OpenRouter gives you model access and provider routing. Nadir adds an auditable model-and-effort decision. Cited from their docs, including where they win.
Questions answered on this page
What is the difference between Nadir and OpenRouter?
OpenRouter gives you model access and provider routing. Nadir gives your existing stack an auditable model-and-effort decision. OpenRouter is a marketplace of 500+ models across 80+ providers behind one API and one bill, with provider-level failover. Strong default privacy: prompts and completions are not logged unless you opt in.
How does OpenRouter decide which model to use?
The Auto Router assigns each prompt one of roughly 30 fine-grained task types with a lightweight classifier, then ranks candidate models by community spend-share over a trailing seven-day window, then keeps the models that fit the cost tier you set. The earlier cost_quality_tradeoff setting is deprecated in favor of a cost_tier band. Nadir decides from a trained difficulty classifier over the prompt, the candidate menu, policy, cache, context, and session economics.
What does OpenRouter do after the model answers?
Nothing. There is no verification or post-generation escalation anywhere in the docs. Nadir's decision-only mode returns before generation. On the managed, non-streaming path a complete response can enter a reference-free verifier and escalate when it misses the configured bar. Streaming bypasses that post-generation cascade.
What does OpenRouter cost compared with Nadir?
OpenRouter: A fee on credit purchases only: 5.5% on Standard, 8% on Business, never per request, with no markup on inference. Bring your own keys and Standard and Business include $25,000 a month of list-price inference with no OpenRouter fee. Above that it is 5% of what the same request would cost at list price, deducted from credits. Nadir has no base fee. Credits for Nadir-managed keys draw down at provider list price, with a 5.5% platform fee (8% on Business) added when you buy them. On your own keys, your provider bills you directly and Nadir adds no fee. Routing savings carry no fee, and shadow and recommendation-only deltas are advisory estimates that are never billed.
What does OpenRouter do well?
500+ models on 80+ providers, with provider-level failover. No prompt or completion logging by default. Fusion, multi-model deliberation behind one model slug.
Why pick Nadir over OpenRouter?
Spend-share is a popularity prior. It tells you what other developers paid for last week, not whether this answer is correct. Nadir returns model, reasoning effort, cache, compaction, and governance advice without replacing the customer's gateway. Shadow decisions and reported outcomes let a team evaluate its own baseline before enforcement; optional complete-response verification can be added later. Nadir publishes no universal deployed savings or quality percentage. The 60% cost and 98% quality-preserved RouterBench result, measured on 11,420 held-out triples, is a reference-assisted research ceiling rather than the live reference-free path.
How do I trial Nadir against OpenRouter?
Keep OpenRouter exactly as it is. Write down the model, reasoning effort and monthly spend it produces today, and pick a week of real traffic, or a set of requests you can grade, as the baseline. Call Nadir's decision API from the same place that calls OpenRouter, in shadow mode. It returns the model, effort, cache and policy recommendation with no provider call, so nothing about execution changes. Read the receipts against what actually ran, and report outcomes through the outcome endpoint. Projected savings stay advisory until you execute a recommendation and report measured usage. Enforce on one workload, keep OpenRouter as the route you fall back to, and widen only when the outcomes clear your own bar.
What Nadir is
Nadir is an LLM router. Nadir sends each prompt to the cheapest model
that can handle it. A small decision model
reads each prompt against your model menu and picks the lowest-cost model
it expects to handle it. When the decision model is uncertain or
unavailable, the request goes to the strongest model on the menu. The
routing step makes no call to your model provider.
Nadir runs two ways. The decision API returns a model, reasoning-effort,
cache, context, and policy recommendation without calling a model
provider, beside the gateway you already run. That is how a shadow-mode
evaluation works, and its projected savings stay advisory. The OpenAI
compatible managed proxy executes the route, and migration is a two-line
change: point the base URL at api.getnadir.com and set model to auto. On
that path an optional verifier can score a complete non-streaming answer
and escalate to a stronger model when it misses the configured bar.
Streaming bypasses post-generation verification. BYOK is supported on
every tier.
For coding agents, Nadir Auto is a terminal launcher for Claude Code or
Codex that asks Nadir for the main-session model before each turn, with
your configured model as the fallback and cost ceiling. Delegation
integrations for Claude Code, Codex, or Cursor instead recommend a model
tier for subagent work, and the agent decides; the Claude plugin can also
move a main-thread turn to Haiku when Nadir's cache check prices it
cheaper, unless its switch_main_model option is off. Either way inference runs
on your own provider account, so Nadir holds no provider keys on that path.
What the numbers are, and what they are not
Nadir publishes each evaluation with its scope. On checkable code,
run-check-escalate solved 392 of 395 common HumanEval and MBPP problems
(99.2%), graded by running the canonical tests; that applies only to tasks
with runnable deterministic tests. Nadir-Tumbler posts an arena_score of
72.3 on RouterArena's public scorer, 5th of 23 routers, which measures the
routing decision on RouterArena's own model pool. A reference-assisted
RouterBench evaluation over 11,420 held-out triples produced a 60% lower
projected cost than always-Opus with about 98% retained quality and a 1.7%
catastrophic-route rate. That experiment gave the verifier the
expensive-model reference answer, which production does not have, so it
is a research ceiling and not the deployed path.
None of these is a production guarantee, a universal savings rate, or a
forecast for any particular workload. Customer savings are reported from
measured execution against a declared baseline, and customer quality only
from outcome-labelled traffic. Projected savings and realized savings are
separate artifacts and are never blended.
Design-partner program
Three rungs, picked by risk appetite. Rung 0 Shadow runs advisory decision
calls alongside live traffic and returns a projected receipt, with nothing
in the request path changed. Rung 1 Hosted is the two-line swap on a
production slice and returns a realized receipt. Rung 2 On-prem is a
supervised six-week proof of concept inside the partner's VPC, where no
prompt, response, or usage reaches Nadir. The commitments are the same at
every rung. Apply for a rung directly:
Rung 0 Shadow,
Rung 1 Hosted, or
Rung 2 On-prem.
Not sure which fits? Start at
getnadir.com/contact/?reason=design-partner.
Licensing
NadirClaw is the self-hosted core, source-available under the PolyForm
Noncommercial License. Source-available is the correct label; NadirClaw is
not open source. Nadir Route's hosted plan has no base fee and charges a
variable fee only on measured savings from requests Nadir executed.