fix: resuming an auto-paused contract no longer discards the backlog

Found by tracing what happens when a back-dated backfill contract cannot
fetch a historical rate. The failure handling itself was fine — period 0
fails, the backlog halts so nothing settles out of order, five ledger rows
record the reason, no money moves, and the contract auto-pauses once the
retry budget is spent. The recovery was not.

The operator fixes the cause (switches to a stated rate, or to current),
clicks Resume, and periods_done jumps 0 -> 6: every unpaid payday silently
written off, contract back to looking healthy, employee never paid. The
confirm dialog even asserted the missed paydays "are written off" — true of
one kind of pause and a lie about the other.

Two features colliding. "Do not backfill a deliberate pause" is right when
the operator paused: the pause *was* the decision not to pay. It is wrong
when payroll paused, because nobody decided anything — the money is still
owed and the operator has just removed whatever blocked it.

Contracts now carry `paused_reason`, set only when payroll pauses them and
cleared by a deliberate pause. Resume infers from it, and an explicit
`catch_up` still overrides either way. The console asks a different question
for each, quoting the reason, and flags a payroll-paused contract in the
table so the distinction is visible before anyone clicks.

Verified end to end: five failing ticks leave periods_done at 0 and pause
with "period 0 (2026-08-01) failed 5 times: no historical EUR rate
available for 2026-08-01"; resuming after switching to a manual rate keeps
the position at 0, and the next tick settles all seven owed periods.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_018jy52j9GRZ6XKa1Zt21LLj

docs/operations.md

@@ -138,9 +138,25 @@ Retries are bounded. After `MAX_PERIOD_ATTEMPTS` (5) failures on the *same*
 period, the contract is **paused** and the operator has to act. Pausing
 rather than abandoning the period is the point: a payday that cannot be
 funded is a fact somebody needs to see, and silently dropping it is the one
-outcome payroll must never produce. Because pausing does not advance the
+outcome payroll must never produce.
-position, resuming after topping up the source wallet retries that same
+
-payday.
+### Two kinds of pause, and why resume must tell them apart
+
+| paused by | `paused_reason` | resume does |
+|---|---|---|
+| the operator | empty | **writes off** the missed paydays |
+| payroll | names the period and cause | **keeps** them; they settle next tick |
+
+These mean opposite things. An operator pause *is* the decision not to pay
+those periods. An automatic pause means payroll could not pay them and
+nobody decided anything — the money is still owed, and the operator has just
+fixed whatever blocked it.
+
+Sharing one path between the two destroys money silently: fix the cause,
+click resume, and the backlog vanishes while the contract looks healthy.
+`resume` therefore infers from `paused_reason`, and `catch_up` overrides it.
+The console asks a different question for each and flags a payroll-paused
+contract in the table with its reason.
 
 ## The payout ledger
 

migrations.py

@@ -112,3 +112,17 @@ async def m003_pricing_mode(db):
     await db.execute(
         "ALTER TABLE payroll.payouts ADD COLUMN rate_source TEXT NOT NULL DEFAULT '';"
     )
+
+
+async def m004_paused_reason(db):
+    """Tell an automatic pause apart from a deliberate one.
+
+    Without this they share a recovery path, and resuming a contract that
+    payroll paused because it could not price a backlog silently writes that
+    backlog off — the operator fixes the cause, clicks resume, and the money
+    owed quietly disappears while the contract looks healthy again.
+    """
+    await db.execute(
+        "ALTER TABLE payroll.contracts "
+        "ADD COLUMN paused_reason TEXT NOT NULL DEFAULT '';"
+    )

models.py

@@ -159,6 +159,12 @@ class Contract(CreateContract):
     employee_username: str = ""
 
     status: ContractStatus = ContractStatus.active
+    # Why the contract is paused, when payroll paused it rather than the
+    # operator. Empty for a deliberate pause. The distinction matters on
+    # resume: a deliberate pause means "do not pay those paydays", while an
+    # automatic one means "could not pay them yet" — opposite intentions
+    # that must not share a recovery path.
+    paused_reason: str = ""
     # Periods *consumed* — paid or deliberately skipped. A failed payout does
     # NOT advance this, which is what makes the next tick retry it rather
     # than silently drop a payday.

services.py

@@ -555,6 +555,10 @@ def _maybe_pause_after_repeated_failure(contract: Contract, payout: Payout) -> N
     if payout.attempt < MAX_PERIOD_ATTEMPTS:
         return
     contract.status = ContractStatus.paused
+    contract.paused_reason = (
+        f"period {payout.period_index} ({payout.payday}) failed "
+        f"{payout.attempt} times: {payout.detail}"
+    )
     logger.error(
         f"payroll: contract {contract.id} paused after {payout.attempt} failed "
         f"attempts at period {payout.period_index} ({payout.payday}): "
@@ -651,29 +655,42 @@ def pause(contract: Contract) -> Contract:
             f"Only an active contract can be paused (is {contract.status.value})."
         )
     contract.status = ContractStatus.paused
+    # A deliberate pause carries no reason, which is what makes resume treat
+    # the missed paydays as written off rather than still owed.
+    contract.paused_reason = ""
     return contract
 
 
 def resume(
-    contract: Contract, today: date | None = None, catch_up: bool = False
+    contract: Contract, today: date | None = None, catch_up: bool | None = None
 ) -> Contract:
     """Put a paused contract back to work.
 
-    By default the paydays that fell during the pause are *not* paid: a
+    What happens to the paydays that fell during the pause depends on who
-    pause is a decision not to pay them, and resuming into a surprise
+    paused it, because the two cases mean opposite things:
-    multi-period transfer is the opposite of what an operator asking to
-    resume expects. The contract's position is fast-forwarded to the next
-    payday on or after today instead.
 
-    `catch_up=True` opts into paying them, for the case where the pause was
+    * **The operator paused it.** Those paydays are written off — the pause
-    an operational hold rather than a decision about the money.
+      *was* the decision not to pay them, and resuming into a surprise
+      multi-period transfer is the opposite of what "resume" implies. The
+      position fast-forwards to the next payday on or after today.
+    * **Payroll paused it** — a period exhausted its retries, because the
+      wallet was empty or the date could not be priced. Nobody decided
+      anything, the money is still owed, and the operator has just fixed
+      whatever blocked it. The backlog is kept and settles on the next tick.
+
+    Sharing one path between those two silently destroys money that is owed,
+    so the inference is on `paused_reason`. `catch_up` overrides it.
     """
     if contract.status != ContractStatus.paused:
         raise LifecycleError(
             f"Only a paused contract can be resumed (is {contract.status.value})."
         )
 
+    if catch_up is None:
+        catch_up = bool(contract.paused_reason)
+
     contract.status = ContractStatus.active
+    contract.paused_reason = ""
     if not catch_up:
         today = today or _today()
         skipped_to = fast_forward_index(contract, today)

static/js/index.js

@@ -436,11 +436,19 @@ window.app = Vue.createApp({
     },
 
     resumeContract(contract) {
-      LNbits.utils
+      // Who paused it decides what happens to the missed paydays, so the
-        .confirmDialog(
+      // question has to be asked differently for each. Telling an operator
-          'Resume this contract? The paydays missed while it was paused ' +
+      // that a backlog payroll could not pay is "written off" would be
+      // false, and acting on it would destroy money that is still owed.
+      const auto = !!contract.paused_reason
+      const message = auto
+        ? `Payroll paused this contract: ${contract.paused_reason}. ` +
+          'Resuming keeps the unpaid periods — they settle on the next tick. ' +
+          'Fix the cause first, or they will just fail again.'
+        : 'Resume this contract? The paydays missed while it was paused ' +
           'are written off — they are not paid retroactively.'
-        )
+      LNbits.utils
+        .confirmDialog(message)
         .onOk(() => this.transition(contract, 'resume'))
     },
 

templates/payroll/index.html

@@ -59,7 +59,18 @@
             <template v-slot:body-cell-status="props">
               <q-td :props="props">
                 <q-chip dense square :color="statusColour(props.row.status)"
-                  text-color="white" :label="props.row.status"></q-chip>
+                  text-color="white" :label="props.row.status">
+                  <q-tooltip v-if="props.row.paused_reason">
+                    ${ props.row.paused_reason }
+                  </q-tooltip>
+                </q-chip>
+                <q-icon v-if="props.row.paused_reason" name="error_outline"
+                  color="negative" size="xs" class="q-ml-xs">
+                  <q-tooltip>
+                    Paused by payroll, not by you — the unpaid periods are
+                    still owed and resuming will settle them.
+                  </q-tooltip>
+                </q-icon>
               </q-td>
             </template>
 

tests/test_lifecycle.py

@@ -105,3 +105,73 @@ def test_cancel_from_a_live_status(status):
 def test_terminal_contracts_cannot_be_cancelled_again(status):
     with pytest.raises(LifecycleError):
         cancel(make_contract(status=status))
+
+
+# --- resuming an automatic pause -------------------------------------------
+
+# Payroll pausing a contract because it could not pay, and an operator
+# pausing one because they chose not to, mean opposite things. Sharing a
+# recovery path silently writes off money that is still owed.
+
+
+def _auto_paused(**kw):
+    contract = make_contract(status=ContractStatus.paused, **kw)
+    contract.paused_reason = "period 0 (2026-01-15) failed 5 times: no rate"
+    return contract
+
+
+def test_resuming_an_auto_paused_contract_keeps_the_backlog():
+    """The operator fixed the cause; those paydays are still owed."""
+    contract = _auto_paused(start_date="2026-01-15", periods_done=0)
+
+    resume(contract, today=date(2026, 4, 10))
+
+    assert contract.status == ContractStatus.active
+    assert contract.periods_done == 0  # nothing written off
+    assert contract.paused_reason == ""
+
+
+def test_resuming_an_operator_pause_still_writes_off():
+    contract = make_contract(
+        start_date="2026-01-15", periods_done=0, status=ContractStatus.paused
+    )
+
+    resume(contract, today=date(2026, 4, 10))
+
+    assert contract.periods_done == 3
+
+
+def test_an_explicit_choice_overrides_the_inference():
+    contract = _auto_paused(start_date="2026-01-15", periods_done=0)
+    resume(contract, today=date(2026, 4, 10), catch_up=False)
+    assert contract.periods_done == 3
+
+
+def test_pausing_by_hand_clears_an_earlier_automatic_reason():
+    """Otherwise a contract that once auto-paused would keep catching up
+    forever, even after a deliberate pause."""
+    contract = _auto_paused(periods_done=2)
+    contract.status = ContractStatus.active
+    pause(contract)
+    assert contract.paused_reason == ""
+
+
+def test_the_pause_reason_names_the_period_and_cause():
+    from ..models import Payout, PayoutStatus
+    from ..services import MAX_PERIOD_ATTEMPTS, _maybe_pause_after_repeated_failure
+
+    contract = make_contract()
+    payout = Payout(
+        id="p1",
+        contract_id=contract.id,
+        period_index=3,
+        payday="2026-04-15",
+        status=PayoutStatus.failed,
+        attempt=MAX_PERIOD_ATTEMPTS,
+        detail="no historical EUR rate available for 2026-04-15",
+    )
+    _maybe_pause_after_repeated_failure(contract, payout)
+
+    assert contract.status == ContractStatus.paused
+    assert "2026-04-15" in contract.paused_reason
+    assert "no historical EUR rate" in contract.paused_reason

views_api.py

@@ -214,14 +214,18 @@ async def api_pause_contract(contract_id: str) -> Contract:
 
 
 @payroll_api_router.post("/api/v1/contracts/{contract_id}/resume")
-async def api_resume_contract(contract_id: str, catch_up: bool = False) -> Contract:
+async def api_resume_contract(
+    contract_id: str, catch_up: bool | None = None
+) -> Contract:
     """Put a paused contract back to work.
 
-    Paydays missed during the pause are skipped by default — a pause is a
+    What happens to the paydays missed during the pause depends on who
-    decision not to pay them, and resuming into an unannounced multi-period
+    paused it. An operator pause *was* the decision not to pay them, so they
-    transfer is the opposite of what "resume" implies. `catch_up=true` pays
+    are written off. A pause payroll applied itself — a period that
-    them, for a pause that was an operational hold rather than a decision
+    exhausted its retries — means the money is still owed and the operator
-    about the money.
+    has just fixed whatever blocked it, so the backlog is kept.
+
+    Pass `catch_up` explicitly to override that inference.
     """
     return await _transition(
         contract_id, lambda c: services.resume(c, catch_up=catch_up)