The product that defined the category; enterprise tier adds admin, SSO, and data controls.
Who actually builds each part
The L1 page explained the journey of a prompt. This page names names: the specific products, open-source projects, and hardware that perform each step — the machinery behind the magic, from chat window to GPU.
Five tags, four zones
Products are grouped into four zones that mirror the prompt’s journey: the workbench, the control room, the engine room, and the power plant. Every product carries tags for how it is delivered.
Selections are representative, not exhaustive, and reflect broad adoption or technical influence as of August 2026. Inclusion is not endorsement; omission is not criticism. Many products span several zones — they are placed where they do the most work.
Where prompts are born and briefs are built
The user-facing surface and the software that assembles the full dossier — L1 steps 1 and 2: chat clients, agent harnesses, protocols, and memory.
Chat clients & front ends
The window the user types into. Enterprises either adopt the model vendors’ own products or self-host a client for control and branding.
Concepts served: prompt, chat UIAnthropic’s assistant family; Claude Code popularized the terminal-based agent harness.
The distribution play: AI inside the tools enterprises already pay for and govern.
The default self-hosted chat UI; pairs with local or remote model servers.
One UI over many providers — a common enterprise pattern for avoiding lock-in at the surface.
What product teams use to build their own streaming chat experiences.
Agent harnesses & frameworks
The chief of staff: assembles system prompt, tools, memory, and history; runs the tool-call loop. The most contested software layer in the stack.
Concepts served: harness, skills & tools, system promptThe machinery behind Claude Code, offered as a library for building agents.
OpenAI’s framework for tool-using, multi-step agents against its models.
Models an agent as a state machine with retries and checkpoints — a common production default.
Specialist in connecting models to enterprise documents and data sources.
Pre-AI infrastructure now widely used to make long agent runs crash-proof and resumable.
The emerging USB-C of tools: one standard way for agents to discover and call external systems.
Memory & retrieval
What the harness pulls into the dossier: conversation memory and document retrieval, usually backed by a vector database.
Concepts served: memory, context assemblyRemembers user facts across sessions so the dossier starts pre-filled.
Builds a temporal knowledge graph from conversations and business data.
Adds vector search to the database enterprises already run — the quiet incumbent.
Dedicated vector search engine; Rust-based, popular for self-hosted retrieval.
The pure-play managed vector DB; buy instead of operate.
Open-source vector DB with hybrid search, strong in European enterprise deployments.
Admit, route, watch
Everything that sits between the harness and the model — L1 steps 3, 6, and 7: gateways that check and route, streaming infrastructure, and the observability layer that records it all.
AI gateways & routers
The front desk: one endpoint for many models, with identity, budgets, fallbacks, and logging. The enterprise control point of the L0 landscape.
Concepts served: API gateway, routerOne OpenAI-compatible interface over 100+ providers; the default open-source gateway.
The incumbent API gateway extending its policy machinery to tokens and models.
Gateway plus guardrails, caching, and analytics aimed at production AI teams.
Lives on Cloudflare’s network, close to users; caching and rate-limiting included.
One API key for nearly every model on the market, priced per token with a markup.
Where Microsoft shops extend existing API governance over AI endpoints.
Observability & evaluation
The paper trail: traces of every request, cost metering, quality scoring, and prompt regression testing.
Concepts served: observability, evidenceThe open-source default for tracing, scoring, and prompt management; self-hostable.
Deep integration with the LangChain/LangGraph ecosystem; strong evaluation tooling.
Open-source observability with strong RAG and drift analysis; built on OpenTelemetry.
Treats evaluation as the core engineering loop; popular with product teams shipping fast.
Brings AI traces into the dashboards enterprises already watch.
The shared standard for what a “span” means in AI systems — the reason tools interoperate.
Models and the software that runs them
L1 steps 4 and 5: the brains themselves (rented frontier or owned open weights), the inference servers that make them fast, and the KV-cache machinery that keeps the economics sane.
Frontier model APIs
The strongest models, consumed per token. Families, not versions — version numbers age in months; the vendors do not.
Concepts served: LLM (frontier)Market default; its API shape became the industry’s de facto interface.
Strong enterprise reputation for coding, long context, and safety posture.
Multimodal from the ground up, bundled with Google’s cloud and TPU hardware.
Challenger scaling aggressively on its own colossal GPU clusters.
Frontier-quality models with an open-weights heritage; the sovereignty option for Europe.
Open-weight models
Downloadable weights you run yourself — the foundation of the self-hosted option from L1.
Concepts served: LLM (self-hosted)The family that made open weights a serious enterprise option; enormous ecosystem.
Prolific family across sizes; often the benchmark leader among open weights.
Proved frontier-adjacent reasoning at a fraction of assumed cost; reset price expectations.
Google’s open line, distilled from Gemini research; strong at small sizes.
Compact, efficient weights with permissive licensing — a self-hosting favorite.
Inference servers
The factory floor managers: batching, scheduling, and GPU-memory juggling that turn a model file into a fast, cheap API.
Concepts served: inference server, decodePagedAttention made GPU memory manageable; the engine under most self-hosted serving.
Co-designed with its RadixAttention cache sharing; a favorite for structured agent workloads.
Squeezes maximum throughput from NVIDIA hardware; the vendor’s own path.
Splits reading (prefill) and writing (decode) onto different GPUs at datacenter scale.
Runs models on a laptop in one command; where most developers first touch local AI.
The earlier generation of open serving; still deployed, now largely legacy beside vLLM.
KV-cache & memory tier
The bookmark, productized: software that stores, shares, and moves cached context so nothing is read twice.
Concepts served: KV-cache, prefix cachingSpills cache from GPU memory to CPU, disk, and network so prefixes survive across requests.
A distributed KV-cache pool proven at Kimi’s production scale; now open source.
NVIDIA’s plumbing for moving cache between GPUs and storage at wire speed.
The physical substrate: scarce on-GPU memory where the cache lives. Its supply is an industry bottleneck.
Managed serving platforms
“Self-hosting without the servers”: open weights run for you, billed per token or per GPU-hour.
Concepts served: LLM (self-hosted, minus the pain)Frontier and open models behind AWS identity, billing, and compliance.
Model catalog plus agent tooling inside the Azure enterprise estate.
Gemini plus third-party models on Google’s TPU/GPU infrastructure.
Fast serving of open weights; also rents dedicated GPU clusters.
Performance-obsessed inference platform; compound-AI positioning.
Production serving with your own autoscaling GPU capacity, minus the platform team.
Chips, clouds, and the wires between
The physical layer everything else rents from: accelerators, the clouds and neoclouds that host them, the networks that bind them, and the orchestration that keeps them busy.
Accelerators
The chips that read and write tokens. One vendor dominates; the rest exist because supply and price demand alternatives.
Concepts served: GPU clusterThe incumbent: hardware plus the CUDA software moat. Scarcity of its top chips shapes the market.
The credible second source; wins on memory capacity per dollar.
Google’s in-house chips; available only through Google Cloud.
Amazon’s cost lever: its own chips for training and inference inside AWS.
Purpose-built for decode speed; the extreme end of “tokens per second.”
Dinner-plate-sized chips that keep entire models on one piece of silicon.
Clouds & neoclouds
Who you rent the chips from: the hyperscalers, plus a new class of GPU-only “neoclouds” born from the shortage.
Concepts served: GPU cluster, hostingLargest cloud estate; GPU capacity plus its own silicon and Bedrock platform.
OpenAI’s home cloud; enterprise agreements make it the default for many corporates.
TPUs plus GPUs; the most vertically integrated AI cloud.
The breakout GPU-specialist cloud; prices in speed of access to the newest chips.
GPU clouds and clusters aimed at AI-native teams and labs.
European-rooted AI cloud building large NVIDIA capacity.
Aggressive GPU capacity deals made it a surprise force in AI infrastructure.
Networking & orchestration
Invisible until it breaks: the fabrics that let thousands of GPUs act as one machine, and the schedulers that place the work.
Concepts served: cluster fabric, schedulingThe high-speed fabric inside a rack of NVIDIA GPUs — why a pod behaves like one giant chip.
The datacenter-scale fabric between racks; Ethernet-based Spectrum-X is the challenger to classic InfiniBand.
The default scheduler of the cloud era, extended to GPUs; where inference fleets live.
The framework behind large-scale training and increasingly behind multi-node inference.
The supercomputing scheduler; still standard on big training clusters.
One request, real products, end to end
Two concrete stacks a company might actually run — one renting the frontier, one owning open weights. Every L1 step, with a name on it.
Names change fast. Positions change slowly.
Individual products will merge, rebrand, and die between editions of this page. What persists is the shape of the machine: a workbench, a control room, an engine room, and a power plant — with an open-source option at every position. Evaluate vendors by the position they occupy, not the logo they wear.