A live opencode run against api.x.ai/v1 surfaced three real bugs:
1. Provider package — grok-build-0.1 is driven via the OpenAI Responses API
(opencode calls model.responses()). @ai-sdk/openai-compatible is
chat/completions only and errors "responses is not a function". Switch the
generated opencode.json provider + the grok image to @ai-sdk/openai.
2. Headless hang — `opencode run` blocks after init without a TTY; close stdin
(`< /dev/null`) in the entrypoint so it proceeds to the model call.
3. Reasoning-token cost — grok-build-0.1 is a reasoning model; reasoning tokens
bill as output but opencode stores them in a separate column. cost_for_session
folds tokens_reasoning into output (else ~22x undercount).
Verified end-to-end against a real session row (input=6120, output=1,
reasoning=226, cache_read=1856): our pricing reproduces opencode's stored USD
cost ($0.0069452) exactly. Tests anchored to that real row.
Confirmed by inspecting a local opencode run: opencode persists per-session
usage in SQLite at ~/.local/share/opencode/opencode.db — the `session` table
carries cost + tokens_input/output/reasoning/cache_read/cache_write. xAI's
response usage object (prompt_tokens, completion_tokens,
prompt_tokens_details.cached_tokens, completion_tokens_details.reasoning_tokens)
maps directly onto those columns.
Add opencode_usage.read_session_usage / cost_for_session: read the opencode DB
and price the tokens via roboco.billing.pricing (our cost stays authoritative;
opencode's own `cost` column is kept for reference). Tested against a fixture DB
mirroring the real schema (single session, summed sessions, missing/empty DB).
Remaining wiring (for the live spawn): mount the opencode data dir on grok
spawn + call cost_for_session at reap to record the usage rollup.
Renn F