feat(tx): tx add --budget assigns a budget by name or id

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

2 files changed, 28 insertions, 0 deletions

diff --git a/firefly_cli/commands/transaction.py b/firefly_cli/commands/transaction.py
index 60af6f4..9f8e130 100644
--- a/firefly_cli/commands/transaction.py
+++ b/firefly_cli/commands/transaction.py
@@ -32,6 +32,8 @@ def _add_args(p):
     p.add_argument("--date", default=None, help="YYYY-MM-DD (default today)")
     p.add_argument("--category", default=None)
     p.add_argument("--tags", default=None, help="comma-separated")
+    p.add_argument("--budget", default=None,
+                   help="budget name or id to assign (must already exist)")
     p.add_argument("--type", default=None,
                    help="withdrawal|deposit|transfer (overrides inference)")
     p.add_argument("--dry-run", dest="dry_run", action="store_true",
@@ -67,6 +69,9 @@ def cmd_add(args, ctx):
         split["category_name"] = args.category
     if args.tags:
         split["tags"] = [t.strip() for t in args.tags.split(",") if t.strip()]
+    if args.budget:
+        # Budgets must pre-exist; resolve name/id -> id (hard error on miss).
+        split["budget_id"] = ctx.resolver.budget(args.budget)["id"]
     if ttype == "transfer":
         # Transfer direction is easy to reverse silently (ISSUES.md #5); echo it
         # to stderr so the user/agent can catch a swapped --from/--to. stdout
diff --git a/tests/unit/test_commands_transaction.py b/tests/unit/test_commands_transaction.py
index 61a09ab..7366b5c 100644
--- a/tests/unit/test_commands_transaction.py
+++ b/tests/unit/test_commands_transaction.py
@@ -430,3 +430,26 @@ class TestTxList(unittest.TestCase):
         rc = tx.cmd_list(args, ctx)
         self.assertEqual(rc, 0)
         self.assertEqual(client.request.call_count, 2)
+
+class TestTxAddBudget(unittest.TestCase):
+    def test_budget_ref_sets_budget_id_on_split(self):
+        from types import SimpleNamespace
+        from unittest.mock import MagicMock
+        import firefly_cli.commands.transaction as tx
+
+        client = MagicMock()
+        client.request.return_value = {"data": {"id": "1", "attributes": {}}}
+        resolver = MagicMock()
+        resolver.account.side_effect = lambda n: {"id": "1", "name": n, "type": "asset"}
+        resolver.budget.return_value = {"id": "12", "name": "Groceries"}
+        ctx = SimpleNamespace(client=client, resolver=resolver, human=False)
+
+        args = SimpleNamespace(
+            amount="10", source="Checking", dest="Shop",
+            source_id=None, dest_id=None, desc=None, date="2026-07-03",
+            category=None, tags=None, type="withdrawal",
+            dry_run=False, skip_dupes=False, budget="Groceries")
+        rc = tx.cmd_add(args, ctx)
+        self.assertEqual(rc, 0)
+        body = client.request.call_args[1]["body"]
+        self.assertEqual(body["transactions"][0]["budget_id"], "12")