People decide free. Agents pay per answer.
A person using the board on this site pays nothing. Machine access uses the keyed CLI, hosted API and MCP server, and it uses prepaid credits. Every machine data endpoint needs an API key. The board's free browser lookups use a Turnstile-verified visit token. No data download. MCP data tools (vocab, model_info, list_use_cases, decide, rank, policy_check) require an API key.
Three ways in: keyed CLI, MCP and HTTP API. Machine data access needs a ModelSpec API key; only human lookup is free. No data download or local decision cache.
uvx --from modelspec-dev modelspec pipx install modelspec-dev pip install modelspec-dev
pip install modelspec is an unrelated project. Use modelspec-dev.
One credit. The low end is the Scale plan's rate; the range covers the plans and packs below. A full explanation costs two credits.
Buy credits for your agents
Pay by card. You get one API key and one balance; every agent that carries the key draws from it.
| Plan | Allowance | Price | Purchase |
|---|---|---|---|
| Solo | 2,500 credits$0.0116/credit | $29/mo | |
| Team | 25,000 credits$0.008/credit | $199/mo | |
| Scale | 150,000 credits$0.0053/credit | $799/mo |
| Pack | Rate | Price | Purchase |
|---|---|---|---|
| 250 credits | $0.02/credit | $5 | |
| 1,300 credits | $0.0192/credit | $25 | |
| 2,750 credits | $0.0182/credit | $50 | |
| 6,000 credits | $0.0167/credit | $100 |
Scale overage is $0.006 per credit, up to 150,000 credits a billing period, coming soon.
A metadata read costs $0.002, one credit per 10 reads, capped at 1,000 reads a key a UTC day.
Checkout is hosted by Stripe; card details never reach ModelSpec. After payment, claim your API key at the Checkout success link. The plan allowance is spent first, then packs, oldest first. Cancel any time. For volume or invoicing, write to [email protected].
Or let your agents pay as they go
Your agent keeps its API key and needs no card. When its balance runs out, the API answers with HTTP 402 and the 4 packs; the agent pays in USDC over x402 and the credits land on its key in the same exchange.
- The packs cost the same in USDC as by card, and expire on the same terms.
- Credits are added only after the payment settles on-chain.
- A call without a key is refused before any payment is offered.
POST https://api.modelspec.dev/v1/decide
MCP https://api.modelspec.dev/mcpWhat will your agents spend?
A month is 30 days. Prices from the published plan and pack list; the arithmetic runs in your browser. On an exact tie, the calculator prefers an option without a subscription.
What an answer costs
| Answer | Cost |
|---|---|
| A decisionranked answer with ties, no explanation or a summary | 1 credit |
| A decision, fully explainedevery fact, source and trade-off behind the order | 2 credits |
| A rankingthe ranked list for one capability | 1 credit |
| A licence and data-residency checkcited commercial-use and residency determinations | 5 credits |
| An error, a refusal, or no model fitsanything that is not a successful answer | free |
How to call it
People decide free on the board. Machines use the hosted API and the MCP server with a key.
- People decide on the board.
- Machines call the hosted API with a key.
- Machines call the MCP server with a key.
What stays free
- The board, for people. Every facet, every tie, every source, on this site. No account. Rate-limited, not charged.
- The public repository. The engine is MIT and the data is CC BY-SA, as a delayed image about nine months behind. Current data is served only through the hosted API and MCP server.
- The sandbox. Unlimited synthetic answers to build and test against. No signup.
Paying never moves a model.
Credits pay for answers and determinations, never for position. No referral fees, no paid placement, no provider-paid visibility. A published commitment you can check.
Only a successful answer draws credits.
Errors, refusals and "no model fits" release the credit reservation. Your balance is one call away.
The same facts, the same answer.
A spec and a snapshot always give the same result, so an agent's choice can be audited later.