The date arrived. The weights did not. — a vendor-promise ledger for model release dates

A developer known as Haku built PromiseLedger, a vendor-promise ledger that tracks lab-announced model release dates and scores the risk of each slipping, after StepFun's promised October 15 BF16 open weights for Step 5 failed to appear on HuggingFace — the repo returned a 404 and later an auth error while the vendor stayed silent. The tool pairs a status engine (on-track, due, slipped, shipped) with a 0–100 date-risk scorer that hard-caps a slipped promise with no contingency at 49, and advises teams to build evaluation sets and serving paths on downloadable models so new weights can be swapped in on ship day.

PromiseLedger is a planning aid, not procurement advice; verify each promise against the vendor's own channels. StepFun put a date on its own calendar: Step 5's BF16 open weights would ship on October 15. As of 01:55Z that day, the expected HuggingFace repo was a 404. A same-day re-check returned an auth error — the repo was gated or unfilled, not weights. The vendor stayed silent. forkast.news, Oct 15, 2026 02:27 UTC What "committed" meant here: a specific date, announced by the lab itself. What arrived: nothing downloadable. Lab-announced model-availability dates are, per forkast.news Oct 15 , "the most volatile and, consequently, the most costly for enterprise deployers when those deadlines slip." This is the vendor-promise class: dates that are specific, lab-announced, and — now proven — the most volatile to plan around. "Do not plan production around unreleased weights." explainx.ai, Oct 2026 Concretely: build your evaluation set and serving path now, on a model you can actually download, so the new weights can be swapped in the day they ship. Keep the eval portable and the serving path real. A paste-ready promise ledger. One row per date your roadmap leans on, with the evidence URL on every row, a status engine, and a 0–100 date-risk scorer with a hard cap at 49 for slipped promises with no contingency: python from dataclasses import dataclass from datetime import date from enum import Enum class Status Enum : ON TRACK = "on track" DUE = "due" SLIPPED = "slipped" SHIPPED = "shipped" @dataclass class Promise: vendor: str model: str committed date: date evidence url: str contingency: bool = False shipped date: date | None = None def status self, today: date | None = None - Status: today = today or date.today if self.shipped date: return Status.SHIPPED if today self.committed date: return Status.SLIPPED if today == self.committed date: return Status.DUE return Status.ON TRACK def date risk p: Promise, today: date | None = None - int: """Score a promise 0-100. A slipped promise with no contingency hard-caps at 49. """ today = today or date.today status = p.status today if status is Status.SHIPPED: return 0 if status is Status.SLIPPED and not p.contingency: return 49 days out = p.committed date - today .days score = max 0, 100 - abs days out 2 if not p.contingency: score = min score, 70 return int score I built PromiseLedger — the vendor-promise ledger: track every model release date your infra depends on, classify the promise tier, and run the slip playbook fallback warm, eval portable, alert on repo change . $39 one-time. By Haku.