diff --git a/api/api.go b/api/api.go
index 7590df7..108a3c3 100644
--- a/api/api.go
+++ b/api/api.go
@@ -1,50 +1,105 @@
 package api
 
 import (
+	"bytes"
+	"compress/gzip"
+	"encoding/json"
+	"fmt"
 	"io"
 	"os"
+	"time"
 )
 
+type Frame struct {
+	Delay float64
+	Data  []byte
+}
+
 type Api interface {
-	CreateAsciicast(*Asciicast) (string, error)
+	CreateAsciicast([]Frame, time.Duration, int, int, string, string) (string, error)
 }
 
 func New(url, token string) *AsciinemaApi {
 	return &AsciinemaApi{
 		url:   url,
 		token: token,
+		http:  &HttpClient{},
 	}
 }
 
 type AsciinemaApi struct {
 	url   string
 	token string
+	http  HTTP
 }
 
-func (a *AsciinemaApi) CreateAsciicast(asciicast *Asciicast) (string, error) {
-	return "/foo", nil
-}
-
-type Asciicast struct {
-	Command  string
-	Title    string
-	Rows     int
-	Cols     int
-	Shell    string
-	Username string
-	Term     string
-	Stdout   io.Reader
-}
-
-func NewAsciicast(command, title string, rows, cols int, stdout io.Reader) *Asciicast {
-	return &Asciicast{
-		Command:  command,
-		Title:    title,
-		Rows:     rows,
-		Cols:     cols,
-		Shell:    os.Getenv("SHELL"),
-		Username: os.Getenv("USER"),
-		Term:     os.Getenv("TERM"),
-		Stdout:   stdout,
+func (a *AsciinemaApi) CreateAsciicast(frames []Frame, duration time.Duration, cols, rows int, command, title string) (string, error) {
+	files := map[string]io.Reader{
+		"asciicast[stdout]:stdout":             gzippedDataReader(frames),
+		"asciicast[stdout_timing]:stdout.time": gzippedTimingReader(frames),
+		"asciicast[meta]:meta.json":            metadataReader(duration, cols, rows, command, title),
 	}
+	// TODO: set proper user agent
+
+	response, err := a.http.PostForm(a.url+"/api/asciicasts", os.Getenv("USER"), a.token, files)
+	if err != nil {
+		return "", err
+	}
+	defer response.Body.Close()
+
+	body := &bytes.Buffer{}
+	_, err = body.ReadFrom(response.Body)
+	if err != nil {
+		return "", err
+	}
+
+	// TODO: handle non-200 statuses
+
+	return body.String(), nil
+}
+
+func gzippedDataReader(frames []Frame) io.Reader {
+	data := &bytes.Buffer{}
+	w := gzip.NewWriter(data)
+
+	for _, frame := range frames {
+		w.Write(frame.Data)
+	}
+
+	w.Close()
+
+	return data
+}
+
+func gzippedTimingReader(frames []Frame) io.Reader {
+	timing := &bytes.Buffer{}
+	w := gzip.NewWriter(timing)
+
+	for _, frame := range frames {
+		w.Write([]byte(fmt.Sprintf("%f %d\n", frame.Delay, len(frame.Data))))
+	}
+
+	w.Close()
+
+	return timing
+}
+
+func metadataReader(duration time.Duration, cols, rows int, command, title string) io.Reader {
+	metadata := map[string]interface{}{
+		"duration": duration.Seconds(),
+		"title":    title,
+		"command":  command,
+		"shell":    os.Getenv("SHELL"),
+		"term": map[string]interface{}{
+			"type":    os.Getenv("TERM"),
+			"columns": cols,
+			"lines":   rows,
+		},
+	}
+
+	buf := &bytes.Buffer{}
+	encoder := json.NewEncoder(buf)
+	encoder.Encode(metadata)
+
+	return buf
 }
diff --git a/api/http.go b/api/http.go
new file mode 100644
index 0000000..7ca48f9
--- /dev/null
+++ b/api/http.go
@@ -0,0 +1,64 @@
+package api
+
+import (
+	"bytes"
+	"io"
+	"mime/multipart"
+	"net/http"
+	"strings"
+)
+
+type HTTP interface {
+	PostForm(string, string, string, map[string]io.Reader) (*http.Response, error)
+}
+
+type HttpClient struct{}
+
+func (c *HttpClient) PostForm(url, username, password string, files map[string]io.Reader) (*http.Response, error) {
+	body, contentType, err := c.multiPartBody(url, files)
+	if err != nil {
+		return nil, err
+	}
+
+	client := &http.Client{}
+
+	req, err := http.NewRequest("POST", url, body)
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Set("Content-Type", contentType)
+	req.SetBasicAuth(username, password)
+
+	return client.Do(req)
+}
+
+func (c *HttpClient) multiPartBody(url string, files map[string]io.Reader) (io.Reader, string, error) {
+	body := &bytes.Buffer{}
+	writer := multipart.NewWriter(body)
+
+	if files != nil {
+		for name, reader := range files {
+			items := strings.Split(name, ":")
+			fieldname := items[0]
+			filename := items[1]
+
+			part, err := writer.CreateFormFile(fieldname, filename)
+			if err != nil {
+				return nil, "", err
+			}
+
+			_, err = io.Copy(part, reader)
+			if err != nil {
+				return nil, "", err
+			}
+		}
+	}
+
+	err := writer.Close()
+	if err != nil {
+		return nil, "", err
+	}
+
+	return body, writer.FormDataContentType(), nil
+}
diff --git a/commands/rec.go b/commands/rec.go
index a017e6d..4ca8293 100644
--- a/commands/rec.go
+++ b/commands/rec.go
@@ -1,11 +1,10 @@
 package commands
 
 import (
-	"bytes"
 	"flag"
 	"fmt"
-	"io"
 	"os"
+	"time"
 
 	"github.com/asciinema/asciinema-cli/api"
 	"github.com/asciinema/asciinema-cli/cli"
@@ -61,15 +60,17 @@ func (c *RecordCommand) Execute(args []string) error {
 	}
 
 	util.Printf("Asciicast recording started.")
-	util.Printf("Hit ctrl-d or type \"exit\" to finish.")
+	util.Printf(`Hit ctrl-d or type "exit" to finish.`)
 
-	stdout := &StdoutStream{}
+	stdout := NewStream()
 
 	err := c.Terminal.Record(c.Command, stdout)
 	if err != nil {
 		return err
 	}
 
+	stdout.Close()
+
 	util.Printf("Asciicast recording finished.")
 
 	if !c.NoConfirm {
@@ -78,9 +79,8 @@ func (c *RecordCommand) Execute(args []string) error {
 	}
 
 	rows, cols, _ = c.Terminal.Size()
-	asciicast := api.NewAsciicast(c.Command, c.Title, rows, cols, stdout.Reader())
 
-	url, err := c.Api.CreateAsciicast(asciicast)
+	url, err := c.Api.CreateAsciicast(stdout.Frames, stdout.Duration(), cols, rows, c.Command, c.Title)
 	if err != nil {
 		return err
 	}
@@ -102,15 +102,36 @@ func defaultRecCommand(recCommand string) string {
 	return recCommand
 }
 
-type StdoutStream struct {
-	data []byte
+type Stream struct {
+	Frames        []api.Frame
+	startTime     time.Time
+	lastWriteTime time.Time
 }
 
-func (s *StdoutStream) Write(p []byte) (int, error) {
-	s.data = append(s.data, p...)
+func NewStream() *Stream {
+	now := time.Now()
+
+	return &Stream{
+		startTime:     now,
+		lastWriteTime: now,
+	}
+}
+
+func (s *Stream) Write(p []byte) (int, error) {
+	now := time.Now()
+	frame := api.Frame{}
+	frame.Delay = now.Sub(s.lastWriteTime).Seconds()
+	frame.Data = make([]byte, len(p))
+	copy(frame.Data, p)
+	s.Frames = append(s.Frames, frame)
+	s.lastWriteTime = now
 	return len(p), nil
 }
 
-func (s *StdoutStream) Reader() io.Reader {
-	return bytes.NewReader(s.data)
+func (s *Stream) Close() {
+	s.lastWriteTime = time.Now()
+}
+
+func (s *Stream) Duration() time.Duration {
+	return s.lastWriteTime.Sub(s.startTime)
 }
diff --git a/commands/rec_test.go b/commands/rec_test.go
index d3911b7..8ee32b0 100644
--- a/commands/rec_test.go
+++ b/commands/rec_test.go
@@ -1,10 +1,10 @@
 package commands_test
 
 import (
-	"bytes"
 	"errors"
 	"io"
 	"testing"
+	"time"
 
 	"github.com/asciinema/asciinema-cli/api"
 	"github.com/asciinema/asciinema-cli/commands"
@@ -24,6 +24,8 @@ func (t *testTerminal) Record(command string, stdoutCopy io.Writer) error {
 	}
 
 	stdoutCopy.Write([]byte("hello"))
+	stdoutCopy.Write([]byte("world"))
+
 	return nil
 }
 
@@ -32,28 +34,31 @@ type testApi struct {
 	t   *testing.T
 }
 
-func (a *testApi) CreateAsciicast(asciicast *api.Asciicast) (string, error) {
-	if asciicast.Command != "ls" {
+func (a *testApi) CreateAsciicast(frames []api.Frame, duration time.Duration, cols, rows int, command, title string) (string, error) {
+	if command != "ls" {
 		a.t.Errorf("expected command to be set on asciicast")
 	}
 
-	if asciicast.Title != "listing" {
+	if title != "listing" {
 		a.t.Errorf("expected title to be set on asciicast")
 	}
 
-	if asciicast.Rows != 15 {
+	if rows != 15 {
 		a.t.Errorf("expected rows to be set on asciicast")
 	}
 
-	if asciicast.Cols != 40 {
+	if cols != 40 {
 		a.t.Errorf("expected cols to be set on asciicast")
 	}
 
-	buf := new(bytes.Buffer)
-	buf.ReadFrom(asciicast.Stdout)
-	stdout := buf.String()
+	stdout := string(frames[0].Data)
 	if stdout != "hello" {
-		a.t.Errorf("expected recorded stdout to be set on asciicast")
+		a.t.Errorf(`expected frame data "%v", got "%v"`, "hello", stdout)
+	}
+
+	stdout = string(frames[1].Data)
+	if stdout != "world" {
+		a.t.Errorf(`expected frame data "%v", got "%v"`, "world", stdout)
 	}
 
 	if a.err != nil {