Jadpo is experimental and not ready for production. These docs follow the compiler's main branch as of 1 Nov 2026. What's built · Install 0.2.0
jadpo
Reference: Tooling

Tooling · rule

email.browser_failed

On this page

A jadpo email open command couldn't start the browser to open a mail's link.

Area 14, Tooling; not declinable; the next step is usually the human's.

Why Jadpo refuses it

jadpo email open <mail> <link> opens a link of a mail the dev inbox caught in your browser: the program BROWSER names, or else the system's opener, open on a Mac and xdg-open elsewhere. When that program isn't there, or can't be run, nothing opens, so the command says which program it tried and gives the link to open by hand.

Jadpo won't choose a browser for you: which program opens links on your machine is yours to set.

What it looks like

jadpo dev caught a welcome mail, and BROWSER names a program that isn't installed. The output was copied from a run rather than checked, since a mail reaches the inbox only through jadpo dev; the mail was written into build/dev/inbox as jadpo dev writes it:

shell
BROWSER=firefx jadpo email open mail_1 1
jadpo email

error The browser couldn't be started

reason
BROWSER names firefx as the browser, and there's no program of that name.
next
Set BROWSER to your browser's command, or open http://localhost:3000/welcome yourself (human)
rule
email.browser_failed
help
https://jadpo.dev/docs/errors/email.browser_failed

(human) at the end of the next: line tells your coding agent to stop and ask you which fix you want, because the choice is yours to make: it decides which program opens links on your machine.

With BROWSER unset, the same refusal names the system's opener.

How to fix it

The question is which browser should open the link.

If you have one in mind, set BROWSER to its command, then open the link again:

shell
export BROWSER=firefoxjadpo email open mail_1 1

The link opens in that browser, and every later jadpo email open in the shell uses it too.

If any will do, leave BROWSER unset, so the system's opener opens it:

shell
unset BROWSERjadpo email open mail_1 1

The link opens in the system's default browser.

Markdown for agents: /docs/errors/email.browser_failed.md.Built from Jadpo main at e00e61f.