diff --git a/Makefile.am b/Makefile.am
index dbe46665..39423f54 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -32,6 +32,7 @@ libsigrok_la_SOURCES = \
 	session_file.c \
 	session_driver.c \
 	hwdriver.c \
+	trigger.c \
 	strutil.c \
 	log.c \
 	version.c \
diff --git a/device.c b/device.c
index f87bb66d..889f02df 100644
--- a/device.c
+++ b/device.c
@@ -306,7 +306,6 @@ SR_PRIV void sr_dev_inst_free(struct sr_dev_inst *sdi)
 	for (l = sdi->channels; l; l = l->next) {
 		ch = l->data;
 		g_free(ch->name);
-		g_free(ch->trigger);
 		g_free(ch);
 	}
 	g_slist_free(sdi->channels);
diff --git a/libsigrok-internal.h b/libsigrok-internal.h
index eb4b1a2c..008fc4f3 100644
--- a/libsigrok-internal.h
+++ b/libsigrok-internal.h
@@ -228,8 +228,6 @@ SR_PRIV int sr_err(const char *format, ...);
 enum {
 	/** The enabled state of the channel has been changed. */
 	SR_CHANNEL_SET_ENABLED = 1 << 0,
-	/** The trigger setup of the channel has been changed. */
-	SR_CHANNEL_SET_TRIGGER = 1 << 1,
 };
 
 SR_PRIV struct sr_channel *sr_channel_new(int index, int type,
@@ -274,6 +272,7 @@ struct sr_session {
 	GSList *devs;
 	/** List of struct datafeed_callback pointers. */
 	GSList *datafeed_callbacks;
+	struct sr_trigger *trigger;
 	GTimeVal starttime;
 	gboolean running;
 
@@ -304,6 +303,7 @@ SR_PRIV int sr_session_send(const struct sr_dev_inst *sdi,
 		const struct sr_datafeed_packet *packet);
 SR_PRIV int sr_session_stop_sync(void);
 SR_PRIV int sr_sessionfile_check(const char *filename);
+SR_PRIV struct sr_trigger *sr_session_trigger_get(void);
 
 /*--- std.c -----------------------------------------------------------------*/
 
diff --git a/libsigrok.h b/libsigrok.h
index abcc2895..ade82771 100644
--- a/libsigrok.h
+++ b/libsigrok.h
@@ -304,6 +304,59 @@ enum sr_mqflag {
 	SR_MQFLAG_AVG = 0x40000,
 };
 
+enum sr_trigger_matches {
+	SR_TRIGGER_ZERO = 1,
+	SR_TRIGGER_ONE,
+	SR_TRIGGER_RISING,
+	SR_TRIGGER_FALLING,
+	SR_TRIGGER_EDGE,
+	SR_TRIGGER_OVER,
+	SR_TRIGGER_UNDER,
+};
+
+/** The representation of a trigger, consisting of one or more stages
+ * containing one or more matches on a channel.
+ */
+struct sr_trigger {
+	/** A name for this trigger. This may be NULL if none is needed. */
+	char *name;
+	/** List of pointers to struct sr_trigger_stage. */
+	GSList *stages;
+};
+
+/** A trigger stage. */
+struct sr_trigger_stage {
+	/** Starts at 0. */
+	int stage;
+	/** List of pointers to struct sr_trigger_match. */
+	GSList *matches;
+};
+
+/** A channel to match and what to match it on. */
+struct sr_trigger_match {
+	/** The channel to trigger on. */
+	struct sr_channel *channel;
+	/** The trigger match to use.
+	 * For logic channels, only the following matches may be used:
+	 * SR_TRIGGER_ZERO
+	 * SR_TRIGGER_ONE
+	 * SR_TRIGGER_RISING
+	 * SR_TRIGGER_FALLING
+	 * SR_TRIGGER_EDGE
+	 *
+	 * For analog channels, only these matches may be used:
+	 * SR_TRIGGER_RISING
+	 * SR_TRIGGER_FALLING
+	 * SR_TRIGGER_OVER
+	 * SR_TRIGGER_UNDER
+	 *
+	 */
+	int match;
+	/** If the trigger match is one of SR_TRIGGER_OVER or SR_TRIGGER_UNDER,
+	 * this contains the value to compare against. */
+	float value;
+};
+
 /**
  * @struct sr_context
  * Opaque structure representing a libsigrok context.
@@ -535,7 +588,8 @@ enum sr_channeltype {
 
 /** Information on single channel. */
 struct sr_channel {
-	/** Number of channels, starting at 0. */
+	/** The index of this channel, starting at 0. Logic channels will
+	 * be encoded according to this index in SR_DF_LOGIC packets. */
 	int index;
 	/** Channel type (SR_CHANNEL_LOGIC, ...) */
 	int type;
@@ -543,8 +597,6 @@ struct sr_channel {
 	gboolean enabled;
 	/** Name of channel. */
 	char *name;
-	/** Trigger string, format like used by sigrok-cli */
-	char *trigger;
 };
 
 /** Structure for groups of channels that have common properties. */
diff --git a/proto.h b/proto.h
index 49353d55..2a2b9a6a 100644
--- a/proto.h
+++ b/proto.h
@@ -90,6 +90,7 @@ SR_API int sr_session_destroy(void);
 SR_API int sr_session_dev_remove_all(void);
 SR_API int sr_session_dev_add(const struct sr_dev_inst *sdi);
 SR_API int sr_session_dev_list(GSList **devlist);
+SR_API int sr_session_trigger_set(struct sr_trigger *trig);
 
 /* Datafeed setup */
 SR_API int sr_session_datafeed_callback_remove_all(void);
@@ -129,6 +130,14 @@ SR_API int sr_output_send(struct sr_output *o,
 		const struct sr_datafeed_packet *packet, GString **out);
 SR_API int sr_output_free(struct sr_output *o);
 
+/*--- trigger.c -------------------------------------------------------------*/
+
+SR_API struct sr_trigger *sr_trigger_new(char *name);
+SR_API void sr_trigger_free(struct sr_trigger *trig);
+SR_API struct sr_trigger_stage *sr_trigger_stage_new(struct sr_trigger *trig);
+SR_API int sr_trigger_match_add(struct sr_trigger_stage *stage,
+		struct sr_channel *ch, int trigger_match, float value);
+
 /*--- strutil.c -------------------------------------------------------------*/
 
 SR_API char *sr_si_string_u64(uint64_t x, const char *unit);
diff --git a/session.c b/session.c
index 0540942f..742619a6 100644
--- a/session.c
+++ b/session.c
@@ -292,6 +292,18 @@ SR_API int sr_session_datafeed_callback_add(sr_datafeed_callback cb, void *cb_da
 	return SR_OK;
 }
 
+SR_PRIV struct sr_trigger *sr_session_trigger_get(void)
+{
+	return session->trigger;
+}
+
+SR_API int sr_session_trigger_set(struct sr_trigger *trig)
+{
+	session->trigger = trig;
+
+	return SR_OK;
+}
+
 /**
  * Call every device in the session's callback.
  *
@@ -347,6 +359,42 @@ static int sr_session_iteration(gboolean block)
 	return SR_OK;
 }
 
+
+static int verify_trigger(struct sr_trigger *trigger)
+{
+	struct sr_trigger_stage *stage;
+	struct sr_trigger_match *match;
+	GSList *l, *m;
+
+	if (!trigger->stages) {
+		sr_err("No trigger stages defined.");
+		return SR_ERR;
+	}
+
+	sr_spew("Checking trigger:");
+	for (l = trigger->stages; l; l = l->next) {
+		stage = l->data;
+		if (!stage->matches) {
+			sr_err("Stage %d has no matches defined.", stage->stage);
+			return SR_ERR;
+		}
+		for (m = stage->matches; m; m = m->next) {
+			match = m->data;
+			if (!match->channel) {
+				sr_err("Stage %d match has no channel.", stage->stage);
+				return SR_ERR;
+			}
+			if (!match->match) {
+				sr_err("Stage %d match is not defined.", stage->stage);
+				return SR_ERR;
+			}
+			sr_spew("Stage %d match on channel %s, match %d", stage->stage,
+					match->channel->name, match->match);
+		}
+	}
+
+	return SR_OK;
+}
 /**
  * Start a session.
  *
@@ -375,6 +423,9 @@ SR_API int sr_session_start(void)
 		return SR_ERR_BUG;
 	}
 
+	if (session->trigger && verify_trigger(session->trigger) != SR_OK)
+		return SR_ERR;
+
 	sr_info("Starting.");
 
 	ret = SR_OK;
diff --git a/trigger.c b/trigger.c
new file mode 100644
index 00000000..97a7ef68
--- /dev/null
+++ b/trigger.c
@@ -0,0 +1,96 @@
+/*
+ * This file is part of the libsigrok project.
+ *
+ * Copyright (C) 2014 Bert Vermeulen <bert@biot.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "libsigrok.h"
+#include "libsigrok-internal.h"
+
+/* * @cond PRIVATE */
+#define LOG_PREFIX "trigger"
+/* * @endcond */
+   
+SR_API struct sr_trigger *sr_trigger_new(char *name)
+{
+	struct sr_trigger *trig;
+
+	trig = g_malloc0(sizeof(struct sr_trigger));
+	if (name)
+		trig->name = g_strdup(name);
+
+	return trig;
+}
+
+SR_API void sr_trigger_free(struct sr_trigger *trig)
+{
+	struct sr_trigger_stage *stage;
+	GSList *l;
+
+	for (l = trig->stages; l; l = l->next) {
+		stage = l->data;
+		g_slist_free_full(stage->matches, g_free);
+	}
+	g_slist_free_full(trig->stages, (GDestroyNotify)g_slist_free);
+
+	g_free(trig->name);
+	g_free(trig);
+}
+
+SR_API struct sr_trigger_stage *sr_trigger_stage_new(struct sr_trigger *trig)
+{
+	struct sr_trigger_stage *stage;
+
+	stage = g_malloc0(sizeof(struct sr_trigger_stage));
+	stage->stage = g_slist_length(trig->stages);
+	trig->stages = g_slist_append(trig->stages, stage);
+
+	return stage;
+}
+
+SR_API int sr_trigger_match_add(struct sr_trigger_stage *stage,
+		struct sr_channel *ch, int trigger_match, float value)
+{
+	struct sr_trigger_match *match;
+
+	if (ch->type == SR_CHANNEL_LOGIC) {
+		if (trigger_match != SR_TRIGGER_ZERO &&
+				trigger_match != SR_TRIGGER_ONE &&
+				trigger_match != SR_TRIGGER_RISING &&
+				trigger_match != SR_TRIGGER_FALLING &&
+				trigger_match != SR_TRIGGER_EDGE) {
+			sr_err("Invalid trigger match for a logic channel.");
+			return SR_ERR_ARG;
+		}
+
+
+	} else if (ch->type == SR_CHANNEL_ANALOG) {
+		if (trigger_match != SR_TRIGGER_FALLING &&
+				trigger_match != SR_TRIGGER_OVER &&
+				trigger_match != SR_TRIGGER_UNDER) {
+			sr_err("Invalid trigger match for an analog channel.");
+			return SR_ERR_ARG;
+		}
+	}
+
+	match = g_malloc0(sizeof(struct sr_trigger_match));
+	match->channel = ch;
+	match->match = trigger_match;
+	match->value = value;
+	stage->matches = g_slist_append(stage->matches, match);
+
+	return SR_OK;
+}