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Launching the open-source gateway

The only AI gateway with built-in observability and evals.

Unified router or provider passthrough for 1,000+ models, with failover, response caching, warn/block limits, and metadata on every logged request.

Respan gateway model catalog with prices, context windows, and capabilities

Reach every model, and stay up.

Point the SDK you already use at one endpoint to reach 1,000+ models, with automatic fallbacks, response caching, and spend limits built in.

One API for every model

Send every request to one endpoint, reach 1,000+ models across every major provider, and switch between them by changing a single word.

99.99%with fallbacks
96.43%single provider
Respan with fallbacks100%Single provider66%
100500
15:0018:0021:0000:0003:0006:00

One model fails, the next takes over

List the models to fall back to, and Respan moves to the next the moment one errors or rate-limits, so an outage never takes you down.

Cache hits128,402
Cost saved$412.90
Tokens saved8.2M
Last usedExpiryHit countCache
4s ago28d1,872summarize the invoice into three bullet points
18s ago27d3,214classify this support ticket by intent
41s ago25d2,905extract the line items and totals as JSON
2m ago24d1,530translate this reply into Spanish
5m ago22d1,204draft a reply to the refund request

Repeat requests served from cache

Cache a request and its response, then serve the same call again instantly, cutting the cost and latency of every repeat to nothing.

$3,000$0$5,000

Budgets and limits at every scope

Set budgets and rate limits per key, per customer, or org-wide, get warned as you near them, and block requests before spend runs away.

You own every integration.

Call each provider directly and you inherit its SDK, quota, outages, and bill, until one endpoint sits in front of them all.

A new model means new code

Every provider ships its own SDK and request shape, so trying a different model turns into a refactor instead of a one-line change.

One provider goes down, so do you

A single upstream error or rate limit lands straight on your users, because there is no second model standing by to take the request.

Rate limits you cannot route around

Traffic sits on one account's quota, so a busy hour throttles everyone at once, with no second key or region to spread it across.

The same answer paid for twice

Identical prompts go upstream again and again, and you pay full price and full latency for a response you already had minutes ago.

Spend you only see on the invoice

Nothing warns you as the bill climbs and nothing stops a request once it passes the cap, so a runaway loop is a month-end surprise.

Every provider in its own dashboard

Usage lives in one console per provider, so there is no single view of a request and no way to split cost by customer or feature.

Start routing with one request.

Point the SDK you already use at one endpoint and switch providers with a model slug, or keep a native SDK on a passthrough URL.

Learn more
main.py
from openai import OpenAI
client = OpenAI(
base_url="https://api.respan.ai/api/",
api_key="YOUR_RESPAN_API_KEY",
)
response = client.chat.completions.create(
model="claude-opus-4-8",
messages=[{"role": "user", "content": "Hello!"}],
extra_body={
"fallback_models": ["gpt-5.4", "gemini-3-flash"],
"cache_enabled": True,
"customer_identifier": "user_123",
"metadata": {"feature": "chatbot", "env": "prod"},
}
)

The AI observability platform behind 80 trillion+ tokens.

Loved by world-class founders, engineers, and product teams.

“Imagine jumping to a log immediately after every LLM call. This is the dream for debugging.”

Daniel Wolf

Product Lead, AlphaSense

“We scaled from 5M to 500M+ monthly API calls quickly. Respan gave us the debugging layer to resolve production issues 10x faster.”

Zexia Zhang

CTO, Retell AI

“Respan legit has some of the best UX/DX I’ve ever seen in my life. I truly don’t think I’ve ever integrated a product that was as easy.”

Rahul Behal

Co-founder, Gumloop

“This one felt pretty nice.”

Fabian Hedin

CTO, Lovable

“Such a no brainer choice over LangSmith or anything else and super easy to set up.”

Andy Wang

CEO, Finta

“Respan has been key in helping us scale to trillions of tokens reliably with real-time observability.”

Deshraj Yadav

CTO, Mem0

“Great product - really love the metrics dashboard.”

Esha Dinne

CTO, Giga

Certified where it counts.

Built to meet the security and privacy standards that enterprise and healthcare teams require.

ISO 27001

The internationally recognized standard for information security management.

SOC 2

Secure, compliant management of your data across all of our systems.

GDPR

Operated under GDPR, the world's strictest standard for data privacy.

HIPAA

HIPAA compliant, with a BAA available for healthcare teams.

Works with your entire stack

Use Respan with your favorite frameworks and tools.

AnthropicAI21 LabsxAIVercel AI SDK
LangChainOpenRouterAssemblyAICursor
LiteLLMGroqBasetenMem0
CohereCogneeLlamaIndexFireworks
DeepSeekLinkupHaystackTogether AI
PerplexityInference.netPostHogRubyLLM
SlackMastraAzure OpenAIMistral
AWS BedrockMoonshotHyperspellBAML
ModaInstructorGoogle GeminiParasail
ReductoZapierAgnoNebius
OpenAINovita AIReplicateSuperagent

Built for AI agents.
Break less.
Ship more.