# Claude Cowork on local models: the open-source answer > Every path Anthropic documents for Claude Cowork runs Claude models, so a local or open-weight model starts with the open-source route. Kortix is the open-source CompanyOS, and it treats the model as a setting on the agent, the session or the message, which is my pick when the model has to be yours; I work on Kortix's marketing, so weigh that accordingly. URL: https://claudecoworkalternative.com/claude-cowork-local-models ## Model choice, in commands A model per session, the models an agent can run, the project's model list, and a provider key of your own. ### One session `terminal` ```sh kortix sessions new --prompt "" --model ``` ### An agent's models `terminal` ```sh kortix agents models ls ``` ### The project's models `terminal` ```sh kortix models ls --json ``` ### Your keys `terminal` ```sh kortix providers set anthropic Paste the key on stdin. ``` ## Kortix and Claude Cowork on model choice Cowork's answers come from Anthropic's product and third-party documentation; Kortix's from its models docs, all checked October 2026. | | Kortix (recommended) | Claude Cowork | | --- | --- | --- | | Source | Open source. Read it, fork it, audit it | Closed | | Models | Any model, your keys | Claude models on every documented path | | Model choice | Agent, session, or message | One pick per session | | Open-weight or local | Your own endpoint, anything OpenAI-compatible | No documented path | | Where it runs | Kortix Cloud, a VPC, or on-prem | Anthropic's cloud, or your Bedrock, Gemini Enterprise Agent Platform or Foundry account | ## What the September merge changed, and what it left alone Claude Cowork is Anthropic's agentic workspace: hand it a goal and it works across your files and tools until there is finished work to review. Since September 16, 2026 it has not been a separate app. The merge folded what Cowork does into any Claude conversation. Chats, tasks, projects, connectors and skills carried over, and the rollout reached Pro, Max and Ultra plans first ([release notes](https://support.claude.com/en/articles/12138966-release-notes), checked October 2026). The merge moved where you find the agent and which plans reach it. It did not touch the model. The same release notes log only Claude launches around the merge: Claude Sonnet and Opus in September, Claude Haiku in October. Memory now runs across chat and Cowork in the Claude cloud. Anthropic's own FAQ frames Cowork the same way, as work that "uses the same agentic approach as Claude Code" ([product page](https://claude.com/product/cowork)). One approach, one model family, and the merge changed neither. ## Three routes to another model, and what each is documented to serve The wish shows up in the open. A [r/ClaudeAI thread](https://www.reddit.com/r/ClaudeAI/comments/1vu3vbz/im_working_on_an_opensource_claude_cowork/) on building an open-source Cowork replacement names cost and model choice as the motive. An [r/LocalLLaMA thread](https://www.reddit.com/r/LocalLLaMA/comments/1v9c1hz/agenta_an_opensource_claude_cowork_alternative/) introduces an alternative to an audience that runs models on its own machines. Between the wish and Cowork sit three routes. Two are documented. The third is where the guides disagree. The first route is your own cloud account. The Cowork product page lists the hosting options: "a Claude account or your own cloud provider: Amazon Bedrock, Gemini Enterprise Agent Platform, or Microsoft Foundry" ([product page](https://claude.com/product/cowork), checked November 2026). On that route the bill and the data boundary move to your cloud tenant. The model stays put. Anthropic's deployment docs describe Microsoft Foundry as Anthropic operating the Claude models, and Bedrock and Google Cloud as serving Claude models in the region you pick ([3P overview](https://claude.com/docs/third-party/claude-desktop/overview)). The second route is your own gateway, and it is the literal bring-your-own-key path. Anthropic documents a Claude Desktop deployment mode, Claude Desktop on 3P, that "routes all model inference through a provider you configure" ([3P overview](https://claude.com/docs/third-party/claude-desktop/overview)). The providers it names are Amazon Bedrock, Google Cloud's Agent Platform, Microsoft Foundry, a gateway you operate, or the Anthropic API directly. The gateway must implement the Anthropic Messages API, and discovery shows "only models whose IDs are recognizably Claude" ([gateway doc](https://claude.com/docs/third-party/claude-desktop/gateway)); the example configuration offers Claude Sonnet and Claude Opus ([models doc](https://claude.com/docs/third-party/claude-desktop/models)). Your endpoint, your credentials, your billing, and the same model family. The third route is the one most of these searches mean: a local or open-weight model. No Anthropic page documents it. Community guides claim the same gateway setting accepts OpenRouter or an Ollama-style proxy, putting GPT, Gemini or a local model behind Cowork ([one walkthrough](https://www.eigent.ai/blog/claude-cowork-on-3p-any-llm)). Other guides answer the opposite way: a gateway "does not make GPT, DeepSeek, or other model families supported in Cowork" ([Opper's guide](https://opper.ai/blog/claude-cowork-third-party-inference)). Anthropic's own wording, a gateway that serves Claude models, supports the second reading. Until the vendor documents it, any-model Cowork is an experiment. So the requirement splits in two, and the documented Cowork answers one half. Your keys on the inference: yes. Your choice of model: no. When the requirement is both, the decision stops being about Cowork at all. ## What model choice looks like when you own the system Kortix is [open source](/is-claude-cowork-open-source), and the model question is answered in its design. Agent files, skill folders, memory and connector entries live in a repository your team holds, and the model is a setting like the rest. Any model provider with your own keys. Or the ChatGPT plan you already pay for. Pin a model on an agent, give one session its own model, or switch mid-conversation in the composer ([Read the docs](https://kortix.com/docs/project/models)). A self-hosted or unlisted endpoint works too, anything OpenAI-compatible, which is how a model on your own hardware joins in. The models Kortix manages itself are open-weight ones; models from the major labs run on your key or your subscription. The choices compose. A cheaper model can carry the bulk of the work while a stronger one takes the steps that justify it, and thousands of agents in parallel on one config each get their own pick. The assignment lives in the repo you version, diff and review with everything else. ## Local-model questions, answered Each answer comes from Anthropic's own pages or the Kortix documentation. ### Can I use my own model with Claude Cowork? Not on a path Anthropic documents. The documented routes move where Claude inference runs, your cloud account or your own gateway, while the models stay Claude. Guides claiming GPT or Gemini behind a gateway describe an undocumented setup. ### Does Claude Cowork run local models? No documented path runs Cowork on a local model. Anthropic's docs describe discovery that shows only models whose IDs are recognizably Claude, with example pickers listing Claude Sonnet and Claude Opus. Community Ollama guides exist; they are not vendor documentation. ### Does Claude Cowork work with OpenRouter? Only as an undocumented gateway. Anthropic requires a gateway implementing the Anthropic Messages API and describes it serving Claude models. Community posts report OpenRouter working anyway, and other guides disagree with them, so treat it as unverified. ### How does Kortix let me pick a model per agent? Pin a model on the agent, the session, or one prompt. An agent's model is the `model:` key in its block in `kortix.yaml`, a session takes `--model ` on `kortix sessions new`, and the composer picker overrides it per message. Keys come from any major provider or your own OpenAI-compatible endpoint. ## Run the model you choose Open source, with the model, the keys and the configuration as files in a repository you own. [Try Kortix](https://kortix.com) · [Read the docs](https://kortix.com/docs) --- A guide written by someone who works on Kortix's marketing. My pick is Kortix: open source, one repo, free to self-host. Revised 2026-11-06 Not affiliated with Anthropic, OpenAI or Microsoft. Claude Cowork, ChatGPT Work and Copilot belong to their owners. © 2026 claudecoworkalternative.com