
+				pb.Stop()
+				if err != context.Canceled {
+					fmt.Printf("❌ %s\n", err)
+				}
+				cancel()
+				return err
+			}
+			testSugs.SetSuggestion(file.Name, testSuggestions)
+		}
+
+		pb.Increment()
+		return nil
+	}, config.NumberThreads(), pb)
+
+	if err != nil {
+		return err
+	}
+	pb.Stop()
+
+	err = userPromptTests(graph, testSugs.suggestions)
+	if err != nil {
+		return err
+	}
+
+	return nil
+}
+
+// generateTestsForModel generates tests for model and writes yml schema for modelName.
+func generateTestsForModel(ctx context.Context, file *fs.File) (map[string][]string, error) {
+	target, err := file.GetTarget()
+	if err != nil {
+		fmt.Println("could not get target for schema")
+		return nil, err
+	}
+	fmt.Println("\n🎯 Target for retrieving schema:", target.ProjectID+"."+target.DataSet)
+
+	// retrieve columns from BigQuery
+	bqColumns, err := getColumnsForModel(ctx, file.Name, target)
+	if err != nil {
+		fmt.Println("Could not retrieve schema")
+		return nil, err
+	}
+	fmt.Println("✅ BQ Schema retrieved. Number of columns in BQ table:", len(bqColumns))
+
+	// iterate through functions which return test sql and definition
+	testFuncs := []func(string, string, string, string) (string, string){
+		schemaTestMacros.TestNotNullMacro,
+		schemaTestMacros.TestUniqueMacro,
+	}
+
+	var allTestQueries []ColumnTestQuery
+	for _, col := range bqColumns {
+		for _, test := range testFuncs {
+			testQuery, testName := test(target.ProjectID, target.DataSet, file.Name, col)
+			allTestQueries = append(allTestQueries, ColumnTestQuery{
+				Column:    col,
+				TestName:  testName,
+				TestQuery: testQuery,
+			})
+		}
+	}
+
+	passedTestQueries, err := runQueriesParallel(ctx, target, allTestQueries)
+	if err != nil {
+		return nil, err
+	}
+	updateSchemaFile(passedTestQueries, file)
+
+	return passedTestQueries, nil
+}
+
+func runQueriesParallel(ctx context.Context, target *config.Target, allTestQueries []ColumnTestQuery) (map[string][]string, error) {
+	// number of parallel query runners
+	numQueryRunners := 100
+
+	queries := make(chan ColumnTestQuery)
+	go func() {
+		for _, q := range allTestQueries {
+			queries <- q
+		}
+		close(queries)
+	}()
+
+	out := make(chan ColumnTestQuery, len(allTestQueries))
+	errs := make(chan error, len(allTestQueries))
+	wg := sync.WaitGroup{}
+
+	wg.Add(numQueryRunners)
+	for i := 0; i < numQueryRunners; i++ {
+		go func(i int) {
+			defer wg.Done()
+			for query := range queries {
+				evaluateTestQuery(ctx, target, query, out, errs, i)
+			}
+		}(i)
+	}
+
+	go func() {
+		wg.Wait()
+		close(out)
+		close(errs)
+	}()
+
+	if err := <-errs; err != nil {
+		// there is at least one error, but we ignore the rest
+		return nil, err
+	}
+
+	passedTestQueries := make(map[string][]string)
+	for passedTestQuery := range out {
+		if _, contains := passedTestQueries[passedTestQuery.Column]; contains {
+			passedTestQueries[passedTestQuery.Column] = append(passedTestQueries[passedTestQuery.Column], passedTestQuery.TestName)
+		} else {
+			passedTestQueries[passedTestQuery.Column] = []string{passedTestQuery.TestName}
+		}
+	}
+
+	return passedTestQueries, nil
+}
+
+func evaluateTestQuery(ctx context.Context, target *config.Target, ctq ColumnTestQuery, out chan ColumnTestQuery,
+	errs chan error, workerIndex int) {
+	results, _, err := bigquery.GetRows(ctx, ctq.TestQuery, target)
+
+	if err == nil {
+		if len(results) != 1 {
+			errs <- fmt.Errorf(fmt.Sprintf(
+				"a schema test should only return 1 row, got %d for %s test on column %s by worker %v",
+				len(results), ctq.TestName, ctq.Column, workerIndex),
+			)
+		} else if len(results[0]) != 1 {
+			errs <- fmt.Errorf(fmt.Sprintf(
+				"a schema test should only return 1 column, got %d for %s test on column %s by worker %v",
+				len(results), ctq.TestName, ctq.Column, workerIndex),
+			)
+		} else {
+			rows, _ := bigquery.ValueAsUint64(results[0][0])
+			if rows == 0 {
+				out <- ctq
+			}
+		}
+	}
+	if err != nil {
+		errs <- err
+	}
+
+}
+
+func updateSchemaFile(passedTestQueries map[string][]string, model *fs.File) {
+	updatedColumns := model.Schema.Columns
+	for colIndex, column := range model.Schema.Columns {
+		if _, exists := passedTestQueries[column.Name]; exists {
+
+			// search for test in existing tests
+			for _, test := range passedTestQueries[column.Name] {
+				testFound := false
+				for _, existingTest := range column.Tests {
+					if existingTest.Name == test {
+						testFound = true
+						break
+					}
+				}
+				if !testFound {
+					column.Tests = append(column.Tests, &properties.Test{
+						Name: test,
+					})
+				}
+			}
+		}
+		updatedColumns[colIndex] = column
+	}
+	model.Schema.Columns = updatedColumns
+}
+
+func userPromptTests(graph *fs.Graph, testSugsMap map[string]map[string][]string) error {
+	if len(testSugsMap) > 0 {
+		fmt.Println("\n🧪 Valid tests found for the following models: ")
+		for model, columnTests := range testSugsMap {
+			fmt.Println("\n🧬 Model:", model)
+			for column, tests := range columnTests {
+				fmt.Println("🏛 Column:", column)
+				testPrint := strings.Join(tests[:], "\n  - ")
+				fmt.Println("  -", testPrint)
+			}
+		}
+		fmt.Println("\n❔ Would you like to add these tests to the schema (y/N)?")
+
+		var userPrompt string
+		fmt.Scanln(&userPrompt)
+
+		if userPrompt == "y" {
+			for file, _ := range graph.ListNodes() {
+				if _, contains := testSugsMap[file.Name]; contains {
+					ymlPath, schemaFile := generateEmptySchemaFile(file)
+					schemaModel := file.Schema
+					schemaFile.Models = properties.Models{schemaModel}
+					err := schemaFile.WriteToFile(ymlPath)
+					if err != nil {
+						fmt.Println("Error writing YML to file in path")
+						return err
+					}
+				}
+			}
+			fmt.Println("✅ Tests added to schema files")
+		}
+	}
+	return nil
+}
diff --git a/schemaTestMacros/testNotNullMacro.go b/schemaTestMacros/testNotNullMacro.go
new file mode 100644
index 0000000..bda5a1e
--- /dev/null
+++ b/schemaTestMacros/testNotNullMacro.go
@@ -0,0 +1,9 @@
+package schemaTestMacros
+
+import "fmt"
+
+func TestNotNullMacro(project string, dataset string, model string, column_name string) (string, string) {
+	return fmt.Sprintf(`select count(*) 
+	from %s.%s.%s where %s is null
+	`, project, dataset, model, column_name), "not_null"
+}
diff --git a/schemaTestMacros/testUniqueMacro.go b/schemaTestMacros/testUniqueMacro.go
new file mode 100644
index 0000000..0c7a168
--- /dev/null
+++ b/schemaTestMacros/testUniqueMacro.go
@@ -0,0 +1,16 @@
+package schemaTestMacros
+
+import "fmt"
+
+func TestUniqueMacro(project string, dataset string, model string, column_name string) (string, string) {
+	return fmt.Sprintf(`select count(*)
+	from (
+		select
+			%s
+		from %s.%s.%s
+		where %s is not null
+		group by %s
+		having count(*) > 1
+	) validation_errors
+	`, column_name, project, dataset, model, column_name, column_name), "unique"
+}
diff --git a/utils/version.go b/utils/version.go
index b54bfad..33ee5fd 100644
--- a/utils/version.go
+++ b/utils/version.go
@@ -1,3 +1,3 @@
 package utils
 
-const DdbtVersion = "0.5.1"
+const DdbtVersion = "0.6.0"