Lines

Rabah may offer the same model through several lines. Lines can differ in price, stability and speed.

You don’t need a key per line: one key reaches every line you can use, and the model name in the request decides which line it takes.

The default line

A request with just the model name, e.g. claude-sonnet-4-6, uses the model’s default line — the one marked “Default” in the Model Plaza.

The platform sets which line is the default, and it isn’t necessarily the cheapest. If price matters to you, pick the line yourself.

When the default line is unavailable

With just the model name, if the default line has no available account at the moment (rate-limited or under maintenance, for example), the request moves on to the next available line instead of failing.

You are then charged that line’s price, which can differ from the default line’s. Usage in the Hub shows the cost of every request; hover over the cost to see the unit prices. To always be billed at one line’s price, pick the line yourself.

Picking a line

Add :line-code to the model name to always use that line:

claude-sonnet-4-6:pro

Line codes are shown when you expand a model in the Model Plaza; “Copy model name” on that row copies the full name.
GET /v1/models also lists the model:line-code form for every line of a model that has several.
Codes are case-insensitive: :PRO is the same as :pro.

A request that names its line never switches lines. If that line is unavailable, the request fails, so you can be sure it is always billed at that line’s price.

Exclusive lines

Besides the public lines everyone can use, the platform can open exclusive lines to particular users; the Model Plaza marks them “Exclusive”.

Exclusive lines appear in the Model Plaza only when you’re signed in, and only to accounts they’ve been opened to.
They work like public lines: a bare model name may use one, and model:line-code picks it explicitly.

Limiting the lines a key can use

When you create or edit a key, Lines & Models limits what it can use:

All lines and models (default): everything you can use, including lines and models added later.
Selected lines and models: only what you tick. A fully ticked line also allows models added to it later.

With just a model name, lines the key may not use are skipped and the next allowed line is used.

Common errors

Status	Message	Cause
404	`Model <name> is not available`	No line offers this model, the line code is wrong, or it names an exclusive line you haven’t been granted. Check the name matches the Model Plaza exactly.
403	`Model <name> is not allowed for this API key`	The model exists, but the key’s “Lines & Models” setting doesn’t allow it. Edit the key in the Hub.
503	`No available accounts` or `Service temporarily unavailable`	The line’s accounts are all busy or limited right now. Bare model names avoid such lines where they can but may still hit this; requests that name a line are more likely to. Retry later or use another line.