---
id: TREV-WP-0013
type: workplan
title: "Remission Credit automation (degeneration policy execution)"
domain: infotech
repo: target-revenue
status: finished
owner: claude
topic_slug: infotech
created: "2026-07-30"
updated: "2026-08-05"
state_hub_workstream_id: "4a423219-2a3e-413c-b0dc-f8542c2afba1"
---

# Remission Credit automation (degeneration policy execution)

Spun out of `workplans/TREV-WP-0012-phase-provenance-and-policy-modeling.md`
(use case 4). Every Phase declares a `degeneration_policy`
(`trsl:policy:linear-longstop-v0` is the accepted v1 norm,
`specs/OpenQuestions-WorkingDefaults.md` Q7), which is supposed to
generate `remission-credit` Target Ledger entries over time when
Development Credit progress is insufficient (FR-6,
`specs/ProductRequirementsDocument.md`). **Nothing in this codebase
previously computed or wrote these entries.** `fold.py` can consume them
if they exist; this workplan produces them. This gap predated the Control
Plane UI work — it was never in scope for WP-0006 (Trust Service) or
WP-0009 (Control Plane), and surfaced when reviewing the UI's
Phase-registration flow prompted a fuller look at what a Phase's lifecycle
actually requires end to end.

Blocked on `workplans/TREV-WP-0012-phase-provenance-and-policy-modeling.md`
T03's decision (how a policy id maps to its spec file) — **unblocked**
when WP-0012 finished and WP-0015 landed `specs/policies/linear-longstop-v0.md`.

```task
id: TREV-WP-0013-T01
status: done
priority: high
state_hub_task_id: "d6ab7448-c009-4398-b616-560e8085cf1a"
```

**Design the remission calculation and scheduling model.** `R(t) = T0 ×
clamp((t - t0)/(tL - t0), 0, 1)` (Q7) needs: a chosen recognition cadence
(daily/monthly UTC per Q7's own text), an idempotent
"has this period's remission already been recorded" check (ledger entries
are append-only — a re-run must not double-remit), and a decision on
where `t0` (Phase activation) comes from if it isn't already a manifest
field (registration time? an explicit `activated_at`?). Cross-check
against whatever `trsl:policy:linear-longstop-v0`'s spec file (once
WP-0012-T03 lands) says, rather than re-deriving the formula from Q7
prose alone.

**Result (2026-08-05):** Design recorded in
`src/target_revenue/remission.py` module docstring and
`specs/policies/linear-longstop-v0.md` Status section:

1. **t0** = Trust Service `phase_manifests.registered_at`. No new
   manifest `activated_at` field for Stage 0 — a Phase is not active
   until registered. Pure callers pass `t0` explicitly.
2. **Cadence / idempotency**: cumulative delta model, not period-keyed
   rows. Each run remits `max(0, R(as_of) − Σ policy remission-credit)`.
   Re-run at the same `as_of` is a no-op; missed schedules catch up
   without double-counting. Dust floor `MIN_REMISSION_AMOUNT = 0.01`.
   Scheduled convention: monthly UTC (1st 00:00) or longstop if sooner.
3. **Actor**: dedicated Licensor credential labeled
   `system:policy-engine` (rights operator), auto-issued on first use.
   Never a null `submitted_by_token`; never a human credential for
   policy-driven rows. Control Plane audit still records which human
   *triggered* an on-demand run.
4. Formula checked against `specs/policies/linear-longstop-v0.md`, not
   re-derived from Q7 prose alone.

```task
id: TREV-WP-0013-T02
status: done
priority: high
state_hub_task_id: "078da2e7-594b-4bd3-85b6-881a808f1ca2"
```

**Implement and test** the calculation as a pure function (mirroring
`fold.py`'s determinism discipline) plus whatever writes the resulting
`remission-credit` entries into the hosted Target Ledger — a scheduled
job, an on-demand Control Plane action, or both. Decide which actor
"submits" these entries for attribution purposes (no human credential
naturally owns a policy-driven entry) and record that decision explicitly
rather than leaving `submitted_by_token` implicitly null.

**Result:** `src/target_revenue/remission.py` — pure
`cumulative_remission` / `plan_remission` / `build_remission_entry_input`
plus hosted `apply_remission_for_phase` /
`apply_remission_for_all_phases`. Trust Service routes:
`POST /phases/{id}/remission` (on-demand, Operator+),
`POST /remission/run` (batch for cron). Control Plane:
`control_plane.apply_policy_remission` + form on phase detail.
Tests: `tests/test_remission.py` (pure), `tests/test_remission_hosting.py`
(Docker Postgres — append, idempotency, `system:policy-engine`
attribution, metrics forecasts).

```task
id: TREV-WP-0013-T03
status: done
priority: medium
state_hub_task_id: "fe12ee80-2868-4857-83ca-04bd7223e270"
```

**Surface it in the Control Plane UI**: `phase_detail.html`'s Ledger
table already renders `remission-credit` rows generically once they
exist; verify that holds, and add a metrics-level explanation (e.g. next
scheduled remission date/amount) if `metrics.py` doesn't already forecast
one.

**Result:** `metrics.compute_metrics` gains optional `activated_at` and
forecasts `remission_if_applied_now`, `next_scheduled_remission_at`,
`next_scheduled_remission_amount` (labeled **forecast**, never facts).
Hosted metrics and Control Plane phase detail pass
`registered_at` as t0. `phase_detail.html` shows the forecast table,
activation/longstop facts, and an Operator+ "Apply policy remission now"
button. Existing ledger table continues to render `remission-credit`
rows generically.