Inkling 256K

Inkling 256K is the extended-context serving option for Thinking Machines Lab's Inkling, its open-weight multimodal mixture-of-experts model.

start building →

compare models

input · usd / 1m tok

$3.74

output · usd / 1m tok

$9.36

context window

262.14ktokens

modalities · in → out

pricing

base api ratesusd per 1m tokens

input: $3.74
output: $9.36
cache read: $0.748

providers

Thinking Machines hosts Inkling 256K. Impossibl routes your request intelligently and handles failover automatically when a provider is down.

Thinking Machines

specifications

takes text and image in, gives text outthinkingmachines/inkling-256k

creatorThinking Machines
model typeText generation
context window262,144 tokens
maximum outputnot published
input
takes text and image in, gives text out
outputtext
tool callingnot verified
releasedjul 15, 2026
endpoint/v1/chat/completions

unknown means the public catalog does not establish that fact. a model's documented capabilities can differ from what a particular api supports. see the model documentation for integration details.

try it · your prompt, this model, live

# responses API
import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["IMPOSSIBL_API_KEY"],
    base_url="https://api.impossibl.com/v1",
)

resp = client.responses.create(
    model="thinkingmachines/inkling-256k",
    input="▌",
)
print(resp.output_text)

edit the prompt, then run

# responses API
import os
from openai import OpenAI

client = OpenAI(
    api_key=os.environ["IMPOSSIBL_API_KEY"],
    base_url="https://api.impossibl.com/v1",
)

resp = client.responses.create(
    model="thinkingmachines/inkling-256k",
    input="▌",
)
print(resp.output_text)

edit the prompt, then run

benchmarks

benchmark results are not available for this model yet.

compare Inkling 256K with other models

frontier labs and open weights, best-ranked firstusd / 1m tok · in / out

anthropic/claude-fable-5-1$10.00 / $50.00compare →
openai/gpt-6-astra$10.00 / $50.00compare →
meta/muse-spark-1.3$1.25 / $4.25compare →
zai/glm-5.3$1.40 / $4.40compare →

impossibl models --all →

frequently asked questions

What is Inkling 256K?

Inkling 256K is the extended-context serving option for Thinking Machines Lab's Inkling, its open-weight multimodal mixture-of-experts model. It runs the same model with a larger context window than the default deployment, for long documents and extended agent sessions.

How much does Inkling 256K cost?

Inkling 256K costs $3.74 per million input tokens and $9.36 per million output tokens through the Impossibl API. Cache reads cost $0.748 per million tokens. All rates are in USD.

view the pricing table ↑

What is the context length of Inkling 256K?

Inkling 256K has a 262,144-token context window through the Impossibl API.

What inputs and outputs does Inkling 256K support?

Inkling 256K accepts text and image as input. Inkling 256K returns text.

How do I use Inkling 256K through an API?

Inkling 256K is available through the Impossibl API. Use thinkingmachines/inkling-256k as the model identifier with /v1/chat/completions. The quickstart explains how to create an API key and send your first request.

follow the api quickstart →

When was Inkling 256K released?

Thinking Machines released Inkling 256K on July 15, 2026.

Creator release announcement ↗

this page describes Inkling 256K as listed by the impossibl public api. prices and availability come from that catalog, refreshed here every five minutes. this is an impossibl offering, not a comparison of independent hosting-provider quotes. model descriptions and release dates, where available, use the creator sources linked under the answers above.

view the source catalog ↗model as markdown ↗report a correction →