diff --git a/bin/if.c b/bin/if.c
index fa2eaaa..ac2ee06 100644
--- a/bin/if.c
+++ b/bin/if.c
@@ -19,12 +19,29 @@ enum mode {
     MODE_IFOPTS,
     MODE_IFADDR,
     MODE_KISS,
-    MODE_BAUD,
-    MODE_FLOW
+    MODE_APRS_IS,
+};
+
+enum mode_kiss {
+    MODE_KISS_DEVICE,
+    MODE_KISS_IFOPTS,
+    MODE_KISS_BAUD,
+    MODE_KISS_FLOW,
+};
+
+enum mode_aprs_is {
+    MODE_APRS_IS_IFOPTS,
+    MODE_APRS_IS_HOST,
+    MODE_APRS_IS_PORT,
+    MODE_APRS_IS_USER,
+    MODE_APRS_IS_PASS,
+    MODE_APRS_IS_APPNAME,
+    MODE_APRS_IS_VERSION,
+    MODE_APRS_IS_FILTER,
 };
 
 static patty_ax25_if *create_kiss(struct context *ctx, int argc, char **argv) {
-    enum mode mode = MODE_KISS;
+    enum mode_kiss mode = MODE_KISS_DEVICE;
 
     patty_kiss_tnc_info info;
 
@@ -40,19 +57,19 @@ static patty_ax25_if *create_kiss(struct context *ctx, int argc, char **argv) {
 
     for (i=0; i<argc; i++) {
         switch (mode) {
-            case MODE_KISS:
+            case MODE_KISS_DEVICE:
                 info.flags |= PATTY_KISS_TNC_DEVICE;
                 info.device = argv[i];
 
-                mode = MODE_IFOPTS;
+                mode = MODE_KISS_IFOPTS;
 
                 break;
 
-            case MODE_IFOPTS:
+            case MODE_KISS_IFOPTS:
                 if (strcmp(argv[i], "baud") == 0) {
-                    mode = MODE_BAUD;
+                    mode = MODE_KISS_BAUD;
                 } else if (strcmp(argv[i], "flow") == 0) {
-                    mode = MODE_FLOW;
+                    mode = MODE_KISS_FLOW;
                 } else {
                     patty_error_fmt(ctx->err, "Invalid parameter '%s'",
                         argv[i]);
@@ -60,7 +77,7 @@ static patty_ax25_if *create_kiss(struct context *ctx, int argc, char **argv) {
 
                 break;
 
-            case MODE_BAUD:
+            case MODE_KISS_BAUD:
                 if (!(argv[i][0] >= '0' && argv[i][0] <= '9')) {
                     patty_error_fmt(ctx->err, "Invalid baud rate '%s'",
                         argv[i]);
@@ -71,11 +88,11 @@ static patty_ax25_if *create_kiss(struct context *ctx, int argc, char **argv) {
                 info.flags |= PATTY_KISS_TNC_BAUD;
                 info.baud   = atoi(argv[i]);
 
-                mode = MODE_IFOPTS;
+                mode = MODE_KISS_IFOPTS;
 
                 break;
 
-            case MODE_FLOW:
+            case MODE_KISS_FLOW:
                 if (strcmp(argv[i], "crtscts") == 0) {
                     info.flags |= PATTY_KISS_TNC_FLOW;
                     info.flow   = PATTY_KISS_TNC_FLOW_CRTSCTS;
@@ -89,7 +106,7 @@ static patty_ax25_if *create_kiss(struct context *ctx, int argc, char **argv) {
                     goto error_invalid;
                 }
 
-                mode = MODE_IFOPTS;
+                mode = MODE_KISS_IFOPTS;
 
                 break;
 
@@ -107,14 +124,113 @@ error_invalid:
     return NULL;
 }
 
+static patty_ax25_if *create_aprs_is(struct context *ctx,
+                                     int argc,
+                                     char **argv) {
+    enum mode_aprs_is mode = MODE_APRS_IS_IFOPTS;
+
+    patty_ax25_aprs_is_info info = {
+        .user    = "N0CALL",
+        .pass    = "-1",
+        .appname = PATTY_AX25_APRS_IS_DEFAULT_APPNAME,
+        .version = PATTY_AX25_APRS_IS_DEFAULT_VERSION,
+        .filter  = "m/25"
+    };
+
+    int i;
+
+    if (argc == 0) {
+        patty_error_fmt(ctx->err, "Too few parameters for 'kiss' interface");
+
+        goto error_invalid;
+    }
+
+    for (i=0; i<argc; i++) {
+        switch (mode) {
+            case MODE_APRS_IS_IFOPTS:
+                if (strcmp(argv[i], "host") == 0) {
+                    mode = MODE_APRS_IS_HOST;
+                } else if (strcmp(argv[i], "port") == 0) {
+                    mode = MODE_APRS_IS_PORT;
+                } else if (strcmp(argv[i], "user") == 0) {
+                    mode = MODE_APRS_IS_USER;
+                } else if (strcmp(argv[i], "pass") == 0) {
+                    mode = MODE_APRS_IS_PASS;
+                } else if (strcmp(argv[i], "appname") == 0) {
+                    mode = MODE_APRS_IS_APPNAME;
+                } else if (strcmp(argv[i], "version") == 0) {
+                    mode = MODE_APRS_IS_VERSION;
+                } else if (strcmp(argv[i], "filter") == 0) {
+                    mode = MODE_APRS_IS_FILTER;
+                } else {
+                    patty_error_fmt(ctx->err, "Invalid parameter '%s'",
+                        argv[i]);
+                }
+
+                break;
+
+            case MODE_APRS_IS_HOST:
+                info.host = argv[i];
+                mode = MODE_APRS_IS_IFOPTS;
+
+                break;
+
+            case MODE_APRS_IS_PORT:
+                info.port = argv[i];
+                mode = MODE_APRS_IS_IFOPTS;
+
+                break;
+
+            case MODE_APRS_IS_USER:
+                info.user = argv[i];
+                mode = MODE_APRS_IS_IFOPTS;
+
+                break;
+
+            case MODE_APRS_IS_PASS:
+                info.pass = argv[i];
+                mode = MODE_APRS_IS_IFOPTS;
+
+                break;
+
+            case MODE_APRS_IS_APPNAME:
+                info.appname = argv[i];
+                mode = MODE_APRS_IS_IFOPTS;
+
+                break;
+
+            case MODE_APRS_IS_VERSION:
+                info.version = argv[i];
+                mode = MODE_APRS_IS_IFOPTS;
+
+                break;
+
+            case MODE_APRS_IS_FILTER:
+                info.filter = argv[i];
+                mode = MODE_APRS_IS_IFOPTS;
+
+                break;
+        }
+    }
+
+    return patty_ax25_if_new( ctx->name,
+                             &ctx->addr,
+                             patty_ax25_aprs_is_driver(),
+                             &info);
+
+error_invalid:
+    return NULL;
+}
+
 struct if_type {
     const char *name;
     patty_ax25_if *(*func)(struct context *ctx, int argc, char **argv);
 };
 
 struct if_type if_types[] = {
-    { "kiss", create_kiss },
-    {  NULL,  NULL        }
+    { "kiss",    create_kiss    },
+    { "aprs-is", create_aprs_is },
+    {  NULL,     NULL           }
 };
 
 patty_ax25_if *patty_bin_if_create(int argc, char **argv, patty_error *e) {
diff --git a/include/patty/ax25.h b/include/patty/ax25.h
index a67a304..01746d0 100644
--- a/include/patty/ax25.h
+++ b/include/patty/ax25.h
@@ -104,6 +104,7 @@ typedef struct _patty_ax25_if patty_ax25_if;
 #include <patty/ax25/frame.h>
 #include <patty/ax25/if.h>
 #include <patty/kiss/tnc.h>
+#include <patty/ax25/aprs_is.h>
 #include <patty/ax25/route.h>
 #include <patty/ax25/sock.h>
 #include <patty/ax25/server.h>
diff --git a/include/patty/ax25/aprs_is.h b/include/patty/ax25/aprs_is.h
new file mode 100644
index 0000000..3b792d1
--- /dev/null
+++ b/include/patty/ax25/aprs_is.h
@@ -0,0 +1,60 @@
+#ifndef _PATTY_AX25_APRS_IS_H
+#define _PATTY_AX25_APRS_IS_H
+
+#include <stdint.h>
+
+#include <patty/ax25.h>
+
+#define PATTY_AX25_APRS_IS_DEFAULT_APPNAME "patty-aprs-is"
+#define PATTY_AX25_APRS_IS_DEFAULT_VERSION "0.0.0"
+
+#define PATTY_AX25_APRS_IS_PAYLOAD_MAX 256
+#define PATTY_AX25_APRS_IS_PACKET_MAX  512
+#define PATTY_AX25_APRS_IS_FRAME_MAX   PATTY_AX25_APRS_IS_PACKET_MAX
+
+typedef struct _patty_ax25_aprs_is patty_ax25_aprs_is;
+
+typedef struct _patty_ax25_aprs_is_info {
+    const char *host,
+               *port,
+               *user,
+               *pass,
+               *appname,
+               *version,
+               *filter;
+} patty_ax25_aprs_is_info;
+
+ssize_t patty_ax25_aprs_is_encode(void *dest,
+                                  const char *src,
+                                  size_t len,
+                                  size_t size);
+
+patty_ax25_aprs_is *patty_ax25_aprs_is_new(patty_ax25_aprs_is_info *info);
+
+void patty_ax25_aprs_is_destroy(patty_ax25_aprs_is *aprs);
+
+ssize_t patty_ax25_aprs_is_readline(patty_ax25_aprs_is *aprs,
+                                    void *buf,
+                                    size_t len);
+
+int patty_ax25_aprs_is_printf(patty_ax25_aprs_is *aprs, const char *fmt, ...);
+
+int patty_ax25_aprs_is_fd(patty_ax25_aprs_is *aprs);
+
+ssize_t patty_ax25_aprs_is_pending(patty_ax25_aprs_is *aprs);
+
+ssize_t patty_ax25_aprs_is_fill(patty_ax25_aprs_is *aprs);
+
+ssize_t patty_ax25_aprs_is_drain(patty_ax25_aprs_is *, void *buf, size_t len);
+
+int patty_ax25_aprs_is_ready(patty_ax25_aprs_is *);
+
+ssize_t patty_ax25_aprs_is_flush(patty_ax25_aprs_is *);
+
+ssize_t patty_ax25_aprs_is_send(patty_ax25_aprs_is *aprs,
+                                const void *buf,
+                                size_t len);
+
+patty_ax25_if_driver *patty_ax25_aprs_is_driver();
+
+#endif /* _PATTY_AX25_APRS_IS_H */
diff --git a/src/Makefile b/src/Makefile
index a979dcd..24fd991 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -7,12 +7,12 @@ CC		= $(CROSS)cc
 CFLAGS		= $(CGFLAGS) -fPIC -Wall -O2 -I$(INCLUDE_PATH)
 LDFLAGS		= -lutil
 
-HEADERS		= kiss.h kiss/tnc.h ax25.h client.h ax25/if.h ax25/frame.h \
-		  ax25/sock.h ax25/route.h ax25/server.h daemon.h \
+HEADERS		= kiss.h kiss/tnc.h ax25/aprs_is.h ax25.h client.h ax25/if.h \
+		  ax25/frame.h ax25/sock.h ax25/route.h ax25/server.h daemon.h \
 		  error.h list.h hash.h dict.h timer.h print.h conf.h
 
-OBJS		= kiss.o tnc.o ax25.o client.o if.o frame.o \
-		  sock.o route.o server.o daemon.o \
+OBJS		= kiss.o tnc.o aprs_is.o ax25.o client.o if.o \
+		  frame.o sock.o route.o server.o daemon.o \
 		  error.o list.o hash.o dict.o timer.o print.o conf.o
 
 VERSION_MAJOR	= 0
diff --git a/src/aprs_is.c b/src/aprs_is.c
new file mode 100644
index 0000000..4e6b589
--- /dev/null
+++ b/src/aprs_is.c
@@ -0,0 +1,349 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <string.h>
+#include <errno.h>
+#include <unistd.h>
+#include <netdb.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+
+#include <patty/ax25/aprs_is.h>
+
+enum state {
+    APRS_IS_HEADER,
+    APRS_IS_COMMENT,
+    APRS_IS_BODY,
+    APRS_IS_COMPLETE
+};
+
+struct _patty_ax25_aprs_is {
+    int fd;
+
+    char rx_buf[PATTY_AX25_APRS_IS_PACKET_MAX],
+         tx_buf[PATTY_AX25_APRS_IS_FRAME_MAX],
+         station[PATTY_AX25_ADDRSTRLEN+1],
+         info[PATTY_AX25_APRS_IS_PAYLOAD_MAX];
+
+    patty_ax25_frame frame;
+
+    size_t rx_bufsz,
+           tx_bufsz,
+           infosz;
+
+    enum state state;
+
+    size_t offset_i,
+           offset_station,
+           offset_info;
+
+    ssize_t readlen,
+            encoded;
+};
+
+static ssize_t send_line(patty_ax25_aprs_is *aprs, char *buf, size_t len) {
+    if (len > PATTY_AX25_APRS_IS_PACKET_MAX - 2) {
+        len = PATTY_AX25_APRS_IS_PACKET_MAX - 2;
+    }
+
+    buf[len]   = '\r';
+    buf[len+1] = '\n';
+
+    return write(aprs->fd, buf, len+2);
+}
+
+static int send_va(patty_ax25_aprs_is *aprs, const char *fmt, va_list args) {
+    size_t len;
+
+    if (vsnprintf(aprs->tx_buf, PATTY_AX25_APRS_IS_PACKET_MAX, fmt, args) < 0) {
+        goto error_vsnprintf;
+    }
+
+    len = strnlen(aprs->tx_buf, PATTY_AX25_APRS_IS_PACKET_MAX);
+
+    if (send_line(aprs, aprs->tx_buf, len) < 0) {
+        goto error_send_line;
+    }
+
+    return 0;
+
+error_send_line:
+error_vsnprintf:
+    return -1;
+}
+
+static int send_fmt(patty_ax25_aprs_is *aprs, const char *fmt, ...) {
+    va_list args;
+
+    va_start(args, fmt);
+
+    if (send_va(aprs, fmt, args) < 0) {
+        goto error_send_va;
+    }
+
+    va_end(args);
+
+    return 0;
+
+error_send_va:
+    return -1;
+}
+
+patty_ax25_aprs_is *patty_ax25_aprs_is_new(patty_ax25_aprs_is_info *info) {
+    patty_ax25_aprs_is *aprs;
+
+    struct addrinfo *ai0,
+                    *ai;
+
+    if (getaddrinfo(info->host, info->port, NULL, &ai0) < 0) {
+        goto error_getaddrinfo;
+    }
+
+    if ((aprs = malloc(sizeof(*aprs))) == NULL) {
+        goto error_malloc_aprs;
+    }
+
+    memset(aprs, '\0', sizeof(*aprs));
+
+    aprs->rx_bufsz = PATTY_AX25_APRS_IS_PACKET_MAX;
+    aprs->tx_bufsz = PATTY_AX25_APRS_IS_FRAME_MAX;
+    aprs->infosz   = PATTY_AX25_APRS_IS_PAYLOAD_MAX;
+    aprs->state    = APRS_IS_HEADER;
+
+    for (ai=ai0; ai; ai=ai->ai_next) {
+        if ((aprs->fd = socket(ai->ai_family,
+                               ai->ai_socktype,
+                               ai->ai_protocol)) < 0) {
+            continue;
+        }
+
+        if (connect(aprs->fd, ai->ai_addr, ai->ai_addrlen) < 0) {
+            close(aprs->fd);
+
+            continue;
+        }
+
+        freeaddrinfo(ai0);
+
+        if (send_fmt(aprs,
+                     "user %s pass %s vers %s %s filter %s",
+                     info->user,
+                     info->pass,
+                     info->appname,
+                     info->version,
+                     info->filter) < 0) {
+            goto error_send_fmt;
+        }
+
+        return aprs;
+    }
+
+error_send_fmt:
+    close(aprs->fd);
+    free(aprs);
+
+error_malloc_aprs:
+error_getaddrinfo:
+    return NULL;
+}
+
+void patty_ax25_aprs_is_destroy(patty_ax25_aprs_is *aprs) {
+    (void)close(aprs->fd);
+
+    free(aprs);
+}
+
+int patty_ax25_aprs_is_fd(patty_ax25_aprs_is *aprs) {
+    return aprs->fd;
+}
+
+ssize_t patty_ax25_aprs_is_pending(patty_ax25_aprs_is *aprs) {
+    return aprs->offset_i < aprs->readlen? 1: 0;
+}
+
+ssize_t patty_ax25_aprs_is_fill(patty_ax25_aprs_is *aprs) {
+    if ((aprs->readlen = read(aprs->fd, aprs->rx_buf, aprs->rx_bufsz)) < 0) {
+        goto error_read;
+    }
+
+    aprs->offset_i = 0;
+
+    return aprs->readlen;
+
+error_read:
+    return -1;
+}
+
+ssize_t patty_ax25_aprs_is_drain(patty_ax25_aprs_is *aprs,
+                                 void *buf,
+                                 size_t len) {
+    ssize_t offset_start = aprs->offset_i;
+
+    while (aprs->offset_i < aprs->readlen) {
+        char c = aprs->rx_buf[aprs->offset_i++];
+
+        switch (aprs->state) {
+            case APRS_IS_HEADER: {
+                patty_ax25_addr *addr = NULL;
+
+                if (c == '#') {
+                    aprs->state = APRS_IS_COMMENT;
+                } else if (c == '>') {
+                    addr = &aprs->frame.src;
+                } else if (c == ',' || c == ':') {
+                    if (aprs->frame.dest.callsign[0]) {
+                        if (aprs->frame.hops == PATTY_AX25_MAX_HOPS) {
+                            errno = EOVERFLOW;
+
+                            goto error;
+                        }
+
+                        addr = &aprs->frame.repeaters[aprs->frame.hops++];
+                    } else {
+                        addr = &aprs->frame.dest;
+                    }
+
+                    if (c == ':') {
+                        aprs->state = APRS_IS_BODY;
+                    }
+                } else if (PATTY_AX25_ADDR_CHAR_VALID(c)) {
+                    if (aprs->offset_station == PATTY_AX25_ADDRSTRLEN) {
+                        errno = EOVERFLOW;
+
+                        goto error;
+                    }
+
+                    aprs->station[aprs->offset_station++] = c;
+                } else {
+                    errno = EINVAL;
+
+                    goto error;
+                }
+
+                if (addr) {
+                    aprs->station[aprs->offset_station] = '\0';
+
+                    if (patty_ax25_pton(aprs->station, addr) < 0) {
+                        (void)patty_ax25_aprs_is_flush(aprs);
+
+                        goto done;
+                    }
+
+                    aprs->offset_station = 0;
+                }
+
+                break;
+            }
+
+            case APRS_IS_COMMENT:
+                if (c == '\r') {
+                    break;
+                } else if (c == '\n') {
+                    aprs->state = APRS_IS_HEADER;
+
+                    goto done;
+                }
+
+                break;
+
+            case APRS_IS_BODY:
+                if (c == '\r') {
+                    break;
+                } else if (c == '\n') {
+                    aprs->state = APRS_IS_COMPLETE;
+
+                    aprs->frame.control = PATTY_AX25_FRAME_UI;
+                    aprs->frame.cr      = PATTY_AX25_FRAME_COMMAND;
+                    aprs->frame.proto   = PATTY_AX25_PROTO_NONE;
+                    aprs->frame.info    = aprs->info;
+                    aprs->frame.infolen = aprs->offset_info;
+
+                    if ((aprs->encoded = patty_ax25_frame_encode(&aprs->frame,
+                                                                 buf,
+                                                                 len)) < 0) {
+                        goto error;
+                    }
+
+                    goto done;
+                } else {
+                    if (aprs->offset_info == aprs->infosz) {
+                        errno = EOVERFLOW;
+
+                        goto error;
+                    }
+
+                    aprs->info[aprs->offset_info++] = c;
+                }
+
+                break;
+
+            case APRS_IS_COMPLETE:
+                goto done;
+        }
+    }
+
+done:
+    return aprs->offset_i - offset_start;
+
+error:
+    return -1;
+}
+
+int patty_ax25_aprs_is_ready(patty_ax25_aprs_is *aprs) {
+    return aprs->state == APRS_IS_COMPLETE? 1: 0;
+}
+
+ssize_t patty_ax25_aprs_is_flush(patty_ax25_aprs_is *aprs) {
+    ssize_t ret = aprs->encoded;
+
+    aprs->state          = APRS_IS_HEADER;
+    aprs->offset_i       = aprs->readlen;
+    aprs->offset_station = 0;
+    aprs->offset_info    = 0;
+    aprs->encoded        = 0;
+
+    memset(&aprs->frame, '\0', sizeof(aprs->frame));
+
+    return ret;
+}
+
+int patty_ax25_aprs_is_printf(patty_ax25_aprs_is *aprs, const char *fmt, ...) {
+    va_list args;
+
+    va_start(args, fmt);
+
+    if (send_va(aprs, fmt, args) < 0) {
+        goto error_send_va;
+    }
+
+    va_end(args);
+
+    return 0;
+
+error_send_va:
+    va_end(args);
+
+    return -1;
+}
+
+ssize_t patty_ax25_aprs_is_send(patty_ax25_aprs_is *aprs,
+                                const void *buf,
+                                size_t len) {
+    return 0;
+}
+
+patty_ax25_if_driver *patty_ax25_aprs_is_driver() {
+    static patty_ax25_if_driver driver = {
+        .create  = (patty_ax25_if_driver_create *)patty_ax25_aprs_is_new,
+        .destroy = (patty_ax25_if_driver_destroy *)patty_ax25_aprs_is_destroy,
+        .fd      = (patty_ax25_if_driver_fd *)patty_ax25_aprs_is_fd,
+        .pending = (patty_ax25_if_driver_pending *)patty_ax25_aprs_is_pending,
+        .fill    = (patty_ax25_if_driver_fill *)patty_ax25_aprs_is_fill,
+        .drain   = (patty_ax25_if_driver_drain *)patty_ax25_aprs_is_drain,
+        .ready   = (patty_ax25_if_driver_ready *)patty_ax25_aprs_is_ready,
+        .flush   = (patty_ax25_if_driver_flush *)patty_ax25_aprs_is_flush,
+        .send    = (patty_ax25_if_driver_send *)patty_ax25_aprs_is_send
+    };
+
+    return &driver;
+};