The Forge

The engine that refuses a confident wrong answer. Per ignem, probatur — proven through fire.

The Forge is the model side of a SAFE-native app-building system: not a model that emits answers, but the harness that refuses to let a confident wrong one stand. It is the engine every builder in the fleet pins, and it needs no live model to run — it works on decisions, plans and build directories the way a linter works on source.

It asks one question of everything that passes through it: has a human already answered this? When the answer is on file, the maker is confirmed, not re-asked. When it is not, the maker is asked once, properly, and the answer is sealed in their own memory. Waved-through answers come back sooner; argued ones go away longer. And every time the engine states a confidence, it finds out afterwards whether that confidence was earned.

What it refuses, and where

From a sentence to a seal

The loop, end to end, with no model in it:

pip install forge-play nestor-meaning      # or, in a checkout: pip install -e '.[test]'

# 1. the entry — Nestor first, then the keyword → major table, then the first
#    decision through the router. Run it twice: asked once, confirmed the second time.
python -m forge.entry "I got sum kol sites for app to spin" --project rally --builder rosalind --choose web

# 2. a plan with a fork in it — extraction, the checkpoint, the calibration wire
python -m forge.decision_extract demo/fixtures/fork_plan.json
python -m forge.build_loop demo/fixtures/fork_plan.json --builder rosalind --choose "where-the-dates-live=exif in place"

# 3. the whole day, as a person would have it — the friction log is the real output
python demo/the_first_bite.py

• forge/keywords.toml — the keyword → major table. A flat file to read and argue with.
• forge/majors.py — the scan over it: a span of text in, hits out. Deterministic, model-free, two callers (the Forge's entry and the corpus's prose lane) through one interface.
• forge/plan_shape.py — the decision-bearing plan: file_write entries plus one fork kind that carries a decision (options, tradeoffs, a recommendation, a confidence). A model-written plan carries forks; nothing else it writes reaches the router.
• forge/decision_extract.py — noticing that a decision is being made, by rule: a fork the proposer declared, a major the sentence left open, two writes to one path.
• forge/build_loop.py — each decision through the checkpoint, the answer substituted back, no fork left; and the prediction recorded before, resolved after.
• forge/calibration_ledger.py — the scorecard: brier, hit rate, overconfidence — and one review item routed to a human when the model promises more than it delivers.

The home

All Forge state hangs off a single root: ~/.forge (override FORGE_HOME), resolved in one place, forge/paths.py. Under it: the per-builder checkpoint memory and calibration ledger (checkpoints/), and the per-project Nestor store (projects/<project>/nestor/) — a store whose whole content is one build's world, disposable, portable, and the first thing the entry asks.

Dependencies

Zero at runtime, on purpose — the same promise kartikeya and jeles make, and the reason willow-mcp can take this package cheaply. Every heavy piece is soft, and the engine degrades around its absence honestly:

The Forge never imports willow-mcp. Willow depends on the Forge; the reverse would be a cycle, and tests/test_no_reach_back.py keeps it that way. Three modules that willow-mcp once owned — human_loop, friction_floor, and the detection half of model_egress — are canonical here, and willow-mcp imports them from forge-play; its friction_floor drift guard hashes this repo's copy against the willow-gate original.

Development

pip install -e '.[test]'
pytest

The suite is green with the soft dependencies present; individual tests skip or fall back when theirs is absent. With the fleet's per-verifier Nestor keyring in your environment the seal tests are correctly refused (a synthetic verifier has no key) — run with NESTOR_KEYRING unset.

Releases are cut by release-please from conventional commits and published to PyPI as forge-play through Trusted Publishing; the version is the git tag, never a literal. tests/test_release_wiring.py holds the fifteen rules that keep the three release files agreeing. Only commits that change what pip install forge-play gives someone cut a release.

Design

docs/design/ holds the founding design — the decisions the engine was built from, and the record of what is built and what is next. Decisions made since live as drafts in the engine's own per-project Nestor, waiting for a human seal. Documents are cited, never sealed.

License

Apache-2.0. See LICENSE and NOTICE.