Mercury 2 is Inception's reasoning diffusion language model. It refines tokens in parallel with tunable reasoning depth, native tool use, and a context window of 128K tokens.
import { streamText } from 'ai'
const result = streamText({ model: 'inception/mercury-2', prompt: 'Why is the sky blue?'})What To Consider When Choosing a Provider
- Configuration: Mercury 2's diffusion architecture generates tokens in parallel rather than sequentially. Latency differs from autoregressive models, so factor that into timeout and streaming configurations for latency-sensitive pipelines.
- Zero Data Retention: AI Gateway does not currently support Zero Data Retention for this model. See the documentation for models that support ZDR.
- Authentication: AI Gateway authenticates requests using an API key or OIDC token. You do not need to manage provider credentials directly.
When to Use Mercury 2
Best For
- Sequential agent loops: Chains of many inference calls need low per-step latency
- Real-time voice backends: Response delay is perceptible to end users
- High-throughput coding assistants: Many simultaneous requests processed concurrently
- Fast structured RAG: Retrieval summarization returned as JSON output
- Token cost optimization: Diffusion-based parallel token refinement reduces per-token inference cost compared to autoregressive models
Consider Alternatives When
- Very long outputs: Tasks push against the cap of 128K tokens
- Domain-specific benchmarks: Evaluation prioritizes specific benchmarks over raw throughput
- Token-by-token streaming: Pipeline assumes autoregressive generation patterns
- Multimodal input required: You need image or audio input alongside text reasoning
Conclusion
Mercury 2 brings a different execution model to production reasoning workloads. Diffusion-based parallel refinement keeps throughput high while preserving tool calling, structured output, and tunable reasoning depth. If inference latency or per-call cost limits how you scale your product, use Mercury 2 on Vercel AI Gateway. Open https://ai-sdk.dev/playground/inception:mercury-2 to try it interactively.
Frequently Asked Questions
What makes Mercury 2 architecturally different from other reasoning models?
It uses diffusion instead of autoregressive generation. Mercury 2 starts with a draft of the full response and refines all token positions simultaneously across iterative steps, rather than generating one token at a time left to right. That follows the same conceptual lineage as image and video diffusion models, applied to language.
How does tunable reasoning depth work in Mercury 2?
You adjust the number of diffusion refinement steps at inference time. Fewer steps yield faster responses; more steps let the model converge on higher-quality answers. You match compute to task difficulty on each request.
What throughput does Mercury 2 achieve compared to autoregressive reasoning models?
Mercury 2 generates faster than autoregressive approaches. Live throughput metrics appear on this page.
Is Mercury 2 compatible with OpenAI client libraries?
Yes. Mercury 2 exposes an OpenAI-compatible API. Route existing codebases that use the OpenAI SDK to Mercury 2 through AI Gateway by swapping the base URL and model identifier.
What context length does Mercury 2 support?
A context window of 128K tokens. That suits long document processing, extended conversation history, and multi-document retrieval tasks.
Does Mercury 2 support structured output for agent orchestration?
Yes. Mercury 2 includes native schema-aligned JSON output and tool use. You can plug it into function-calling orchestration frameworks without extra parsing middleware.
How is Mercury 2 priced?
This page lists the current rates. Multiple providers can serve Mercury 2, so AI Gateway surfaces live pricing rather than a single fixed figure.
