diff --git a/doc/SPEC-implementation.md b/doc/SPEC-implementation.md
index d77384ee..22075e04 100644
--- a/doc/SPEC-implementation.md
+++ b/doc/SPEC-implementation.md
@@ -676,7 +676,7 @@ Per-agent schedule fields in `adapter_config`:
 
 - `enabled` boolean
 - `intervalSec` integer (minimum 30)
-- `maxConcurrentRuns` integer; new agents default to `5`
+- `maxConcurrentRuns` integer; new agents default to `20`; scheduler clamps configured values to `1..50`
 
 Scheduler must skip invocation when:
 
diff --git a/packages/shared/src/constants.ts b/packages/shared/src/constants.ts
index 8b196e93..8cbe9eef 100644
--- a/packages/shared/src/constants.ts
+++ b/packages/shared/src/constants.ts
@@ -72,7 +72,7 @@ export const AGENT_ROLE_LABELS: Record<AgentRole, string> = {
   general: "General",
 };
 
-export const AGENT_DEFAULT_MAX_CONCURRENT_RUNS = 5;
+export const AGENT_DEFAULT_MAX_CONCURRENT_RUNS = 20;
 export const WORKSPACE_BRANCH_ROUTINE_VARIABLE = "workspaceBranch";
 
 export const MODEL_PROFILE_KEYS = ["cheap"] as const;
diff --git a/server/src/__tests__/agent-permissions-routes.test.ts b/server/src/__tests__/agent-permissions-routes.test.ts
index 85d4f180..624f3772 100644
--- a/server/src/__tests__/agent-permissions-routes.test.ts
+++ b/server/src/__tests__/agent-permissions-routes.test.ts
@@ -901,7 +901,7 @@ describe.sequential("agent permission routes", () => {
           heartbeat: {
             enabled: false,
             intervalSec: 3600,
-            maxConcurrentRuns: 5,
+            maxConcurrentRuns: 20,
           },
         },
       }),
@@ -939,7 +939,7 @@ describe.sequential("agent permission routes", () => {
           heartbeat: {
             enabled: false,
             intervalSec: 3600,
-            maxConcurrentRuns: 5,
+            maxConcurrentRuns: 20,
           },
         },
       }),
diff --git a/server/src/__tests__/company-portability.test.ts b/server/src/__tests__/company-portability.test.ts
index 01794385..fecd7a78 100644
--- a/server/src/__tests__/company-portability.test.ts
+++ b/server/src/__tests__/company-portability.test.ts
@@ -2158,7 +2158,7 @@ describe("company portability", () => {
       runtimeConfig: {
         heartbeat: {
           enabled: false,
-          maxConcurrentRuns: 5,
+          maxConcurrentRuns: 20,
         },
       },
     });
@@ -2237,7 +2237,7 @@ describe("company portability", () => {
       runtimeConfig: {
         heartbeat: {
           enabled: false,
-          maxConcurrentRuns: 5,
+          maxConcurrentRuns: 20,
         },
       },
     }));
diff --git a/server/src/services/heartbeat.ts b/server/src/services/heartbeat.ts
index f7c0a220..41383f6f 100644
--- a/server/src/services/heartbeat.ts
+++ b/server/src/services/heartbeat.ts
@@ -145,7 +145,7 @@ const MAX_RUN_EVENT_PAYLOAD_OBJECT_KEYS = 100;
 const MAX_RUN_EVENT_PAYLOAD_DEPTH = 6;
 const HEARTBEAT_MAX_CONCURRENT_RUNS_DEFAULT = AGENT_DEFAULT_MAX_CONCURRENT_RUNS;
 const HEARTBEAT_MAX_CONCURRENT_RUNS_MIN = 1;
-const HEARTBEAT_MAX_CONCURRENT_RUNS_MAX = 10;
+const HEARTBEAT_MAX_CONCURRENT_RUNS_MAX = 50;
 const LIVENESS_BOOKKEEPING_ACTIVITY_ACTIONS = [
   "environment.lease_acquired",
   "environment.lease_released",
diff --git a/ui/src/lib/new-agent-runtime-config.test.ts b/ui/src/lib/new-agent-runtime-config.test.ts
index f33cdc85..3a72943c 100644
--- a/ui/src/lib/new-agent-runtime-config.test.ts
+++ b/ui/src/lib/new-agent-runtime-config.test.ts
@@ -1,5 +1,6 @@
 // @vitest-environment node
 import { describe, expect, it } from "vitest";
+import { AGENT_DEFAULT_MAX_CONCURRENT_RUNS } from "@paperclipai/shared";
 import { buildNewAgentRuntimeConfig } from "./new-agent-runtime-config";
 
 describe("buildNewAgentRuntimeConfig", () => {
@@ -10,7 +11,7 @@ describe("buildNewAgentRuntimeConfig", () => {
         intervalSec: 300,
         wakeOnDemand: true,
         cooldownSec: 10,
-        maxConcurrentRuns: 5,
+        maxConcurrentRuns: AGENT_DEFAULT_MAX_CONCURRENT_RUNS,
       },
     });
   });
@@ -27,7 +28,7 @@ describe("buildNewAgentRuntimeConfig", () => {
         intervalSec: 3600,
         wakeOnDemand: true,
         cooldownSec: 10,
-        maxConcurrentRuns: 5,
+        maxConcurrentRuns: AGENT_DEFAULT_MAX_CONCURRENT_RUNS,
       },
     });
   });