diff --git a/TODO.md b/TODO.md
index 2dbb1af..88d3dc6 100644
--- a/TODO.md
+++ b/TODO.md
@@ -19,7 +19,7 @@
  - [ ] Eight things eight, try it out! - maybe even write the python webhook extension.
   - [ ] Port this document to gitea issue tracking
   - [x] enable PATH-able programs and argv in the command section
-  - [ ] custom environment variable passing. Something like `-e MY_TOKEN` ala docker-style
+  - [x] custom environment variable passing. Something like `-e MY_TOKEN` ala docker-style
   - [x] address sanitizers please.
  - [ ] Ninth things ninth, fix bugs, see below
  - [ ] Tenth things tenth, write manpages, choose license
diff --git a/include/executor.h b/include/executor.h
index 7c42747..c32b8b7 100644
--- a/include/executor.h
+++ b/include/executor.h
@@ -1,7 +1,9 @@
 #ifndef SCI_EXECUTOR_H
 #define SCI_EXECUTOR_H
+#include "strlist.h"
 
 void executor(void* pipeline_event);
 void set_logdir(const char* logdir);
+void set_shared_environment(const strlist_node* root);
 
 #endif
diff --git a/include/util.h b/include/util.h
index d85d8e2..5589305 100644
--- a/include/util.h
+++ b/include/util.h
@@ -40,6 +40,7 @@ typedef void(*line_handler)(const char*);
 void per_line(const char* file, line_handler handler);
 
 char* join(const char* a, const char* b);
+char* join3(const char* a, const char* b, const char* c);
 
 const char* skip_arg(const char* cp);
 char* skip_spaces(const char* str);
diff --git a/src/executor.c b/src/executor.c
index 88324a8..b822ed1 100644
--- a/src/executor.c
+++ b/src/executor.c
@@ -2,6 +2,7 @@
 #include "log.h"
 #include "optional.h"
 #include "pipeline.h"
+#include "strlist.h"
 #include "util.h"
 #include <fcntl.h>
 #include <linux/limits.h>
@@ -13,6 +14,11 @@
 #include <uuid/uuid.h>
 
 const char* log_dir = "./"; // NOTE: must end with a /
+const strlist_node* shared_environment = NULL;
+
+void set_shared_environment(const strlist_node* root) {
+    shared_environment = root;
+}
 
 void set_logdir(const char* logdir) {
     log_dir = logdir;
@@ -49,6 +55,38 @@ optional_int open_logfile(const char* const pipeline_id) {
     return result;
 }
 
+void add_joined_str(strlist_node* root, const char* a, const char* b) {
+    char* tmp = join(a, b);
+    add_str(tmp, root);
+    free(tmp);
+}
+
+void add_env(strlist_node* root, const char* env) {
+    char* tmp = join3(env, "=", getenv(env));
+    add_str(tmp, root);
+    free(tmp);
+}
+
+char** create_environment(const pipeline_event* const e, const char* pipeline_id) {
+    char* tmp = join("PATH=", getenv("PATH")); // TODO: consider removing PATH default, since it can be done as -e PATH
+    strlist_node* env = create_strlist_node(tmp);
+    free(tmp);
+    add_joined_str(env, "SCI_PIPELINE_NAME=", e->name);
+    add_joined_str(env, "SCI_PIPELINE_URL=", e->url);
+    add_joined_str(env, "SCI_PIPELINE_TRIGGER=", e->trigger);
+    add_joined_str(env, "SCI_PIPELINE_ID=", pipeline_id);
+    if(shared_environment != NULL) {
+        const strlist_node* cursor = shared_environment;
+        while(cursor != NULL) {
+            add_env(env, cursor->str);
+            cursor = cursor->next;
+        }
+    }
+    char** envp = strlist_to_array(env);
+    clear_strlist(env);
+    return envp;
+}
+
 void executor(void* data) {
     // Create pipeline id
     char* pipeline_id = create_pipeline_id();
@@ -67,12 +105,7 @@ void executor(void* data) {
     posix_spawn_file_actions_adddup2(&actions, fd.value, STDOUT_FILENO);
     posix_spawn_file_actions_adddup2(&actions, fd.value, STDERR_FILENO);
     const pipeline_event* const e = data;
-    char* path = join("PATH=", getenv("PATH"));
-    char* name = join("SCI_PIPELINE_NAME=", e->name);
-    char* url = join("SCI_PIPELINE_URL=", e->url);
-    char* trigger = join("SCI_PIPELINE_TRIGGER=", e->trigger);
-    char* id = join("SCI_PIPELINE_ID=", pipeline_id);
-    char* envp[] = { path, name, url, trigger, id, NULL };
+    char** envp = create_environment(e, pipeline_id);
     int argc;
     char** argv = argv_split(e->command, &argc);
     log_trace("executing pipeline %s with argv:", e->name);
@@ -98,9 +131,11 @@ end:
     argv_free(argv);
     close(fd.value);
     free(pipeline_id);
-    free(name);
-    free(url);
-    free(trigger);
-    free(id);
     free(data);
+    char** cursor = envp;
+    while(*cursor != NULL) {
+        free(*cursor);
+        cursor++;
+    }
+    free(envp);
 }
diff --git a/src/main.c b/src/main.c
index b726a2f..e0b41a6 100644
--- a/src/main.c
+++ b/src/main.c
@@ -110,6 +110,9 @@ int main(int argc, char** argv) {
         fprintf(stderr, "no such file or directory %s\n", args.config_file.value);
         exit(EXIT_FAILURE);
     }
+
+    if(args.environment_vars.has_value)
+        set_shared_environment(args.environment_vars.value);
     
     pool = threadpool_create(args.executors);
     per_line(args.config_file.value, &config_interpret_line);
diff --git a/src/strlist.c b/src/strlist.c
index be27000..3f26f57 100644
--- a/src/strlist.c
+++ b/src/strlist.c
@@ -76,7 +76,8 @@ char** strlist_to_array(strlist_node* root) {
     if(len <= 0)
         return NULL;
     char** result = malloc(sizeof(char*) * (len + 1));
-    memset(result, len+1, (size_t)NULL);
+    for(int i = 0; i < len+1; i++)
+        result[i] = NULL;
     strlist_node* cursor = root;
     for(int i = 0; i < len; i++) {
         if(cursor == NULL)
diff --git a/src/util.c b/src/util.c
index 1f8973a..6bd6085 100644
--- a/src/util.c
+++ b/src/util.c
@@ -63,6 +63,15 @@ char* join(const char* a, const char* b) {
 	return result;
 }
 
+char* join3(const char* a, const char* b, const char* c) {
+	size_t alen = strlen(a);
+	size_t blen = strlen(b);
+	size_t clen = strlen(c);
+	char* result = malloc(alen + blen + clen + 1);
+	sprintf(result, "%s%s%s", a, b, c);
+	return result;
+}
+
 const char* skip_arg(const char* cp) {
 	while(*cp && !isspace(*cp))
 		cp++;