OpenRouter Alternatives — How to Choose an AI API Aggregator

image2.5 from $0.0085 per 1K image · Seedance 2.5 from $0.0961/sec · cached LLM input from $0.40/M — one OpenAI-compatible endpoint at https://api.apimart.ai/v1, no monthly plan required. (observed 2026-09-17)

Get an API key · Live pricing · Model page

Why teams route through APIMart

• One key, entire catalog. The same https://api.apimart.ai/v1 base URL and Authorization header reach the whole catalog behind one key and 300+ other image, video and language models — switch the model field, not your client.
• $1 minimum, pay as you go. No subscription and no prepaid plan to size up front: top up from $1 and spend it on calls. There is no free quota to burn through first, so the price in this table is the price you pay.
• The charge comes back in the response. Every call reports the amount billed (cost / credits_cost), so a spend number is read per call instead of guessed at month end.
• Async by design. Submit, take the task_id, poll GET /v1/tasks/{id} — batching and retries are ordinary queue work, not a bespoke integration.

Looking for OpenRouter alternatives usually means one of three things: the price moved, a model you need is missing, or you want the same single-key convenience with a billing unit you can predict. This repository gives you the dimensions to compare on, the migration checklist, and a script so the decision is reproducible instead of vibes.

python tools/migrate_checklist.py --dimensions             # the questions to answer first
python tools/migrate_checklist.py --from openrouter --to per-unit-relay

Full archetype data (with the traits and scores this checklist is derived from) lives in data/alternatives.json. Named products appear only as examples of an archetype.

Score them with your own weights on the gateway side of this series (llm-gateway-comparison) — the method is identical.

examples/swap_base_url.py shows the whole change: the request body and messages stay, only base_url, the key and the model id move.

from openai import OpenAI

client = OpenAI(base_url="https://api.apimart.ai/v1", api_key=os.environ["APIMART_API_KEY"])
client.chat.completions.create(model="gpt-5.5", messages=[{"role": "user", "content": "hi"}])

Then run the checklist and keep these rules:

1. Pin configuration. Base URL, key and model ids in environment variables, so rollback is not a code change.
2. Reuse idempotency keys. A retried submit without one is a second charge.
3. Replace inline results with submit → poll → download if the target's generation routes are asynchronous.
4. Reconcile before scaling. Sum cost of completed tasks; compare against the invoice; then canary 1% → 5% → 25%.
5. Re-check the catalogue. Model ids and prices move; the catalogue in unified-ai-api-model-catalog is regenerated daily for exactly that reason.

Linear at the observed per-unit rate, no volume discount assumed. Snapshot 2026-09-17; re-check the live table before committing a budget.

What is the cheapest OpenRouter alternative? Cheapest depends on your unit. Per-image and per-second routes make cost a multiplication, which beats token billing on uniform batches; token billing with cache hits wins on small, repetitive requests. Compute cost per accepted artefact for both before declaring a winner.

Can I keep the same code when switching? Often yes for chat: the OpenAI request shape is widely implemented. Image, video and vision routes are where adapters appear — different parameter names, different batch caps, and an asynchronous job model.

How do I compare free tiers honestly? Treat free credits as a trial, not a price: measure what happens at the rate limit (queue, error, or silent downgrade) and what the paid unit costs immediately after the free quota ends.

What breaks first in a migration? Assumptions about synchronous completion and about model ids. Both surface as timeouts or validation errors rather than wrong output, which is the good version of this failure.

• openrouter alternatives
• openrouter alternative free models
• ai api aggregator
• unified ai api
• llm api comparison
• cheapest llm api
• openai compatible api

Start with $1. Get an API key → check live pricing → open the whole catalog behind one key in the model library. The first call is three steps: submit, poll task_id, read the charged amount off the response.

Outbound APIMart links are minted through the promo link API; hand-made tracking parameters are rejected by tools/check_links.py in CI.

This repository documents how to compare and migrate between AI API aggregators; it is published to document that method, not to claim official status for any vendor. Product names are used as examples only and belong to their owners. Nothing here is a vendor scorecard: verify every cell against the provider's own documentation for your account.

README.md                    the nine questions, archetypes, migration workflow
data/alternatives.json       dimensions, archetype traits and scores (schema: openrouter-alternatives-v1)
tools/migrate_checklist.py   checklist generator
examples/swap_base_url.py    the minimal code change
tools/check_links.py         attribution guard (CI)

MIT — see LICENSE.