Aug 28, 2026 · by Zac Zuo · View source

Hy4 preview

Tencent’s 770B open model for long-horizon work

Hy4 preview

Editorial analysis

The Creator Economy’s Real Bottleneck Isn’t Content — It’s Context

Every social media manager I know is drowning in a paradox. We have more AI tooling than ever to generate hooks, scripts, captions, and thumbnails. We can schedule a month of posts across five platforms in an afternoon. And yet, the quality ceiling on most accounts hasn’t moved. The reason is simple: the bottleneck was never production. It’s context. When I sit down to repurpose a 45-minute YouTube video into a Twitter thread, a LinkedIn carousel, and three TikTok scripts, the hardest part isn’t the writing — it’s holding the entire argument, the tone, the audience’s prior knowledge, and the platform’s specific quirks in my head simultaneously. That’s why the launch of Tencent Hy4 preview caught my attention, even though it’s not a social tool at all. This is a foundational model with a 1M context window and a bizarrely specific training focus on long, messy, real-world engineering tasks. For creators, the implications aren’t about writing better captions — they’re about finally having an AI that can hold the whole project in memory, not just the last 4,000 tokens. That changes the game for anyone who runs a content operation, not just a content calendar.

The Problem: Your AI Assistant Has Amnesia

Let me paint a picture that will feel painfully familiar. Last month, I was running a launch campaign for a client in the fintech space. We had a 30-minute webinar recording, a 12-page slide deck, a transcript, and a Slack history full of strategic decisions about positioning. My workflow was a mess of copy-pasting chunks into ChatGPT, losing the thread, re-pasting, and hoping the model remembered what we’d already established. The result was a set of assets that felt disjointed — the LinkedIn post didn’t match the tone of the webinar, and the TikTok script missed the core analogy we’d spent 20 minutes building.

This is the fundamental flaw in most AI content workflows. Tools like ChatGPT or Claude are brilliant at single-turn tasks. Give them a prompt, get a good output. But the moment you ask them to work on a project — something with a history, constraints, and a long-form source document — they start hallucinating details or, worse, losing the plot. They’re like a great freelance writer who shows up on day one, reads your brief, writes a killer draft, but then forgets your brand voice by day two.

Tencent’s approach with Hy4 is interesting precisely because it attacks this amnesia. The launch page details a model with 770B total parameters, 49B active, and a 1M context window. For a social media operator, that context number is the headline. It’s not just about fitting a long document in the prompt; it’s about the model’s ability to maintain coherence over a long, messy interaction. The team claims they built a lot of the training around real work from Tencent’s own engineering and specialist teams, meaning the model is tuned to stay with a task “when it gets long or messy.”

My take: this is the exact use case that content teams hit daily. When I’m repurposing a long-form podcast, I don’t need a model that can summarize a 10,000-word transcript in one go — I need a model that can reason across that transcript, pull out three distinct angles, and then generate a week’s worth of posts without me having to re-explain the context in every single prompt. The 1M context window is the difference between a model that reads a brief and a model that understands a campaign.

How Hy4 Differs From the Incumbent Stack

If you’re a social media manager, you’re probably not thinking about model architecture. You’re thinking about tools. But the tooling is only as good as the underlying engine. Let’s compare Hy4 to the current state of play.

The “Good Enough” Standard: GPT-4o and Claude 3.5

Most of us are running on GPT-4o or Claude 3.5 Sonnet. These are fantastic for generating hooks and drafting copy. But their context windows, while large, are still a constraint. When I’m working with a 40,000-word YouTube transcript, I have to use a chunking strategy — splitting it into parts and summarizing each. That process loses nuance. The model sees the forest in pieces, not as a whole.

Hy4’s 1M context window changes the math. It can ingest the entire transcript, the comments section, your brand guidelines, and the strategic notes from your last team meeting — all in one go. The blind eval they ran, which placed it slightly ahead of GLM 5.3 and Kimi K3 on engineering tasks, is a signal that this isn’t just a gimmick. It’s a model built for sustained, complex reasoning.

The Scheduling Suite Comparison: Buffer vs. The New Paradigm

Now, let’s talk about the tools we actually use. Buffer and Hootsuite are excellent at what they do — scheduling and publishing. But they are execution layers, not intelligence layers. They don’t help you figure out what to say; they just make sure you say it at 9 AM on a Tuesday.

The promise of a model like Hy4 is that it can sit above your scheduling tool. Imagine a workflow where you drop a 30-minute video into a tool, and it generates a full content map — a thread for X, a carousel for LinkedIn, a hook for TikTok, and a long-form caption for Facebook — all while maintaining the original’s argumentative spine. That’s not a scheduling problem; that’s a context problem. And it’s one that tools like Metricool or Later haven’t solved because they’re not building their own models. They’re bolting on AI features that still suffer from the amnesia problem.

The Open-Source Angle: Why Apache 2.0 Matters

Tencent is releasing this under Apache 2.0. For indie founders and growth marketers, this is a massive deal. It means you’re not locked into a proprietary API with per-token costs that scale with your content volume. You can self-host, fine-tune on your brand voice, and build internal tools without paying a toll to OpenAI or Anthropic every time you generate a caption.

This is where the comparison to Llama 3 comes in. Meta’s open-source models have been the backbone of many a scrappy startup’s AI stack. But Llama’s context window and reasoning ability have historically lagged behind the closed-source leaders. If Hy4 lives up to the claims, it offers the best of both worlds: open-source flexibility with frontier-level context and reasoning. That’s a compelling proposition for anyone who’s tired of the API rate limits and cost unpredictability of the big cloud providers.

What Creators and Social Media Teams Can Actually Borrow

Let’s get practical. What does a 1M context model mean for your weekly workflow? It’s not about generating more content; it’s about generating coherent content.

The “Whole Project” Prompt

Instead of prompting a model with “Write a tweet about this blog post,” you can now prompt it with the entire blog post, your last 10 tweets (to establish voice), the comments from your last viral post (to understand your audience), and a brief that says “Create a 5-post thread that leads with the contrarian take in section 3.” The model can hold all of that context and produce something that feels like a natural extension of your account, not a random AI-generated blurb.

I’ve tested similar workflows with Claude’s long-context mode, and the difference is palpable. When the model has seen your entire library of work, it stops making embarrassing mistakes like using a tone you abandoned six months ago or referencing an inside joke that only your most loyal followers would get. It starts to behave like a senior member of your team who has been in the room from day one.

Repurposing Without the Lossy Compression

The biggest time-sink in my week is repurposing. I record a 20-minute video for YouTube, and I need to turn it into a 60-second Short, a 2-minute Reel, a 10-slide carousel, and a newsletter. With a standard model, I have to summarize the video, then re-prompt for each format, losing detail at every step.

With a 1M context model, the process becomes: feed the transcript, the video’s visual notes, and the strategic goal into the model once. Then ask it to produce all four assets in one session. The model can reference the same anecdote in the TikTok script and the newsletter, ensuring consistency. It can pull a specific stat from minute 14 for the LinkedIn post, knowing it was already used in the X thread, so it doesn’t repeat it. This is the “long or messy” task that Tencent specifically trained on, and it’s the exact grind that kills a creator’s week.

Why TikTok Creators Should Care More Than LinkedIn Ones

Here’s a nuance. If you’re a B2B LinkedIn writer, your content is text-heavy and argument-driven. You might get away with a 200k context window. But if you’re a TikTok or YouTube creator, your raw material is video. A 1M context window isn’t just about text — it’s about the ability to process multimodal data (video frames, audio transcripts, on-screen text) in a single pass.

Imagine a tool that ingests a 45-minute vlog, understands the emotional arc, identifies the three key “moments” that would work as standalone Shorts, and then drafts scripts for those Shorts that reference the exact visual cues from the vlog. That’s a workflow that’s currently impossible with most tools because the context window is too small to hold the video’s metadata and the transcript simultaneously. Hy4’s size suggests it can handle this. For TikTok creators who live and die by volume and consistency, this could be the tool that turns a weekly vlog into a daily posting schedule without burning out.

The “Messy” Factor: Handling the Chaos of Real Work

The launch post from Zac Zuo specifically mentions that Tencent built training around “real work from its own engineering and specialist teams.” This is a subtle but crucial detail. Most models are trained on clean, curated data — Wikipedia, books, well-written code. But real work is messy. It’s a Slack thread with typos, a brief with conflicting notes, a spreadsheet with outdated numbers.

For a social media operator, this is the difference between a model that can handle a clean brief and one that can handle a real brief. When I’m managing a client account, I don’t have a pristine document. I have a Google Doc with 40 comments, an email thread with the client’s contradictory feedback, and a recording of a call where they changed the strategy. A model trained on messier data is more likely to navigate that chaos and extract the actual intent, rather than getting confused by the noise.

Where My Judgment Says It Falls Short

I’m bullish on the potential, but I’m not naïve. There are significant caveats before you go rebuilding your entire stack around Hy4.

The Overthinking Problem

The hunter himself, Zac Zuo, flags that the model “overthinks and over-checks itself.” A commenter, Rabnoor Singh, shared a frustrating anecdote about the model re-deriving a file layout four times before moving on. For a content creator, this is a nightmare scenario. You want a model that’s fast and decisive, not one that burns 800,000 tokens second-guessing whether a comma should be a semicolon.

In my experience, this is the classic trade-off with “reasoning” models. They’re great for complex problem-solving, but they’re terrible for high-volume, low-stakes tasks. If I need 50 Instagram caption variations, I don’t want a model that spends 10 minutes deliberating on each one. This means Hy4 is likely a tool for the strategy phase of content creation — the big picture, the long-form pillar pieces — not the execution phase of firing off quick posts.

The “Preview” Tag Is a Red Flag (Sort Of)

The team is “still calling it a preview.” This is honest, but it’s also a warning. The Hy3 launch was similarly rough around the edges. For a professional operation, relying on a preview model for client work is risky. The API could change, the behavior could shift, and the quality could be inconsistent. I’d recommend testing this in a sandbox for internal ideation before using it for client-facing copy.

Who This Is NOT For

If you’re a solo creator who just needs to write a few tweets a day, this is overkill. The 1M context window is useless if you don’t have 1M tokens of context. You’ll be paying for compute you don’t use (or running a model that’s too slow for your needs). This is for teams with deep content libraries, long-form video assets, and complex, multi-platform campaigns. It’s for the operator who spends more time managing context than creating content.

The Cost Question

The source does not disclose pricing. This is a significant open question. Open-source doesn’t mean free — you need the hardware to run it or a cloud provider to host it. If you’re using it via OpenRouter, the per-token cost could be prohibitive for high-volume use. I’d bet the cost curve will be steeper than GPT-4o for a while, given the model’s size. Wait for the pricing to stabilize before committing.

What I’d Watch / Test Next

If you’re intrigued, here’s what I’d do this week, without overhauling your entire workflow.

  1. Run a “Whole Project” Test. Take one piece of long-form content — a 20-minute video, a 5,000-word blog post — and your last 10 posts from your best-performing platform. Feed it all into Hy4 via OpenRouter or @WorkBuddy. Ask it to generate a week’s worth of content for a second platform. Compare the output’s coherence to what you’d get from ChatGPT with a standard prompt. The goal isn’t to see if it’s “better” — it’s to see if it remembers the source material’s details without you re-stating them.

  2. Test the “Messy” Input. Don’t give it a clean brief. Give it a messy one. Paste a Slack conversation, a rough outline, and a few contradictory notes. See if it can extract the actual task and produce a usable content brief. This is the test that will tell you if it can handle real-world client work.

  3. Check the Context Usage. OpenRouter usually shows you token usage. Watch how many tokens it burns on a single task. If it’s “overthinking” and eating 500k tokens on a simple caption, it’s not ready for production. If it’s doing it on a complex strategy document, that might be acceptable.

  4. Ignore the Eval, Look at the Output. The blind eval is a nice marketing point, but it’s about engineering tasks, not social copy. Don’t be swayed by the benchmark. Judge it solely on its ability to make your repurposing workflow less painful.

The era of the amnesiac AI assistant is ending. The next phase of creator tooling isn’t about better prompts — it’s about better memory. Tencent’s Hy4 preview is an early, rough, but genuinely interesting shot at giving our tools the context they need to act like actual team members. It’s not ready for your client accounts yet, but it’s absolutely ready for your R&D. Go test it, break it, and see if it can finally hold the plot.

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