Connect your agents · lasso docs · Execution Associates

lasso exposes two MCP servers, and an agent CLI needs both registered to use everything lasso offers:

Server name	URL	What it gives an agent
`lasso`	`<lasso URL>/mcp`	Create, list, inspect and close agents on any host; `whoami`; `notify` the human; `open_file` in the human's sidebar; lasso's browsers and their tabs; and the `browser_*` tools, chrome-devtools-mcp's (navigate, click, fill, screenshot, console, network, ...) against those browsers. See MCP tools and Browser tools.
`lasso-herdr`	`<lasso URL>/herdr-mcp`	herdr's socket API, one tool per herdr method (`pane_list`, `pane_split`, `agent_prompt`, ...), on any host lasso drives. See The herdr MCP.

lasso-herdr is a separate server because ninety raw herdr methods are a different job from orchestrating agents and driving a browser.

lasso connect#

lasso connect

lasso connect finds the supported agent CLIs installed on this machine and registers every server with each of them, through each CLI's own mechanism. Re-running it is safe: an entry that is already identical is left alone, and a different one is replaced. "Identical" is decided by reading what the CLI actually stored, so a hand edit is noticed.

Before it registers anything it asks the server:

/mcp must answer, with the same headers the CLIs will send. If it doesn't, nothing is registered, lasso connect prints the likeliest reason, and it exits 1.
It asks shared_browser whether /mcp's browser tools can run, which needs Chrome or Chromium and chrome-devtools-mcp installed on lasso's machine. When they can't, lasso is registered anyway and the output says what is missing; installing it later needs no re-registration.
lasso-herdr is registered only when /herdr-mcp lists herdr's tools, which needs herdr installed on lasso's machine (lasso reads the tool list from herdr api schema --json). -herdr=false skips it.

The probe never launches the browser.

An entry named lasso-browser (an MCP server at <lasso URL>/browser-mcp, which lasso does not serve) is removed from every detected CLI on every run, since the browser tools are on /mcp; the output mentions it only when there was one to remove.

Which CLIs it handles#

CLI	Detected when	How it registers
Claude Code	`claude` is on `PATH`	`claude mcp add --transport http --scope <scope>`. An existing entry is removed first with `claude mcp remove`, since Claude Code refuses to add a name that exists.
Codex	`codex` is on `PATH`	`codex mcp add <name> --url <url>`, which replaces in place. Headers are then written into that entry's `http_headers` in Codex's `config.toml`.
OpenCode	`opencode` is on `PATH`	`opencode mcp add <name> --url <url> --header K=V`, run from your home directory so it writes the global config.
Oh My Pi (`omp`)	`omp` is on `PATH`, or `~/.omp/agent` exists	Edits `~/.omp/agent/mcp.json` directly (omp has no `mcp` subcommand), keeping any other keys you put on the entry.
Pi (`pi`)	`pi` is on `PATH`	Skipped: pi has no MCP client. Its agents can call lasso's tools from the shell with `lasso mcp`.

The output has one line per CLI and server, with a status such as added, updated, unchanged, skipped: not installed or failed: <reason>.

Flags#

Flag	Default	Effect
`-url <url>`	`$LASSO_URL`, else `http://$LASSO_LISTEN`, else `http://127.0.0.1:8090`	The URL this machine reaches lasso on. A trailing `/mcp`, `/herdr-mcp` or `/browser-mcp` is dropped, since every server hangs off the base URL.
`-token <token>`	`$LASSO_MCP_TOKEN`	Bearer token to register, sent as `Authorization: Bearer <token>`.
`-header 'Name: value'`	none	An extra header to probe with and register. Repeatable. A header with the same name as one lasso adds (such as `Authorization`) replaces it.
`-only a,b`	all	Only these CLIs: any of `claude`, `codex`, `opencode`, `omp`, `pi`.
`-scope <s>`	`user`	Claude Code scope: `user`, `local` or `project`. Ignored by the other CLIs.
`-remove`	off	Unregister both servers (and any `lasso-browser` entry) from every CLI instead.
`-dry-run`	off	Print every command it would run and every file edit it would make, and change nothing.
`-force`	off	Skip the probe and register even if lasso does not answer.

lasso connect -h prints the same reference.

Authentication#

With no flags, the entries carry whatever credential the environment offers:

$LASSO_MCP_TOKEN (or -token) becomes Authorization: Bearer <token>.
Otherwise $UI_AUTH (user:pass) becomes Authorization: Basic ....
Otherwise there is no auth header, which is right for a loopback lasso with /mcp open, and for a lasso on your tailnet, which identifies the machine itself.

Behind Cloudflare Access, the service token's headers go in with -header, and a lasso token for host scope rides beside them as -header 'X-Lasso-Token: <token>'. lasso reads X-Lasso-Token exactly like Authorization: Bearer, and it still works when something else needs Authorization.

Secrets are masked in everything lasso connect prints. Claude Code and OpenCode only accept headers on their command line, so for those two the header values are briefly visible in this machine's process list while the command runs. Codex and omp get theirs written straight into their config files, and the first rewrite of a config file leaves a .bak copy beside it.

For how tokens are minted and scoped per host, see Agent scope and MCP OAuth.

Where Claude Code's entry lands#

`-scope`	File
`user`	`~/.claude.json` (or `$CLAUDE_CONFIG_DIR/.claude.json`), top-level `mcpServers`
`local`	The same file, under this directory's project entry
`project`	`./.mcp.json` in the current directory

user is the default and usually what you want: add the servers once and every Claude Code session on the machine has them. A session that never calls a browser tool costs nothing on lasso's side.

Connecting from another machine#

On a machine other than lasso's, 127.0.0.1 would point that machine's agents at themselves. Pass the URL that machine actually reaches lasso on:

# over a tailnet (lasso started with -tailnet)
lasso connect -url https://myhost.example-tailnet.ts.net:8090

# behind Cloudflare Access, with a service token
lasso connect -url https://lasso.example.com \
  -header 'CF-Access-Client-Id: <id>.access' \
  -header 'CF-Access-Client-Secret: <secret>'

# the same, held to this machine's own host (lasso has MCP_OAUTH set)
lasso connect -url https://lasso.example.com \
  -header 'CF-Access-Client-Id: <id>.access' \
  -header 'CF-Access-Client-Secret: <secret>' \
  -header 'X-Lasso-Token: <lasso token>'

lasso must let that machine in. On a tailnet, a machine you own gets in as you; a tagged one needs its tag in lasso's LASSO_ALLOW. Behind Access, the service token needs a Service Auth policy on the Access application. A tagged machine or a service token reaches the MCP servers and /cdp, not the UI. See Security.

The lasso binary on that machine is only used as the installer here; it does not need a server of its own running. When lasso connect can't reach /mcp, its hint depends on the URL: for an https:// URL with no CF-Access-Client-Id header it suggests a service token, and for a loopback URL it asks whether lasso is running there.

Undo#

lasso connect -remove

This removes lasso, lasso-herdr and any lasso-browser entry from every detected CLI. Claude Code and Codex are asked to remove them (claude mcp remove, codex mcp remove); omp's mcp.json is edited. OpenCode has no remove command, so lasso deletes the entry from whichever of opencode.jsonc, opencode.json or config.json holds it. A file that contains comments or trailing commas is refused rather than rewritten (a rewrite would drop them); delete mcp.lasso and mcp.lasso-herdr (and mcp.lasso-browser, if present) from it by hand.

Combine with -dry-run to see what would be removed first.

Registering by hand#

Any MCP client that speaks streamable HTTP can add the URLs itself. For Claude Code:

claude mcp add --transport http lasso       http://127.0.0.1:8090/mcp
claude mcp add --transport http lasso-herdr http://127.0.0.1:8090/herdr-mcp

For Codex and OpenCode:

codex mcp add lasso --url http://127.0.0.1:8090/mcp
codex mcp add lasso-herdr --url http://127.0.0.1:8090/herdr-mcp

opencode mcp add lasso --url http://127.0.0.1:8090/mcp
opencode mcp add lasso-herdr --url http://127.0.0.1:8090/herdr-mcp

For omp, in ~/.omp/agent/mcp.json:

{
  "mcpServers": {
    "lasso": { "type": "http", "url": "http://127.0.0.1:8090/mcp" },
    "lasso-herdr": { "type": "http", "url": "http://127.0.0.1:8090/herdr-mcp" }
  }
}

A gated lasso needs the credential as a header on each entry, for example --header "Authorization: Bearer <token>" with claude mcp add. Under UI_AUTH alone /mcp is open, but its browser tools need the UI_AUTH basic credentials (--header "Authorization: Basic <base64 user:pass>").

Settings → General → Terminal & browser in the web UI also shows lasso's MCP URL and a ready-to-copy claude mcp add command for it.

Next#

MCP overview: what the three servers are for and how they are secured.
MCP tools: every tool on /mcp and its parameters.
The lasso CLI for agents: lasso notify, lasso open, lasso mcp, for agents without MCP.