You pay frontier prices for review, status checks, and "where were we" because nothing cheaper can be trusted. Cheaper models guess; when a chat ends, the work's memory dies with it; the next session reconstructs from a scrollback buffer and invents what it can't recover.

Open Scaffold keeps a repo-native work record — git-tracked, observed-fact files about what your agents did — and turns it into three things:

• Record (ambient). Extracted from observed facts — transcripts, receipts, test results — costing the working model nothing. osc capture --from claude-code|codex reads a finished session into a record with no worker cooperation. Add a plan and evidence files to check claims against intent; feedback and lessons carry forward instead of being relearned.
• Handoff. osc handoff compiles the record into a budgeted, secret-redacted packet so the next reader — a fresh session, a smaller model, another vendor's agent, or a teammate — resumes from truth instead of re-deriving or inventing it.
• Review and gate. osc review reports plateaus, failing criteria, and requirements worth questioning; osc gate turns that into a retry authorization with stop authority outside the worker. Any file-reading model can be the judge. Fails closed: no parseable verdict means no authorization.

The interesting result is not "the scaffold makes your agent smarter" — measured, it does not. A naked frontier model matched or beat every scaffolded arm on in-session task quality. That dead result is published at equal weight with the wins.

What the record fixes is amnesia and memory errors. In preregistered trials, a mid-tier reviewer model answering factual questions about finished work — graded against answer keys committed before it ran — hit 94% accuracy with the record vs 30% without, zero confident wrong-history answers, at half the review cost. The record turns a cheap model into a trustworthy auditor. Boundaries in docs/PROOF_HARNESS.md.

A bounded Codex cold-resume fixture: a 1,557-byte resume capsule vs 419,233 bytes of raw transcript, three replicates per arm, decision quality tied at 6/6 on a deterministic human-facing reader-usability rubric, 4.330033x fewer tokens (median 137,327 → 31,715). One cold-resume decision, not a universal claim. This is not a production-readiness claim.

Audit every receipt, zero spend: REPRODUCE.md.

npx open-scaffold@latest first-run

Three questions produce MISSION.md, an active plan with acceptance criteria, and an evidence skeleton. Work however you already work; the record accumulates as files:

osc verify
osc evidence new first-slice
osc close first-slice --message "verified first slice"

Scope changed? osc amend first-slice --message "what changed" — plans are immutable, learnings appended. More plans: osc plan new <slug> --stage active. Fresh session: osc handoff.

Want the discipline without the CLI? SKILL.md — the methodology works with plain files.

MISSION.md                     why this repo exists
.osc/plans/                    scoped work with acceptance criteria (active/backlog/done/blocked)
.osc/runs/<run>/run.json       handoff package for a worker or reviewer
.osc/releases/                 evidence notes and release records

No daemon, no database, no SaaS — reviewable in a PR, survives any tool change.

• You own the goal, taste, risk, merge, and publish gates.
• Your agent does the work — Open Scaffold never runs or disciplines it.
• Open Scaffold keeps the record: what was asked, what happened, what was claimed versus verified, what the next session needs to know.

Use for multi-session AI work, PRs needing intent and evidence, audit-sensitive delivery. Skip for one-off scripts and prototypes that die in one session.

Pre-1.0 (v0.33.x). Does not make your model smarter — it makes the loop around the model disciplined. Maturity contract: docs/STABILITY.md. Claim ledger: docs/PROOF_HARNESS.md. Raw receipts: harness-bench.

• docs/START_HERE.md — the single entry point.
• docs/PROOF_HARNESS.md — measured claims, raw pointers, proof boundaries.
• docs/STABILITY.md — command maturity, version truth, honest limits.
• REPRODUCE.md — audit every receipt, zero spend.
• SKILL.md — the methodology as a portable agent skill.
• docs/FAQ.md — deeper questions.
• docs/GLOSSARY.md — the vocabulary.

Open Scaffold is built with Open Scaffold. This repo carries its own mission, plans, run records, evidence notes, decisions, and releases — inspect the method instead of taking it on faith.