diff --git a/internal/search/platform.go b/internal/search/platform.go
new file mode 100644
index 0000000..c29acf6
--- /dev/null
+++ b/internal/search/platform.go
@@ -0,0 +1,72 @@
+package search
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	glean "github.com/gleanwork/api-client-go"
+	"github.com/gleanwork/api-client-go/models/components"
+)
+
+// datasourceField is the facet filter field that both API surfaces route to
+// a dedicated datasource filter instead of the generic filter mechanism.
+const datasourceField = "datasource"
+
+// BuildPlatformSearchRequest converts Options into the platform API's
+// components.PlatformSearchRequest. The platform surface is deliberately
+// narrower than the classic SearchRequest: flags without a platform
+// equivalent are simply not mapped (cmd/search reports those to the user via
+// flags.Changed, which knows what was explicitly set).
+func BuildPlatformSearchRequest(opts *Options) components.PlatformSearchRequest {
+	req := components.PlatformSearchRequest{
+		Query: opts.Query,
+	}
+
+	if opts.PageSize > 0 {
+		pageSize := int64(opts.PageSize)
+		req.PageSize = &pageSize
+	}
+	if opts.Cursor != "" {
+		cursor := opts.Cursor
+		req.Cursor = &cursor
+	}
+
+	if opts.RequestOptions != nil {
+		for _, ff := range opts.RequestOptions.FacetFilters {
+			// Mirror the classic builder: datasource filtering uses the
+			// dedicated field, not the generic filter mechanism.
+			if ff.FieldName == datasourceField {
+				for _, v := range ff.Values {
+					req.Datasources = append(req.Datasources, v.Value)
+				}
+				continue
+			}
+			filter := components.PlatformFilter{Field: ff.FieldName}
+			for _, v := range ff.Values {
+				filter.Values = append(filter.Values, v.Value)
+			}
+			req.Filters = append(req.Filters, filter)
+		}
+	}
+
+	return req
+}
+
+// RunPlatformSearch executes a search against the platform API
+// (POST /api/search) and returns the raw platform response. The classic
+// request carries timeoutMillis in the body; the platform API does not, so
+// --timeout is honored via a context deadline instead.
+func RunPlatformSearch(ctx context.Context, opts *Options, sdk *glean.Glean) (*components.PlatformSearchResponse, error) {
+	if opts.TimeoutMillis > 0 {
+		var cancel context.CancelFunc
+		ctx, cancel = context.WithTimeout(ctx, time.Duration(opts.TimeoutMillis)*time.Millisecond)
+		defer cancel()
+	}
+
+	result, err := sdk.Search.Query(ctx, BuildPlatformSearchRequest(opts))
+	if err != nil {
+		return nil, fmt.Errorf("search request failed: %w", err)
+	}
+	return result.PlatformSearchResponse, nil
+}
diff --git a/internal/search/platform_test.go b/internal/search/platform_test.go
new file mode 100644
index 0000000..074778f
--- /dev/null
+++ b/internal/search/platform_test.go
@@ -0,0 +1,88 @@
+package search
+
+import (
+	"context"
+	"encoding/json"
+	"io"
+	"net/http"
+	"testing"
+
+	glean "github.com/gleanwork/api-client-go"
+	"github.com/gleanwork/glean-cli/internal/testutils"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestBuildPlatformSearchRequest_Basic(t *testing.T) {
+	opts := &Options{Query: "vacation policy", PageSize: 25}
+	req := BuildPlatformSearchRequest(opts)
+
+	assert.Equal(t, "vacation policy", req.Query)
+	require.NotNil(t, req.PageSize)
+	assert.Equal(t, int64(25), *req.PageSize)
+	assert.Nil(t, req.Cursor)
+	assert.Empty(t, req.Datasources)
+	assert.Empty(t, req.Filters)
+}
+
+func TestBuildPlatformSearchRequest_ZeroPageSizeOmitted(t *testing.T) {
+	req := BuildPlatformSearchRequest(&Options{Query: "q"})
+	assert.Nil(t, req.PageSize, "unset page size defers to the API default")
+}
+
+func TestBuildPlatformSearchRequest_Cursor(t *testing.T) {
+	req := BuildPlatformSearchRequest(&Options{Query: "q", Cursor: "next-page-token"})
+	require.NotNil(t, req.Cursor)
+	assert.Equal(t, "next-page-token", *req.Cursor)
+}
+
+func TestBuildPlatformSearchRequest_DatasourceUsesDedicatedField(t *testing.T) {
+	opts := &Options{Query: "q", RequestOptions: &RequestOptions{}}
+	AddFacetFilter(opts, "datasource", []string{"confluence", "slack"})
+	AddFacetFilter(opts, "type", []string{"document"})
+
+	req := BuildPlatformSearchRequest(opts)
+
+	assert.Equal(t, []string{"confluence", "slack"}, req.Datasources)
+	require.Len(t, req.Filters, 1)
+	assert.Equal(t, "type", req.Filters[0].Field)
+	assert.Equal(t, []string{"document"}, req.Filters[0].Values)
+}
+
+func TestRunPlatformSearch_HitsPlatformEndpoint(t *testing.T) {
+	body, err := json.Marshal(map[string]any{
+		"results": []map[string]any{{
+			"url":        "https://example.com/doc",
+			"title":      "Example Doc",
+			"datasource": "confluence",
+			"snippets":   []string{"an excerpt"},
+		}},
+		"has_more":   false,
+		"request_id": "req-123",
+	})
+	require.NoError(t, err)
+
+	mock := &testutils.MockTransport{Body: body, ContentType: "application/json"}
+	sdk := glean.New(
+		glean.WithServerURL("https://test-company-be.glean.com"),
+		glean.WithSecurity("test-token"),
+		glean.WithClient(mock),
+	)
+
+	resp, err := RunPlatformSearch(context.Background(), &Options{Query: "example", TimeoutMillis: 5000}, sdk)
+	require.NoError(t, err)
+
+	require.Len(t, mock.Requests, 1)
+	sent := mock.Requests[0]
+	assert.Equal(t, "/api/search", sent.URL.Path)
+	assert.Equal(t, http.MethodPost, sent.Method)
+
+	sentBody, err := io.ReadAll(sent.Body)
+	require.NoError(t, err)
+	assert.Contains(t, string(sentBody), `"query":"example"`)
+
+	require.NotNil(t, resp)
+	require.Len(t, resp.Results, 1)
+	assert.Equal(t, "Example Doc", resp.Results[0].Title)
+	assert.Equal(t, "req-123", resp.RequestID)
+}
diff --git a/internal/search/utils.go b/internal/search/utils.go
index 2ed281f..8c50963 100644
--- a/internal/search/utils.go
+++ b/internal/search/utils.go
@@ -65,7 +65,7 @@ func BuildSearchRequest(opts *Options) components.SearchRequest {
 			// The Glean API has a dedicated DatasourcesFilter field that must
 			// be used for datasource filtering — the generic FacetFilters
 			// mechanism does not filter by datasource correctly.
-			if ff.FieldName == "datasource" {
+			if ff.FieldName == datasourceField {
 				for _, v := range ff.Values {
 					sdkOpts.DatasourcesFilter = append(sdkOpts.DatasourcesFilter, v.Value)
 				}