darkroom

Evidence-based autonomous software delivery: agents build, sealed exams judge, and every claim ships with proof.

darkroom runs a convergence loop in which a builder agent works toward criteria it is never shown. A non-LLM harness drives the system under test as a black box and captures typed evidence (HTTP transcripts, command output, screenshots, screencasts); a judge scores that evidence against rubrics sealed in a vault the builder cannot address; gates ratchet so no scenario ships below its peak. The exam lives outside the repository, the scores live outside the builder's reach, and the manifest, not the code, is what you review, diff, and gate on.

This is proven live, not aspirational. A greenfield example app was delivered by agents under darkroom: its API, its security behaviors, its full UI and design language, even its Makefile, every behavior converging to a gated 100 on captured evidence, at a metered equivalent of single-digit dollars per campaign, with the exams' screencasts as the receipts.

The name references the dark factory pattern (lights-off autonomous production) and the clean room pattern (independent implementation from specification). A darkroom is a controlled, light-sealed environment where evidence is developed and evaluated without contamination from the implementation side.

New here? Start with the Quickstart: four stages, ~15 minutes, covering first evidence, the exam, the convergence loop with zero spend, then real agents. Its runnable stages are executed by CI, so it cannot rot.

Install

pip install darkroom-ai

The core is dependency-free. Extras add capabilities:

The distribution is named darkroom-ai (the bare darkroom name is squatted on PyPI); the import name is darkroom throughout. The CLI installs as darkroom (alias: darkrm).

How it works

A tenant repository declares only run-me facts in darkroom.toml:

[project]
name = "quicknotes"

[commands]
serve = "make serve PORT={port}"
test = "darkroom drive"

A tenant that needs a database beside the app declares it once, as a fact, and every scenario gets a fresh one:

[[environment.services]]
name = "postgres"
image = "postgres:16"
port = 5432
env = { POSTGRES_PASSWORD = "exam" }

serve = "make serve PORT={port} DATABASE_URL=postgres://postgres:exam@{postgres.host}:{postgres.port}/postgres"

An image whose entrypoint wants arguments declares them as command (a Postgres tuned for throwaway exams, say):

[[environment.services]]
name = "postgres"
image = "postgres:16"
port = 5432
env = { POSTGRES_PASSWORD = "exam" }
command = ["postgres", "-c", "fsync=off", "-c", "synchronous_commit=off"]

A service is handed to the app once its port accepts a connection — which, for a JVM store, is seconds before it can answer. Declare ready_path and the engine also waits for an HTTP response there:

[[environment.services]]
name = "objects"
image = "adobe/s3mock:latest"
port = 9090
ready_path = "/"

What every scenario shares, the adapter says once — an exam then carries only what differs:

[serve.defaults]        # every scenario's [serve] starts here
ttl = 120

[serve.env]             # the engine sets the served process's environment
APP_TTL_SECONDS = "{ttl}"
APP_DATABASE_URL = "postgresql://postgres:exam@{postgres.host}:{postgres.port}/postgres"

[browser.defaults]
webauthn = true

The exam is data, held operator-side as one proof per scenario — a folder in the project's darkroom home (~/.darkroom/projects/<name>/proofs/<scenario>/), never in the repo the builder works in. A proof is two files with two authors: the exposure (QA's — the steps that drive the app as a black box and capture every exchange as evidence) and the rubric (product's — the criteria that score what was captured). The quickstart's stage 4 puts them there, and darkroom auto refuses to run while exam material is still inside the tenant:

# proofs/note_saved/exposure.toml
scenario = "note_saved"
record = true          # screencast the whole scenario

[[step]]
name = "save"
method = "POST"
url = "{base_url}/notes"
json = { text = "first light" }
expect = { status = 201 }
save = { note_id = "$.id" }

[[step]]
name = "read_back"
url = "{base_url}/notes/{note_id}"
expect = { status = 200, body_contains = "first light" }

# proofs/note_saved/rubric.toml
version = "1"

[[criterion]]
id = "saved_and_readable"
points = 10
description = "a saved note reads back with its text"
witnesses = ["save", "read_back"]     # evidence kinds follow from the steps cited

darkroom expose runs the exposure (darkroom drive, its older name, still does). The builder, for its part, publishes the interface it chose beside each spec — scenarios/<name>.surfaces, the routes, commands, pages, and files the build exposes — and darkroom audit holds every exposure to that publication both ways: a step probing something unpublished, a published surface nothing proves. Setup many exposures share (founding, joining, signing in) is named once in the home's backdrops.toml and posed ahead with backdrop = [...].

Step kinds cover HTTP, commands, Ed25519 keygen/signing, assertions, waits, container failure injection, and real browser interaction (goto/click/fill/screenshot, with viewport control and headless passkey ceremonies via a virtual authenticator). A failing scenario keeps its evidence: a failing scenario is still judgeable, which is the point.

darkroom verify checks each run against an evidence contract (per-scenario required kinds, counts, steps, trials) — derived from the proofs' criteria at run time, so a tenant on proofs commits no contract at all — and "this build produced its evidence" is a CI gate before any judging happens.

The loop, darkroom auto, runs assess → judge → build to convergence. Judge and builder can be shell hooks (see the Quickstart's zero-spend demo) or full agents configured operator-side:

# ~/.darkroom/projects/quicknotes/operator.toml (never in the tenant)
[judge]
model = "claude-opus-5"

[builder]
model = "claude-sonnet-5"
escalated_model = "claude-opus-5"

[loop]
max_iterations = 6

darkroom auto --scenario note_saved     # operator config discovered from the home

Authority lives in the per-project darkroom home (~/.darkroom/projects/<name>/, mode 700): operator config, proofs, backdrops, loop state, and the vault, through which the judge is handed each proof's rubric — criteria, never steps — and the addresses of the build's published surfaces, never the builder's prose about them; the builder reads none of it. darkroom vault seal validates the proofs (or, on the older layout, moves rubrics out of the tenant); the OpenBao backend adds token-gated reads and server-side audit. Every manifest names the exam it answered — the exposure's digest and the rubric's version — so a verdict is never ambiguous about what it judged. The loop stagnation-escalates (diagnostic access, model escalation, sharper feedback), rolls back regressions to the best checkpoint, and ratchets the gates in the home's state on convergence. A red gate always means something real: rubric changes re-baseline; they never masquerade as regressions. Projects on the older drive-script + rubric layout keep working; darkroom migrate turns each pair into a proof folder and each spec's Build: note into a draft .surfaces.

Every agent invocation is metered (model, tokens, cost) into loop state, and darkroom dossier assembles the cross-run record into one operator-facing bundle: score trajectories, checkpoints, escalations, gates, spend.

Evidence capture without the loop

The capture layer stands alone. Installing the package registers a pytest plugin; tests request the evidence fixture and runs become manifest-backed:

def test_login_flow(page, evidence):
    evidence.screenshot(page, "after_login", full_page=True)
    evidence.log("api_response", {"status": 200})

EVIDENCE_MODE=1 EVIDENCE_DIR=./evidence pytest

The same API is importable directly (EvidenceCapture, start_run/end_run), and darkroom gallery renders any run as a static contact sheet.

The formats are a spec

Every artifact (manifest, contract, evaluation, gates, tickets, drive scripts, role hooks, dossier) is a written, versioned format with conformance rules and a trust-boundary map: see docs/spec/. Any harness in any language can emit a darkroom manifest; any judge infrastructure can consume one.

Claude skills

Four skills ship inside the package, version-locked to the engine:

• darkroom-interview: the intent interview, covering charter, scenario enumeration, thresholds, rubric drafting under the capturable-evidence rule (with structured witness citations), gaming self-audit, preflight-validated artifacts.
• darkroom-converge: the operator's run-a-scenario loop — author the drive, audit, dry-run before spending, commit both repos, launch auto, triage blockers, regress, deploy.
• darkroom-status: the standing report — where every scenario's campaign stands now, blockers with their triage, what is shipped versus merely gated, the queue, spend — in one fixed shape, every number from darkroom status.
• darkroom-chronicle: narrates a project's delivery from its dossier, covering progression, what the judge witnessed, sticking points, novelties, spend.

Install them either way:

# as a Claude Code plugin, pinned to the release you are running
claude plugin marketplace add withtwoemms/darkroom
claude plugin install darkroom@darkroom          # -> darkroom:interview, :converge, :status, :chronicle

# or from the installed package
darkroom skills install                          # symlinks into ~/.claude/skills (--copy to copy)
darkroom skills check                            # exit 1 if any installed copy drifts from this engine

darkroom skills check compares every installed copy against the packaged one by content hash, so a stale or hand-edited skill is reported rather than quietly steering an operator wrong.

Documentation

• Quickstart -- first evidence to real agents in four stages
• docs/spec/ -- the format specifications (the handoff contracts, frozen at 1.0)
• ROADMAP.md -- milestones from foundation through v1 and beyond
• CHANGELOG.md -- the release-by-release record
• The Judge & Builder: implementing a dark factory -- the pattern essay: why evaluation must be structurally separated from implementation
• docs/vision.md -- design fiction: building a web app in the dark
• docs/rubric-lifecycle.md -- how a rubric is made, hardened, and revised
• docs/generalization-plan.md -- how darkroom absorbed the Judge-Builder framework

Development

make venv       # create virtualenv and install deps
make test-unit  # run unit tests
make test       # run all tests with coverage
make help       # see all targets

Licensed under Apache-2.0.