Cleanup deps.

CMakeLists.txt

@@ -3,6 +3,8 @@ project(j7s_diagnostics_ros CXX)
 
 find_package(ament_cmake REQUIRED)
 find_package(rclcpp REQUIRED)
+find_package(diagnostic_msgs REQUIRED)
+find_package(fmt REQUIRED)
 include(FetchContent)
 
 FetchContent_Declare(
@@ -14,14 +16,11 @@ FetchContent_MakeAvailable(Corrosion)
 
 set(CMAKE_CXX_STANDARD 20)
 
+# Rust bindings.
 corrosion_import_crate(MANIFEST_PATH j7s_diagnostics_cxx/Cargo.toml)
 corrosion_add_cxxbridge(j7s_diagnostics_cxx_bridge
   CRATE j7s_diagnostics_cxx
   FILES lib.rs)
-
-add_executable(test_bin src/test.cpp)
-target_link_libraries(test_bin PRIVATE j7s_diagnostics_cxx_bridge j7s_diagnostics_cxx)
-
 corrosion_install(TARGETS j7s_diagnostics_cxx
   EXPORT export_${PROJECT_NAME}
   ARCHIVE DESTINATION lib
@@ -29,8 +28,42 @@ corrosion_install(TARGETS j7s_diagnostics_cxx
   RUNTIME DESTINATION bin
 )
 
+# The rest of the stuff.
+# Note that rust/cxx doesn't support shared libraries so
+# this library (and anything that uses it) will have
+# to be statically linked.
+add_library(conversions STATIC src/conversions.cpp)
+target_include_directories(conversions PUBLIC
+  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+  $<INSTALL_INTERFACE:include/${PROJECT_NAME}>)
+target_link_libraries(conversions PUBLIC
+            j7s_diagnostics_cxx_bridge
+            j7s_diagnostics_cxx
+            fmt
+            ${diagnostic_msgs_TARGETS}
+)
+
+add_executable(test_bin src/test.cpp)
+target_include_directories(test_bin PUBLIC
+  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+  $<INSTALL_INTERFACE:include/${PROJECT_NAME}>)
+target_link_libraries(test_bin PRIVATE
+    conversions
+)
+
+add_executable(j7s_diagnostic_node src/j7s_diagnostic_node.cpp)
+target_include_directories(j7s_diagnostic_node PUBLIC
+  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
+  $<INSTALL_INTERFACE:include/${PROJECT_NAME}>)
+target_link_libraries(j7s_diagnostic_node PRIVATE
+    conversions
+    rclcpp::rclcpp
+)
+
 install(TARGETS
+  conversions
   test_bin
+  j7s_diagnostic_node
   DESTINATION lib/${PROJECT_NAME})
 
 ament_export_targets(export_${PROJECT_NAME})

LICENSE

@@ -0,0 +1,373 @@
+Mozilla Public License Version 2.0
+==================================
+
+1. Definitions
+--------------
+
+1.1. "Contributor"
+    means each individual or legal entity that creates, contributes to
+    the creation of, or owns Covered Software.
+
+1.2. "Contributor Version"
+    means the combination of the Contributions of others (if any) used
+    by a Contributor and that particular Contributor's Contribution.
+
+1.3. "Contribution"
+    means Covered Software of a particular Contributor.
+
+1.4. "Covered Software"
+    means Source Code Form to which the initial Contributor has attached
+    the notice in Exhibit A, the Executable Form of such Source Code
+    Form, and Modifications of such Source Code Form, in each case
+    including portions thereof.
+
+1.5. "Incompatible With Secondary Licenses"
+    means
+
+    (a) that the initial Contributor has attached the notice described
+        in Exhibit B to the Covered Software; or
+
+    (b) that the Covered Software was made available under the terms of
+        version 1.1 or earlier of the License, but not also under the
+        terms of a Secondary License.
+
+1.6. "Executable Form"
+    means any form of the work other than Source Code Form.
+
+1.7. "Larger Work"
+    means a work that combines Covered Software with other material, in 
+    a separate file or files, that is not Covered Software.
+
+1.8. "License"
+    means this document.
+
+1.9. "Licensable"
+    means having the right to grant, to the maximum extent possible,
+    whether at the time of the initial grant or subsequently, any and
+    all of the rights conveyed by this License.
+
+1.10. "Modifications"
+    means any of the following:
+
+    (a) any file in Source Code Form that results from an addition to,
+        deletion from, or modification of the contents of Covered
+        Software; or
+
+    (b) any new file in Source Code Form that contains any Covered
+        Software.
+
+1.11. "Patent Claims" of a Contributor
+    means any patent claim(s), including without limitation, method,
+    process, and apparatus claims, in any patent Licensable by such
+    Contributor that would be infringed, but for the grant of the
+    License, by the making, using, selling, offering for sale, having
+    made, import, or transfer of either its Contributions or its
+    Contributor Version.
+
+1.12. "Secondary License"
+    means either the GNU General Public License, Version 2.0, the GNU
+    Lesser General Public License, Version 2.1, the GNU Affero General
+    Public License, Version 3.0, or any later versions of those
+    licenses.
+
+1.13. "Source Code Form"
+    means the form of the work preferred for making modifications.
+
+1.14. "You" (or "Your")
+    means an individual or a legal entity exercising rights under this
+    License. For legal entities, "You" includes any entity that
+    controls, is controlled by, or is under common control with You. For
+    purposes of this definition, "control" means (a) the power, direct
+    or indirect, to cause the direction or management of such entity,
+    whether by contract or otherwise, or (b) ownership of more than
+    fifty percent (50%) of the outstanding shares or beneficial
+    ownership of such entity.
+
+2. License Grants and Conditions
+--------------------------------
+
+2.1. Grants
+
+Each Contributor hereby grants You a world-wide, royalty-free,
+non-exclusive license:
+
+(a) under intellectual property rights (other than patent or trademark)
+    Licensable by such Contributor to use, reproduce, make available,
+    modify, display, perform, distribute, and otherwise exploit its
+    Contributions, either on an unmodified basis, with Modifications, or
+    as part of a Larger Work; and
+
+(b) under Patent Claims of such Contributor to make, use, sell, offer
+    for sale, have made, import, and otherwise transfer either its
+    Contributions or its Contributor Version.
+
+2.2. Effective Date
+
+The licenses granted in Section 2.1 with respect to any Contribution
+become effective for each Contribution on the date the Contributor first
+distributes such Contribution.
+
+2.3. Limitations on Grant Scope
+
+The licenses granted in this Section 2 are the only rights granted under
+this License. No additional rights or licenses will be implied from the
+distribution or licensing of Covered Software under this License.
+Notwithstanding Section 2.1(b) above, no patent license is granted by a
+Contributor:
+
+(a) for any code that a Contributor has removed from Covered Software;
+    or
+
+(b) for infringements caused by: (i) Your and any other third party's
+    modifications of Covered Software, or (ii) the combination of its
+    Contributions with other software (except as part of its Contributor
+    Version); or
+
+(c) under Patent Claims infringed by Covered Software in the absence of
+    its Contributions.
+
+This License does not grant any rights in the trademarks, service marks,
+or logos of any Contributor (except as may be necessary to comply with
+the notice requirements in Section 3.4).
+
+2.4. Subsequent Licenses
+
+No Contributor makes additional grants as a result of Your choice to
+distribute the Covered Software under a subsequent version of this
+License (see Section 10.2) or under the terms of a Secondary License (if
+permitted under the terms of Section 3.3).
+
+2.5. Representation
+
+Each Contributor represents that the Contributor believes its
+Contributions are its original creation(s) or it has sufficient rights
+to grant the rights to its Contributions conveyed by this License.
+
+2.6. Fair Use
+
+This License is not intended to limit any rights You have under
+applicable copyright doctrines of fair use, fair dealing, or other
+equivalents.
+
+2.7. Conditions
+
+Sections 3.1, 3.2, 3.3, and 3.4 are conditions of the licenses granted
+in Section 2.1.
+
+3. Responsibilities
+-------------------
+
+3.1. Distribution of Source Form
+
+All distribution of Covered Software in Source Code Form, including any
+Modifications that You create or to which You contribute, must be under
+the terms of this License. You must inform recipients that the Source
+Code Form of the Covered Software is governed by the terms of this
+License, and how they can obtain a copy of this License. You may not
+attempt to alter or restrict the recipients' rights in the Source Code
+Form.
+
+3.2. Distribution of Executable Form
+
+If You distribute Covered Software in Executable Form then:
+
+(a) such Covered Software must also be made available in Source Code
+    Form, as described in Section 3.1, and You must inform recipients of
+    the Executable Form how they can obtain a copy of such Source Code
+    Form by reasonable means in a timely manner, at a charge no more
+    than the cost of distribution to the recipient; and
+
+(b) You may distribute such Executable Form under the terms of this
+    License, or sublicense it under different terms, provided that the
+    license for the Executable Form does not attempt to limit or alter
+    the recipients' rights in the Source Code Form under this License.
+
+3.3. Distribution of a Larger Work
+
+You may create and distribute a Larger Work under terms of Your choice,
+provided that You also comply with the requirements of this License for
+the Covered Software. If the Larger Work is a combination of Covered
+Software with a work governed by one or more Secondary Licenses, and the
+Covered Software is not Incompatible With Secondary Licenses, this
+License permits You to additionally distribute such Covered Software
+under the terms of such Secondary License(s), so that the recipient of
+the Larger Work may, at their option, further distribute the Covered
+Software under the terms of either this License or such Secondary
+License(s).
+
+3.4. Notices
+
+You may not remove or alter the substance of any license notices
+(including copyright notices, patent notices, disclaimers of warranty,
+or limitations of liability) contained within the Source Code Form of
+the Covered Software, except that You may alter any license notices to
+the extent required to remedy known factual inaccuracies.
+
+3.5. Application of Additional Terms
+
+You may choose to offer, and to charge a fee for, warranty, support,
+indemnity or liability obligations to one or more recipients of Covered
+Software. However, You may do so only on Your own behalf, and not on
+behalf of any Contributor. You must make it absolutely clear that any
+such warranty, support, indemnity, or liability obligation is offered by
+You alone, and You hereby agree to indemnify every Contributor for any
+liability incurred by such Contributor as a result of warranty, support,
+indemnity or liability terms You offer. You may include additional
+disclaimers of warranty and limitations of liability specific to any
+jurisdiction.
+
+4. Inability to Comply Due to Statute or Regulation
+---------------------------------------------------
+
+If it is impossible for You to comply with any of the terms of this
+License with respect to some or all of the Covered Software due to
+statute, judicial order, or regulation then You must: (a) comply with
+the terms of this License to the maximum extent possible; and (b)
+describe the limitations and the code they affect. Such description must
+be placed in a text file included with all distributions of the Covered
+Software under this License. Except to the extent prohibited by statute
+or regulation, such description must be sufficiently detailed for a
+recipient of ordinary skill to be able to understand it.
+
+5. Termination
+--------------
+
+5.1. The rights granted under this License will terminate automatically
+if You fail to comply with any of its terms. However, if You become
+compliant, then the rights granted under this License from a particular
+Contributor are reinstated (a) provisionally, unless and until such
+Contributor explicitly and finally terminates Your grants, and (b) on an
+ongoing basis, if such Contributor fails to notify You of the
+non-compliance by some reasonable means prior to 60 days after You have
+come back into compliance. Moreover, Your grants from a particular
+Contributor are reinstated on an ongoing basis if such Contributor
+notifies You of the non-compliance by some reasonable means, this is the
+first time You have received notice of non-compliance with this License
+from such Contributor, and You become compliant prior to 30 days after
+Your receipt of the notice.
+
+5.2. If You initiate litigation against any entity by asserting a patent
+infringement claim (excluding declaratory judgment actions,
+counter-claims, and cross-claims) alleging that a Contributor Version
+directly or indirectly infringes any patent, then the rights granted to
+You by any and all Contributors for the Covered Software under Section
+2.1 of this License shall terminate.
+
+5.3. In the event of termination under Sections 5.1 or 5.2 above, all
+end user license agreements (excluding distributors and resellers) which
+have been validly granted by You or Your distributors under this License
+prior to termination shall survive termination.
+
+************************************************************************
+*                                                                      *
+*  6. Disclaimer of Warranty                                           *
+*  -------------------------                                           *
+*                                                                      *
+*  Covered Software is provided under this License on an "as is"       *
+*  basis, without warranty of any kind, either expressed, implied, or  *
+*  statutory, including, without limitation, warranties that the       *
+*  Covered Software is free of defects, merchantable, fit for a        *
+*  particular purpose or non-infringing. The entire risk as to the     *
+*  quality and performance of the Covered Software is with You.        *
+*  Should any Covered Software prove defective in any respect, You     *
+*  (not any Contributor) assume the cost of any necessary servicing,   *
+*  repair, or correction. This disclaimer of warranty constitutes an   *
+*  essential part of this License. No use of any Covered Software is   *
+*  authorized under this License except under this disclaimer.         *
+*                                                                      *
+************************************************************************
+
+************************************************************************
+*                                                                      *
+*  7. Limitation of Liability                                          *
+*  --------------------------                                          *
+*                                                                      *
+*  Under no circumstances and under no legal theory, whether tort      *
+*  (including negligence), contract, or otherwise, shall any           *
+*  Contributor, or anyone who distributes Covered Software as          *
+*  permitted above, be liable to You for any direct, indirect,         *
+*  special, incidental, or consequential damages of any character      *
+*  including, without limitation, damages for lost profits, loss of    *
+*  goodwill, work stoppage, computer failure or malfunction, or any    *
+*  and all other commercial damages or losses, even if such party      *
+*  shall have been informed of the possibility of such damages. This   *
+*  limitation of liability shall not apply to liability for death or   *
+*  personal injury resulting from such party's negligence to the       *
+*  extent applicable law prohibits such limitation. Some               *
+*  jurisdictions do not allow the exclusion or limitation of           *
+*  incidental or consequential damages, so this exclusion and          *
+*  limitation may not apply to You.                                    *
+*                                                                      *
+************************************************************************
+
+8. Litigation
+-------------
+
+Any litigation relating to this License may be brought only in the
+courts of a jurisdiction where the defendant maintains its principal
+place of business and such litigation shall be governed by laws of that
+jurisdiction, without reference to its conflict-of-law provisions.
+Nothing in this Section shall prevent a party's ability to bring
+cross-claims or counter-claims.
+
+9. Miscellaneous
+----------------
+
+This License represents the complete agreement concerning the subject
+matter hereof. If any provision of this License is held to be
+unenforceable, such provision shall be reformed only to the extent
+necessary to make it enforceable. Any law or regulation which provides
+that the language of a contract shall be construed against the drafter
+shall not be used to construe this License against a Contributor.
+
+10. Versions of the License
+---------------------------
+
+10.1. New Versions
+
+Mozilla Foundation is the license steward. Except as provided in Section
+10.3, no one other than the license steward has the right to modify or
+publish new versions of this License. Each version will be given a
+distinguishing version number.
+
+10.2. Effect of New Versions
+
+You may distribute the Covered Software under the terms of the version
+of the License under which You originally received the Covered Software,
+or under the terms of any subsequent version published by the license
+steward.
+
+10.3. Modified Versions
+
+If you create software not governed by this License, and you want to
+create a new license for such software, you may create and use a
+modified version of this License if you rename the license and remove
+any references to the name of the license steward (except to note that
+such modified license differs from this License).
+
+10.4. Distributing Source Code Form that is Incompatible With Secondary
+Licenses
+
+If You choose to distribute Source Code Form that is Incompatible With
+Secondary Licenses under the terms of this version of the License, the
+notice described in Exhibit B of this License must be attached.
+
+Exhibit A - Source Code Form License Notice
+-------------------------------------------
+
+  This Source Code Form is subject to the terms of the Mozilla Public
+  License, v. 2.0. If a copy of the MPL was not distributed with this
+  file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+If it is not possible or desirable to put the notice in a particular
+file, then You may include the notice in a location (such as a LICENSE
+file in a relevant directory) where a recipient would be likely to look
+for such a notice.
+
+You may add additional accurate notices of copyright ownership.
+
+Exhibit B - "Incompatible With Secondary Licenses" Notice
+---------------------------------------------------------
+
+  This Source Code Form is "Incompatible With Secondary Licenses", as
+  defined by the Mozilla Public License, v. 2.0.

include/j7s_diagnostics_ros/conversions.hpp

@@ -0,0 +1,41 @@
+//
+// Copyright 2026 James Pace
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+//
+// This Source Code Form is "Incompatible With Secondary Licenses", as
+// defined by the Mozilla Public License, v. 2.0.
+//
+#pragma once
+
+#include <diagnostic_msgs/msg/diagnostic_array.hpp>
+#include <diagnostic_msgs/msg/diagnostic_status.hpp>
+
+#include "j7s_diagnostics_cxx_bridge/lib.h"
+
+std::string convertString(const rust::String & rust);
+
+j7s_diagnostics_cxx::DiagnosticLevel convertLevel(const uint8_t rosLevel);
+
+uint8_t convertLevel(const j7s_diagnostics_cxx::DiagnosticLevel & level);
+
+std::vector<diagnostic_msgs::msg::KeyValue> convertValues(
+    const rust::Box<j7s_diagnostics_cxx::StringMap> & map);
+
+rust::Box<j7s_diagnostics_cxx::StringMap> convertValues(
+    const std::vector<diagnostic_msgs::msg::KeyValue> & map);
+
+j7s_diagnostics_cxx::DiagnosticStatus fromMsg(const diagnostic_msgs::msg::DiagnosticStatus & msg);
+
+diagnostic_msgs::msg::DiagnosticStatus toMsg(const j7s_diagnostics_cxx::DiagnosticStatus & status);
+
+rust::Vec<j7s_diagnostics_cxx::DiagnosticStatus> fromMsg(
+    const diagnostic_msgs::msg::DiagnosticArray & msg);
+
+rust::Vec<j7s_diagnostics_cxx::DiagnosticStatus> fromMsg(
+    const std::vector<diagnostic_msgs::msg::DiagnosticStatus> & msgs);
+
+diagnostic_msgs::msg::DiagnosticArray toMsg(
+    const rust::Vec<j7s_diagnostics_cxx::DiagnosticStatus> & statuses);

include/j7s_diagnostics_ros/j7s_diagnostic_node.hpp

@@ -0,0 +1,30 @@
+//
+// Copyright 2026 James Pace
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+//
+// This Source Code Form is "Incompatible With Secondary Licenses", as
+// defined by the Mozilla Public License, v. 2.0.
+//
+#pragma once
+#include <diagnostic_msgs/msg/diagnostic_array.hpp>
+#include <diagnostic_msgs/msg/diagnostic_status.hpp>
+#include <rclcpp/rclcpp.hpp>
+
+namespace j7s
+{
+class DiagnosticAggregator : public rclcpp::Node
+{
+public:
+    DiagnosticAggregator(const rclcpp::NodeOptions & options);
+
+private:
+    std::shared_ptr<rclcpp::Publisher<diagnostic_msgs::msg::DiagnosticArray>> m_publisher;
+    std::shared_ptr<rclcpp::Subscription<diagnostic_msgs::msg::DiagnosticArray>> m_subscriber;
+    rclcpp::TimerBase::SharedPtr m_timer;
+
+    std::vector<diagnostic_msgs::msg::DiagnosticStatus> m_queue;
+};
+}  // namespace j7s

j7s_diagnostics_cxx/Cargo.lock

@@ -16,9 +16,9 @@ checksum = "330a5ed07fa54e4702c9d6c4174f74427fc0ef6e214bbd677ae50a5099946470"
 
 [[package]]
 name = "cc"
-version = "1.3.0"
+version = "1.4.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c89588d05638b5b4594a3348a2d6c20277e43a7f5c5202b05cc56888475a47b8"
+checksum = "a3eb0f42d6c360dc3f8a821f6bf2fdea7f72bfd36b3076eb0e6d1e9e0752fff4"
 dependencies = [
  "find-msvc-tools",
  "shlex",
@@ -26,18 +26,18 @@ dependencies = [
 
 [[package]]
 name = "clap"
-version = "4.6.2"
+version = "4.6.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "dd059f9da4f5c36b3787f65d38ccaab1cc315f07b01f89abc8359ee6a8205011"
+checksum = "aa8876b300ab35ba921adea3dfd70157a46249b33f95c9084ae5709785478946"
 dependencies = [
  "clap_builder",
 ]
 
 [[package]]
 name = "clap_builder"
-version = "4.6.2"
+version = "4.6.7"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "f09628afdcc538b57f3c6341e9c8e9970f18e4a481690a64974d7023bd33548b"
+checksum = "ec0797fb7aeb1406c84efac526901f7ec3ead2124f946b494e72879d4b54704d"
 dependencies = [
  "anstyle",
  "clap_lex",
@@ -46,9 +46,9 @@ dependencies = [
 
 [[package]]
 name = "clap_lex"
-version = "1.1.0"
+version = "1.1.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c8d4a3bb8b1e0c1050499d1815f5ab16d04f0959b233085fb31653fbfc9d98f9"
+checksum = "1c133bc6a41be0d194c306b5506d15e6feeea7b1d6604bd3f8310dfb2ca96486"
 
 [[package]]
 name = "codespan-reporting"
@@ -63,9 +63,9 @@ dependencies = [
 
 [[package]]
 name = "cxx"
-version = "1.0.198"
+version = "1.0.202"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6fe442a792c7c736eea18b32a7f8a3b63cf8aafabda6760042dc2fdeda456291"
+checksum = "13f6de320895f42e6e081abb5c7983bedcf0b6d0ff9323de0d33f620c8ac1199"
 dependencies = [
  "cc",
  "cxx-build",
@@ -78,9 +78,9 @@ dependencies = [
 
 [[package]]
 name = "cxx-build"
-version = "1.0.198"
+version = "1.0.202"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e3184a94384c663718698311a78a51ac00c484c10b4eeac06fb0a068c5f64fa2"
+checksum = "4fde53ca86b9704a943fef0f1e1d836239a6aedca5de3c65fa9f97ec0bd46d39"
 dependencies = [
  "cc",
  "codespan-reporting",
@@ -93,9 +93,9 @@ dependencies = [
 
 [[package]]
 name = "cxxbridge-cmd"
-version = "1.0.198"
+version = "1.0.202"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "0148d8fd1199329ddf1d157a5e134e51ceff37c6a7ddd38615c399d81cb05d8d"
+checksum = "07bae89236c811fd4d08ed3441759ac4ac98d752cbfd3de341315ba16ad20ec3"
 dependencies = [
  "clap",
  "codespan-reporting",
@@ -107,15 +107,15 @@ dependencies = [
 
 [[package]]
 name = "cxxbridge-flags"
-version = "1.0.198"
+version = "1.0.202"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "52850339faed2eaadd24e286dc1d8268cc6f8a7bd9524d713adc9099566b4c89"
+checksum = "49045042e5fced01b80742aba5508de82aa4f13677ed3fa2b4cda709c40c5918"
 
 [[package]]
 name = "cxxbridge-macro"
-version = "1.0.198"
+version = "1.0.202"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "2c77c856545d886c9bd5215409ebb63b925e262135248b50c79e5a5f194ee47c"
+checksum = "b181252e2e3d3b5d183afbdc033a3958b445eb3e1a0ae65fc3d4f5259f5da6fd"
 dependencies = [
  "indexmap",
  "proc-macro2",
@@ -131,9 +131,9 @@ checksum = "877a4ace8713b0bcf2a4e7eec82529c029f1d0619886d18145fea96c3ffe5c0f"
 
 [[package]]
 name = "find-msvc-tools"
-version = "0.1.9"
+version = "0.1.12"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5baebc0774151f905a1a2cc41989300b1e6fbb29aff0ceffa1064fdd3088d582"
+checksum = "3e0f1c7c3a72c66fd80abe965175f7523475c0489a87d3ff9d6e8c87d87a9d2d"
 
 [[package]]
 name = "foldhash"
@@ -149,20 +149,28 @@ checksum = "ed5909b6e89a2db4456e54cd5f673791d7eca6732202bbf2a9cc504fe2f9b84a"
 
 [[package]]
 name = "indexmap"
-version = "2.14.0"
+version = "2.14.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "d466e9454f08e4a911e14806c24e16fba1b4c121d1ea474396f396069cf949d9"
+checksum = "cc4e190f5d26ca7051642629da2c52fc03bde85a03197c99408dcd291734c855"
 dependencies = [
  "equivalent",
  "hashbrown",
 ]
 
+[[package]]
+name = "itoa"
+version = "1.0.18"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8f42a60cbdf9a97f5d2305f08a87dc4e09308d1276d28c869c684d7777685682"
+
 [[package]]
 name = "j7s_diagnostics"
 version = "0.1.0"
-source = "git+https://git.jpace121.net/public/j7s_diagnostics.git?branch=main#f40b64151807cbca03a021e66cb3bf3558e4619d"
+source = "git+ssh://git@git.jpace121.net:2222/public/j7s_diagnostics.git?branch=main#c8b5db719c0de550a22b87f88c34ac7c0489f78c"
 dependencies = [
  "limbo_graph",
+ "serde",
+ "serde_json",
  "thiserror",
 ]
 
@@ -190,6 +198,12 @@ dependencies = [
  "cc",
 ]
 
+[[package]]
+name = "memchr"
+version = "2.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "cf8baf1c55e62ffcace7a9f06f4bd9cd3f0c4beb022d3b367256b91b87513d98"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.107"
@@ -244,6 +258,19 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "serde_json"
+version = "1.0.151"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c841b55ecdae098c80dcae9cf767f6f8a0c2cdb3416bbef72181df4d0fe73f14"
+dependencies = [
+ "itoa",
+ "memchr",
+ "serde",
+ "serde_core",
+ "zmij",
+]
+
 [[package]]
 name = "shlex"
 version = "2.0.1"
@@ -258,9 +285,9 @@ checksum = "7da8b5736845d9f2fcb837ea5d9e2628564b3b043a70948a3f0b778838c5fb4f"
 
 [[package]]
 name = "syn"
-version = "3.0.1"
+version = "3.0.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "5edbec4ed188954a10c12c038215f8ce7606b2d5c973cd8dc43e8795065c5f2f"
+checksum = "8593e8e72159ed2257d083c7a454a85cbf854f37a0966d8d483aff8c8a3ebcee"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -278,18 +305,18 @@ dependencies = [
 
 [[package]]
 name = "thiserror"
-version = "2.0.19"
+version = "2.0.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "09a43598840e33d5b0331f38c5e30d13bb11c11210a4b58f0d9b18a5a5eefcd9"
+checksum = "ec86235f5fcc2a73650310756d2ac5b138a5780bbbdfae3eeccec992c435ba4f"
 dependencies = [
  "thiserror-impl",
 ]
 
 [[package]]
 name = "thiserror-impl"
-version = "2.0.19"
+version = "2.0.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "43cbfe0cf76104d42a574802844187e84a305e531ed54455f11fbde0f10541cd"
+checksum = "bc04cd3e1236dd4a98afca4569f2deb3f120e5422a4023be2cb683f8486292af"
 dependencies = [
  "proc-macro2",
  "quote",
@@ -298,9 +325,9 @@ dependencies = [
 
 [[package]]
 name = "unicode-ident"
-version = "1.0.24"
+version = "1.0.25"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "e6e4313cd5fcd3dad5cafa179702e2b244f760991f45397d14d4ebf38247da75"
+checksum = "ab72a15cf68d77cb0987d3684aa8a45c5ef827e8cb49ee2f30bfd7ba2feb519f"
 
 [[package]]
 name = "unicode-width"
@@ -331,3 +358,9 @@ checksum = "ae137229bcbd6cdf0f7b80a31df61766145077ddf49416a728b02cb3921ff3fc"
 dependencies = [
  "windows-link",
 ]
+
+[[package]]
+name = "zmij"
+version = "1.0.23"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29666d0abbfad1e3dc4dcf6144730dd3a3ab225bbbdac83319345b1b44ccfc1b"

j7s_diagnostics_cxx/Cargo.toml

@@ -9,7 +9,7 @@ crate-type = ["staticlib"]
 [dependencies]
 anyhow = "1.0.103"
 cxx = "1.0"
-j7s_diagnostics = { branch = "main", git="https://git.jpace121.net/public/j7s_diagnostics.git" }
+j7s_diagnostics = { branch="main", git="ssh://git@git.jpace121.net:2222/public/j7s_diagnostics.git", features=["std"] }
 
 [build-dependencies]
 cxx-build = "1.0"

j7s_diagnostics_cxx/src/lib.rs

@@ -1,8 +1,18 @@
+//
+// Copyright 2026 James Pace
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+//
+// This Source Code Form is "Incompatible With Secondary Licenses", as
+// defined by the Mozilla Public License, v. 2.0.
+//
 #![allow(non_snake_case)]
 use anyhow::anyhow;
 use std::collections::BTreeMap;
 
-#[cxx::bridge]
+#[cxx::bridge(namespace = "j7s_diagnostics_cxx")]
 mod ffi {
     // Shared structs whose fields can be seen in both C++ and Rust.
     #[derive(Clone, PartialOrd, PartialEq, Default)]
@@ -21,13 +31,16 @@ mod ffi {
         name: String,
         message: String,
         hardware_id: String,
-        values: Box<StringMap>
+        values: Box<StringMap>,
     }
 
     extern "Rust" {
         // Functions in here can be seen on both sides, but are
         // defined in rust.
         // types can be seen in both languages, but only opaquely in C++.
+        #[Self = "DiagnosticStatus"]
+        fn build() -> DiagnosticStatus;
+
         type OptionalString;
         #[Self = "OptionalString"]
         fn some(val: String) -> Box<OptionalString>;
@@ -36,29 +49,81 @@ mod ffi {
         fn is_some(self: &OptionalString) -> bool;
         fn value(self: &OptionalString) -> Result<String>;
 
-
         type StringMap;
         #[Self = "StringMap"]
         fn build() -> Box<StringMap>;
         fn get(self: &StringMap, key: &String) -> Box<OptionalString>;
         fn insert(self: &mut StringMap, key: String, value: String);
+        fn keys(self: &StringMap) -> Vec<String>;
 
         type DiagnosticTree;
         #[Self = "DiagnosticTree"]
         fn build() -> Box<DiagnosticTree>;
-        fn add_statuses(self: &mut DiagnosticTree, statuses: &Vec<DiagnosticStatus>) -> Result<()> ;
+        fn add_statuses(self: &mut DiagnosticTree, statuses: &Vec<DiagnosticStatus>) -> Result<()>;
+        fn add_status(self: &mut DiagnosticTree, status: &DiagnosticStatus) -> Result<()>;
         fn reconcile(self: &mut DiagnosticTree) -> Result<()>;
         fn aggregate(self: &DiagnosticTree) -> Result<Vec<DiagnosticStatus>>;
 
     }
 }
 
-fn diagnostic_status_to_rust(cpp: &crate::ffi::DiagnosticStatus) -> j7s_diagnostics::DiagnosticStatus {
+fn diagnostic_level_to_rust(cpp: &crate::ffi::DiagnosticLevel) -> j7s_diagnostics::DiagnosticLevel {
-    todo!()
+    match cpp {
+        &crate::ffi::DiagnosticLevel::UNSET => j7s_diagnostics::DiagnosticLevel::UNSET,
+        &crate::ffi::DiagnosticLevel::OK => j7s_diagnostics::DiagnosticLevel::OK,
+        &crate::ffi::DiagnosticLevel::WARN => j7s_diagnostics::DiagnosticLevel::WARN,
+        &crate::ffi::DiagnosticLevel::ERROR => j7s_diagnostics::DiagnosticLevel::ERROR,
+        &crate::ffi::DiagnosticLevel::STALE => j7s_diagnostics::DiagnosticLevel::STALE,
+        _ => j7s_diagnostics::DiagnosticLevel::UNSET,
+    }
 }
 
-fn diagnostic_status_from_rust(rust: &j7s_diagnostics::DiagnosticStatus) -> crate::ffi::DiagnosticStatus {
+fn diagnostic_level_from_rust(
-    todo!()
+    rust: &j7s_diagnostics::DiagnosticLevel,
+) -> crate::ffi::DiagnosticLevel {
+    match rust {
+        &j7s_diagnostics::DiagnosticLevel::UNSET => crate::ffi::DiagnosticLevel::UNSET,
+        &j7s_diagnostics::DiagnosticLevel::OK => crate::ffi::DiagnosticLevel::OK,
+        &j7s_diagnostics::DiagnosticLevel::WARN => crate::ffi::DiagnosticLevel::WARN,
+        &j7s_diagnostics::DiagnosticLevel::ERROR => crate::ffi::DiagnosticLevel::ERROR,
+        &j7s_diagnostics::DiagnosticLevel::STALE => crate::ffi::DiagnosticLevel::STALE,
+    }
+}
+
+fn diagnostic_status_to_rust(
+    cpp: &crate::ffi::DiagnosticStatus,
+) -> j7s_diagnostics::DiagnosticStatus {
+    j7s_diagnostics::DiagnosticStatus::new(
+        diagnostic_level_to_rust(&cpp.level),
+        cpp.name.clone(),
+        cpp.message.clone(),
+        cpp.hardware_id.clone(),
+        cpp.values.to_btree(),
+    )
+}
+
+fn diagnostic_status_from_rust(
+    rust: &j7s_diagnostics::DiagnosticStatus,
+) -> crate::ffi::DiagnosticStatus {
+    crate::ffi::DiagnosticStatus {
+        level: diagnostic_level_from_rust(&rust.level()),
+        name: rust.name(),
+        message: rust.message(),
+        hardware_id: rust.hardware_id(),
+        values: Box::new(StringMap::from_btree(rust.values())),
+    }
+}
+
+impl crate::ffi::DiagnosticStatus {
+    fn build() -> Self {
+        Self {
+            level: crate::ffi::DiagnosticLevel::default(),
+            name: String::default(),
+            message: String::default(),
+            hardware_id: String::default(),
+            values: StringMap::build(),
+        }
+    }
 }
 
 #[derive(Clone)]
@@ -69,13 +134,14 @@ pub struct DiagnosticTree {
 impl DiagnosticTree {
     pub fn build() -> Box<DiagnosticTree> {
         let graph = j7s_diagnostics::DiagnosticGraph::new();
-        let tree = DiagnosticTree {
+        let tree = DiagnosticTree { graph: graph };
-            graph: graph
-        };
         Box::new(tree)
     }
 
-    pub fn add_statuses(self: &mut DiagnosticTree, statuses: &Vec<crate::ffi::DiagnosticStatus>) -> anyhow::Result<()> {
+    pub fn add_statuses(
+        self: &mut DiagnosticTree,
+        statuses: &Vec<crate::ffi::DiagnosticStatus>,
+    ) -> anyhow::Result<()> {
         let mut converted_statuses = Vec::new();
         for status in statuses.iter() {
             converted_statuses.push(diagnostic_status_to_rust(&status));
@@ -83,6 +149,10 @@ impl DiagnosticTree {
         Ok(self.graph.add_status_vec(&converted_statuses)?)
     }
 
+    fn add_status(self: &mut DiagnosticTree, status: &crate::ffi::DiagnosticStatus) -> anyhow::Result<()> {
+        Ok(self.graph.add_status(diagnostic_status_to_rust(&status))?)
+    }
+
     pub fn reconcile(self: &mut DiagnosticTree) -> anyhow::Result<()> {
         Ok(self.graph.reconcile_levels()?)
     }
@@ -99,21 +169,17 @@ impl DiagnosticTree {
 
 #[derive(Clone)]
 pub struct OptionalString {
-    val: Option<String>
+    val: Option<String>,
 }
 
 impl OptionalString {
     pub fn some(val: String) -> Box<Self> {
-        let raw = Self {
+        let raw = Self { val: Some(val) };
-            val: Some(val)
-        };
         Box::new(raw)
     }
 
     pub fn none() -> Box<Self> {
-        let raw = Self {
+        let raw = Self { val: None };
-            val: None
-        };
         Box::new(raw)
     }
 
@@ -131,22 +197,34 @@ impl OptionalString {
 
 #[derive(Clone)]
 pub struct StringMap {
-    map: BTreeMap<String, String>
+    map: BTreeMap<String, String>,
 }
 
 impl StringMap {
     pub fn build() -> Box<Self> {
         let raw = Self {
-            map: BTreeMap::<String, String>::new()
+            map: BTreeMap::<String, String>::new(),
         };
         Box::new(raw)
     }
 
+    pub fn from_btree(map: BTreeMap<String, String>) -> Self {
+        Self { map: map }
+    }
+
+    fn keys(&self) -> Vec<String> {
+        self.map.keys().map(|s| s.clone()).collect()
+    }
+
+    pub fn to_btree(&self) -> BTreeMap<String, String> {
+        self.map.clone()
+    }
+
     pub fn get(&self, key: &String) -> Box<OptionalString> {
-       match self.map.get(key) {
+        match self.map.get(key) {
-           None => OptionalString::none(),
+            None => OptionalString::none(),
-           Some(val) => OptionalString::some(val.clone()),
+            Some(val) => OptionalString::some(val.clone()),
-       }
+        }
     }
 
     pub fn insert(&mut self, key: String, value: String) {

package.xml

@@ -9,6 +9,8 @@
 
   <buildtool_depend>ament_cmake</buildtool_depend>
 
+  <depend>diagnostic_msgs</depend>
+
   <export>
     <build_type>ament_cmake</build_type>
   </export>

src/conversions.cpp

@@ -0,0 +1,149 @@
+//
+// Copyright 2026 James Pace
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+//
+// This Source Code Form is "Incompatible With Secondary Licenses", as
+// defined by the Mozilla Public License, v. 2.0.
+//
+#include <j7s_diagnostics_ros/conversions.hpp>
+
+std::string convertString(const rust::String & rust)
+{
+    auto copy = rust;
+    return std::string(copy.c_str());
+}
+
+j7s_diagnostics_cxx::DiagnosticLevel convertLevel(const uint8_t rosLevel)
+{
+    switch (rosLevel)
+    {
+        case diagnostic_msgs::msg::DiagnosticStatus::OK:
+            return j7s_diagnostics_cxx::DiagnosticLevel::OK;
+        case diagnostic_msgs::msg::DiagnosticStatus::WARN:
+            return j7s_diagnostics_cxx::DiagnosticLevel::WARN;
+        case diagnostic_msgs::msg::DiagnosticStatus::ERROR:
+            return j7s_diagnostics_cxx::DiagnosticLevel::ERROR;
+        case diagnostic_msgs::msg::DiagnosticStatus::STALE:
+        default:
+            return j7s_diagnostics_cxx::DiagnosticLevel::STALE;
+    }
+}
+
+uint8_t convertLevel(const j7s_diagnostics_cxx::DiagnosticLevel & level)
+{
+    switch (level)
+    {
+        case j7s_diagnostics_cxx::DiagnosticLevel::OK:
+            return diagnostic_msgs::msg::DiagnosticStatus::OK;
+        case j7s_diagnostics_cxx::DiagnosticLevel::WARN:
+            return diagnostic_msgs::msg::DiagnosticStatus::WARN;
+        case j7s_diagnostics_cxx::DiagnosticLevel::ERROR:
+            return diagnostic_msgs::msg::DiagnosticStatus::ERROR;
+        case j7s_diagnostics_cxx::DiagnosticLevel::STALE:
+        case j7s_diagnostics_cxx::DiagnosticLevel::UNSET:
+        default:
+            return diagnostic_msgs::msg::DiagnosticStatus::STALE;
+    }
+}
+
+std::vector<diagnostic_msgs::msg::KeyValue> convertValues(
+    const rust::Box<j7s_diagnostics_cxx::StringMap> & map)
+{
+    std::vector<diagnostic_msgs::msg::KeyValue> toReturn;
+
+    const rust::Vec<rust::String> keys = map->keys();
+    if (keys.empty())
+    {
+        return toReturn;
+    }
+
+    for (const auto & key : keys)
+    {
+        const auto value = map->get(key);
+        diagnostic_msgs::msg::KeyValue msg;
+        msg.key = convertString(key);
+        msg.value = std::string(value->value().c_str());
+        toReturn.emplace_back(msg);
+    }
+
+    return toReturn;
+}
+
+rust::Box<j7s_diagnostics_cxx::StringMap> convertValues(
+    const std::vector<diagnostic_msgs::msg::KeyValue> & map)
+{
+    rust::Box<j7s_diagnostics_cxx::StringMap> toReturn = j7s_diagnostics_cxx::StringMap::build();
+
+    for (const auto & pair : map)
+    {
+        toReturn->insert(rust::String(pair.key), rust::String(pair.value));
+    }
+
+    return toReturn;
+}
+
+j7s_diagnostics_cxx::DiagnosticStatus fromMsg(const diagnostic_msgs::msg::DiagnosticStatus & msg)
+{
+    auto toReturn = j7s_diagnostics_cxx::DiagnosticStatus::build();
+    toReturn.level = convertLevel(msg.level);
+    toReturn.name = rust::String(msg.name);
+    toReturn.message = rust::String(msg.message);
+    toReturn.hardware_id = rust::String(msg.hardware_id);
+    toReturn.values = convertValues(msg.values);
+
+    return toReturn;
+}
+
+rust::Vec<j7s_diagnostics_cxx::DiagnosticStatus> fromMsg(
+    const diagnostic_msgs::msg::DiagnosticArray & msg)
+{
+    rust::Vec<j7s_diagnostics_cxx::DiagnosticStatus> toReturn;
+    toReturn.reserve(msg.status.size());
+
+    for (const auto & rosMsg : msg.status)
+    {
+        toReturn.emplace_back(fromMsg(rosMsg));
+    }
+    return toReturn;
+}
+
+rust::Vec<j7s_diagnostics_cxx::DiagnosticStatus> fromMsg(
+    const std::vector<diagnostic_msgs::msg::DiagnosticStatus> & msgs)
+{
+    rust::Vec<j7s_diagnostics_cxx::DiagnosticStatus> toReturn;
+    toReturn.reserve(msgs.size());
+
+    for (const auto & rosMsg : msgs)
+    {
+        toReturn.emplace_back(fromMsg(rosMsg));
+    }
+    return toReturn;
+}
+
+diagnostic_msgs::msg::DiagnosticStatus toMsg(const j7s_diagnostics_cxx::DiagnosticStatus & status)
+{
+    diagnostic_msgs::msg::DiagnosticStatus toReturn;
+    toReturn.level = convertLevel(status.level);
+    toReturn.name = convertString(status.name);
+    toReturn.message = convertString(status.message);
+    toReturn.hardware_id = convertString(status.hardware_id);
+    toReturn.values = convertValues(status.values);
+
+    return toReturn;
+}
+
+diagnostic_msgs::msg::DiagnosticArray toMsg(
+    const rust::Vec<j7s_diagnostics_cxx::DiagnosticStatus> & statuses)
+{
+    diagnostic_msgs::msg::DiagnosticArray msg;
+    msg.status.reserve(statuses.size());
+
+    for (const auto & status : statuses)
+    {
+        msg.status.emplace_back(toMsg(status));
+    }
+    return msg;
+}

src/j7s_diagnostic_node.cpp

@@ -0,0 +1,60 @@
+//
+// Copyright 2026 James Pace
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+//
+// This Source Code Form is "Incompatible With Secondary Licenses", as
+// defined by the Mozilla Public License, v. 2.0.
+//
+#include <chrono>
+#include <j7s_diagnostics_ros/conversions.hpp>
+#include <j7s_diagnostics_ros/j7s_diagnostic_node.hpp>
+
+using namespace std::chrono_literals;
+
+namespace j7s
+{
+DiagnosticAggregator::DiagnosticAggregator(const rclcpp::NodeOptions & options) :
+    Node("j7s_diagnostic_agg", options)
+{
+    m_publisher =
+        this->create_publisher<diagnostic_msgs::msg::DiagnosticArray>("/diagnostics_agg", 1);
+    m_subscriber = this->create_subscription<diagnostic_msgs::msg::DiagnosticArray>(
+        "/diagnostics", 1,
+        [this](const diagnostic_msgs::msg::DiagnosticArray & msg)
+        {
+            for (const auto status : msg.status)
+            {
+                m_queue.emplace_back(status);
+            }
+        });
+    m_timer = this->create_timer(
+        1s,
+        [this]()
+        {
+            const auto queueCopy = m_queue;
+            m_queue.clear();
+
+            auto tree = j7s_diagnostics_cxx::DiagnosticTree::build();
+            tree->add_statuses(fromMsg(queueCopy));
+            tree->reconcile();
+            const auto aggregate = toMsg(tree->aggregate());
+            m_publisher->publish(aggregate);
+        });
+}
+};  // namespace j7s
+
+int main(int argc, char * argv[])
+{
+    rclcpp::init(argc, argv);
+
+    auto node = std::make_shared<j7s::DiagnosticAggregator>(rclcpp::NodeOptions());
+
+    rclcpp::spin(node);
+
+    rclcpp::shutdown();
+
+    return 0;
+}

src/test.cpp

@@ -1,18 +1,64 @@
-#include "j7s_diagnostics_cxx_bridge/lib.h"
+//
+// Copyright 2026 James Pace
+//
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+//
+// This Source Code Form is "Incompatible With Secondary Licenses", as
+// defined by the Mozilla Public License, v. 2.0.
+//
+#include <fmt/core.h>
 
 #include <iostream>
+#include <j7s_diagnostics_ros/conversions.hpp>
 
-int main(int argc, char *argv[])
+diagnostic_msgs::msg::DiagnosticStatus make_test_status(const std::string & name, uint8_t level)
 {
-    const auto my_string = OptionalString::some(rust::String("test"));
+    diagnostic_msgs::msg::DiagnosticStatus status;
-    if(my_string->is_some())
+    status.name = name;
-    {
+    status.level = level;
-        auto as_string = my_string->value();
-        std::cout << as_string.c_str() << std::endl;
-    }
 
-    auto my_map = StringMap::build();
+    return status;
-    my_map->insert(rust::String("a"), rust::String("b"));
+}
+
+std::string levelToString(uint8_t level)
+{
+    switch (level)
+    {
+        case diagnostic_msgs::msg::DiagnosticStatus::OK:
+            return "OK";
+        case diagnostic_msgs::msg::DiagnosticStatus::WARN:
+            return "WARN";
+        case diagnostic_msgs::msg::DiagnosticStatus::ERROR:
+            return "ERROR";
+        case diagnostic_msgs::msg::DiagnosticStatus::STALE:
+            return "STALE";
+        default:
+            return "N/A";
+    }
+}
+
+int main(int argc, char * argv[])
+{
+    diagnostic_msgs::msg::DiagnosticArray diagArray;
+    diagArray.status.emplace_back(
+        make_test_status("a", diagnostic_msgs::msg::DiagnosticStatus::OK));
+    diagArray.status.emplace_back(
+        make_test_status("a/b", diagnostic_msgs::msg::DiagnosticStatus::WARN));
+    diagArray.status.emplace_back(
+        make_test_status("a/c", diagnostic_msgs::msg::DiagnosticStatus::OK));
+    diagArray.status.emplace_back(
+        make_test_status("a/c/d", diagnostic_msgs::msg::DiagnosticStatus::OK));
+
+    auto tree = j7s_diagnostics_cxx::DiagnosticTree::build();
+    tree->add_statuses(fromMsg(diagArray));
+    tree->reconcile();
+    const auto aggregate = toMsg(tree->aggregate());
+    for (const auto & status : aggregate.status)
+    {
+        fmt::println("Name: {} Level: {}", status.name, levelToString(status.level));
+    }
 
     return 0;
 }