Compare

Most of the field improves the prompt.

Nearly everything train.cloud gets compared to operates on context: a better prompt, a bigger retrieval window, a smarter scaffold. All of it is thrown away when the session ends. train.cloud operates on weights — which is a different kind of thing, and the reason the matrix below mostly explains itself.

The columns are categories, not enemies — train.cloud pairs fine with an eval cloud, and it drives the harness you already use.
Capabilitytrain.cloudthe loopCapture & eval cloudsLangSmith · Braintrust · WeaveTuning platformsTogether · Fireworks · managed FTRL toolkitsprime-rl · verifiers · verlAgent harnessesClaude Code · Codex · Cursor
Kind of thingA loop: capture → mine → train → deploy → switchA dashboard over runs you already madeA service you hand a finished dataset toLibraries you assemble and operate yourselfThe agent doing the work — not a competitor
What your agent's work becomesWeights. Mined into tasks, trained on, served back.A trace you can search. It never becomes a model.Whatever you turned it into first — they train what you hand them.Weights, if you build and run the pipeline that gets it there.Context, discarded when the session ends.
Who builds the training settask-mine does — dedup, provenance, verifiersYou, before you arriveYou, plus an environment per task
What you own at the endThe weights. Export them, self-host, air-gap.Your traces, and the dashboard over themVaries — some export the adapter, some only serve itEverything. It is your cluster.Nothing to own — same base model tomorrow
Improves without you starting itYes — retrains as you shipNo — each run is a job you launchNo — you operate the loopNo — better prompts, same weights
Where raw traces liveYour machine. PII redacted at source, before upload.Their cloud by default; several offer self-hostingWherever you put the datasetYour infrastructureThe vendor's, per their terms
Runs offlineThe capture half does — Border Collie needs no accountYes
The deciding row

The row that sorts the field is the second one: what your agent's work becomes once the task is over. Everything else on this page follows from that answer.

Honest boundaries

What each one is better at.

We are in private beta and Border Collie is not public yet. Against shipped tools, that matters — so here is where they win.

Capture & eval clouds

Seeing what happened

Their tracing, dataset curation and eval UX are mature in a way ours is not. If the question you need answered is what did my agent do and did it get better, that is what they are for, and train.cloud does not replace them.

Tuning platforms

A dataset you already have

If your training data is already clean and labelled, a managed fine-tune is fewer moving parts than a loop, and it is available today. The loop earns its keep only when building the dataset is the expensive part — which, for agent traces, it usually is.

RL toolkits

Track record and ecosystem

PrimeIntellect has trained frontier-scale models — INTELLECT-1 at 10B, INTELLECT-2 at 32B — and their Environments Hub is live with hundreds of community environments. Ours are per-tenant and unbuilt. Those are real advantages of a shipped project over a young one, and they stand until our own milestones retire them.

Agent harnesses

Doing the actual work

Claude Code, Codex, Cursor and Gemini are not on the other side of this table. Border Collie drives them through one adapter contract, and the model you train is served back to whichever one you already use. Nothing about your setup changes except the base URL.

Straight answers

One-liners, for deciding fast.

train.cloud vs LangSmith / Braintrust / Weave
They show you what your agents did. train.cloud turns what they did into a model. If your problem is visibility, use them — their eval and tracing UX is years ahead of ours, and we do not try to replace it.
train.cloud vs Together / Fireworks fine-tuning
They train the dataset you bring. The hard part was never the training job — it was building the dataset and knowing which examples were worth learning from. That is the part train.cloud automates. If you already have a clean dataset, they are simpler and cheaper than a loop.
train.cloud vs prime-rl / verifiers
The most complete open RL stack there is, and we adopt its structure openly. They have trained frontier-scale models; we are greenfield. The difference is that they are a toolkit you operate and train.cloud is a loop that runs — and that we target trusted central pooling rather than untrusted compute over the open internet.
train.cloud vs verl
verl is the reference RL implementation and our training tier is a Rust port of its algorithm registry, verified against it with golden files. If you want to run RLVR yourself on your own cluster, use verl. train.cloud is the thing that decides what to train on.
train.cloud vs just using a bigger model
A bigger model is the right answer until the cost per token or the latency stops working. A tuned small model gets cheaper and faster the more specific your work is; a frontier model does not learn your codebase between sessions.
train.cloud vs RAG and context engineering
Retrieval puts the right text in the window. It works, and it resets every session. Weights carry the behaviour across sessions without spending context on it. The two compose — this is not either/or.
train.cloud vs Claude Code / Codex / Cursor
Not a comparison. Those are the harnesses train.cloud drives and improves; you keep using the one you already use, and switch it onto your own model with one base-URL flip.
Weights, not context

A loop, not another dashboard.