tinyhumansai/openhuman · error

browser.backend='auto' found no usable backend (playwright m

Error message

browser.backend='auto' found no usable backend (playwright missing, agent-browser missing, rust-native unavailable, computer-use invalid: {err})

What it means

With browser.backend='auto', every candidate backend was tried and none was usable; this variant fires when the computer-use probe itself errored (config invalid), so the computer-use failure text is embedded in the message. It is the aggregate 'nothing available' report of the fallback chain.

Source

Thrown at src/openhuman/tools/impl/browser/browser.rs:260

                if Self::rust_native_compiled() && self.rust_native_available() {
                    return Ok(ResolvedBackend::RustNative);
                }
                if Self::is_playwright_available().await {
                    return Ok(ResolvedBackend::Playwright);
                }
                if Self::is_agent_browser_available().await {
                    return Ok(ResolvedBackend::AgentBrowser);
                }

                let computer_use_err = match self.computer_use_available() {
                    Ok(true) => return Ok(ResolvedBackend::ComputerUse),
                    Ok(false) => None,
                    Err(err) => Some(err.to_string()),
                };

                if Self::rust_native_compiled() {
                    if let Some(err) = computer_use_err {
                        anyhow::bail!(
                            "browser.backend='auto' found no usable backend (playwright missing, agent-browser missing, rust-native unavailable, computer-use invalid: {err})"
                        );
                    }
                    anyhow::bail!(
                        "browser.backend='auto' found no usable backend (playwright missing, agent-browser missing, rust-native unavailable, computer-use sidecar unreachable)"
                    )
                }

                if let Some(err) = computer_use_err {
                    anyhow::bail!(
                        "browser.backend='auto' needs Playwright, agent-browser tool, browser-native, or valid computer-use sidecar (error: {err})"
                    );
                }

                anyhow::bail!(
                    "browser.backend='auto' needs Playwright, agent-browser tool, browser-native, or computer-use sidecar"
                )
            }

View on GitHub (pinned to 7491200858)

Solutions

1. Install Playwright (see the browser tool docs) or the agent-browser tool.
2. Fix the computer-use config error quoted in the message.
3. Enable the browser-native feature and its WebDriver driver.
4. Switch browser.backend to an explicitly available backend.

When it happens

Trigger: Thrown at src/openhuman/tools/impl/browser/browser.rs:260 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of tinyhumansai/openhuman@7491200858 (2026-08-17). Data as JSON: /api/errors/4ce688ef8fc1b0c7. Report an issue: GitHub.