diff --git a/.github/workflows/shell.yml b/.github/workflows/shell.yml
index a234cde..b869223 100644
--- a/.github/workflows/shell.yml
+++ b/.github/workflows/shell.yml
@@ -288,6 +288,7 @@ jobs:
         test:
           - agent-state-ownership
           - agents-md-backup-retention
+          - agents-md-failure-does-not-abort-upgrade
           - carried-claude-code-plugin
           - ci-coverage
           - codex-runtime
diff --git a/tests/agents-md-failure-does-not-abort-upgrade.sh b/tests/agents-md-failure-does-not-abort-upgrade.sh
new file mode 100755
index 0000000..f03eb57
--- /dev/null
+++ b/tests/agents-md-failure-does-not-abort-upgrade.sh
@@ -0,0 +1,115 @@
+#!/bin/bash
+# tests/agents-md-failure-does-not-abort-upgrade.sh
+#
+# A failed AGENTS.md composition must fail the run WITHOUT truncating it.
+#
+# upgrade.sh runs under `set -e`, and regenerate_agents_md is the only phase
+# function in it with a non-zero return path. Called bare, one stale memory file
+# ended the run at that line: eleven reconciliation phases and print_summary
+# never executed, and the log stopped with nothing saying the rest had been
+# skipped (#607).
+#
+# This runs the real execute block from upgrade.sh against stubbed phases rather
+# than asserting on its source text, so it fails if the capture is dropped no
+# matter how the call is written.
+set -eu
+
+ROOT_DIR="$(cd "$(dirname "$0")/.." && pwd)"
+UPGRADE="$ROOT_DIR/upgrade.sh"
+WORK="$(mktemp -d "${TMPDIR:-/tmp}/wpca-agents-md-abort.XXXXXX")"
+trap 'rm -rf "$WORK"' EXIT
+
+# The execute block is everything from the first status accumulator to EOF.
+sed -n '/^PLUGIN_ONLY_EXIT_STATUS=0$/,$p' "$UPGRADE" > "$WORK/execute.sh"
+if [ ! -s "$WORK/execute.sh" ]; then
+  echo "FAIL: could not extract the execute block from upgrade.sh" >&2
+  exit 1
+fi
+
+# Every phase reached after regenerate_agents_md. If the abort returns, these
+# stop appearing in the transcript.
+PHASES_AFTER=(
+  runtime_guidance_sync_managed_codex_projection
+  sync_claude_code_runtime
+  sync_runtime_signature
+  sync_runtime_instructions
+  opencode_project_subagents_optional
+  update_chat_bridge_systemd
+  update_chat_bridge_launchd
+  reconcile_wordpress_service
+  reconcile_datamachine_worker_service
+  refresh_opencode_runtime_signature_phase
+  installation_profile_write
+  print_summary
+)
+
+{
+  echo 'set -eu'
+  # Narrow-scope flags off; this is the full default upgrade path.
+  for flag in PLUGINS_ONLY SKILLS_ONLY KIMAKI_ONLY AGENTS_MD_ONLY RECONCILE_SERVICES_ONLY DRY_RUN; do
+    echo "${flag}=false"
+  done
+  echo 'SITE_PATH=/tmp/site'
+  echo 'SCRIPT_DIR=/tmp/wpca'
+  echo 'INSTALLATION_OPERATION_UPGRADE=upgrade'
+  echo '_run_filter_active() { return 0; }'
+  echo 'update_data_machine_plugins() { :; }'
+  echo 'convergence_run() { :; }'
+  echo 'reconciler_print_partial_evidence() { echo "RAN reconciler_print_partial_evidence"; }'
+
+  # Phases before the failing one, plus the unconditional ones.
+  for phase in reconcile_provider_and_service_state sync_cli_transport_runtime \
+    update_ai_gateway sync_chat_bridge_config systems_capabilities_apply \
+    check_opencode_json_drift ai_gateway_configure_opencode sync_skills \
+    "${PHASES_AFTER[@]}"; do
+    echo "${phase}() { echo \"RAN ${phase}\"; }"
+  done
+
+  # The failure under test.
+  echo 'regenerate_agents_md() { echo "RAN regenerate_agents_md"; return 1; }'
+
+  cat "$WORK/execute.sh"
+} > "$WORK/harness.sh"
+
+set +e
+transcript="$(bash "$WORK/harness.sh" 2>&1)"
+status=$?
+set -e
+
+failed=0
+
+if [ "$status" -eq 0 ]; then
+  echo "FAIL: a failed AGENTS.md composition must still exit non-zero (got 0)" >&2
+  failed=1
+fi
+
+for phase in "${PHASES_AFTER[@]}"; do
+  case "$transcript" in
+    *"RAN ${phase}"*) ;;
+    *)
+      echo "FAIL: ${phase} did not run after the AGENTS.md failure" >&2
+      failed=1
+      ;;
+  esac
+done
+
+# Guard the inverse: the capture must not swallow the failure into a clean exit
+# reported as success by the summary.
+case "$transcript" in
+  *"RAN regenerate_agents_md"*) ;;
+  *)
+    echo "FAIL: harness never reached regenerate_agents_md" >&2
+    failed=1
+    ;;
+esac
+
+if [ "$failed" -ne 0 ]; then
+  echo "--- transcript ---" >&2
+  echo "$transcript" >&2
+  echo "--- exit status: $status ---" >&2
+  exit 1
+fi
+
+echo "ok   remaining phases run after an AGENTS.md composition failure"
+echo "ok   the run still exits non-zero (${status})"
+echo "OK (tests/agents-md-failure-does-not-abort-upgrade.sh)"
diff --git a/upgrade.sh b/upgrade.sh
index 13081a8..bd89b2e 100755
--- a/upgrade.sh
+++ b/upgrade.sh
@@ -1302,6 +1302,10 @@ print_summary() {
     warn "Plugin upgrade partially completed."
   elif [ "${CONVERGENCE_EXIT_STATUS:-0}" -ne 0 ]; then
     warn "Desired-state convergence partially completed."
+  elif [ "${AGENTS_MD_EXIT_STATUS:-0}" -ne 0 ]; then
+    # Named here rather than left to the reader: every other phase converged,
+    # so without this line a non-zero exit has no visible cause in the summary.
+    warn "Upgrade completed except AGENTS.md — composition failed; see above."
   else
     log "Upgrade complete."
   fi
@@ -1457,6 +1461,7 @@ _print_plugins_only_verify_block() {
 
 PLUGIN_ONLY_EXIT_STATUS=0
 CONVERGENCE_EXIT_STATUS=0
+AGENTS_MD_EXIT_STATUS=0
 update_data_machine_plugins || PLUGIN_ONLY_EXIT_STATUS=$?
 if [ "$PLUGINS_ONLY" != true ]; then
   CONVERGENCE_ENTRYPOINT="$SCRIPT_DIR/upgrade.sh"
@@ -1482,7 +1487,14 @@ if _run_filter_active reconciliation; then
   ai_gateway_configure_opencode
 fi
 sync_skills
-regenerate_agents_md
+# Captured, not aborted. This is the only phase function here with a non-zero
+# return path, and under `set -e` a bare call made one stale memory file end the
+# run: eleven reconciliation phases and print_summary never happened, and the
+# log simply stopped mid-phase with nothing saying the rest had been skipped.
+# A failed compose is still worth a non-zero exit at the end — see the
+# AGENTS_MD_EXIT_STATUS check below — but not worth abandoning service
+# reconciliation halfway through.
+regenerate_agents_md || AGENTS_MD_EXIT_STATUS=$?
 if _run_filter_active agents-md; then
   runtime_guidance_sync_managed_codex_projection
 fi
@@ -1508,3 +1520,6 @@ if [ "$CONVERGENCE_EXIT_STATUS" -ne 0 ]; then
   reconciler_print_partial_evidence
   exit "$CONVERGENCE_EXIT_STATUS"
 fi
+if [ "$AGENTS_MD_EXIT_STATUS" -ne 0 ]; then
+  exit "$AGENTS_MD_EXIT_STATUS"
+fi