diff --git a/profiles/sets/coding/agents/agents.nix b/profiles/sets/coding/agents/agents.nix
index 6fc5f2c..af0e130 100644
--- a/profiles/sets/coding/agents/agents.nix
+++ b/profiles/sets/coding/agents/agents.nix
@@ -19,11 +19,14 @@
   };
 
   imports = [
-    # OpenCode and Pi agent configurations
+    # OpenCode, Pi, and Babysitter agent configurations
+    ./babysitter.nix
     ./opencode.nix
     ./pi.nix
   ];
 
+  coding.agents.babysitter.enable = true;
+
   coding.agents.skills = {
     agentsInput = inputs.agents;
     externalSkills = [
diff --git a/profiles/sets/coding/agents/babysitter.nix b/profiles/sets/coding/agents/babysitter.nix
new file mode 100644
index 0000000..12216df
--- /dev/null
+++ b/profiles/sets/coding/agents/babysitter.nix
@@ -0,0 +1,142 @@
+# Babysitter user profile for Pi/agent workflows.
+{
+  config,
+  lib,
+  ...
+}: let
+  cfg = config.coding.agents.babysitter;
+  defaultTimestamp = "2026-05-29T00:00:00.000Z";
+
+  defaultUserProfile = {
+    name = config.home.username;
+    specialties = [
+      {
+        domain = "declarative-system-configuration";
+        subdomains = ["nix" "home-manager" "agents"];
+      }
+    ];
+    expertiseLevels = {};
+    goals = [
+      {
+        id = "goal-agents-declarative-profile";
+        description = "Keep Babysitter user preferences declarative and reproducible across systems.";
+        category = "agents";
+        priority = "medium";
+        status = "active";
+      }
+    ];
+    preferences = {
+      verbosity = "concise";
+      autonomyLevel = "semi-autonomous";
+      riskTolerance = "conservative";
+    };
+    toolPreferences = {
+      packageManagers = ["nix"];
+      languages = ["nix"];
+      operatingSystem = "nixos";
+    };
+    breakpointTolerance = {
+      global = "moderate";
+      skipBreakpointsForKnownPatterns = false;
+      alwaysBreakOn = ["destructive-operations" "secrets" "external-publication"];
+    };
+    communicationStyle = {
+      tone = "technical";
+      language = "en";
+      useEmojis = false;
+      explanationDepth = "brief";
+      preferredResponseFormat = "markdown";
+    };
+    experience = {};
+    installedPlugins = ["babysitter-pi"];
+    installedSkills = ["babysit" "call" "plan" "resume" "doctor" "yolo"];
+    installedAgents = [];
+    createdAt = defaultTimestamp;
+    updatedAt = defaultTimestamp;
+    version = 1;
+  };
+
+  effectiveProfile = lib.recursiveUpdate cfg.profile cfg.profileOverrides;
+  profileJsonTarget = "${cfg.profileDirectory}/user-profile.json";
+  profileMarkdownTarget = "${cfg.profileDirectory}/user-profile.md";
+  profilePreferences = effectiveProfile.preferences or {};
+  profileBreakpointTolerance = effectiveProfile.breakpointTolerance or {};
+
+  listMarkdown = values:
+    lib.concatMapStringsSep "\n" (value: "- ${toString value}") values;
+
+  specialtyDomains = map (specialty: specialty.domain or "unspecified") (effectiveProfile.specialties or []);
+
+  profileMarkdown = ''
+    # Babysitter User Profile
+
+    This file is generated by Home Manager from `coding.agents.babysitter`.
+
+    - Name: ${effectiveProfile.name or "unspecified"}
+    - Breakpoint tolerance: ${profileBreakpointTolerance.global or "unspecified"}
+    - Autonomy level: ${profilePreferences.autonomyLevel or "unspecified"}
+    - Risk tolerance: ${profilePreferences.riskTolerance or "unspecified"}
+
+    ## Specialties
+
+    ${listMarkdown specialtyDomains}
+
+    ## Installed Babysitter Pi Skills
+
+    ${listMarkdown (effectiveProfile.installedSkills or [])}
+  '';
+in {
+  options.coding.agents.babysitter = {
+    enable = lib.mkEnableOption "Babysitter user profile for Pi/agent workflows";
+
+    profileDirectory = lib.mkOption {
+      type = lib.types.str;
+      default = ".a5c";
+      description = ''
+        Home-relative directory where Babysitter reads the user profile.
+        Babysitter Pi documents the user profile at ~/.a5c/user-profile.json.
+      '';
+    };
+
+    profile = lib.mkOption {
+      type = lib.types.attrsOf lib.types.anything;
+      default = defaultUserProfile;
+      description = "Complete non-secret Babysitter user profile JSON.";
+    };
+
+    profileOverrides = lib.mkOption {
+      type = lib.types.attrsOf lib.types.anything;
+      default = {};
+      description = ''
+        Recursive overrides merged into the default Babysitter user profile.
+        Keep this non-secret; the result is written into the Nix store.
+      '';
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    assertions = [
+      {
+        assertion = cfg.profileDirectory != "" && !lib.hasPrefix "/" cfg.profileDirectory;
+        message = "coding.agents.babysitter.profileDirectory must be a non-empty home-relative path.";
+      }
+      {
+        assertion = effectiveProfile ? name && builtins.isString effectiveProfile.name;
+        message = "coding.agents.babysitter profile must include a string name.";
+      }
+      {
+        assertion = effectiveProfile ? specialties && builtins.isList effectiveProfile.specialties;
+        message = "coding.agents.babysitter profile must include a specialties list.";
+      }
+      {
+        assertion = effectiveProfile ? breakpointTolerance && effectiveProfile.breakpointTolerance ? global;
+        message = "coding.agents.babysitter profile must include breakpointTolerance.global.";
+      }
+    ];
+
+    home.file = {
+      "${profileJsonTarget}".text = builtins.toJSON effectiveProfile + "\n";
+      "${profileMarkdownTarget}".text = profileMarkdown;
+    };
+  };
+}