diff --git a/plugins/os-backlog/lib/backlog/config.rb b/plugins/os-backlog/lib/backlog/config.rb
index 0bdddb1..65c4376 100644
--- a/plugins/os-backlog/lib/backlog/config.rb
+++ b/plugins/os-backlog/lib/backlog/config.rb
@@ -1,15 +1,26 @@
-require "yaml"
-
 module Backlog
-  # The parsed contents of a repo's `.cc-os/config` (YAML). Only the
-  # `board` key matters to the resolver: an explicit board-name override.
+  # The parsed contents of a repo's `.cc-os/config`. The file format is
+  # '#'-commented key=value lines — the contract is owned by os-status
+  # (plugins/os-status/hooks/state.py); legacy `key: value` YAML lines
+  # from earlier os-backlog versions are still read for compatibility.
   # Never touches the filesystem itself — callers read the file and pass
   # its contents (or nil, if absent) in.
   class Config
     def initialize(contents)
-      @data = contents.to_s.strip.empty? ? {} : (YAML.safe_load(contents) || {})
-    rescue Psych::SyntaxError
       @data = {}
+      contents.to_s.each_line do |line|
+        line = line.strip
+        next if line.empty? || line.start_with?("#") || line == "---"
+
+        if line.include?("=")
+          key, value = line.split("=", 2)
+        elsif line.include?(": ")
+          key, value = line.split(": ", 2)
+        else
+          next
+        end
+        @data[key.strip] = value.strip
+      end
     end
 
     # @return [String, nil] the explicit board name override, if configured
@@ -28,18 +39,19 @@ module Backlog
     # @return [Hash] a copy of the parsed config data
     def to_h = @data.dup
 
-    # Return new YAML contents with `key` set to `value`, preserving every
-    # other key already present in `contents`. Pure — does not touch the
+    # Return new key=value contents with `key` set to `value`, preserving
+    # every other key already present in `contents` (legacy YAML-style
+    # lines are rewritten to key=value). Pure — does not touch the
     # filesystem; callers read/write the file themselves.
     #
     # @param contents [String, nil] existing raw `.cc-os/config` contents
     # @param key [String, Symbol] key to set
     # @param value [Object] value to set it to
-    # @return [String] the updated YAML contents
+    # @return [String] the updated key=value contents
     def self.merge(contents, key, value)
       data = new(contents).to_h
-      data[key.to_s] = value
-      YAML.dump(data)
+      data[key.to_s] = value.to_s
+      data.map { |k, v| "#{k}=#{v}\n" }.join
     end
   end
 end
diff --git a/plugins/os-backlog/tests/config_test.rb b/plugins/os-backlog/tests/config_test.rb
index bd0bf69..0d5e4e0 100644
--- a/plugins/os-backlog/tests/config_test.rb
+++ b/plugins/os-backlog/tests/config_test.rb
@@ -13,39 +13,45 @@ class ConfigTest < Minitest::Test
   end
 
   def test_reads_board_key
-    config = Backlog::Config.new("board: llf-schema\n")
+    config = Backlog::Config.new("board=llf-schema\n")
     assert config.configured?
     assert_equal "llf-schema", config.board
   end
 
-  def test_malformed_yaml_is_treated_as_unconfigured
-    config = Backlog::Config.new("board: [unterminated\n")
+  def test_reads_legacy_yaml_style_board_key
+    config = Backlog::Config.new("---\nboard: llf-schema\n")
+    assert config.configured?
+    assert_equal "llf-schema", config.board
+  end
+
+  def test_lines_without_separator_are_ignored
+    config = Backlog::Config.new("# comment\njunk line\n")
     refute config.configured?
   end
 
-  def test_yaml_without_board_key_is_unconfigured
-    config = Backlog::Config.new("other: value\n")
+  def test_contents_without_board_key_is_unconfigured
+    config = Backlog::Config.new("other=value\n")
     refute config.configured?
   end
 
   def test_reads_tracker_key
-    config = Backlog::Config.new("tracker: forgejo:jared/cc-os\n")
+    config = Backlog::Config.new("tracker=forgejo:jared/cc-os\n")
     assert config.tracker_configured?
     assert_equal "forgejo:jared/cc-os", config.tracker
   end
 
   def test_tracker_unconfigured_when_absent
-    config = Backlog::Config.new("board: llf-schema\n")
+    config = Backlog::Config.new("board=llf-schema\n")
     refute config.tracker_configured?
   end
 
   def test_merge_sets_new_key_on_nil_contents
-    updated = Backlog::Config.new(Backlog::Config.merge(nil, "tracker", "forgejo:jared/cc-os"))
-    assert_equal "forgejo:jared/cc-os", updated.tracker
+    contents = Backlog::Config.merge(nil, "tracker", "forgejo:jared/cc-os")
+    assert_equal "tracker=forgejo:jared/cc-os\n", contents
   end
 
   def test_merge_preserves_other_keys
-    existing = "board: llf-schema\nother: kept\n"
+    existing = "board=llf-schema\nother=kept\n"
     updated_contents = Backlog::Config.merge(existing, "tracker", "planka:llf-schema")
     updated = Backlog::Config.new(updated_contents)
 
@@ -55,7 +61,7 @@ class ConfigTest < Minitest::Test
   end
 
   def test_merge_overwrites_existing_value_for_key
-    existing = "tracker: repo:old\n"
+    existing = "tracker=repo:old\n"
     updated = Backlog::Config.new(Backlog::Config.merge(existing, "tracker", "repo:new"))
     assert_equal "repo:new", updated.tracker
   end