Upstream Proxy

Moltis can route all outbound HTTP traffic through an upstream proxy. This is useful when running behind a corporate firewall, in a restricted network, or when you need to audit/filter outbound connections.

Configuration

Add upstream_proxy to the top level of your moltis.toml:

upstream_proxy = "http://proxy.corp.example.com:8080"

Supported schemes

Proxy authentication

Include credentials in the URL:

upstream_proxy = "http://user:password@proxy.corp.example.com:8080"

What is proxied

When upstream_proxy is set, the following traffic routes through the proxy:

• LLM provider API calls (Anthropic, OpenAI, Gemini, etc.)
• Tool HTTP requests (web fetch, web search, Firecrawl)
• OAuth flows (device auth, token exchange)
• MCP server auth (OAuth for remote MCP servers)
• Channel outbound (Slack streaming, MS Teams API calls)

Localhost and loopback addresses (127.0.0.1, ::1, localhost) are automatically excluded from the proxy (no_proxy).

Slack caveat

Slack streaming messages (progressive edits) are proxied via reqwest. However, regular chat.postMessage calls go through the slack-morphism library’s built-in hyper connector, which does not use the upstream proxy. If you need full Slack proxy coverage, also set the HTTPS_PROXY environment variable.

Telegram caveat

Telegram uses teloxide which bundles its own HTTP client (reqwest 0.11). The upstream_proxy config does not apply to Telegram traffic directly. To proxy Telegram, set the standard HTTPS_PROXY environment variable, which teloxide’s reqwest honours:

export HTTPS_PROXY=http://proxy.corp.example.com:8080
moltis

Or use the env section in moltis.toml:

[env]
HTTPS_PROXY = "http://proxy.corp.example.com:8080"

Environment variable fallback

When upstream_proxy is not set in moltis.toml, reqwest automatically honours the standard proxy environment variables:

• HTTP_PROXY / http_proxy
• HTTPS_PROXY / https_proxy
• ALL_PROXY / all_proxy
• NO_PROXY / no_proxy

Setting upstream_proxy in the config takes precedence over these variables for all traffic except Telegram (see caveat above).

Interaction with Trusted Network

If you use both upstream_proxy and trusted network mode (network = "trusted"), they serve different purposes:

• Trusted network proxy is a local domain-filtering proxy for sandbox tool execution. It controls which domains tools can reach.
• Upstream proxy routes traffic through your corporate/network proxy to reach the internet.

When both are active, tool traffic routes through the trusted-network proxy (which enforces domain allowlists), while provider and channel traffic routes through the upstream proxy.