diff --git a/configuration/services/conduit.nix b/configuration/services/conduit.nix
index bf63305..871b5e2 100644
--- a/configuration/services/conduit.nix
+++ b/configuration/services/conduit.nix
@@ -1,4 +1,5 @@
 {
+  pkgs,
   config,
   lib,
   flake-inputs,
@@ -30,6 +31,87 @@ in {
     };
   };
 
+  systemd.services.heisenbridge = let
+    replaceSecretBin = "${pkgs.replace-secret}/bin/replace-secret";
+    registrationFile = builtins.toFile "heisenbridge-registration.yaml" (builtins.toJSON {
+      id = "heisenbridge";
+      url = "http://127.0.0.1:9898";
+      as_token = "@AS_TOKEN@";
+      hs_token = "@HS_TOKEN@";
+      rate_limited = false;
+      sender_localpart = "heisenbridge";
+      namespaces = {
+        users = [
+          {
+            regex = "@irc_.*";
+            exclusive = true;
+          }
+          {
+            regex = "@heisenbridge:.*";
+            exclusive = true;
+          }
+        ];
+        aliases = [];
+        rooms = [];
+      };
+    });
+
+    # TODO(tlater): Starting with systemd 253 it will become possible
+    # to do the credential setup as part of ExecStartPre/preStart
+    # instead.
+    #
+    # This will also make it possible to actually set caps on the
+    # heisenbridge process using systemd, so that we can run the
+    # identd process.
+    execScript = pkgs.writeShellScript "heisenbridge" ''
+      cp ${registrationFile} "$RUNTIME_DIRECTORY/heisenbridge-registration.yaml"
+      chmod 600 $RUNTIME_DIRECTORY/heisenbridge-registration.yaml
+      ${replaceSecretBin} '@AS_TOKEN@' "$CREDENTIALS_DIRECTORY/heisenbridge_as-token" "$RUNTIME_DIRECTORY/heisenbridge-registration.yaml"
+      ${replaceSecretBin} '@HS_TOKEN@' "$CREDENTIALS_DIRECTORY/heisenbridge_hs-token" "$RUNTIME_DIRECTORY/heisenbridge-registration.yaml"
+      chmod 400 $RUNTIME_DIRECTORY/heisenbridge-registration.yaml
+
+      ${pkgs.heisenbridge}/bin/heisenbridge \
+          --config $RUNTIME_DIRECTORY/heisenbridge-registration.yaml \
+          --owner @tlater:matrix.tlater.net \
+          'http://localhost:${toString cfg.settings.global.port}'
+    '';
+  in {
+    description = "Matrix<->IRC bridge";
+    wantedBy = ["multi-user.target"];
+    after = ["conduit.service"];
+
+    serviceConfig = {
+      Type = "simple";
+
+      LoadCredential = "heisenbridge:/run/secrets/heisenbridge";
+
+      ExecStart = execScript;
+
+      DynamicUser = true;
+      RuntimeDirectory = "heisenbridge";
+      RuntimeDirectoryMode = "0700";
+
+      RestrictNamespaces = true;
+      PrivateUsers = true;
+      ProtectHostname = true;
+      ProtectClock = true;
+      ProtectKernelTunables = true;
+      ProtectKernelModules = true;
+      ProtectKernelLogs = true;
+      ProtectControlGroups = true;
+      RestrictAddressFamilies = ["AF_INET AF_INET6"];
+      LockPersonality = true;
+      RestrictRealtime = true;
+      ProtectProc = "invisible";
+      ProcSubset = "pid";
+      UMask = 0077;
+
+      # For the identd port
+      # CapabilityBoundingSet = ["CAP_NET_BIND_SERVICE"];
+      # AmbientCapabilities = ["CAP_NET_BIND_SERVICE"];
+    };
+  };
+
   # Pass in the TURN secret via EnvironmentFile, not supported by
   # upstream module currently.
   #
diff --git a/configuration/sops.nix b/configuration/sops.nix
index 21613b2..d02b3f0 100644
--- a/configuration/sops.nix
+++ b/configuration/sops.nix
@@ -6,6 +6,8 @@
       group = "nextcloud";
     };
     secrets."steam/tlater" = {};
+    secrets."heisenbridge/as-token" = {};
+    secrets."heisenbridge/hs-token" = {};
     secrets."turn/env" = {};
     secrets."turn/secret" = {
       owner = "turnserver";
diff --git a/keys/production.yaml b/keys/production.yaml
index 6bc16ad..666b893 100644
--- a/keys/production.yaml
+++ b/keys/production.yaml
@@ -2,6 +2,9 @@ nextcloud:
     tlater: ENC[AES256_GCM,data:zNsPm4uFaIRe3LjcwmayRg==,iv:5wam6bP5zP708jC9UrLV0s8qspl3Pm4fPzbMFYBUyPQ=,tag:apnJUMeJwMn9q0NhO4ptmA==,type:str]
 steam:
     tlater: ENC[AES256_GCM,data:HNsve/Wid40ftclO9n09yXg=,iv:VQxAz4eR9lfxEvM0zl1FpJpbKrEFxjIYLyCqL9Aool0=,tag:LHcpHCXAHe8p2kOvOnKXyw==,type:str]
+heisenbridge:
+    as-token: ENC[AES256_GCM,data:+2yo6T18j34622H8ZWblAFB2phLw1q0k0vUQEZ5sFj7dQaRnkEiAMi0R3p17Zq0pOtGEC0RRZuPLYkcZ1oKP0w==,iv:lGwrQYp//FufpmJocrLIVyy9RK7lEEVcpAi0wmkjr34=,tag:yV06UbhAYJQz36O2XdhY+A==,type:str]
+    hs-token: ENC[AES256_GCM,data:u52WpkQFd/J7JFoE/rfNluebyZQLOokvkVdL7+AEAvrhJhrkJli1ztkD79lbC+6tGUH4tT3T+nX9wvGKnrRUQg==,iv:as+9fVuvMg2IoE2WIKD9mHi+znhNcWRh5Zq+yr0xcDQ=,tag:mZ7fh7U0MfgI8hyq/28Bcg==,type:str]
 turn:
     env: ENC[AES256_GCM,data:kt5nhVo9pb/ZbPUEcqSYXxN9YMgQKnFb5VRfFFS/qoIaJ73uD2fuJKqcxAyVRrdLqnSAWSQBgTgunBzdP7xqLAK2qt8DYAQWHkIe9uxFbSXZpdmw,iv:9lq6SFwTFN4GGm6gPiJpUMasMdnHVF6XLGYrsyG3kjU=,tag:428Qf9DOiiHt/Wjb188b8g==,type:str]
     secret: ENC[AES256_GCM,data:si7ee6Xfhdgdyzbp6aQpF7pz3TmTBb7iQ82lRPVXNDg9JfHI+lbmgAsSnRLX5qMCA6P9R045sSMosqidL8QwRg==,iv:SrhpZKK8D45yxCEfDb9P3TwtA14+qEI+wcRqcN/a6pw=,tag:PiwV+mOL9xHJgJft6sc61g==,type:str]
@@ -14,8 +17,8 @@ sops:
     azure_kv: []
     hc_vault: []
     age: []
-    lastmodified: "2022-11-05T18:45:55Z"
-    mac: ENC[AES256_GCM,data:xPCfjqVkewEqrUjHroXa9RGHITntVj2uGPaRZfj0lqTUPFG6GQDn3Yq6L6cV3EPOYQ4OedJlaVXy05OHkzZwjYEbBQVGQ0aH/ZOP7X301eebBX5MvHLFU4mcnjMITWGH/E7SXz3pPF75s9eM/onx374PcQt6zevbBF+Jp0Fz71I=,iv:84JL69nF3ougygMAVFOoTaCn37thvm4lF6HYdgTiftg=,tag:ATQ18acehgUAE/dX+vYugQ==,type:str]
+    lastmodified: "2023-02-21T10:51:11Z"
+    mac: ENC[AES256_GCM,data:uMqT+7ljd6t1RpF9IH7illO62pq5cERoAtJlRic5BNOeawy/+7ufVorhhya15m39WTKnlGyIY0MEd3tDueHBm4rjf+Pmh6PQ+owRv+deXHv0jXYWX2sz/6i1aYbv9DDMWsvNbkdidKEme+ctY6EVgjSjN5nxxcx+vH+u1OyQ3t0=,iv:VKXznTlMH34SOS+4dpfOVaoiiUTRmIbUMnTPNpyawvY=,tag:onA5C4o/tcGjdBxO9JxMGw==,type:str]
     pgp:
         - created_at: "2022-10-12T00:46:51Z"
           enc: |
diff --git a/keys/staging.yaml b/keys/staging.yaml
index 069a405..41e20ac 100644
--- a/keys/staging.yaml
+++ b/keys/staging.yaml
@@ -2,6 +2,9 @@ nextcloud:
     tlater: ENC[AES256_GCM,data:91kDcO4hpng=,iv:ayuILRmRru4ZxTCur9H2xHuLjkDzwPdS/4lEog/tesU=,tag:qYhJxnNDcCwUM7xe7Tlcjw==,type:str]
 steam:
     tlater: ENC[AES256_GCM,data:jcW4wacGzOQ=,iv:KstKGHflscSWDFXGbnAZUcsqGN4Ot+w7sRbsAUwZNHQ=,tag:n9sRWvaKSgagpIgV/NF/Og==,type:str]
+heisenbridge:
+    as-token: ENC[AES256_GCM,data:tXbOeo7nv8I=,iv:wJAKcOXX9nGIw4n38ThOoj29u7dUWhsxSQG/p79JlEw=,tag:rTVaGS2UuWcea1uBa8YX2g==,type:str]
+    hs-token: ENC[AES256_GCM,data:VBwvwomv0Xg=,iv:q6INtJ+rg+QiXj8uBdBzQYQZUBBXp+9odxDHwvu8Jxc=,tag:XKhm8nxygAkKaiVPJ2Fcdg==,type:str]
 turn:
     env: ENC[AES256_GCM,data:xjIz/AY109lyiL5N01p5T3HcYco/rM5CJSRTtg==,iv:16bW6OpyOK/QL0QPGQp/Baa9xyT8E3ZsYkwqmjuofk0=,tag:J5re3uKxIykw3YunvQWBgg==,type:str]
     secret: ENC[AES256_GCM,data:eQ7dAocoZtg=,iv:fgzjTPv30WqTKlLy+yMn5MsKQgjhPnwlGFFwYEg3gWs=,tag:1ze33U1NBkgMX/9SiaBNQg==,type:str]
@@ -14,8 +17,8 @@ sops:
     azure_kv: []
     hc_vault: []
     age: []
-    lastmodified: "2023-01-11T01:49:31Z"
-    mac: ENC[AES256_GCM,data:5IcHdNQ/mh6Jz60dlpgqbBtVGKYml4EOs7YXsBcejgAoPzZqEK+xb3f9+rq2G6sCcMXzROHJsdQUfp1wMgfp8DwVm4H+XO+SQh/E1kFuWO8G/IpXOT4P9RQC+wHxrVuxHd8pwl9CLv6uuMnO+FNg9TeWB2GAVxIBsY8JHwGN/BA=,iv:/Yqfij58LGNooyyhmr8aWCpknd4dN+b4iSvokVoDGls=,tag:XHm8Qcg75B1+pTOcgZubIQ==,type:str]
+    lastmodified: "2023-02-21T08:32:04Z"
+    mac: ENC[AES256_GCM,data:ZZtL4zYX7FsYeGJ1CcTq5AzRkrvOxIeCoVf77JyEj9k3gApm3k7z2eXe/D+8qvwahlleuvAqhVCUH/I5yHaQSjXXsHO1flULiTnQVk4hrX0fDwXp97NQwpvDovSRyGqx4F25dISfYLVhFpb+64yaPxqMzThVk+Q7Xn40GCY5PR8=,iv:xNeyqB5K2EBDDJEq72IDwpGqzKkAlcxHO6GlJY/iHmM=,tag:Qxz0GTQ/I4EsZhFZh2VxKg==,type:str]
     pgp:
         - created_at: "2022-10-12T16:48:23Z"
           enc: |