Agentic coding research
Evaluate an open-weight reasoning model in coding harnesses and tool-using agents with full control over prompts, runtime, and checkpoints.
Independent tool overview
Inkling-Small is Thinking Machines Lab's open-weight multimodal reasoning model for coding, agents, chat, retrieval, and text analysis. It accepts text, images, and audio and generates text, supports controllable reasoning effort, and exposes 276B total parameters while activating roughly 12B per token. The Apache 2.0 weights can be self-hosted or fine-tuned, while Tinker offers managed training and beta serverless inference. Despite the name, the full model is a very large deployment: 'Small' means smaller than the 975B-parameter Inkling, not laptop-sized.
Visit the official Inkling-Small site ↗
Overview
Thinking Machines released the final Inkling-Small weights on July 30, 2026 after previewing the model alongside Inkling. It is a 42-layer decoder-only Mixture-of-Experts transformer with 276B total parameters, 12B active parameters per token, hybrid local and global attention, and controllable reasoning effort.
The model natively processes text, images, and audio in one decoder and returns text. Thinking Machines lists a context window of up to one million tokens for the weights, while Tinker's managed training variants currently expose 64K or 256K contexts and its beta inference endpoint uses 256K. Product limits therefore depend on the serving path, not only the theoretical model maximum.
The full weights are available in BF16 and NVFP4 under Apache 2.0, with documented deployment paths through Transformers, vLLM, SGLang, TokenSpeed, Unsloth, and community quantizations. Open weights allow inspection, fine-tuning, and self-hosting, but do not make the model cheap to run: all 276B parameters must still be stored even though only a fraction are active for each token.
Thinking Machines reports strong reasoning, coding, tool-use, instruction-following, vision, and audio results, including 80.2% on SWE-bench Verified and 31.6% on text-only Humanity's Last Exam at its stated evaluation settings. Those numbers are useful screening evidence, not a substitute for workload-specific testing; several comparisons combine provider-reported results and internal harnesses.
The model card explicitly warns about hallucinations, imperfect instruction following, long-conversation degradation, uneven language and demographic performance, and weak factual recall relative to some alternatives. Production systems should add retrieval, validation, moderation, least-privilege tools, monitoring, and human review for consequential outputs.
Use cases
The strongest fit depends on the job you need the product to complete, not the size of its feature list.
Evaluate an open-weight reasoning model in coding harnesses and tool-using agents with full control over prompts, runtime, and checkpoints.
Build systems that combine text with image or audio understanding while keeping output in a conventional text interface.
Customize an Apache 2.0 checkpoint locally or through Tinker for domain behavior, graders, synthetic data, or specialized agents.
Operate the weights in a chosen environment when a hosted closed model does not meet governance or customization requirements.
Sweep the model's thinking-effort setting to measure the latency, token, and quality tradeoff for a defined workload.
Use a large sparse model when the organization already has the GPU capacity, serving expertise, observability, and safety controls to run it well.
Capabilities
Routes each token to six of 256 experts plus two shared experts, activating about 12B parameters per token rather than the full parameter count.
Processes text, pixel-based images, and 16kHz WAV audio jointly and returns text responses.
Lets applications vary inference effort to trade additional reasoning tokens and cost for potential performance gains.
The released model supports up to one million tokens, although managed Tinker endpoints currently publish smaller 64K and 256K configurations.
Publishes BF16 and NVFP4 checkpoints under Apache 2.0 for research, modification, fine-tuning, and compatible commercial use.
Official guidance points to Transformers, vLLM, SGLang, TokenSpeed, Unsloth, and available quantizations.
The model was trained and evaluated for agentic coding, function use, multi-step instructions, and general agent workflows.
Managed Tinker workflows support sampling, supervised fine-tuning, reinforcement learning, adapter export, and variable effort.
Provides an easier hosted interface for trying text, image, and audio conversations without deploying the checkpoint.
Documents architecture, training-data categories, evaluations, safety testing, intended uses, limitations, and deployment guidance.
Process
Step 1
Specify modalities, context size, latency, throughput, tool access, accuracy target, data sensitivity, and the cost of a wrong answer.
Step 2
Compare self-hosting, a third-party provider, Tinker Playground, Tinker training, and beta Tinker inference against the required reliability and control.
Step 3
Confirm Apache 2.0 obligations and the current Thinking Machines Model Acceptable Use Policy for the intended product, users, and jurisdiction.
Step 4
Estimate weight storage, GPU memory, quantization, routing overhead, context cache, concurrency, network transfer, and operations; do not size infrastructure from the 12B active count alone.
Step 5
Test real prompts, languages, images, audio, long context, factuality, refusal behavior, tool calls, structured outputs, latency, and total cost.
Step 6
Compare the same test set with smaller open models and hosted alternatives before accepting provider benchmark results as relevant to the use case.
Step 7
Sweep effort levels and output limits to find the smallest reasoning budget that meets the quality target without uncontrolled token growth.
Step 8
Use current retrieval sources, schema validation, deterministic business rules, citations, and independent checks for facts or tool arguments.
Step 9
Give tools least privilege, validate every argument outside the model, isolate untrusted content, and require human approval for consequential actions.
Step 10
Treat uploaded files as untrusted, enforce type and size limits, scan content, strip unnecessary metadata, and guard against instructions embedded in images, audio, or documents.
Step 11
Log privacy-safe traces, model and infrastructure cost, response quality, refusal and escalation rates, tool failures, and human corrections.
Step 12
Run the evaluation suite when changing checkpoints, quantization, serving software, prompts, tools, context length, fine-tunes, or safety layers.
Cost
The model weights are downloadable without a model license fee, but self-hosting still carries substantial compute, storage, and operations costs. Tinker publishes per-million-token training rates and a separate beta serverless inference price. Its Inkling-Small training rates were under a limited-time 50% discount when checked, so the crossed-out standard rates are also included below and buyers should verify current billing before a run.
$0 model license fee
Download Apache 2.0 BF16 or NVFP4 weights and operate them on your own or rented infrastructure.
Promo: $0.58 prefill / $1.44 sample / $1.73 train per 1M tokens
Managed 64K-context training access during the published limited-time 50% discount.
Promo: $1.16 prefill / $2.89 sample / $3.47 train per 1M tokens
Managed longer-context training during the published limited-time 50% discount.
$0.30 input / $1.20 output per 1M tokens
A 256K-context NVFP4 hosted endpoint for Inkling-Small.
Pricing checked . Check current pricing at the source ↗
Assessment
Compare
The right alternative depends on the specific output, workflow, controls and budget your project requires.
Consumer
A larger open-weight MoE alternative with strong agentic and vision positioning for teams comparing frontier-scale customizable models.
Explore Kimi K2.6 →Coding
A more coding-focused open-weight model for teams that prioritize agentic software tasks over audio capability.
Explore Qwen3-Coder-Next →Consumer
Google's open-weight family offers multiple sizes for teams seeking a broader deployment-footprint range.
Explore Gemma 4 →Business Operations
A widely deployed model and hosted assistant ecosystem for teams comparing cost, reasoning, and self-hosted options.
Explore DeepSeek →Coding
A local-model runtime rather than a model, useful when the main priority is easy operation of smaller compatible checkpoints.
Explore Ollama →Questions
Inkling-Small is Thinking Machines Lab's open-weight multimodal reasoning model. It accepts text, images, and audio, produces text, supports tool use and variable reasoning effort, and can be self-hosted or customized through Tinker.
Its model weights are released under the permissive Apache 2.0 license, so 'open-weight' is the most precise description. The provider also publishes a Model Acceptable Use Policy that users and deployers must follow.
It has 276B total parameters and activates about 12B per token through sparse Mixture-of-Experts routing. It is one quarter of the total parameter count of the larger Inkling model, but it is still a very large checkpoint.
The official full-precision and NVFP4 checkpoints are designed for substantial accelerator infrastructure. Community quantizations may broaden hardware options, but speed, memory use, context length, multimodal support, and quality should be tested rather than inferred from the 12B active count.
It accepts UTF-8 text, pixel-based images, and 16kHz WAV audio and generates UTF-8 text. The model card recommends image dimensions from 40 to 4096 pixels and audio clips ideally under two minutes.
The released model is described as supporting up to a one-million-token context. Current Tinker training variants expose 64K or 256K, and beta Tinker inference publishes 256K, so verify the limit for the exact runtime.
The weights have no model license fee, but self-hosting compute and operations can be substantial. On August 31, 2026, Tinker listed discounted training rates and beta hosted inference at $0.30 per million input tokens, $0.06 cached input, and $1.20 per million output tokens.
Thinking Machines labels serverless inference beta and says it does not recommend the service for intensive production use yet. Teams with production volume or latency needs are directed to a waitlist.
Thinking Machines reports 80.2% on SWE-bench Verified, 55.9% on SWE-bench Pro public, and 64.7% on Terminal-Bench 2.1 using the stated harnesses and settings. Run a private repository evaluation because benchmark conditions, tool access, contamination controls, latency, and task mix can differ from production.
It exceeds the larger model on some published reasoning, coding, and instruction-following evaluations while using less active compute, but Inkling retains stronger knowledge coverage and factuality on the provider's published results. Neither is uniformly better.
Yes. The Apache 2.0 weights can be customized with compatible infrastructure, and Thinking Machines offers managed supervised and reinforcement-learning workflows through Tinker.
Use application-layer moderation, retrieval and fact checks, least-privilege tools, deterministic argument validation, rate limits, privacy-aware logging, adversarial tests, human approval for impactful actions, and a kill switch. Do not rely on model refusals alone.
Bottom line
Inkling-Small is an attractive open-weight candidate for teams that need strong reasoning, agentic coding, and native image or audio understanding with the freedom to customize the model. Its main trap is the name: 12B active parameters improve sparse inference economics, but a 276B checkpoint is still infrastructure-heavy. Shortlist it only after measuring the exact serving footprint, factuality, safety, latency, and cost against smaller open models and stable hosted APIs on your own workload.
Visit Inkling-Small website ↗
Get access to all our AI courses, hundreds of real-world AI use cases, live expert-led workshops, an exclusive network of AI early adopters, and more.
Get unlimited access to all of our current & upcoming industry-specific AI courses for the duration of your subscription.
To keep up with the rapid pace of AI, our team publishes AI implementation guides daily. Our library contains 300+ practical use cases to automate real-world work.
Join weekly, live, interactive sessions with industry leaders who are at the forefront of AI for hands-on implementation guidance and exclusive insights.
Network with an exclusive community of AI-first professionals who are working smarter with AI. Learn how early adopters are using AI in their work and businesses.