Subconscious

Excellent speed, cost, and accuracy on tasks that need 200k+ tokens.

Founded
2025
Example models
GLM 5.3, DeepSeek V4.1 Flash

By The Subconscious Team · Updated

What is Subconscious?

Subconscious is an MIT CSAIL spinout in Kendall Square that builds inference for long-horizon agents, the workloads where a single trace runs past 200K tokens and often into the millions. Its runtime drops in as a replacement for vLLM or SGLang. Instead of rereading an ever-growing context on every step, it prunes the KV cache and preserves suffix state, and Subconscious co-designs the runtime with post-trained model variants it calls Marathon. Against open models on standard inference, Subconscious delivers 2x faster task completion, delivers a 5M+ effective context window, cuts cost 50% and up to 80%, and scores neutral to 10% better on agentic benchmarks.

That design changes the bill. Subconscious charges for tokens its system actually processes after compression, not tokens sent, so a request that sends 1M tokens might bill for 200K. The managed API serves GLM 5.3 and DeepSeek V4.1 Flash, and dedicated or on-prem deployments can run nearly any open model. It speaks the OpenAI and Anthropic SDK formats and plugs straight into Claude Code, Codex, Cursor, GitHub Copilot and OpenCode. Subconscious records no prompts or inputs, only usage data.

Subconscious pros, cons and use cases

Upsides

  • Speed, cost and accuracy that improve as context grows past 200K tokens, where most hosts get slower and pricier.
  • Billing on processed tokens rewards the long, cache-heavy traces coding agents produce.

Core use cases

  • Coding agents working over 200k tokens.
  • Research, review and multi-step enterprise agents.
  • Agentic user-facing products across domains.

Downsides

  • A focused catalog of a few open models on the managed API.
  • Short, single-turn requests see little of the advantage, since the gains come from long traces.

Subconscious alternatives compared

Pick any row for the full head-to-head.

ProviderModel accessFlagship modelsSpeedPriceCustomizationDeploymentLong contextCompare
SubconsciousOpen weightsGLM 5.3, DeepSeek V4.1 Flash2x faster task completion50–80% lower cost; billed on processed tokensMarathon post-trained variantsManaged API, dedicated, on-prem5M+ effective context
OpenAIClosed, plus open gpt-ossGPT-6 Astra, GPT-5.6 Sol, Terra, LunaFast mode: up to 2.5x at 2x price$0.20–$10 in, $1.20–$50 out per 1MN/AAPI, Azure OpenAI, Bedrock1.05M; 2x input past 272KCompare
AnthropicClosedClaude Fable 5.1, Opus, Sonnet, Haiku 4.5Fable is the slowest tier$1–$10 in, $5–$50 out per 1MN/AAPI, Bedrock, Vertex AI, Microsoft Foundry1M, no surcharge past 200KCompare
Google Vertex AIClosed and open, 200+ modelsGemini 3.8 Flash, Claude, GemmaFlash tier built for low latencyGemini 3.8 Flash $0.75 in, $3.75 outCustom training on GPUs or TPUsManaged on Google Cloud1M on Gemini 3.8 FlashCompare
Amazon BedrockClosed and open, 100+ modelsClaude, GPT-6 Astra, Nova, DeepSeekLatency-optimized option on some models~20–35% above direct; Claude at parityFine-tuning, Custom Model ImportManaged on AWS, AgentCoreVaries by modelCompare
Together AIOpen weightsKimi K3, DeepSeek V4, GLM 5.2, Qwen 3.80.99s TTFT on DeepSeek V4 ProParity with Fireworks and BasetenLoRA and full SFT; RL in betaServerless, dedicated, GPU clusters512K on DeepSeek V4 ProCompare
Fireworks AIOpen weightsDeepSeek V4 Pro, Kimi K3167–174 tok/s on DeepSeek V4 ProFine-tunes served at base priceSFT, DPO, RFT; Training APIServerless, dedicated GPUsFull 1M on DeepSeek V4 ProCompare
BasetenOpen weights, 13 curatedGLM 5.2, DeepSeek V4, Kimi K3, gpt-oss 120B0.49s TTFT, lowest measuredH100 about $6.50/hr dedicatedDeploy any model with TrussModel APIs, dedicated, self-hostVaries by modelCompare
GroqOpen weightsGPT-OSS 120B, Qwen 3.6 27B500–1,000 tok/sNear the floor on small modelsNo fine-tuned model hostingGroqCloud APIAround 131K maxCompare
CerebrasOpen weightsGPT-OSS 120B, Gemma 4 31B~3,000 tok/s on GPT-OSS 120B$0.35 in, $0.75 out (GPT-OSS 120B)UnknownShared API, dedicated, partnersUnknownCompare
DeepInfraOpen weightsDeepSeek V4 Flash, Llama 3.1 8B~33 tok/s on DeepSeek V4 Pro (FP4)From $0.02 per 1MNo managed fine-tuningShared API, no contracts66K on FP4 DeepSeek V4 ProCompare
ModalBring your own weightsNone hosted~1s container bootPer second; H100 $3.95/hr listRun any training codeServerless GPU containersDepends on the model you deployCompare
xAIClosedGrok 4.6, Grok 4.20, grok-build~54 tok/s on Grok 4.6$2 in, $6 out (Grok 4.6); 2x past 200KUnknownFirst-party API500K (4.6), 1M (4.20, 4.3)Compare
DeepSeekOpen weights (MIT)DeepSeek V4.1 Flash, V4 Pro~35 tok/s on V4 ProOff-peak hours at half priceOpen weights to fine-tuneFirst-party API, Hugging Face weights1M, 384K max outputCompare
Moonshot AIOpen weights, custom licenseKimi K3, Kimi K2.6~33 tok/s on Kimi K3$3 in, $15 out (Kimi K3)Open weights to fine-tuneAPI, Kimi Code, OpenRouter1MCompare
Z.aiOpen weights (MIT)GLM-5.3, GLM-5.3-Flash~80 tok/s on GLM-5.3$1.40 in, $4.40 out (GLM-5.3); free Flash tierOpen weights, no license limitsAPI, GLM Coding Plan1M (GLM-5.3)Compare
Alibaba CloudClosed Max; open smaller QwenQwen 3.8-Max, Qwen 3.7-Max~40 tok/s on Qwen 3.8-Max$2 in, $6 out internationalNo fine-tuning on MaxModel Studio on Alibaba Cloud1M (Qwen 3.8-Max)Compare
MetaClosed API; open Muse GlimmerMuse Spark 1.3, Muse Glimmer~145–233 tok/s on Muse Spark 1.3$1.25 in, $4.25 out; Contributor tier cheaperOpen Muse Glimmer weights to fine-tuneMeta Model API (preview)1MCompare
SambaNovaOpen weightsMiniMax M2.7, GPT-OSS 120B, DeepSeek~820 tok/s on MiniMax M2.7 (SN50)$0.22 in, $0.59 out (GPT-OSS 120B)UnknownSambaCloud, racks for neocloudsUp to 192K (MiniMax M2.7)Compare
NebiusOpen weights, 60+ modelsDeepSeek, Qwen, GLM, Kimi, GPT-OSSAmong top hosts on throughputFrom $0.06 per 1M inputServe uploaded fine-tunesToken Factory, dedicated, raw GPUsVaries by modelCompare
falHosted media modelsFLUX, Kling, SeedreamCold starts on less popular endpointsPer image, per video second, GPU timeLoRA training endpointsHosted API, serverless GPUsNot applicableCompare
Novita AIOpen weightsDeepSeek V4 Pro, Gemma 4~36 tok/s on DeepSeek V4 ProFrom $0.02 per 1M; batch 50% offHot-swappable LoRA adaptersServerless, GPU cloud, dedicatedFull 1M on DeepSeek V4 ProCompare
ParasailAny Hugging Face modelGTE-Qwen2, Qwen3-VL-8B-Instruct600ms p99 real-time budgetPer-parameter rates; batch 50% offPrivate Hugging Face reposServerless, elastic, dedicated, batchVaries by modelCompare
Inference.netOpen, closed and customCustomer fine-tunesBatch windows of 24h to 7 daysDiscounted spare GPU capacityDistill traces into custom modelsBatch API, gateway, dedicated GPUsVaries by modelCompare
GMI CloudOpen and third-party modelsGLM-4.7-Flash, Google VeoNear bare-metal performance$0.07 in, $0.40 out (GLM-4.7-Flash)UnknownShared, autoscaling, reserved GPUsVaries by modelCompare
Sail ResearchOpen weightsKimi K2.6, GLM-5, GPT-OSS 120BMinutes per turn by design30–80% off by completion windowCustomer LoRA fine-tunesAPI plus SailboxesVaries by modelCompare
MorphSpecialist modelsmorph-v3-fast, morph-v3-large10,500+ tok/s Fast Apply~40% fewer tokens than full rewritesFine-tuning offeredOpenAI-compatible APIUnknownCompare
RelaceSpecialist modelsrelace-apply-3, agentic search~10,000 tok/s apply3x+ cheaper than full rewritesUnknownHosted API or self-hosted128K maxCompare
TypeSafe AIDecision modelsJev, jev-1.13~100ms per callA fraction of an LLM callUnknownEarly-access APIUnknownCompare
StepFunOpen (Apache 2.0) and API modelsStep 3.7 Flash, Step3~128 tok/s on Step 3.7 Flash$0.20 in, $1.15 out (Step 3.7 Flash)Open weights to fine-tuneFirst-party API, OpenRouter256KCompare
RunwareHosted media modelsSeedance 2.5, Qwen-Image-3.0UnknownImages from fractions of a centFine-tuned diffusion checkpointsUnified API, raw GPUsNot applicableCompare
StreamLakeProprietary coding modelsKAT-Coder-Pro V2.5, KAT-Coder-AirUnknownPer token or KwaiKAT Coding PlanUnknownMaaS API, bare metalUnknownCompare
WaferOpen weightsQwen 3.5 397B Turbo, GLM 5.1 Turbo2–2.8x vs stock vLLM or SGLangWafer Pass from $10 a weekAgent-tuned dedicated deploymentsServerless pass, dedicatedVaries by modelCompare
RunInfraOpen weightsNemotron 3.5 Lightning 30B, Qwen 3.8 27BCold starts under 2sCoding plans from $10 a monthUploads up to 50 GB; auto-quantizationModel APIs, agent-built endpointsVaries by modelCompare
Particle.AIOpen weightsDeepSeek V4.1 Flash, GLM 5.3 Flash~157 tok/s on DeepSeek V4.1 Flash$0.10 in, $0.40 out (GLM 5.3 Flash)UnknownVia Vercel AI Gateway1MCompare

Frequently asked questions

What is Subconscious?

Subconscious is an MIT CSAIL spinout in Kendall Square that builds inference for long-horizon agents, the workloads where a single trace runs past 200K tokens and often into the millions. Its runtime drops in as a replacement for vLLM or SGLang. Instead of rereading an ever-growing context on every step, it prunes the KV cache and preserves suffix state, and Subconscious co-designs the runtime with post-trained model variants it calls Marathon. Against open models on standard inference, Subconscious delivers 2x faster task completion, delivers a 5M+ effective context window, cuts cost 50% and up to 80%, and scores neutral to 10% better on agentic benchmarks.

What is Subconscious best for?

Coding agents working over 200k tokens; Research, review and multi-step enterprise agents; Agentic user-facing products across domains.

How much does Subconscious cost?

Subconscious pricing at a glance: 50–80% lower cost; billed on processed tokens. Rates change often, so check Subconscious's pricing page before committing.

How much context does Subconscious support?

Subconscious's long-context support: 5M+ effective context.

What are the downsides of Subconscious?

A focused catalog of a few open models on the managed API; Short, single-turn requests see little of the advantage, since the gains come from long traces.

What are the best alternatives to Subconscious?

Common alternatives include OpenAI, Anthropic, Google Vertex AI, Amazon Bedrock, Together AI. Each has a head-to-head comparison with Subconscious on this site.

Sources: Subconscious. Pricing and model lineups change often; figures are a snapshot.