diff --git a/services/www/src/docs/content/console/api/inference.mdx b/services/www/src/docs/content/console/api/inference.mdx
index f3302399231..19a0fde4983 100644
--- a/services/www/src/docs/content/console/api/inference.mdx
+++ b/services/www/src/docs/content/console/api/inference.mdx
@@ -121,9 +121,10 @@ usage chunk for Chat Completions with `stream_options.include_usage`, `response.
 
 | Field                     | Meaning                                                                                                                      |
 | ------------------------- | ---------------------------------------------------------------------------------------------------------------------------- |
-| `cost`                    | US dollars charged to your balance. `0` for free models and for [Go](/console/go) usage within its limits. Absent when the request used your own provider key. |
+| `cost`                    | US dollars charged to your balance. `0` for free models and for [Go](/console/go) usage within its limits. With your own provider key, an estimate of what your provider charges, unless it reports its own; absent when the model has no price. |
 | `opencode.billing_source` | `free`, `balance`, `go`, `go-plus`, or `byok` (your own provider key).                                                       |
 | `opencode.list_cost`      | US dollars at the model's price, including peak hours and long-context pricing.                                              |
+| `opencode.estimated`      | `true` when `cost` is an estimate at the model's price rather than an amount OpenCode charged. Only set with your own provider key. |
 | `opencode.allowance`      | Go only: how much the request counted toward your [usage limits](/console/go#usage-limits), in dollars of the plan's monthly limit. |
 | `opencode.tokens`         | The tokens you were billed for. `input` excludes cache reads and writes; `output` includes `reasoning`.                      |