[myk1yt]

Supersedes #1733, which was auto-closed by the stale bot after CodeRabbit APPROVED — the only remaining gate then was 'resolve merge conflicts', now resolved: this branch includes a merge of current main (post #1906/#2034 era). Full context and review history: #1733

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Related GitHub Issue

Closes: #1727

Description

For Anthropic and MiniMax models, the task cost shown in the UI omits the output-token portion of the bill, because the streaming loop never adopts the cumulative message_delta.usage.output_tokens into the local accumulator used for the final totalCost chunk — only the message_start seed (0/1) is counted.

This PR adopts the cumulative value (replace, not add — the final message_delta carries the message total, per the pinned SDK's replace semantics) in both src/api/providers/anthropic.ts and src/api/providers/minimax.ts, so the end-of-stream cost chunk reflects the real output tokens. Scope note: anthropic-vertex.ts never emits a totalCost chunk and is unaffected; opencode-go.ts consumes the same cumulative delta but with pre-existing += accumulation in streamAnthropicMessage — that file is intentionally not changed here and will be addressed in a separate follow-up.

Test Procedure

• New regression test in each provider spec: stream message_start usage {input:100, output:1} + message_delta usage {output_tokens:500} → final usage chunk's totalCost equals calculateApiCostAnthropic(info, 100, 500), not the starved (info, 100, 1). Verified failing before the fix, passing after.
• vitest run api/providers/__tests__/anthropic.spec.ts api/providers/__tests__/minimax.spec.ts → 147/147 passed (2 files, incl. describe-nested cases).
• pnpm run test:coverage:core → exit 0 (162 files / 3015 passed).
• vitest run --coverage --config vitest.api.config.ts → exit 0; changed lines covered (anthropic.ts:295, minimax.ts:153).
• pnpm run check-types → 0 errors. ESLint on changed files → clean, suppression counts unchanged.

Pre-Submission Checklist

• Issue Linked: This PR is linked to an approved GitHub Issue (see "Related GitHub Issue" above).
• Scope: My changes are focused on the linked issue (one major feature/fix per PR).
• Self-Review: I have performed a thorough self-review of my code.
• Testing: New and/or updated tests have been added to cover my changes (if applicable).
• Visual Snapshot (UI changes only): N/A.
• Documentation Impact: No documentation updates are required.
• Contribution Guidelines: I have read and agree to the Contributor Guidelines.

Visual Snapshots

N/A.

Videos (interaction / animation only)

N/A.

Documentation Updates

• No documentation updates are required.

Additional Notes

Pre-existing (out of scope): the consumer in Task.ts sums the cumulative delta yield into its own display accumulator, so displayed tokensOut can read ~1 over — cosmetic; the cost figure this PR fixes is now exact.

Get in Touch

GitHub: @myk1yt — please tag me here; I monitor notifications.

[coderabbitai]

📝 Summary

Summary by CodeRabbit

• Bug Fixes
  • Corrected usage-based cost calculations for Anthropic and MiniMax streaming responses. Final costs now reflect the latest cumulative output-token count, while later zero-value updates no longer overwrite an existing count.

Anthropic and MiniMax now use cumulative message_delta output-token counts when calculating final streaming costs. Regression tests check that a later zero-valued delta does not replace a previously reported count.

Changes: Streaming cost calculation

Layer / File(s)	Summary
Cumulative output-token handling and cost tests src/api/providers/anthropic.ts, src/api/providers/minimax.ts, src/api/providers/__tests__/anthropic.spec.ts, src/api/providers/__tests__/minimax.spec.ts	Both handlers adopt nonzero cumulative output-token counts from message_delta and retain the prior count when the reported count is zero. Tests verify that final cost uses the cumulative count.

Priority: Normal

Estimated code review effort: 2 (Simple) | ~10 minutes

Change: Bug fix · Severity of issue fixed: Medium

Possibly related issues

• Issue 2215, “This issue requires cost and token data in local task usage history.” This change corrects task cost values but does not implement local usage history.

Merge Risk: Minimal · up to 36c9a

The change corrects final streaming costs to use cumulative output-token counts. No actionable merge-blocking risk is identified in the supplied evidence; merge after normal checks pass.

Pre-merge checks: 8

Check name	Status	Explanation
Title check		The title clearly and concisely identifies the API fix: adopting cumulative output tokens for Anthropic and MiniMax cost calculations.
Linked Issues check		Issue #1727 is the only direct linked issue, and it is open. Its coding requirement is to adopt the cumulative message_delta output-token count, not add it to the message_start seed, so the end-of-str…
Out of Scope Changes check		The PR changes four files, per the change summary. Two are source files: anthropic.ts and minimax.ts. Two are provider test files: anthropic.spec.ts and minimax.spec.ts. Each source change is a single…
Regression Evidence		Focused provider-level coverage is present for both changed handlers. Each new test streams a message_start seed, a positive cumulative message_delta, and a zero delta, then asserts the final totalCos…
Security Boundaries		PASS. The changed paths only replace the local output-token accumulator with the cumulative message_delta.usage.output_tokens value in src/api/providers/anthropic.ts:301-303 and `src/api/providers…
Persistence Integrity		PASS. The pull request changes only Anthropic/MiniMax streaming token accumulation and provider tests. The changed paths do not create, update, or delete persisted state, so no changed persistence pat…
Lifecycle Resource Cleanup		No changed lifecycle path can leak a resource or duplicate work. The provider diff adds only cumulative-token assignments inside existing for await loops. Both loops already wrap the stream with `wi…
Description check		The description follows the repository template. It links issue #1727, explains the fix and scope, documents test procedures and results, completes the checklist, and addresses documentation, snapshot…

Full details: Linked Issues check

Explanation

Issue #1727 is the only direct linked issue, and it is open. Its coding requirement is to adopt the cumulative message_delta output-token count, not add it to the message_start seed, so the end-of-stream totalCost uses the real output count. Diffs at head versus merge base: src/api/providers/anthropic.ts adds outputTokens = chunk.usage.output_tokens || outputTokens in the message_delta case. src/api/providers/minimax.ts adds the same statement in its message_delta case. In minimax.ts, the final totalCost chunk calls calculateApiCostAnthropic with the outputTokens accumulator, so the fix reaches the reported cost. The summary reports regression tests in anthropic.spec.ts and minimax.spec.ts. These tests stream message_start output 1 and message_delta output 500, then assert totalCost equals cost for 500 output tokens. The test assertions were not read directly. The anthropic.ts final cost path was not read directly. It is taken from the issue text and the PR summary, and the change mirrors the minimax.ts pattern. Both requirements are met by the code evidence.

Full details: Out of Scope Changes check

Explanation

The PR changes four files, per the change summary. Two are source files: anthropic.ts and minimax.ts. Two are provider test files: anthropic.spec.ts and minimax.spec.ts. Each source change is a single statement with a short explanatory comment, and it implements #1727. The test additions support that fix. The PR states that anthropic-vertex.ts and the Task.ts display token count are unchanged. The Task.ts display discrepancy is pre-existing and is not changed here. The merge with main does not add unrelated file changes in the reviewed summary. No out-of-scope change was found.

Full details: Regression Evidence

Explanation

Focused provider-level coverage is present for both changed handlers. Each new test streams a message_start seed, a positive cumulative message_delta, and a zero delta, then asserts the final totalCost uses the cumulative count and not the seed. This covers adoption, replacement rather than addition, and zero-value fallback. No changed UI component requires a Playwright snapshot.

Full details: Security Boundaries

Explanation

PASS. The changed paths only replace the local output-token accumulator with the cumulative message_delta.usage.output_tokens value in src/api/providers/anthropic.ts:301-303 and src/api/providers/minimax.ts:168-172. The value is used only for numeric cost calculation. The changes do not expose secrets or PII, execute input, or bypass approval or allowlist controls.

Full details: Persistence Integrity

Explanation

PASS. The pull request changes only Anthropic/MiniMax streaming token accumulation and provider tests. The changed paths do not create, update, or delete persisted state, so no changed persistence path can lose or corrupt state through missing awaits, non-atomic writes, missing rollback, or an unpropagated persisted default.

Full details: Lifecycle Resource Cleanup

Explanation

No changed lifecycle path can leak a resource or duplicate work. The provider diff adds only cumulative-token assignments inside existing for await loops. Both loops already wrap the stream with withFinallyCleanup, which detaches the abort listener on completion, failure, or consumer cancellation. The test changes only add coverage and imports.

Full details: Description check

Explanation

The description follows the repository template. It links issue #1727, explains the fix and scope, documents test procedures and results, completes the checklist, and addresses documentation, snapshots, videos, and reviewer notes.

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[github-actions]

Review status

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✅ All modified and coverable lines are covered by tests.

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