API reference

Embeddings

Turn text into vectors.

POST/v1/embeddings

Turn text into vectors. The route follows the OpenAI Embeddings API, so client.embeddings.create works unchanged with the base URL https://demo-api.routerplus.com/v1. https://demo-api.routerplus.com/embeddings is an alias. The route returns one JSON response and does not stream.

Examples

curl

curl https://dev2-api.routerplus.com/v1/embeddings \
  -H "Authorization: Bearer $ROUTERPLUS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"model": "text-embedding-3-small", "input": ["first text", "second text"]}'

python

from openai import OpenAI

client = OpenAI(base_url="https://demo-api.routerplus.com/v1", api_key="tm_vk_...")
result = client.embeddings.create(model="text-embedding-3-small", input="hello world")
print(len(result.data[0].embedding), result.usage.prompt_tokens)

Send your key as Authorization: Bearer tm_vk_... or as x-api-key: tm_vk_.... A missing or invalid key returns 401.

Models

Model	Provider	Price per 1M input tokens	Max tokens per input
`text-embedding-3-small`	OpenAI	$0.02	8,191
`text-embedding-3-large`	OpenAI	$0.13	8,191
`baai/bge-m3`	DeepInfra	$0.01	8,192
`qwen/qwen3-embedding-8b`	DeepInfra	$0.01	32,768
`intfloat/multilingual-e5-large`	DeepInfra	$0.01	512

GET /v1/models?output_modalities=embeddings lists the embeddings models your key can use. You pay for input tokens only. Output tokens are free.

Request

The body is JSON, at most 10 MB. RouterPlus checks every rule below before it reserves money or calls a provider. A refused request has no ledger row and no charge.

Parameter	Type	Behavior
`model`	string, required	An embeddings model id. A chat, image, video or decision model is a 400 that names its own route. An id that is not in the catalog is a 404.
`input`	required	A string, an array of strings, a token array (integers), or an array of token arrays. At most 2,048 inputs. An empty string, an empty array or an empty token array is a 400.
`encoding_format`	string	`float` (the default) or `base64`.
`dimensions`	integer	A positive integer. Only models that support it shorten their vectors (`text-embedding-3-*` and some open models).
`user`	string	Sent to the provider as is.
`provider`	object	Routing controls. RouterPlus reads them and does not send them to the provider. See Provider routing.

RouterPlus drops any other field and names it in the x-tm-dropped-params header. With provider.require_parameters: true, a dropped field is a 400.

A 400 message starts with the field name, for example input[1]: must not be an empty string.

Response

json

{
  "object": "list",
  "data": [
    { "object": "embedding", "index": 0, "embedding": [0.0123, -0.0456] }
  ],
  "model": "text-embedding-3-small",
  "usage": { "prompt_tokens": 5, "total_tokens": 5, "cost": 0.0000001 }
}

Field	Meaning
`data`	One item per input, in the order you sent them.
`embedding`	An array of floats. With `encoding_format: "base64"`, a base64 string of little-endian float32 values.
`model`	The id you sent.
`usage.prompt_tokens`	The count the provider reports. You are billed on it.
`usage.cost`	The charge in USD for this request.

Billing

01
Before the call, RouterPlus holds the estimated cost of your input on your balance.
02
After the call, it charges usage.prompt_tokens at the model's input price and releases the rest of the hold.
03
If the provider reports no usage, RouterPlus charges the estimate it held.

A failed attempt costs nothing. GET /v1/generation shows each attempt.

Routing and failover

RouterPlus picks the provider with the same rules as chat. Guardrails apply: a model your guardrail does not allow is a 403 with error_type: "guardrail_blocked".

If a provider fails before it answers (a 5xx, a 429 or a timeout), RouterPlus tries the next provider of the model. x-tm-attempts gives the number of attempts. x-tm-provider names the provider that answered.

A key with an OpenAI connection sends OpenAI embeddings requests on your own OpenAI key. See Bring your own key.

For agents: /docs/api-embeddings.md and /llms.txt