The Inference API Built for Agents
Synrouter treats sessions as a first-class primitive. Prompt cache persists across your entire agent loop — so you stop paying full price for tokens you already sent.
100 Agent Turns · Opus-class Model
The Problem
Every agent team builds
the same workarounds
Paying 100% on Repeat
System prompts, tool schemas, conversation history — all billed fresh every turn. 85–95% of your tokens are identical to the last request.
Cache TTL ≠ Session Life
Anthropic's 5-minute cache TTL vs your 2-hour coding session. One coffee break resets the cache — and your costs spike 30%.
Context is Your Burden
State recovery, compression, checkpoints — every agent team writes the same boilerplate. Engineering hours wasted on infrastructure, not product.
The Solution
Session as a
First-Class Citizen
The first inference API where your conversation state lives on the server — not rebuilt each request.
BEFORE — Standard API
AFTER — Synrouter
The Math
The numbers are simple
100-turn Opus session, 50K avg tokens/turn. Only 5% of tokens are new content.
Monthly cost calculator
Estimated using 85% cache hit rate, 50K avg tokens/turn, Opus pricing.
Features
Everything your agent needs.
Nothing it doesn't.
Session Lifecycle Cache
Cache TTL tied to your session — not a fixed clock. No more re-paying for cold starts when Anthropic silently rolls back their TTL.
Auto Context Compression
Before hitting the context window, we summarize old turns using a cheap model — automatically, server-side. Your session keeps running.
Parallel Tool Execution
Your agent requests 3 tools simultaneously? We run them in parallel. Merge and return in one RTT instead of three.
Tiered Model Routing
Summarization → Haiku. Code generation → Opus. Your agent picks the intent; we route to the optimal cost/quality model automatically.
Session Checkpoints
Agent crashed mid-task? Network dropped? Resume from the last checkpoint — not from turn one. Never lose work again.
Full Observability
Per-session cache hit rate, token cost, turn count, compression events. Not just request logs — agent-aware metrics.
Compatibility
Drop-in replacement
for your agent
OpenAI-compatible API. Works with every agent framework you already use.
No code refactoring. No new SDK to learn. Fully compatible with the Anthropic SDK and OpenAI SDK.
Early Access
Join the waiting list.
We're onboarding agent teams first.
Early access members get Pro Tier free for 3 months.
No spam. We'll only email when your spot is ready.