@tessera-llm/vercel-ai
Advanced tools
Drop-in Tessera integration for the Vercel AI SDK. One line of config routes generateText / streamText / generateObject / streamObject through Tessera's auto-route + auto-cache + auto-compress + auto-batch proxy. Compatible with @ai-sdk/openai, @ai-sdk/an
@tessera-llm/vercel-aiDrop-in cost optimization for the Vercel AI SDK. One line of config routes your existing generateText / streamText / generateObject / streamObject calls through the Tessera optimization proxy — auto-route to cheaper-equivalent models, exact + provider-prompt-cache hits, prompt compression with per-stack quality canary, batch arbitrage on async-tolerant calls. Free Sandbox tier: 60M tokens/month, no card. Paid tiers: flat monthly subscription by token volume, keep 100% of savings.
Companion to tessera-sdk (vanilla provider SDKs), tessera-langchain (LangChain integration), tessera-llamaindex (LlamaIndex integration), tessera-mastra (Mastra Agent framework integration), tessera-pydantic-ai (Pydantic AI integration), tessera-crewai (CrewAI multi-agent integration), and tessera-autogen (AutoGen 0.4+ multi-agent integration). Same proxy, same mechanic stack, Vercel AI SDK-shaped API.
import { generateText } from "ai";
import { createOpenAI } from "@ai-sdk/openai";
import { tesseraOpenAIConfig } from "@tessera-llm/vercel-ai";
const openai = createOpenAI({
apiKey: process.env.OPENAI_API_KEY!,
...tesseraOpenAIConfig({ apiKey: process.env.TESSERA_API_KEY! }),
});
const { text } = await generateText({
model: openai("gpt-4o"),
prompt: "Summarize this customer support ticket in 2 sentences.",
});
Three changes in your code: one import, three lines in the constructor call. Your existing generateText / streamText / generateObject calls work unchanged.
Or use the convenience factory (skips the explicit createOpenAI import):
import { generateText } from "ai";
import { tesseraOpenAI } from "@tessera-llm/vercel-ai";
const openai = await tesseraOpenAI({
openaiApiKey: process.env.OPENAI_API_KEY!,
tesseraApiKey: process.env.TESSERA_API_KEY!,
});
const { text } = await generateText({
model: openai("gpt-4o"),
prompt: "Summarize this customer support ticket in 2 sentences.",
});
npm install @tessera-llm/vercel-ai
# Plus whichever provider package you use:
npm install @ai-sdk/openai # or @ai-sdk/anthropic / @ai-sdk/mistral / @ai-sdk/groq / @ai-sdk/cohere
The @ai-sdk/* packages are peer dependencies — install only the providers you actually use. The ai core SDK is whatever version you already have.
Get a free Tessera 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.
| Provider | @ai-sdk package | Tessera config function | Convenience factory |
|---|---|---|---|
| OpenAI | @ai-sdk/openai | tesseraOpenAIConfig | tesseraOpenAI |
| Anthropic | @ai-sdk/anthropic | tesseraAnthropicConfig | tesseraAnthropic |
| Mistral | @ai-sdk/mistral | tesseraMistralConfig | tesseraMistral |
| Groq | @ai-sdk/groq | tesseraGroqConfig | tesseraGroq |
| Cohere | @ai-sdk/cohere | tesseraCohereConfig | tesseraCohere |
Generic dispatcher available too: tesseraConfig("openai", { apiKey: "tk_..." }) — returns the right { baseURL, headers } object regardless of provider. Useful when the provider is parameterized at runtime.
Real customer-support agent on gpt-4o, 5B tokens/month, OpenAI list prices:
| Stage | Cost / mo | Saved |
|---|---|---|
| Baseline — OpenAI direct via Vercel AI SDK | $24,000 | — |
| + Tessera (route, cache, prompt-cache headers, compress, M9 ceiling, batch) | $9,400 | $14,600 |
| Tessera subscription (Growth tier, flat) | $999 | — |
| You net pay | $10,399 | $13,601 / mo saved |
Verify the savings math yourself. Every billable line traces back to two immutable cost figures pinned to a multi-source pricing catalog snapshot captured at request time. Two engineers, three hours, can re-derive any month from raw inputs. Full procedure at tesseraai.io/trust.
Quality canary across the full mechanic stack: mean-score 0.96 (floor 0.95) — 0.95 SLA held all 30 days. Full breakdown: /blog/cut-openai-bill-48-percent-without-quality-regression.
Same mechanic stack as the main tessera-sdk. Each mechanic is opt-in per workload, observable per request, and bypasses when its quality canary drops below the per-stack 0.95 floor.
| Mechanic | What it does | Typical savings |
|---|---|---|
| Auto-route (m1) | Route to a cheaper-equivalent model gated by a daily promptfoo canary on your eval set | 15–35% on routed calls |
| Auto-cache (m2) | sha256 cache on the canonical request body, 7-day TTL, Cloudflare edge KV | 5–40% depending on prompt repetition |
| Auto-compress (m3) | Per-role heuristic compression (system + user toggles independent). Preserves code fences and JSON shapes. | 5–15% on prompt tokens |
| Prompt cache (m6) | Inject provider-native cache headers — OpenAI cached-input (50% off), Anthropic cache_control: ephemeral (90% off cache reads) | 50–90% on cached prefixes |
| Context prune (m7) | Conservative trim on long conversations (system + last 8 turns; TF-IDF rerank on RAG attachments) | 5–25% on multi-turn workloads |
| Output-length ceiling (m9) | Daily compute fits p90 of completion length per workload, injects maxTokens = p90 × 1.3 | 5–15% on completion cost |
| Batch arbitrage (m10) | Route async-tolerant calls to provider Batch APIs (OpenAI Batch + Anthropic Message Batches both 50% off) | 50% on batch-eligible traffic |
| Per-provider circuit breaker | (Reliability primitive, above the mechanics.) Rolling 5xx-rate state machine per upstream — when a provider degrades, auto-route skips its intra-provider alternative mappings until the half-open probe succeeds. | n/a — keeps the savings stack honest |
Existing customers of tessera-sdk and tessera-langchain keep their rate_locked_pct (if any) on this package too — same tk_… key, same billing record.
tessera-langchain and tessera-sdk?Same proxy. Same mechanics. Same billing. The three packages target different code surfaces:
tessera-sdk — patches the underlying provider client constructors (OpenAI, Anthropic, etc.) directly via tessera.activate(key). Use when calling provider SDKs without a framework.tessera-langchain — wires into LangChain ChatModel constructors. Use when you're on LangChain.tessera-vercel-ai (this package) — wires into the Vercel AI SDK provider factories (createOpenAI, createAnthropic, etc.). Use when you're on ai core + @ai-sdk/*.Pick whichever fits your codebase. Side-by-side install is supported — all three resolve to the same proxy and same billing record.
No. The Vercel AI SDK provider object behaves identically — generateText, streamText, generateObject, streamObject all work unchanged. Schema-constrained outputs pass through. Tools pass through (auto-route gates on tool-calling capability). Streaming streams.
Your application gets HTTP errors instead of LLM responses. On the proxy side, a per-provider circuit breaker tracks rolling 5xx rates and skips degraded providers in auto-route decisions. Cross-provider failover (re-routing to a different provider entirely when an upstream is down) is on the roadmap, not shipped yet.
They pass through. Tessera does not aggregate quotas across customers. Your provider rate limits apply normally; the proxy enforces only the Tessera tier limits (30 rpm Free Sandbox, 60 rpm Production by default — higher on request).
No. We log only token counts, cost deltas, mechanics_stack, and provider response status. Prompts and completions are never persisted. Full data handling on tesseraai.io/security.
tesseraOpenAIConfig vs tesseraOpenAI)?The config function returns the kwargs object you spread into createOpenAI(...) — explicit, easy to combine with other settings (organization, custom fetch, etc.). The convenience factory imports createOpenAI for you and pre-merges. Use whichever you find more readable. Both ship in the same package.
Yes. @tessera-llm/vercel-ai is a thin ESM/CJS dual package with no runtime dependencies on its own — same compatibility as the Vercel AI SDK itself.
Open-source SDK ↔ closed-source proxy. This package is a thin client that adds one HTTP hop. The actual mechanic decisions (route, cache, compress, etc.) run inside the Tessera Cloudflare Worker proxy at api.tesseraai.io. The split is intentional: the wire format is open so you can audit what we send; the mechanic implementations are closed because that's the asymmetric IP. See the tessera-sdk README's "Architecture" note for the longer explanation.
Apache-2.0. See LICENSE.
We accept PRs that:
@ai-sdk/* provider package (paste-and-mirror the existing config function shape)examples/ showing a real Vercel AI SDK pipelineWe do not accept PRs that change the proxy's HTTP contract — that lives in the closed-source worker.
Semver. Wire format compatibility committed across minor releases; breaking changes only on major bumps.
See SECURITY.md. Coordinated disclosure address: security@tesseraai.io.
Tessera is the substrate layer for LLM cost optimization, also called the Optimize Layer in our product surface. A thin proxy that sits in your application's request-path, applies a conservative cascade of optimization mechanics, and measures every saved dollar against an audit-immutable baseline. We bill a flat monthly subscription by token volume (Starter $199, Growth $999, Scale $3,999, Enterprise custom); you keep 100% of measured savings. No per-token gateway fee; the category we operate in is "LLM cost optimizer," distinct from per-token AI gateways and observability dashboards.
Where observability tools tell you what you spent and AI gateways re-shape the request without measuring the cost delta, Tessera is the layer that does both, and proves the measured savings line by line. The verified-savings ledger at ledger.tesseraai.io shows every original-vs-actual cost pair, snapshot-pinned to a pricing_catalog version captured at request time. Mid-contract price changes don't retroactively alter past savings. This is the FinOps-friendly model for AI inference: every line of the bill traces to a code-enforced rule.
Operated by Fintechagency OÜ (Tallinn, Estonia, registry code 16638667).
FAQs
Drop-in Tessera integration for the Vercel AI SDK. One line of config routes generateText / streamText / generateObject / streamObject through Tessera's auto-route + auto-cache + auto-compress + auto-batch proxy. Compatible with @ai-sdk/openai, @ai-sdk/an
We found that @tessera-llm/vercel-ai demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
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