tessera-langchain

Drop-in cost optimization for LangChain ChatModels. One line of config in your existing ChatOpenAI / ChatAnthropic / ChatMistralAI / ChatGroq / ChatCohere constructor routes your traffic through the Tessera proxy — auto-route, exact + provider-prompt-cache hits, per-role compression, output-length ceiling, batch arbitrage. Free Sandbox tier: 60M tokens/month, no card. Paid tiers: flat monthly subscription by token volume, keep 100% of savings.

Companion package to tessera-llm-proxy — same proxy, LangChain-shaped API.

Install

pip install tessera-langchain

Quickstart

from langchain_openai import ChatOpenAI
from tessera_langchain import tessera_openai_config

llm = ChatOpenAI(
    model="gpt-4o",
    openai_api_key="sk-...",                      # your OpenAI key, unchanged
    **tessera_openai_config(api_key="tk_..."),   # one line, routes through Tessera
)

# Existing LangChain code (agents, chains, tools, streaming) runs unchanged.
response = llm.invoke("Summarize a Kubernetes operator architecture in 3 bullets.")

Same pattern for the other providers — tessera_anthropic_config, tessera_mistral_config, tessera_groq_config, tessera_cohere_config.

Or wrap an existing instance:

from tessera_langchain import wrap_openai

llm = wrap_openai(my_existing_ChatOpenAI, tessera_api_key="tk_...")

Free key

Get a free API key (60M tokens/mo, no card) at tesseraai.io/dev — sign-up takes ~30 seconds and returns an instant tk_… key plus magic-link dashboard access.

Documentation

Full README with worked-numbers example ($24k → $9.4k OpenAI bill cut), mechanic table, FAQ, and architecture notes:

→ github.com/tessera-llm/tessera-langchain

Tessera platform:

→ tesseraai.io

License

Apache-2.0. The SDK is open source; the optimization proxy at api.tesseraai.io is closed. Wire format is open; mechanic implementations are not.