diff --git a/.github/workflows/bot.yml b/.github/workflows/bot.yml
index 21950459ae8..1ebe8b8f424 100644
--- a/.github/workflows/bot.yml
+++ b/.github/workflows/bot.yml
@@ -55,7 +55,7 @@ jobs:
         working-directory: contribs/github-bot
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
-        run: echo "pr-numbers=$(go run . matrix)" >> "$GITHUB_OUTPUT"
+        run: go run . matrix -matrix-key 'pr-numbers' -verbose
 
   # This job processes each pull request in the matrix individually while ensuring
   # that a same PR cannot be processed concurrently by mutliple runners
diff --git a/contribs/github-bot/internal/matrix/cmd.go b/contribs/github-bot/internal/matrix/cmd.go
index fb8095bae50..e1cd37a824f 100644
--- a/contribs/github-bot/internal/matrix/cmd.go
+++ b/contribs/github-bot/internal/matrix/cmd.go
@@ -2,11 +2,22 @@ package matrix
 
 import (
 	"context"
+	"flag"
+	"fmt"
+	"os"
 
 	"github.com/gnolang/gno/tm2/pkg/commands"
 )
 
+type matrixFlags struct {
+	Verbose   bool
+	MatrixKey string
+	flagSet   *flag.FlagSet
+}
+
 func NewMatrixCmd(verbose bool) *commands.Command {
+	flags := &matrixFlags{Verbose: verbose}
+
 	return commands.NewCommand(
 		commands.Metadata{
 			Name:       "matrix",
@@ -14,9 +25,29 @@ func NewMatrixCmd(verbose bool) *commands.Command {
 			ShortHelp:  "parses GitHub Actions event and defines matrix accordingly",
 			LongHelp:   "This tool retrieves the GitHub Actions context, parses the attached event, and defines the matrix with the pull request numbers to be processed accordingly",
 		},
-		commands.NewEmptyConfig(),
+		flags,
 		func(_ context.Context, _ []string) error {
-			return execMatrix()
+			flags.validateFlags()
+			return execMatrix(flags)
 		},
 	)
 }
+
+func (flags *matrixFlags) RegisterFlags(fs *flag.FlagSet) {
+	fs.StringVar(
+		&flags.MatrixKey,
+		"matrix-key",
+		"",
+		"key of the matrix to set in Github Actions output (required)",
+	)
+
+	flags.flagSet = fs
+}
+
+func (flags *matrixFlags) validateFlags() {
+	if flags.MatrixKey == "" {
+		fmt.Fprintf(flags.flagSet.Output(), "Error: no matrix-key provided\n\n")
+		flags.flagSet.Usage()
+		os.Exit(1)
+	}
+}
diff --git a/contribs/github-bot/internal/matrix/matrix.go b/contribs/github-bot/internal/matrix/matrix.go
index fb5f3b876f9..3e3db4ea789 100644
--- a/contribs/github-bot/internal/matrix/matrix.go
+++ b/contribs/github-bot/internal/matrix/matrix.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"os"
 	"strings"
 
 	"github.com/gnolang/gno/contribs/github-bot/internal/client"
@@ -11,19 +12,24 @@ import (
 	"github.com/sethvargo/go-githubactions"
 )
 
-func execMatrix() error {
+func execMatrix(flags *matrixFlags) error {
 	// Get GitHub Actions context to retrieve event.
 	actionCtx, err := githubactions.Context()
 	if err != nil {
 		return fmt.Errorf("unable to get GitHub Actions context: %w", err)
 	}
 
+	// If verbose is set, print the Github Actions event for debugging purpose.
+	if flags.Verbose {
+		fmt.Println("Event:", actionCtx.Event)
+	}
+
 	// Init Github client using only GitHub Actions context.
 	owner, repo := actionCtx.Repo()
 	gh, err := client.New(context.Background(), &client.Config{
 		Owner:   owner,
 		Repo:    repo,
-		Verbose: false,
+		Verbose: flags.Verbose,
 		DryRun:  true,
 	})
 	if err != nil {
@@ -36,12 +42,35 @@ func execMatrix() error {
 		return err
 	}
 
-	// Print PR list for GitHub Actions matrix definition.
+	// Format PR list for GitHub Actions matrix definition.
 	bytes, err := prList.MarshalText()
 	if err != nil {
 		return fmt.Errorf("unable to marshal PR list: %w", err)
 	}
-	fmt.Printf("[%s]", string(bytes))
+	matrix := fmt.Sprintf("%s=[%s]", flags.MatrixKey, string(bytes))
+
+	// If verbose is set, print the matrix for debugging purpose.
+	if flags.Verbose {
+		fmt.Printf("Matrix: %s\n", matrix)
+	}
+
+	// Get the path of the GitHub Actions environment file used for output.
+	output, ok := os.LookupEnv("GITHUB_OUTPUT")
+	if !ok {
+		return errors.New("unable to get GITHUB_OUTPUT var")
+	}
+
+	// Open GitHub Actions output file
+	file, err := os.OpenFile(output, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
+	if err != nil {
+		return fmt.Errorf("unable to open GitHub Actions output file: %w", err)
+	}
+	defer file.Close()
+
+	// Append matrix to GitHub Actions output file
+	if _, err := fmt.Fprintf(file, "%s\n", matrix); err != nil {
+		return fmt.Errorf("unable to write matrix in GitHub Actions output file: %w", err)
+	}
 
 	return nil
 }