Supported agents

Which host you run decides what OMNI can do, and the ceiling is the host’s, not the pipeline’s. This page is worth reading before judging whether OMNI is earning its place.

The tiers

omni doctor     # prints the tier for every installed host

Savings are only ever counted where the model actually received less. A host that cannot apply the rewrite will not move the distillation numbers however good the filters get, and claiming otherwise would be the same defect as a distiller reporting a saving it did not make.

Installing for each

omni init --claude       omni init --cursor      omni init --zed
omni init --cline        omni init --roo         omni init --roo-code
omni init --copilot      omni init --gemini      omni init --opencode
omni init --codex        omni init --openclaw    omni init --antigravity
omni init --hermes       omni init --vscode      omni init --pi
omni init --all

Host-specific notes

Codex CLI runs only hooks it has been told to trust, and skips the rest without a word. After omni init --codex, start codex once and approve them under “Hooks need review”. omni doctor fails until you do. This has bitten before: Codex ran zero hooks for a whole release while everything looked correctly installed.

Cursor cannot rewrite its built-in shell tool’s output. Intercepting the shell by denying execution and returning output as a hook message is technically possible and was rejected: it tells the agent its command was blocked, loses the exit code, moves execution semantics into OMNI, and bypasses the host’s approval flow.

Claude Code matches more than Bash. The post-tool matcher is Bash|Read|Grep|WebFetch, which is what finally let the file-read, search and fetch distillers run at all. Three of them had been fully written and tested and had never executed on a real session.

It is also the host where omni init installs two things and only one of them does the work. The hooks are what shortens output. The MCP server is a convenience that puts omni_retrieve and omni_explain_savings where the agent can call them, and on this host it is a trade against the prompt cache: those two definitions are 471 bytes of JSON in the prefix of every request, and the host discards the whole cache when an MCP server connects or disconnects with its tools loaded, which a server process can do by exiting and reconnecting mid-session without you touching anything. omni init --claude registers it. The plugin route adds no tool definitions at all. To keep the hooks and drop the trade, install that half on its own:

omni init --hook     # hooks, no MCP registration
omni init --mcp      # the MCP server on its own, if you change your mind

omni doctor then reports the MCP server as not registered rather than as a fault, and neither it nor --fix puts it back (#757). Naming the host, omni init --claude, still installs both.

OpenClaw is Full on a later turn, not the current one. Its tool_result_persist hook rewrites the tool result OpenClaw persists, so the model reads the distilled bytes every time the transcript is re-read, while the turn that ran the command still sees the raw output. That is where a tool result’s cost sits anyway, since it is re-read many times, but it is a narrower Full than Claude Code’s.

Hermes hands OMNI every tool result, not only the terminal, which is the widest reach of any host here: it is what runs the file-read, search and fetch distillers on a host that has them. It also has its own integration page: Hermes Agent.

Windows is supported. Paths, line endings and the .exe suffix are handled, and the CI matrix includes windows-latest.

Several agents at once

Give each its own identity so the numbers stay separable:

OMNI_AGENT_ID=claude ...
OMNI_AGENT_ID=cursor ...

omni_agents reports which agents are currently active on the project. Every distillation row carries the id, and any figure that blends them is describing a mix rather than a product.

Adding a host

The agent modules live in src/agents/, one file per host, and each writes that host’s own configuration format in that host’s own location. The pattern is small and mostly mechanical.

The part that is not mechanical is verification. “Provider unreachable” is not a reason to leave a hook path unverified: serve the API and fake only the model. Hooks that had never run in production have been found on three hosts by doing exactly that.