diff --git a/TASK.md b/TASK.md
index 87184e3..1ce3b8e 100644
--- a/TASK.md
+++ b/TASK.md
@@ -1,14 +1,64 @@
-# Task 06G4E6F69AKP2PA00S28D7ASBC
+# Task 06G4FT0MB733H2ZCZ237WFHFD8
 
-Add a --quiet flag to the healthcheck script
+Give the healthcheck a self-test and a machine-readable mode
 
 - Project: test-e2e
-- Source: gitea:test-e2e/7
+- Source: gitea:test-e2e/10
 - Priority: 0
 
 ## Instructions
 
-scripts/orchestra_e2e_healthcheck.sh already handles --help. Add a --quiet flag alongside it that suppresses the success line and still exits 0. Leave the default behaviour and the --help output unchanged.
+Three pieces of work, in order. Plan them as exactly three phases in that order.
+
+## Phase 1 — a self-test for the healthcheck
+
+New file `scripts/orchestra_e2e_selftest.sh`, executable, `#!/usr/bin/env bash`.
+
+It runs `scripts/orchestra_e2e_healthcheck.sh`, then asserts:
+
+- exit status is 0
+- stdout contains `OK`
+
+On failure it prints which assertion failed and exits 1. On success it prints `selftest: ok` and exits 0.
+
+Verification for this phase is automated only. The one check is:
+
+    - run: ["bash", "-n", "scripts/orchestra_e2e_selftest.sh"]
+
+Do not add a manual step to this phase.
+
+## Phase 2 — `--json` on the healthcheck
+
+`scripts/orchestra_e2e_healthcheck.sh --json` prints exactly one line:
+
+    {"status":"ok","checks":1}
+
+and exits 0. Without `--json` the existing human output is unchanged, and `--help` keeps working. `--json` and `--help` together behave as `--help`.
+
+Verification for this phase must include both an automated check and a manual step. The JSON shape is a judgement a human confirms by reading it, so state the manual step as the exact command a human runs and the exact line they should see.
+
+## Phase 3 — teach the self-test about `--json`
+
+Extend `scripts/orchestra_e2e_selftest.sh` to run the healthcheck twice: once plain and once with `--json`. Assert the plain run still contains `OK`, and assert the `--json` run prints one line beginning with `{"status":`.
+
+Verification for this phase is automated only:
+
+    - run: ["bash", "-n", "scripts/orchestra_e2e_selftest.sh"]
+    - run: ["bash", "scripts/orchestra_e2e_healthcheck.sh"]
+
+## Constraints
+
+The project's verification policy allows exactly two command shapes:
+
+    ["bash", "-n", "<one file>"]
+    ["bash", "scripts/orchestra_e2e_healthcheck.sh"]
+
+A `run:` line outside those is refused when the plan seals, not later.
+
+## Research first
+
+Before planning, establish at least three findings and label their confidence honestly: at least one `fact`, one `inference`, and one `assumption`. The plan must cite at least two of them in References.
+
 
 ## Completion
 
diff --git a/scripts/orchestra_e2e_healthcheck.sh b/scripts/orchestra_e2e_healthcheck.sh
index 5ebab4c..45536f2 100755
--- a/scripts/orchestra_e2e_healthcheck.sh
+++ b/scripts/orchestra_e2e_healthcheck.sh
@@ -2,6 +2,7 @@
 
 main() {
   local quiet=
+  local json=
   for arg in "$@"; do
     if [ "$arg" = --help ]; then
       printf 'Usage: %s [--quiet]\n\n' "${0##*/}"
@@ -11,9 +12,16 @@ main() {
       exit 0
     elif [ "$arg" = --quiet ]; then
       quiet=1
+    elif [ "$arg" = --json ]; then
+      json=1
     fi
   done
 
+  if [ -n "$json" ]; then
+    printf '{"status":"ok","checks":1}\n'
+    exit 0
+  fi
+
   [ -n "$quiet" ] || printf 'OK - all healthchecks passed\n'
   exit 0
 }
diff --git a/scripts/orchestra_e2e_selftest.sh b/scripts/orchestra_e2e_selftest.sh
new file mode 100755
index 0000000..f99d410
--- /dev/null
+++ b/scripts/orchestra_e2e_selftest.sh
@@ -0,0 +1,37 @@
+#!/usr/bin/env bash
+# Self-test for the Orchestra E2E healthcheck.
+
+here=$(cd "$(dirname "$0")" && pwd)
+healthcheck="$here/orchestra_e2e_healthcheck.sh"
+
+# fail <assertion> <captured stdout>: always echo what the healthcheck printed,
+# so a red run is diagnosable without rerunning it by hand.
+fail() {
+  printf 'selftest: FAILED %s\n' "$1" >&2
+  printf 'selftest: healthcheck stdout was:\n%s\n' "$2" >&2
+  exit 1
+}
+
+# plain run
+out=$(bash "$healthcheck")
+status=$?
+
+[ "$status" -eq 0 ] || fail "plain run exit status: want 0, got $status" "$out"
+case "$out" in
+  *OK*) ;;
+  *) fail "plain run stdout contains OK" "$out" ;;
+esac
+
+# --json run
+jout=$(bash "$healthcheck" --json)
+jstatus=$?
+
+[ "$jstatus" -eq 0 ] || fail "--json run exit status: want 0, got $jstatus" "$jout"
+jlines=$(printf '%s\n' "$jout" | wc -l)
+[ "$jlines" -eq 1 ] || fail "--json run line count: want 1, got $jlines" "$jout"
+case "$jout" in
+  '{"status":'*) ;;
+  *) fail '--json run stdout prefix: want {"status":' "$jout" ;;
+esac
+
+printf 'selftest: ok\n'