Using Downsizing with Amp

Why Amp isn't supported yet

Amp is a managed service: inference runs through Sourcegraph's own backend at ampcode.com, and the CLI/extension have no documented setting — no settings.json key, no environment variable like ANTHROPIC_BASE_URL or AMP_URL — for pointing model traffic at a custom Anthropic- or OpenAI-compatible endpoint.

Amp previously had an "Isolated Mode" that let users bring their own provider API keys, but Sourcegraph removed it (see their "No More BYOK" announcement), citing provider rate-limit and compatibility problems. Amp's Owner's Manual now mentions only a "regional endpoint support for bring-your-own-key model providers" capability, and it is gated behind Amp Enterprise and requires contacting Sourcegraph's sales team directly — there is no public configuration surface we can target, and no documented mechanism we can verify against.

Because we won't fabricate a config schema that hasn't been verified against real Amp behavior, we're not shipping a ds link amp integration until Amp exposes a documented, self-serve way to set a custom provider endpoint.

What you can do instead

If you want Downsizing's cost savings today, check out our other supported integrations — most editors and CLIs that support a custom Anthropic or OpenAI base URL (Claude Code, Cursor, Cline, Goose, Codex, and more) work out of the box.

If Sourcegraph adds a documented BYOK/custom-endpoint option for Amp in the future, we'll add first-class support here. If you have information about such a mechanism (e.g. Enterprise-only settings you have access to), please let us know.