diff --git a/cli/cli.egg b/cli/cli.egg
index a703db7..e8977bb 100644
--- a/cli/cli.egg
+++ b/cli/cli.egg
@@ -3,7 +3,7 @@
  (author "puck")
  (dependencies r7rs zilch zilch-lang-go)
  (component-options 
-  (csc-options "-X" "r7rs" "-R" "r7rs" "-optimize-level" "3"))
+  (csc-options "-X" "r7rs" "-R" "r7rs" "-optimize-level" "3" "-C" "-D_GNU_SOURCE"))
  (components
   (program zilch-cli-go
    (source "zilch-go.scm"))))
diff --git a/cli/zilch-go.scm b/cli/zilch-go.scm
index 605b9a1..1fd5e35 100644
--- a/cli/zilch-go.scm
+++ b/cli/zilch-go.scm
@@ -1,4 +1,9 @@
-(import (scheme base) (scheme write) (zilch statusbar) (zilch nix daemon) (zilch lib getopt) (scheme process-context) (chicken process-context) (srfi 146) (chicken port))
+(import (scheme base) (scheme write) (zilch statusbar) (zilch nix daemon) (zilch magic) (zilch lib getopt) (scheme process-context) (chicken process-context) (srfi 146) (chicken port) (chicken foreign))
+(foreign-declare "#include <sched.h>")
+(define get-cpu-count
+  (foreign-lambda* int ()
+    "cpu_set_t set; sched_getaffinity(0, sizeof(set), &set); C_return(CPU_COUNT(&set));"))
+
 (define (print-help msg)
   (when msg
     (write-string (string-append msg "\n\n") (current-error-port)))
@@ -10,6 +15,10 @@ executables in the module, if unspecified)
   -h, --help              Print this help message.
   -b, --build             Build the store paths, rather than show their
                           derivations.
+  -j, --max-jobs COUNT    The maximum amount of builds to run. Defaults
+                          to the amount of cores.
+  -v, --verbose           Increase the verbosity configured in the Nix
+                          daemon.
   -L, --print-build-logs  Print derivation logs as they come in.
   -m, --module-dir DIR    The directory to use as root module.
   -r, --replace DIR       Replace the module specified by the go.mod
@@ -25,19 +34,20 @@ executables in the module, if unspecified)
 (define-values (options args)
  (getopt
   '((help #f #\h)
-    (module-dir #t #\m)
-    (print-build-logs #f #\L)
     (build #f #\b)
+    (max-jobs #t #\j)
+    (verbose #f #\v)
+    (print-build-logs #f #\L)
+    (module-dir #t #\m)
     (replace #t #\r)
     (debug #f))
   (list->vector (cdr (command-line)))
   print-help))
+
 (when (assoc 'help options) (print-help #f))
 
-(define module-dir (if (assoc 'module-dir options) (cdr (assoc 'module-dir options)) (current-directory)))
-
+;; Set up the logger.
 (define (set-print-logs val) #f)
-
 (when (terminal-port? (current-error-port))
   (let-values (((new-out new-err statusbar-set-print-logs logger) (statusbar-logger (current-output-port) (current-error-port) (assoc 'print-build-logs options))))
     (current-output-port new-out)
@@ -45,8 +55,18 @@ executables in the module, if unspecified)
     (set! set-print-logs statusbar-set-print-logs)
     (*logger* logger)))
 
-(define do-build (assoc 'build options))
-(define do-debug (assoc 'debug options))
+;; Flags passed to the nix daemon:
+(define max-jobs (if (assoc 'max-jobs options) (string->number (cdr (assoc 'max-jobs options))) (get-cpu-count)))
+(define verbosity 3)
+(for-each (lambda (val) (when (eq? (car val) 'verbose) (set! verbosity (+ 1 verbosity)))) options)
+(write-string (string-append "Connected to Nix daemon, version " (daemon-link-daemon-version (*daemon*)) "\n") (current-error-port))
+
+;; Set the options, ensuring the Go toolchain is substituted where possible.
+(daemon-wop-set-options (*daemon*) verbosity max-jobs #t)
+(import (zilch lang go core))
+(store-path-build go-toolchain)
+(daemon-wop-set-options (*daemon*) verbosity max-jobs #f)
+
 
 (import
   (scheme file) (chicken file) (chicken format)
@@ -55,6 +75,10 @@ executables in the module, if unspecified)
   (zilch nix drv)
   (zilch lang go))
 
+(define module-dir (if (assoc 'module-dir options) (cdr (assoc 'module-dir options)) (current-directory)))
+(define do-build (assoc 'build options))
+(define do-debug (assoc 'debug options))
+
 (unless (file-exists? (string-append module-dir "/go.mod"))
   (set-print-logs #t)
   (fprintf (current-error-port) "Refusing to use directory ~S as it contains no go.mod.\n" module-dir)