One base_url change. Per-engineer attribution, budgets, and routing to the
cheapest model that will pass, for Claude Code, Cursor, Codex, and eleven backends. Runs on your machine;
never metered by us.
Free 60 days·~20MB binary·localhost-only·honest receipts
A monthly invoice never changed anyone's behavior. Prefex coaches the habit inline, in the moment, so the savings actually change how you work, not just what you read in a report.
Live coaching, in the moment:
Numbers from real sessions, read from the provider's own billing fields, not computed by us. What you save depends on your workload, which is exactly why the dashboard shows you the receipt per request instead of a headline.
From the maintainer's own machine, March to May 2026. Every figure is read from the provider's own billing fields, not computed by us. Your numbers depend entirely on your workload, which is why the dashboard shows you the receipt per request instead of a headline.
The lab's cache, shown for context. The 88% below is the model provider's own prompt caching, which you already get free and which we take no credit for. It is here so the receipt underneath has something to sit against.
| Number on your dashboard | What it means | Whose credit |
|---|---|---|
| Saved by Prefex | What routing, trimming and limits added beyond the native caching you already get free. | Prefex |
| vs no optimization at all | Every token repriced at full strong-model rate with no caching discount. The bigger number, shown only for context. | mostly the provider's free caching |
Most eye-catching "X% saved" figures elsewhere are really Anthropic's native caching, which you get without us. Prefex only takes credit for what it adds.
Twelve layers and a dozen-plus optimizations in one proxy. Drop it in front of your existing client, change nothing else, and watch a local dashboard account for every cent.
Every turn is assigned to the cheapest model that will pass it, and the hard ones stay with the senior. An explainable rules router decides, you can read why, and you can overrule it per project. Routing is table stakes now; what matters is that the decision is on the record.
Prefix detection, a cache warmer, prefix-stabilization, and prewarm-on-switch keep your cached context hot — including pre-paying the re-write before a model switch or a proxy stop, so you never eat the cold-turn spike.
Lossless-first compaction of tool output, logs, and JSON. Cache-boundary-safe and recoverable. Never lossy on code.
Typed facts extracted from your sessions and re-injected by project, so a new session starts with what the last one learned. Strictly project-scoped: one project's memory never leaks into another.
When a session ends, prefex distills a structured note — goal, progress, key files, blockers, next steps — and hands it to your next session in that project. Injected once, cache-safely, so continuity costs nothing per turn.
Loop guards, think-caps, and lean reasoning catch runaway turns before they bill.
Allow, ask, or deny on every tool call, in 3.7 ms — starting in observe mode, where nothing is denied and you just watch. A signed, hash-chained audit that carries derived facts and never raw arguments. Mapped to CMMC, ISO 42001, the EU AI Act, and SOC 2.
Savings attributed per mechanism, in honest incremental terms, then surfaced inline as you work so the numbers actually change how you spend.
An optional on-device encoder, a frozen ModernBERT trunk that runs fully offline, scores prompt complexity for sharper routing than rules alone. Opt-in and default-off; the fast heuristic router runs until you switch it on.
A background sentinel reads your live request stream and flags the expensive stuff the moment it happens: big cold cache writes, prefix flapping, rate limits, and spend spikes, straight to your status line.
Trims model verbosity on mechanical turns — measured ~11% fewer output tokens, the ones that bill at 5× input and never cache. Honest number, honestly measured.
prefex wrap codex (or aider, cursor, zed) routes any tool through the same shared daemon — one dashboard, one savings ledger, per-tool attribution. Codex rides the OpenAI Responses API natively. Pricing for ~3k models resolves automatically from an embedded snapshot; unknown models are flagged, never silently guessed.
A local dashboard at localhost:8019: honest savings per request, every layer, full control. No account, localhost-only, no auth.
// shown with sample data, localhost-only, your data never leaves your machine
Every PromptForce tool is local-first, single-binary, and honest about what it does. We launch with Prefex. ReadyBase is next. More are in the distillery.
A local-first proxy for Claude Code, Codex, Cursor and anything that speaks the Anthropic or OpenAI API. Smart model routing,
prompt-cache assist, cross-session memory, request compression, and spend guardrails, all behind one
base_url change. It shows the honest savings it adds beyond the native caching you
already get free, request by request.
A dependency and co-change graph that scores how ready your repo is for AI agents, and guards high-blast-radius edits. It knows which files are cold, hot, and risky, so your agents (and Prefex) work with context, not guesswork.
We study the sharpest ideas in AI tooling and rebuild the ones that clear our bar as native, fail-open tools. The roadmap follows the thesis below.
Try the full toolkit on your own machine, no strings. Add team features when you are ready.
Every optimization layer, the full dashboard, all of Prefex, free for 60 days. No credit card, no call-home. Renew online in a click when the trial ends. Your keys and prompts never leave your machine.
Shared caches, organization-wide routing policy, per-developer attribution, budgets and spend alerts, SSO, and consolidated billing, built on the same single binary. Available on request, tailored to your setup.
If the ledger shows less saving beyond native caching than the licence in a month, that month is free. Scoped to accounts whose agent seat spend is at least three times the licence — below that the licence is not the thing costing you money, and we would rather say so than sell you one. The ledger is the same one you read on your own dashboard; we do not get a second set of numbers.
Two short reads: running Prefex solo, and rolling it out across a team.
The cost breakdown, the optimization stack, and how to get savings from the first request as an individual developer.
Read the solo guide →Admin setup, onboarding developers, spend and access controls, SSO, shared knowledge, and the numbers at scale.
Read the team guide →Download, review the script, run it. The installer starts Prefex and connects Claude Code for you.
Run it now — nothing below is gated. Free for 60 days, no credit card; the licence flow handles the trial on its own. Leave an email only if you want the release notes and the benchmark scripts.
prefex preview first to see exactly what would change.curl -fsSL https://promptforce.ai/install.sh -o install.sh && less install.shbash install.shopen http://localhost:8019/dashboard~20 MB standalone binary, zero dependencies. Your prompts and keys never leave your machine.
curl -fsSL https://promptforce.ai/install.sh -o install.sh && less install.shbash install.shxdg-open http://localhost:8019/dashboard~20 MB standalone binary, zero dependencies.
iwr https://promptforce.ai/install.ps1 -OutFile install.ps1Get-Content install.ps1 | more.\install.ps1Start-Process http://localhost:8019/dashboardRequires PowerShell 5.1+ and Windows 10/11. Windows support is lightly tested, issues to contact@daytwoai.com.
Prefex is a local proxy. Anything that lets you set a custom API base URL works out of the box.
| Tool | How to connect | Status |
|---|---|---|
| Claude Code | Set ANTHROPIC_BASE_URL in ~/.claude/settings.json | Auto-configured |
| Cursor | Set ANTHROPIC_BASE_URL env var in your shell | Supported |
| Continue.dev | Set apiBase per model in ~/.continue/config.json | Supported |
| Aider | Run with --api-base http://localhost:8019 | Supported |
| Codex CLI | prefex wrap codex, routes this session only | Supported |
| Python / Node SDK | Pass base_url="http://localhost:8019" to the client | Supported |
Coding agents can read llms.txt and AGENTS.md for install and config context, or call the MCP server directly at /api/mcp — search_catalog, get_install_command, get_product_overview.
Prefex runs entirely on localhost. No telemetry, no analytics, no external logging. If any internal component fails, requests pass through to the upstream API unchanged. Prefex never blocks a request because of its own failure.
Uninstall is one command. It stops Prefex, restores settings.json, and (with --purge) deletes ~/.prefex.
Prefex makes every AI token cheaper. ReadyBase makes every token count. Run either alone. Running both is strictly additive.
A proxy that makes every agent token cheaper, with receipts. Prefex rows cheaper.
Explore Prefex →Makes your AI coding tool act like it grew up in this codebase. ReadyBase steers smarter.
Explore ReadyBase →macOS, Linux & Windows · ~20 MB binary · zero dependencies · free for 60 days, no obligation.