diff --git a/codex.nim b/codex.nim
index c190592e..efaf9289 100644
--- a/codex.nim
+++ b/codex.nim
@@ -19,13 +19,11 @@ import pkg/confutils/toml/std/uri as confTomlUri
 import pkg/toml_serialization
 import pkg/libp2p
 
-when defined(chronosFuturesInstrumentation):
-  import ./codex/utils/asyncprofiler
-
 import ./codex/conf
 import ./codex/codex
 import ./codex/units
 import ./codex/utils/keyutils
+import ./codex/utils/asyncprofiler
 
 export codex, conf, libp2p, chronos, chronicles
 
@@ -57,6 +55,11 @@ when isMainModule:
   config.setupLogging()
   config.setupMetrics()
 
+  # TODO this should not be here, but currently can't have it in setupMetrics
+  #   or we get a circular import.
+  when chronosFuturesInstrumentation:
+    AsyncProfilerInfo.initDefault(k = config.profilerMaxMetrics)
+
   case config.cmd:
   of StartUpCommand.noCommand:
 
@@ -109,18 +112,6 @@ when isMainModule:
 
       notice "Stopping Codex"
 
-      when defined(chronosFuturesInstrumentation):
-        let metrics = getFutureSummaryMetrics()
-        for (k,v) in metrics.pairs():
-          let count = v.count
-          if count > 0:
-            echo ""
-            echo "metric: ", $k
-            echo "count: ", count
-            echo "avg execTime:\t", v.totalExecTime div count, "\ttotal: ", v.totalExecTime
-            echo "avg wallTime:\t", v.totalWallTime div count, "\ttotal: ", v.totalWallTime
-            echo "avg runTime:\t", v.totalRunTime div count, "\ttotal: ", v.totalRunTime
-
     try:
       setControlCHook(controlCHandler)
     except Exception as exc: # TODO Exception
diff --git a/codex/conf.nim b/codex/conf.nim
index 2c0e75d5..61502f81 100644
--- a/codex/conf.nim
+++ b/codex/conf.nim
@@ -106,6 +106,11 @@ type
       abbr: "d"
       name: "data-dir" }: OutDir
 
+    profilerMaxMetrics* {.
+      desc: "Maximum number of metrics to export to Prometheus."
+      defaultValue: 100
+      name: "profiler-max-metrics" }: int
+
     case cmd* {.
       command
       defaultValue: noCommand }: StartUpCommand
diff --git a/codex/utils/asyncprofiler/metricscollector.nim b/codex/utils/asyncprofiler/metricscollector.nim
index 7f1773e6..edc0142b 100644
--- a/codex/utils/asyncprofiler/metricscollector.nim
+++ b/codex/utils/asyncprofiler/metricscollector.nim
@@ -181,12 +181,15 @@ when defined(metrics):
     resetMetric(chronos_largest_exec_time_total)
     resetMetric(chronos_largest_exec_time_max)
 
-  var asyncProfilerInfo* {.global.}: AsyncProfilerInfo = AsyncProfilerInfo.newCollector(
+  var asyncProfilerInfo* {.global.}: AsyncProfilerInfo
+
+  proc initDefault*(AsyncProfilerInfo: typedesc, k: int) =
+    asyncProfilerInfo = AsyncProfilerInfo.newCollector(
       perfSampler = getFutureSummaryMetrics,
-      k = 10,
+      k = k,
       # We want to collect metrics every 5 seconds.
       sampleInterval = initDuration(seconds = 5),
       clock = proc (): Time = getTime(),
     )
 
-  setChangeCallback(proc (): void = asyncProfilerInfo.collect())
+    setChangeCallback(proc (): void = asyncProfilerInfo.collect())
diff --git a/tests/codex/blockexchange/engine/testengine.nim b/tests/codex/blockexchange/engine/testengine.nim
index 45505f04..22791e77 100644
--- a/tests/codex/blockexchange/engine/testengine.nim
+++ b/tests/codex/blockexchange/engine/testengine.nim
@@ -16,9 +16,8 @@ import pkg/codex/chunker
 import pkg/codex/discovery
 import pkg/codex/blocktype
 import pkg/codex/utils/asyncheapqueue
+import pkg/codex/utils/asyncprofiler
 
-when defined(chronosFuturesInstrumentation):
-  import pkg/codex/utils/asyncprofiler
 import ../../helpers
 import ../../examples