An open-source project by Kith AI Lab

Carbon Cost — struck through. tret is an open-source AI workbench that routes every task to the optimal model.

Tret is an AI workbench that routes every task to the optimal model. 60%+ savings for climate and the bottom line, with receipts.

Get notified repo launches sept 28 Apache-2.0

Use it. Build on it. Embed it.

One engine, three depths. Most knowledge work isn't code — tret meets your team where it is, and devs everywhere else.

01 · use it

The workbench your team runs today.

Colleagues hand it plain-language tasks — memos, filings, pipelines. Every run is routed, logged, and receipted. No terminal required.

The tret workbench UI: a chat view where each completed task shows a receipt line with its cost in dollars and footprint in grams of CO2e, alongside month-to-date totals and suggestion cards.

02 · build on it

Like Claude Code — a harness for knowledge work.

The workbench is just the reference UI. Underneath is the harness — same routing, same receipts, your front end. Be the person who greens your org's AI.

$ tret run "summarize the 40 filings in ./q3"

→ task profiled · extraction, long-context, no frontier needed

→ routed to qwen3.8 · −71% cost · −68% CO₂e vs default

✓ summary written to q3-filings.md

receipt · $0.021 · 0.4 gCO₂e · ledger #b7a2

03 · embed it

The orchestrator inside your product.

Route your agents' calls through tret and ship the receipts to your own users — cost and carbon accounting as a feature, not a promise.

# your agent product

from tret import Router

result = Router().run(task)

result.receipt # $ and gCO₂e, per call

Impact, logged and tracked.

The harness creates impact by choosing the most efficient model per call. Cost and carbon drop as much as 60%, and the tracker shows it.

Never say “green” where you can show the receipt.

tret · run 4c81 2026-08-19 14:02 UTC

portfolio risk summary · 6 calls · completed ✓

default$0.095
this run$0.038
default2.3 g
this run0.9 g
$0.038cost, all calls
0.9 gCO₂efootprint, estimate → derivation

vs. frontier-only default: −60% cost · −60% carbon

An open-source unlock.

tret is a gateway to low- and no-cost models. Tap them without sacrificing task performance.

Auditable workflows.

tret keeps a ledger of its work, addressing the “black box” criticism of AI. QA and QC become integrated, not afterthoughts.

ledger · run 4c81 6 entries
14:02:11input received · 3 files#a41f
14:02:14figure computed · source linked#c2e8
14:02:31QC check passed · 12 of 12#9b04
14:06:52signed off · m.okafor#f7d3

Extend it to your field.

Packs add a field's methods, checks, and vocabulary to the core. The flagship is climate risk, by Kith Climate — the advisory that runs its client work on tret.

climate-risk

by Kith Climate · physical risk, transition exposure, footprint

flagship

your-field

legal, finance, compliance — same harness, your methods

contribute →

The repo opens
September 28.

Core harness, workbench UI, and the climate-risk pack — Apache-2.0 from day one.

What

tret · core + workbench + climate-risk

When

Sept 28, 2026

Launch event

Sept 30 · 9Zero, San Francisco

during The AI Conference SF · save your spot ↓

Get notified

or watch the repo on github ↗ · one email at launch, nothing else