diff --git a/packages/agents/content/scripts/__tests__/get_ticket_id_test.sh b/packages/agents/content/scripts/__tests__/get_ticket_id_test.sh
new file mode 100644
index 00000000..65fdb1a0
--- /dev/null
+++ b/packages/agents/content/scripts/__tests__/get_ticket_id_test.sh
@@ -0,0 +1,417 @@
+#!/usr/bin/env bash
+
+# Source the script under test (main guard prevents execution).
+Include "$PROJECT_ROOT/content/scripts/get-ticket-id.sh"
+
+Describe "extract_jira_id"
+It "extracts a bare Jira-style ID"
+When call extract_jira_id "COMPPLAN-795"
+The output should equal "COMPPLAN-795"
+End
+
+It "extracts a Jira-style ID from an author-prefixed branch"
+When call extract_jira_id "wt/COMPPLAN-795"
+The output should equal "COMPPLAN-795"
+End
+
+It "extracts a Jira-style ID followed by a description slug"
+When call extract_jira_id "wt/JIRA-123-and-some-message"
+The output should equal "JIRA-123"
+End
+
+It "extracts a Jira-style ID embedded inside a slug with multiple separators"
+When call extract_jira_id "feat/COMPPLAN-795-add-foo"
+The output should equal "COMPPLAN-795"
+End
+
+It "preserves the .{N} sub-ticket suffix"
+When call extract_jira_id "COMPPLAN-795.2"
+The output should equal "COMPPLAN-795.2"
+End
+
+It "preserves the .{N} sub-ticket suffix on a prefixed branch"
+When call extract_jira_id "wt/COMPPLAN-795.2/some-slug"
+The output should equal "COMPPLAN-795.2"
+End
+
+It "returns the first match when multiple Jira-style IDs appear"
+When call extract_jira_id "FOO-1/touches-BAR-2"
+The output should equal "FOO-1"
+End
+
+It "returns empty when no Jira-style ID is present"
+When call extract_jira_id "feat/foo-2"
+The output should equal ""
+End
+
+It "returns empty for a plain word branch"
+When call extract_jira_id "main"
+The output should equal ""
+End
+
+It "does not match a lowercase letter prefix"
+When call extract_jira_id "feat-2"
+The output should equal ""
+End
+
+It "does not match a lowercase Jira-style ID on an author-prefixed branch"
+When call extract_jira_id "wt/mac-130"
+The output should equal ""
+End
+End
+
+Describe "extract_bare_number"
+It "extracts a bare number that is the entire branch name"
+When call extract_bare_number "152"
+The output should equal "152"
+End
+
+It "extracts a bare number followed by a separator"
+When call extract_bare_number "147/feat/foo"
+The output should equal "147"
+End
+
+It "extracts a bare number followed by a hyphen"
+When call extract_bare_number "42-something"
+The output should equal "42"
+End
+
+It "extracts a bare number followed by an underscore"
+When call extract_bare_number "42_something"
+The output should equal "42"
+End
+
+It "returns empty when digits are not at the start of the branch name"
+When call extract_bare_number "feat/foo-2"
+The output should equal ""
+End
+
+It "returns empty when the branch contains no digits"
+When call extract_bare_number "main"
+The output should equal ""
+End
+End
+
+Describe "read_ticket_ref_prefix"
+setup_tmpdir() {
+  tmpdir=$(mktemp -d)
+}
+
+cleanup_tmpdir() {
+  rm -rf "$tmpdir"
+}
+
+BeforeEach "setup_tmpdir"
+AfterEach "cleanup_tmpdir"
+
+It "returns the value of a single-quoted prefix"
+write_yaml() {
+  cat >"$tmpdir/prefs.yaml" <<'YAML'
+project:
+  ticket_ref_prefix: 'MAC-'
+YAML
+}
+test_read() {
+  write_yaml
+  read_ticket_ref_prefix "$tmpdir/prefs.yaml"
+}
+When call test_read
+The output should equal "MAC-"
+End
+
+It "returns the value of a double-quoted prefix"
+write_yaml() {
+  cat >"$tmpdir/prefs.yaml" <<'YAML'
+project:
+  ticket_ref_prefix: "MAC-"
+YAML
+}
+test_read() {
+  write_yaml
+  read_ticket_ref_prefix "$tmpdir/prefs.yaml"
+}
+When call test_read
+The output should equal "MAC-"
+End
+
+It "returns # for a single-quoted hash even when followed by an inline comment"
+write_yaml() {
+  cat >"$tmpdir/prefs.yaml" <<'YAML'
+project:
+  ticket_ref_prefix: '#' # ignored in file names
+YAML
+}
+test_read() {
+  write_yaml
+  read_ticket_ref_prefix "$tmpdir/prefs.yaml"
+}
+When call test_read
+The output should equal "#"
+End
+
+It "returns the value of an unquoted prefix"
+write_yaml() {
+  cat >"$tmpdir/prefs.yaml" <<'YAML'
+project:
+  ticket_ref_prefix: MAC-
+YAML
+}
+test_read() {
+  write_yaml
+  read_ticket_ref_prefix "$tmpdir/prefs.yaml"
+}
+When call test_read
+The output should equal "MAC-"
+End
+
+It "strips a trailing inline comment from an unquoted prefix"
+write_yaml() {
+  cat >"$tmpdir/prefs.yaml" <<'YAML'
+project:
+  ticket_ref_prefix: MAC- # tracked in Jira
+YAML
+}
+test_read() {
+  write_yaml
+  read_ticket_ref_prefix "$tmpdir/prefs.yaml"
+}
+When call test_read
+The output should equal "MAC-"
+End
+
+It "returns empty when the key is absent"
+write_yaml() {
+  cat >"$tmpdir/prefs.yaml" <<'YAML'
+project:
+  slug: example
+YAML
+}
+test_read() {
+  write_yaml
+  read_ticket_ref_prefix "$tmpdir/prefs.yaml"
+}
+When call test_read
+The output should equal ""
+End
+
+It "returns empty when the file does not exist"
+When call read_ticket_ref_prefix "$tmpdir/nonexistent.yaml"
+The output should equal ""
+End
+
+It "returns empty when the value is absent"
+write_yaml() {
+  cat >"$tmpdir/prefs.yaml" <<'YAML'
+project:
+  ticket_ref_prefix:
+YAML
+}
+test_read() {
+  write_yaml
+  read_ticket_ref_prefix "$tmpdir/prefs.yaml"
+}
+When call test_read
+The output should equal ""
+End
+
+It "returns empty when the value is replaced by an inline comment"
+write_yaml() {
+  cat >"$tmpdir/prefs.yaml" <<'YAML'
+project:
+  ticket_ref_prefix: # legacy comment, no value
+YAML
+}
+test_read() {
+  write_yaml
+  read_ticket_ref_prefix "$tmpdir/prefs.yaml"
+}
+When call test_read
+The output should equal ""
+End
+
+It "skips a commented-out preference line and reads the active one below it"
+write_yaml() {
+  cat >"$tmpdir/prefs.yaml" <<'YAML'
+project:
+  # ticket_ref_prefix: 'OLD-'
+  ticket_ref_prefix: 'NEW-'
+YAML
+}
+test_read() {
+  write_yaml
+  read_ticket_ref_prefix "$tmpdir/prefs.yaml"
+}
+When call test_read
+The output should equal "NEW-"
+End
+
+It "returns empty when only a commented-out preference line is present"
+write_yaml() {
+  cat >"$tmpdir/prefs.yaml" <<'YAML'
+project:
+  # ticket_ref_prefix: 'OLD-'
+YAML
+}
+test_read() {
+  write_yaml
+  read_ticket_ref_prefix "$tmpdir/prefs.yaml"
+}
+When call test_read
+The output should equal ""
+End
+
+It "defaults to .agents/preferences.yaml in the current working directory"
+prepare() {
+  mkdir -p "$tmpdir/workdir/.agents"
+  cat >"$tmpdir/workdir/.agents/preferences.yaml" <<'YAML'
+project:
+  ticket_ref_prefix: 'MAC-'
+YAML
+  cd "$tmpdir/workdir"
+}
+test_read() {
+  prepare
+  read_ticket_ref_prefix
+}
+When call test_read
+The output should equal "MAC-"
+End
+End
+
+Describe "format_bare_ticket_id"
+It "returns the bare number alone for the # prefix"
+When call format_bare_ticket_id "152" "#"
+The output should equal "152"
+End
+
+It "concatenates a Jira-style prefix with the bare number"
+When call format_bare_ticket_id "147" "MAC-"
+The output should equal "MAC-147"
+End
+
+It "returns the bare number alone for an empty prefix"
+When call format_bare_ticket_id "42" ""
+The output should equal "42"
+End
+End
+
+Describe "extract_ticket_id (end-to-end via main)"
+script="$PROJECT_ROOT/content/scripts/get-ticket-id.sh"
+
+setup_tmpdir() {
+  tmpdir=$(mktemp -d)
+  original_pwd="$PWD"
+  mkdir -p "$tmpdir/workdir/.agents"
+  cd "$tmpdir/workdir"
+}
+
+cleanup_tmpdir() {
+  cd "$original_pwd"
+  rm -rf "$tmpdir"
+}
+
+BeforeEach "setup_tmpdir"
+AfterEach "cleanup_tmpdir"
+
+# Each end-to-end case runs the script as a child process so the
+# preferences-file lookup honors the test's working directory.
+
+It "returns COMPPLAN-795 for an author-prefixed branch"
+When run bash "$script" "wt/COMPPLAN-795"
+The output should equal "COMPPLAN-795"
+The status should be success
+End
+
+It "returns JIRA-123 for an embedded ticket inside a slug"
+When run bash "$script" "wt/JIRA-123-and-some-message"
+The output should equal "JIRA-123"
+The status should be success
+End
+
+It "returns COMPPLAN-795 for a feat-prefixed branch with a description"
+When run bash "$script" "feat/COMPPLAN-795-add-foo"
+The output should equal "COMPPLAN-795"
+The status should be success
+End
+
+It "returns COMPPLAN-795 for a bare Jira-style branch"
+When run bash "$script" "COMPPLAN-795"
+The output should equal "COMPPLAN-795"
+The status should be success
+End
+
+It "preserves the sub-ticket suffix"
+When run bash "$script" "COMPPLAN-795.2"
+The output should equal "COMPPLAN-795.2"
+The status should be success
+End
+
+It "returns 152 for a bare-numeric branch with the # prefix"
+write_prefs() {
+  cat >".agents/preferences.yaml" <<'YAML'
+project:
+  ticket_ref_prefix: '#'
+YAML
+}
+run_script() {
+  write_prefs
+  bash "$script" "152"
+}
+When call run_script
+The output should equal "152"
+End
+
+It "returns MAC-147 for a bare-numeric branch with a Jira-style prefix"
+write_prefs() {
+  cat >".agents/preferences.yaml" <<'YAML'
+project:
+  ticket_ref_prefix: 'MAC-'
+YAML
+}
+run_script() {
+  write_prefs
+  bash "$script" "147/feat/foo"
+}
+When call run_script
+The output should equal "MAC-147"
+End
+
+It "returns the bare number when no preferences file exists"
+When run bash "$script" "42"
+The output should equal "42"
+The status should be success
+End
+
+It "returns empty for a slug-embedded number with no leading bare number"
+When run bash "$script" "feat/foo-2"
+The output should equal ""
+The status should be success
+End
+
+It "returns empty for a plain word branch"
+When run bash "$script" "main"
+The output should equal ""
+The status should be success
+End
+
+It "prefers a Jira-style match over a leading bare number when both could apply"
+When run bash "$script" "123/MAC-456"
+The output should equal "MAC-456"
+The status should be success
+End
+
+It "ignores an inline comment when reading a single-quoted hash prefix"
+write_prefs() {
+  cat >".agents/preferences.yaml" <<'YAML'
+project:
+  ticket_ref_prefix: '#' # ignored in file names
+YAML
+}
+run_script() {
+  write_prefs
+  bash "$script" "525"
+}
+When call run_script
+The output should equal "525"
+End
+End
diff --git a/packages/agents/content/scripts/get-ticket-id.sh b/packages/agents/content/scripts/get-ticket-id.sh
new file mode 100755
index 00000000..de9fb8c0
--- /dev/null
+++ b/packages/agents/content/scripts/get-ticket-id.sh
@@ -0,0 +1,137 @@
+#!/usr/bin/env bash
+# Extract a Jira-style ticket ID from a branch name.
+#
+# Tries the Jira-style pattern first (`[A-Z]+-[0-9]+` with an optional
+# `.{N}` sub-ticket suffix). Falls back to a bare-numeric match anchored
+# at the start of the branch name, formatted using `project.ticket_ref_prefix`
+# from `.agents/preferences.yaml`.
+#
+# Usage:
+#   get-ticket-id.sh [BRANCH_NAME]
+#
+# Arguments:
+#   BRANCH_NAME   Branch to extract from. Defaults to the current git branch.
+#
+# Output: The resolved ticket ID on stdout, or an empty string when no ID
+# can be derived. Exit status is always 0.
+
+set -euo pipefail
+
+readonly PROG="$(basename "$0")"
+
+# Match a Jira-style ticket ID anywhere in the branch name. Returns the first
+# match or empty. Pattern: one or more uppercase letters, hyphen, one or more
+# digits, with an optional `.{N}` sub-ticket suffix. Deliberately unanchored
+# so author-prefixed branches (e.g., `wt/COMPPLAN-795`) match correctly.
+extract_jira_id() {
+  local branch_name="$1"
+  echo "$branch_name" | grep -oE '[A-Z]+-[0-9]+(\.[0-9]+)?' | head -1 || true
+}
+
+# Match a bare-numeric prefix at the start of the branch name. Anchored
+# deliberately so digits embedded in slugs (e.g., `feat/foo-2`) do not match.
+extract_bare_number() {
+  local branch_name="$1"
+  echo "$branch_name" | grep -oE '^[0-9]+' | head -1 || true
+}
+
+# Read `project.ticket_ref_prefix` from a preferences YAML file. Defaults to
+# `.agents/preferences.yaml`. Returns empty when the key is absent or the
+# file does not exist. Handles both quoted and unquoted values, and strips
+# trailing inline comments (`# ...`) from unquoted values. A `#` inside
+# single or double quotes is preserved as part of the value.
+read_ticket_ref_prefix() {
+  local file="${1:-.agents/preferences.yaml}"
+  if [[ ! -f "$file" ]]; then
+    return
+  fi
+
+  local line
+  # Anchor the match at the start of the line (allowing leading whitespace) so
+  # commented-out preference lines (`# ticket_ref_prefix: ...`) are skipped.
+  line=$(grep -E '^[[:space:]]*ticket_ref_prefix:' "$file" 2>/dev/null | head -1) || true
+  if [[ -z "$line" ]]; then
+    return
+  fi
+
+  # Strip everything up through `ticket_ref_prefix:` and any leading whitespace.
+  line="${line#*ticket_ref_prefix:}"
+  line="${line#"${line%%[![:space:]]*}"}"
+
+  # No value (`ticket_ref_prefix:`) or a comment-only value
+  # (`ticket_ref_prefix: # note`) both resolve to empty.
+  if [[ -z "$line" || "$line" == "#"* ]]; then
+    return
+  fi
+
+  # Quoted value: capture the contents between the matching quotes. This
+  # preserves `#` characters that appear inside the value.
+  if [[ "$line" =~ ^\'([^\']*)\' ]]; then
+    echo "${BASH_REMATCH[1]}"
+    return
+  fi
+  if [[ "$line" =~ ^\"([^\"]*)\" ]]; then
+    echo "${BASH_REMATCH[1]}"
+    return
+  fi
+
+  # Unquoted value: strip a trailing ` # comment` and surrounding whitespace.
+  line="${line%% #*}"
+  line="${line%"${line##*[![:space:]]}"}"
+  echo "$line"
+}
+
+# Combine a bare number with the configured prefix to produce a ticket ID.
+# - `#` prefix: return the bare number alone (the `#` is a GitHub display
+#   convention and must not appear in returned values or file paths).
+# - Other non-empty prefix: return `{prefix}{number}` (e.g., `MAC-147`).
+# - Empty prefix: return the bare number unchanged.
+format_bare_ticket_id() {
+  local bare_number="$1"
+  local prefix="$2"
+
+  if [[ "$prefix" == "#" ]]; then
+    echo "$bare_number"
+  elif [[ -n "$prefix" ]]; then
+    echo "${prefix}${bare_number}"
+  else
+    echo "$bare_number"
+  fi
+}
+
+# Resolve a ticket ID for the given branch name. Tries the Jira-style match
+# first; falls back to the bare-numeric prefix when no Jira-style ID is
+# found. Returns empty when neither matches.
+extract_ticket_id() {
+  local branch_name="$1"
+  local ticket_id
+
+  ticket_id="$(extract_jira_id "$branch_name")"
+  if [[ -n "$ticket_id" ]]; then
+    echo "$ticket_id"
+    return
+  fi
+
+  local bare_number
+  bare_number="$(extract_bare_number "$branch_name")"
+  if [[ -z "$bare_number" ]]; then
+    return
+  fi
+
+  local prefix
+  prefix="$(read_ticket_ref_prefix)"
+  format_bare_ticket_id "$bare_number" "$prefix"
+}
+
+main() {
+  local branch_name="${1:-}"
+  if [[ -z "$branch_name" ]]; then
+    branch_name="$(git branch --show-current)"
+  fi
+  extract_ticket_id "$branch_name"
+}
+
+# Allow sourcing for testing without executing main.
+if [[ "${BASH_SOURCE[0]}" == "$0" ]]; then
+  main "$@"
+fi
diff --git a/packages/agents/content/skills/get-ticket-id/SKILL.md b/packages/agents/content/skills/get-ticket-id/SKILL.md
index ecba3406..a6c0d021 100644
--- a/packages/agents/content/skills/get-ticket-id/SKILL.md
+++ b/packages/agents/content/skills/get-ticket-id/SKILL.md
@@ -22,25 +22,13 @@ Extract a Jira-style ticket ID from the current context.
 
 ### From branch name
 
-In branch names, `_` and `/` are interchangeable separators (see `branch-format.md`). The regex below extracts correctly regardless of which separator is used.
+The script `{platform_home_dir}/scripts/get-ticket-id.sh` extracts a ticket ID from a branch name. It accepts an optional branch name (defaults to the current branch) and prints the resolved ticket ID, or an empty string when no ID can be derived.
 
-```bash
-branch_name="${1:-$(git branch --show-current)}"
-echo "$branch_name" | grep -oE '[A-Z]+-[0-9]+(\.[0-9]+)?' | head -1
-```
-
-### From commit message
+In branch names, `_` and `/` are interchangeable separators (see `branch-format.md`). The Jira-style match is unanchored, so it extracts the ID regardless of which separator is used or whether an author/scope prefix appears (e.g., `wt/COMPPLAN-795`, `feat/COMPPLAN-795-add-foo`).
 
-```bash
-commit="${1:-HEAD}"
-git log -1 --pretty=format:'%s' "$commit" | grep -oE '[A-Z]+-[0-9]+(\.[0-9]+)?' | head -1
-```
+When no Jira-style ID matches, the script falls back to a **bare issue number** anchored to the start of the branch name (terminated by `/`, `_`, `-`, or end-of-string). The anchor on the fallback prevents false matches against digits embedded in slugs like `feat/foo-2`.
 
-### From branch name: bare numeric branches
-
-If the Jira-style pattern `[A-Z]+-[0-9]+` does not match, check for a **bare issue number**: one or more digits anchored to the start of the branch name, terminated by `/`, `_`, `-`, or end-of-string.
-
-When a bare number is found, read `project.ticket_ref_prefix` from `.agents/preferences.yaml` to determine the returned ticket ID:
+When the bare-numeric fallback fires, the script reads `project.ticket_ref_prefix` from `.agents/preferences.yaml` to format the result:
 
 - If `ticket_ref_prefix` is `#`: return the **bare number only**. The `#` is a GitHub display convention and must not appear in file paths or returned values.
 - If `ticket_ref_prefix` is a Jira-style prefix (e.g., `MAC-`): return `{prefix}{number}` (e.g., `MAC-147`).
@@ -54,28 +42,14 @@ When a bare number is found, read `project.ticket_ref_prefix` from `.agents/pref
 
 ```bash
 branch_name="${1:-$(git branch --show-current)}"
+ticket_id=$({platform_home_dir}/scripts/get-ticket-id.sh "$branch_name")
+```
+
+### From commit message
 
-# Try Jira-style first
-ticket_id=$(echo "$branch_name" | grep -oE '^[A-Z]+-[0-9]+(\.[0-9]+)?' | head -1)
-
-# Fall back to bare numeric
-if [ -z "$ticket_id" ]; then
-  bare_number=$(echo "$branch_name" | grep -oE '^[0-9]+' | head -1)
-  if [ -n "$bare_number" ]; then
-    # Read ticket_ref_prefix from preferences (yq or manual YAML parsing)
-    prefix=$(grep 'ticket_ref_prefix:' .agents/preferences.yaml 2>/dev/null \
-      | head -1 | sed "s/.*ticket_ref_prefix:[[:space:]]*['\"]\\{0,1\\}\\([^'\"]*\\)['\"]\\{0,1\\}/\\1/")
-    if [ "$prefix" = "#" ]; then
-      ticket_id="$bare_number"
-    elif [ -n "$prefix" ]; then
-      ticket_id="${prefix}${bare_number}"
-    else
-      ticket_id="$bare_number"
-    fi
-  fi
-fi
-
-echo "$ticket_id"
+```bash
+commit="${1:-HEAD}"
+git log -1 --pretty=format:'%s' "$commit" | grep -oE '[A-Z]+-[0-9]+(\.[0-9]+)?' | head -1
 ```
 
 ### From current context (default)