Trismegistus
Trismegistus

Trismegistus API

One key, one base URL, every model. The API is OpenAI-compatible — point any OpenAI SDK at our base URL and call any model by its slug. Frontier models route direct to the vendor; you get one bill in credits.

Base URL
https://trismegistus.app/api/v1

Quickstart

Install the OpenAI SDK, set your key, and make your first call.

python
from openai import OpenAI

client = OpenAI(base_url="https://trismegistus.app/api/v1", api_key="$TRISMEGISTUS_API_KEY")

resp = client.chat.completions.create(
    model="anthropic/claude-sonnet-4.6",
    messages=[{"role": "user", "content": "Explain consensus in one sentence."}],
)
print(resp.choices[0].message.content)

Authentication

Every request needs a bearer token. Create a key in your account — it starts with tris_. Send it in the Authorization header.

http
Authorization: Bearer tris_xxxxxxxxxxxxxxxxxxxx

Chat completions

POST /chat/completions — identical shape to OpenAI. The model field takes any slug from the catalog.

curl
curl https://trismegistus.app/api/v1/chat/completions \
  -H "Authorization: Bearer $TRISMEGISTUS_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "openai/gpt-4.1",
    "messages": [{"role": "user", "content": "Hello!"}],
    "temperature": 0.7,
    "max_tokens": 512
  }'

The response includes an x_trismegistus.credits_charged field so you can reconcile spend per call.

Streaming

Set stream: true for token-by-token Server-Sent Events, in the same data: {...} chunk format as OpenAI, terminated by data: [DONE].

node
import OpenAI from "openai";
const client = new OpenAI({ baseURL: "https://trismegistus.app/api/v1", apiKey: process.env.TRISMEGISTUS_API_KEY });

const stream = await client.chat.completions.create({
  model: "google/gemini-2.5-flash",
  messages: [{ role: "user", content: "Write a haiku about routing." }],
  stream: true,
});
for await (const chunk of stream) {
  process.stdout.write(chunk.choices[0]?.delta?.content ?? "");
}

List models

GET /models returns every available model with pricing, context, and capabilities.

curl
curl https://trismegistus.app/api/v1/models -H "Authorization: Bearer $TRISMEGISTUS_API_KEY"

Embeddings

POST /embeddings — OpenAI-compatible. Route across providers by slug (openai/, google/, together/) to compare price and quality.

python
client.embeddings.create(
    model="together/BAAI/bge-large-en-v1.5",
    input=["The quick brown fox", "jumps over the lazy dog"],
)

Entity API (multi-model)

Beyond single models, you can call a saved Entity — a multi-model blend with judging and synthesis (our Ensemble differentiator) — by its slug: POST /api/v1/chat with { "entity": "<slug>", "message": "…" }. Build one in the builder.

Pricing & credits

Usage is billed in credits. Every plan and credit pack shows exactly what you pay — no surprise per-token math. Per-model prices are on each model's page. Track spend in Credits.

Errors & rate limits

Errors use OpenAI's shape:

json
{ "error": { "message": "…", "type": "invalid_request_error" } }
  • 401 — missing/invalid key
  • 402 — out of credits
  • 404 — unknown model (see /models)
  • 429 — plan rate limit; upgrade for higher throughput
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