diff --git a/tools/subagent_generate b/tools/subagent_generate
index 864d58f..aa27699 100755
--- a/tools/subagent_generate
+++ b/tools/subagent_generate
@@ -1,64 +1,98 @@
-#!/usr/bin/env bash
-# description: Generate a JIT subagent config. No args prints the JSON template. With JSON on stdin, creates the config and prints the agent name.
+#!/usr/bin/env python3
+# description: Generate a JIT subagent config. No args prints the JSON template. With JSON as first arg or on stdin, creates the config and prints the agent name.
 # Args: [json] — JSON config as first arg, or piped via stdin
-# Stdin: JSON with structured fields (role, roster, shared_task, protocol, constraints) or legacy "prompt"
-# Output: template (no stdin) or agent name
-set -euo pipefail
+# Output: template (no input) or agent name
 
-OLLIE="${OLLIE:-$HOME/mnt/ollie}"
+import json
+import os
+import secrets
+import sys
 
-die() { printf 'agent_generate: %s\n' "$*" >&2; exit 1; }
+OLLIE = os.environ.get("OLLIE", os.path.expanduser("~/mnt/ollie"))
+AGENTS_DIR = f"{OLLIE}/a"
+BASE_CONFIG = f"{AGENTS_DIR}/default.json"
 
-if [ -t 0 ] && [ $# -eq 0 ]; then
-    printf '{\n  "name": "",\n  "role": "",\n  "roster": "",\n  "shared_task": "",\n  "protocol": "",\n  "constraints": [],\n  "prompt": ""\n}\n'
-    exit 0
-fi
+TEMPLATE = {
+    "name": "",
+    "role": "",
+    "roster": "",
+    "shared_task": "",
+    "protocol": "",
+    "constraints": [],
+    "prompt": "",
+}
 
-if [ $# -gt 0 ]; then
-    cfg="$1"
-else
-    cfg=$(cat) || die "failed to read stdin"
-fi
-[ -z "$cfg" ] && die "empty input"
 
-name=$(printf '%s' "$cfg" | python3 -c "
-import json, sys, secrets
-
-raw = json.load(sys.stdin)
-name = raw.get('name', '') or 'jit-' + secrets.token_hex(8)
-
-role = raw.get('role', '')
-roster = raw.get('roster', '')
-shared_task = raw.get('shared_task', '')
-protocol = raw.get('protocol', '')
-constraints = raw.get('constraints', [])
-legacy = raw.get('prompt', '')
-
-if not role and not legacy:
-    print('error: role or prompt required', file=sys.stderr)
+def die(msg):
+    print(f"subagent_generate: {msg}", file=sys.stderr)
     sys.exit(1)
 
-if role:
-    parts = ['## Role', role]
-    if roster: parts += ['## Roster', roster]
-    if shared_task: parts += ['## Shared Task', shared_task]
-    if protocol: parts += ['## Coordination Protocol', protocol]
-    if constraints: parts += ['## Constraints', '\n'.join('- ' + c for c in constraints)]
-    identity = '\n\n'.join(parts)
-else:
-    identity = legacy
 
-base = sys.argv[1]
-with open(base) as f:
-    cfg = json.load(f)
+def main():
+    # No input: print template.
+    if len(sys.argv) < 2 and sys.stdin.isatty():
+        json.dump(TEMPLATE, sys.stdout, indent=2)
+        print()
+        return
 
-cfg['prompt'] = ['\$OLLIE/x/prime SYSTEM_PROMPT', 'echo ' + json.dumps(identity)]
+    # Read config from arg or stdin.
+    if len(sys.argv) > 1:
+        text = sys.argv[1]
+    else:
+        text = sys.stdin.read()
+    if not text.strip():
+        die("empty input")
 
-out = sys.argv[2] + '/' + name + '.json'
-with open(out, 'w') as f:
-    json.dump(cfg, f, indent=2)
+    try:
+        raw = json.loads(text)
+    except json.JSONDecodeError as e:
+        die(f"invalid JSON: {e}")
 
-print(name)
-" "$OLLIE/a/default.json" "$OLLIE/a") || die "failed to generate agent config"
+    name = raw.get("name", "") or f"jit-{secrets.token_hex(8)}"
+    role = raw.get("role", "")
+    roster = raw.get("roster", "")
+    shared_task = raw.get("shared_task", "")
+    protocol = raw.get("protocol", "")
+    constraints = raw.get("constraints", [])
+    legacy = raw.get("prompt", "")
 
-printf '%s\n' "$name"
+    if not role and not legacy:
+        die("role or prompt required")
+
+    # Build identity text.
+    if role:
+        parts = ["## Role", role]
+        if roster:
+            parts += ["## Roster", roster]
+        if shared_task:
+            parts += ["## Shared Task", shared_task]
+        if protocol:
+            parts += ["## Coordination Protocol", protocol]
+        if constraints:
+            parts += ["## Constraints", "\n".join(f"- {c}" for c in constraints)]
+        identity = "\n\n".join(parts)
+    else:
+        identity = legacy
+
+    # Load base config.
+    try:
+        with open(BASE_CONFIG) as f:
+            cfg = json.load(f)
+    except (OSError, json.JSONDecodeError) as e:
+        die(f"failed to read base config: {e}")
+
+    cfg["prompt"] = ["$OLLIE/x/prime SYSTEM_PROMPT", f"echo {json.dumps(identity)}"]
+
+    # Write JIT config.
+    out_path = f"{AGENTS_DIR}/{name}.json"
+    try:
+        with open(out_path, "w") as f:
+            json.dump(cfg, f, indent=2)
+    except OSError as e:
+        die(f"failed to write config: {e}")
+
+    print(name)
+
+
+if __name__ == "__main__":
+    main()
diff --git a/tools/subagent_spawn b/tools/subagent_spawn
index df78426..78b9401 100755
--- a/tools/subagent_spawn
+++ b/tools/subagent_spawn
@@ -1,7 +1,7 @@
 #!/usr/bin/env bash
 # description: Spawn a subagent session, submit a prompt, and return immediately. The subagent runs independently; use prompt files for coordination.
 # Args: [-name NAME] [-agent A] [-backend B] [-model M] [-cwd DIR] <prompt...>
-# Output: session path (e.g. s/my-session)
+# Output: structured KV (session, path, backend, model)
 set -euo pipefail
 
 OLLIE="${OLLIE:-$HOME/mnt/ollie}"