# Changelog

## [Unreleased]

### Added

- Added Vercel AI Gateway provider with model discovery and `AI_GATEWAY_API_KEY` env support ([#689](https://github.com/badlogic/pi-mono/pull/689) by [@timolins](https://github.com/timolins))

### Fixed

- Fixed z.ai thinking/reasoning: z.ai uses `thinking: { type: "enabled" }` instead of OpenAI's `reasoning_effort`. Added `thinkingFormat` compat flag to handle this. ([#688](https://github.com/badlogic/pi-mono/issues/688))

## [0.45.3] - 2026-01-13

## [0.45.2] - 2026-01-13

## [0.45.1] - 2026-01-13

## [0.45.0] - 2026-01-13

### Added

- MiniMax provider support with M2 and M2.1 models via Anthropic-compatible API ([#656](https://github.com/badlogic/pi-mono/pull/656) by [@dannote](https://github.com/dannote))
- Add Amazon Bedrock provider with prompt caching for Claude models (experimental, tested with Anthropic Claude models only) ([#494](https://github.com/badlogic/pi-mono/pull/494) by [@unexge](https://github.com/unexge))
- Added `serviceTier` option for OpenAI Responses requests ([#672](https://github.com/badlogic/pi-mono/pull/672) by [@markusylisiurunen](https://github.com/markusylisiurunen))
- **Anthropic caching on OpenRouter**: Interactions with Anthropic models via OpenRouter now set a 5-minute cache point using Anthropic-style `cache_control` breakpoints on the last assistant or user message. ([#584](https://github.com/badlogic/pi-mono/pull/584) by [@nathyong](https://github.com/nathyong))
- **Google Gemini CLI provider improvements**: Added Antigravity endpoint fallback (tries daily sandbox then prod when `baseUrl` is unset), header-based retry delay parsing (`Retry-After`, `x-ratelimit-reset`, `x-ratelimit-reset-after`), stable `sessionId` derivation from first user message for cache affinity, empty SSE stream retry with backoff, and `anthropic-beta` header for Claude thinking models ([#670](https://github.com/badlogic/pi-mono/pull/670) by [@kim0](https://github.com/kim0))

## [0.44.0] - 2026-01-12

## [0.43.0] - 2026-01-11

### Fixed

- Fixed Google provider thinking detection: `isThinkingPart()` now only checks `thought === true`, not `thoughtSignature`. Per Google docs, `thoughtSignature` is for context replay and can appear on any part type. Also removed `id` field from `functionCall`/`functionResponse` (rejected by Vertex AI and Cloud Code Assist), and added `textSignature` round-trip for multi-turn reasoning context. ([#631](https://github.com/badlogic/pi-mono/pull/631) by [@theBucky](https://github.com/theBucky))

## [0.42.5] - 2026-01-11

## [0.42.4] - 2026-01-10

## [0.42.3] - 2026-01-10

### Changed

- OpenAI Codex: switched to bundled system prompt matching opencode, changed originator to "pi", simplified prompt handling

## [0.42.2] - 2026-01-10

### Added

- Added `GOOGLE_APPLICATION_CREDENTIALS` env var support for Vertex AI credential detection (standard for CI/production).
- Added `supportsUsageInStreaming` compatibility flag for OpenAI-compatible providers that reject `stream_options: { include_usage: true }`. Defaults to `true`. Set to `false` in model config for providers like gatewayz.ai. ([#596](https://github.com/badlogic/pi-mono/pull/596) by [@XesGaDeus](https://github.com/XesGaDeus))
- Improved Google model pricing info ([#588](https://github.com/badlogic/pi-mono/pull/588) by [@aadishv](https://github.com/aadishv))

### Fixed

- Fixed `os.homedir()` calls at module load time; now resolved lazily when needed.
- Fixed OpenAI Responses tool strict flag to use a boolean for LM Studio compatibility ([#598](https://github.com/badlogic/pi-mono/pull/598) by [@gnattu](https://github.com/gnattu))
- Fixed Google Cloud Code Assist OAuth for paid subscriptions: properly handles long-running operations for project provisioning, supports `GOOGLE_CLOUD_PROJECT` / `GOOGLE_CLOUD_PROJECT_ID` env vars for paid tiers, and handles VPC-SC affected users ([#582](https://github.com/badlogic/pi-mono/pull/582) by [@cmf](https://github.com/cmf))

## [0.42.1] - 2026-01-09

## [0.42.0] - 2026-01-09

### Added

- Added OpenCode Zen provider support with 26 models (Claude, GPT, Gemini, Grok, Kimi, GLM, Qwen, etc.). Set `OPENCODE_API_KEY` env var to use.

## [0.41.0] - 2026-01-09

## [0.40.1] - 2026-01-09

## [0.40.0] - 2026-01-08

## [0.39.1] - 2026-01-08

## [0.39.0] - 2026-01-08

### Fixed

- Fixed Gemini CLI abort handling: detect native `AbortError` in retry catch block, cancel SSE reader when abort signal fires ([#568](https://github.com/badlogic/pi-mono/pull/568) by [@tmustier](https://github.com/tmustier))
- Fixed Antigravity provider 429 errors by aligning request payload with CLIProxyAPI v6.6.89: inject Antigravity system instruction with `role: "user"`, set `requestType: "agent"`, and use `antigravity` userAgent. Added bridge prompt to override Antigravity behavior (identity, paths, web dev guidelines) with Pi defaults. ([#571](https://github.com/badlogic/pi-mono/pull/571) by [@ben-vargas](https://github.com/ben-vargas))
- Fixed thinking block handling for cross-model conversations: thinking blocks are now converted to plain text (no `<thinking>` tags) when switching models. Previously, `<thinking>` tags caused models to mimic the pattern and output literal tags. Also fixed empty thinking blocks causing API errors. ([#561](https://github.com/badlogic/pi-mono/issues/561))

## [0.38.0] - 2026-01-08

### Added

- `thinkingBudgets` option in `SimpleStreamOptions` for customizing token budgets per thinking level on token-based providers ([#529](https://github.com/badlogic/pi-mono/pull/529) by [@melihmucuk](https://github.com/melihmucuk))

### Breaking Changes

- Removed OpenAI Codex model aliases (`gpt-5`, `gpt-5-mini`, `gpt-5-nano`, `codex-mini-latest`, `gpt-5-codex`, `gpt-5.1-codex`, `gpt-5.1-chat-latest`). Use canonical model IDs: `gpt-5.1`, `gpt-5.1-codex-max`, `gpt-5.1-codex-mini`, `gpt-5.2`, `gpt-5.2-codex`. ([#536](https://github.com/badlogic/pi-mono/pull/536) by [@ghoulr](https://github.com/ghoulr))

### Fixed

- Fixed OpenAI Codex context window from 400,000 to 272,000 tokens to match Codex CLI defaults and prevent 400 errors. ([#536](https://github.com/badlogic/pi-mono/pull/536) by [@ghoulr](https://github.com/ghoulr))
- Fixed Codex SSE error events to surface message, code, and status. ([#551](https://github.com/badlogic/pi-mono/pull/551) by [@tmustier](https://github.com/tmustier))
- Fixed context overflow detection for `context_length_exceeded` error codes.

## [0.37.8] - 2026-01-07

## [0.37.7] - 2026-01-07

## [0.37.6] - 2026-01-06

### Added

- Exported OpenAI Codex utilities: `CacheMetadata`, `getCodexInstructions`, `getModelFamily`, `ModelFamily`, `buildCodexPiBridge`, `buildCodexSystemPrompt`, `CodexSystemPrompt` ([#510](https://github.com/badlogic/pi-mono/pull/510) by [@mitsuhiko](https://github.com/mitsuhiko))

## [0.37.5] - 2026-01-06

## [0.37.4] - 2026-01-06

## [0.37.3] - 2026-01-06

### Added

- `sessionId` option in `StreamOptions` for providers that support session-based caching. OpenAI Codex provider uses this to set `prompt_cache_key` and routing headers.

## [0.37.2] - 2026-01-05

### Fixed

- Codex provider now always includes `reasoning.encrypted_content` even when custom `include` options are passed ([#484](https://github.com/badlogic/pi-mono/pull/484) by [@kim0](https://github.com/kim0))

## [0.37.1] - 2026-01-05

## [0.37.0] - 2026-01-05

### Breaking Changes

- OpenAI Codex models no longer have per-thinking-level variants (e.g., `gpt-5.2-codex-high`). Use the base model ID and set thinking level separately. The Codex provider clamps reasoning effort to what each model supports internally. (initial implementation by [@ben-vargas](https://github.com/ben-vargas) in [#472](https://github.com/badlogic/pi-mono/pull/472))

### Added

- Headless OAuth support for all callback-server providers (Google Gemini CLI, Antigravity, OpenAI Codex): paste redirect URL when browser callback is unreachable ([#428](https://github.com/badlogic/pi-mono/pull/428) by [@ben-vargas](https://github.com/ben-vargas), [#468](https://github.com/badlogic/pi-mono/pull/468) by [@crcatala](https://github.com/crcatala))
- Cancellable GitHub Copilot device code polling via AbortSignal

### Fixed

- Codex requests now omit the `reasoning` field entirely when thinking is off, letting the backend use its default instead of forcing a value. ([#472](https://github.com/badlogic/pi-mono/pull/472))

## [0.36.0] - 2026-01-05

### Added

- OpenAI Codex OAuth provider with Responses API streaming support: `openai-codex-responses` streaming provider with SSE parsing, tool-call handling, usage/cost tracking, and PKCE OAuth flow ([#451](https://github.com/badlogic/pi-mono/pull/451) by [@kim0](https://github.com/kim0))

### Fixed

- Vertex AI dummy value for `getEnvApiKey()`: Returns `"<authenticated>"` when Application Default Credentials are configured (`~/.config/gcloud/application_default_credentials.json` exists) and both `GOOGLE_CLOUD_PROJECT` (or `GCLOUD_PROJECT`) and `GOOGLE_CLOUD_LOCATION` are set. This allows `streamSimple()` to work with Vertex AI without explicit `apiKey` option. The ADC credentials file existence check is cached per-process to avoid repeated filesystem access.

## [0.35.0] - 2026-01-05

## [0.34.2] - 2026-01-04

## [0.34.1] - 2026-01-04

## [0.34.0] - 2026-01-04

## [0.33.0] - 2026-01-04

## [0.32.3] - 2026-01-03

### Fixed

- Google Vertex AI models no longer appear in available models list without explicit authentication. Previously, `getEnvApiKey()` returned a dummy value for `google-vertex`, causing models to show up even when Google Cloud ADC was not configured.

## [0.32.2] - 2026-01-03

## [0.32.1] - 2026-01-03

## [0.32.0] - 2026-01-03

### Added

- Vertex AI provider with ADC (Application Default Credentials) support. Authenticate with `gcloud auth application-default login`, set `GOOGLE_CLOUD_PROJECT` and `GOOGLE_CLOUD_LOCATION`, and access Gemini models via Vertex AI. ([#300](https://github.com/badlogic/pi-mono/pull/300) by [@default-anton](https://github.com/default-anton))

### Fixed

- **Gemini CLI rate limit handling**: Added automatic retry with server-provided delay for 429 errors. Parses delay from error messages like "Your quota will reset after 39s" and waits accordingly. Falls back to exponential backoff for other transient errors. ([#370](https://github.com/badlogic/pi-mono/issues/370))

## [0.31.1] - 2026-01-02

## [0.31.0] - 2026-01-02

### Breaking Changes

- **Agent API moved**: All agent functionality (`agentLoop`, `agentLoopContinue`, `AgentContext`, `AgentEvent`, `AgentTool`, `AgentToolResult`, etc.) has moved to `@mariozechner/pi-agent-core`. Import from that package instead of `@mariozechner/pi-ai`.

### Added

- **`GoogleThinkingLevel` type**: Exported type that mirrors Google's `ThinkingLevel` enum values (`"THINKING_LEVEL_UNSPECIFIED" | "MINIMAL" | "LOW" | "MEDIUM" | "HIGH"`). Allows configuring Gemini thinking levels without importing from `@google/genai`.
- **`ANTHROPIC_OAUTH_TOKEN` env var**: Now checked before `ANTHROPIC_API_KEY` in `getEnvApiKey()`, allowing OAuth tokens to take precedence.
- **`event-stream.js` export**: `AssistantMessageEventStream` utility now exported from package index.

### Changed

- **OAuth uses Web Crypto API**: PKCE generation and OAuth flows now use Web Crypto API (`crypto.subtle`) instead of Node.js `crypto` module. This improves browser compatibility while still working in Node.js 20+.
- **Deterministic model generation**: `generate-models.ts` now sorts providers and models alphabetically for consistent output across runs. ([#332](https://github.com/badlogic/pi-mono/pull/332) by [@mrexodia](https://github.com/mrexodia))

### Fixed

- **OpenAI completions empty content blocks**: Empty text or thinking blocks in assistant messages are now filtered out before sending to the OpenAI completions API, preventing validation errors. ([#344](https://github.com/badlogic/pi-mono/pull/344) by [@default-anton](https://github.com/default-anton))
- **Thinking token duplication**: Fixed thinking content duplication with chutes.ai provider. The provider was returning thinking content in both `reasoning_content` and `reasoning` fields, causing each chunk to be processed twice. Now only the first non-empty reasoning field is used.
- **zAi provider API mapping**: Fixed zAi models to use `openai-completions` API with correct base URL (`https://api.z.ai/api/coding/paas/v4`) instead of incorrect Anthropic API mapping. ([#344](https://github.com/badlogic/pi-mono/pull/344), [#358](https://github.com/badlogic/pi-mono/pull/358) by [@default-anton](https://github.com/default-anton))

## [0.28.0] - 2025-12-25

### Breaking Changes

- **OAuth storage removed** ([#296](https://github.com/badlogic/pi-mono/issues/296)): All storage functions (`loadOAuthCredentials`, `saveOAuthCredentials`, `setOAuthStorage`, etc.) removed. Callers are responsible for storing credentials.
- **OAuth login functions**: `loginAnthropic`, `loginGitHubCopilot`, `loginGeminiCli`, `loginAntigravity` now return `OAuthCredentials` instead of saving to disk.
- **refreshOAuthToken**: Now takes `(provider, credentials)` and returns new `OAuthCredentials` instead of saving.
- **getOAuthApiKey**: Now takes `(provider, credentials)` and returns `{ newCredentials, apiKey }` or null.
- **OAuthCredentials type**: No longer includes `type: "oauth"` discriminator. Callers add discriminator when storing.
- **setApiKey, resolveApiKey**: Removed. Callers must manage their own API key storage/resolution.
- **getApiKey**: Renamed to `getEnvApiKey`. Only checks environment variables for known providers.

## [0.27.7] - 2025-12-24

### Fixed

- **Thinking tag leakage**: Fixed Claude mimicking literal `</thinking>` tags in responses. Unsigned thinking blocks (from aborted streams) are now converted to plain text without `<thinking>` tags. The TUI still displays them as thinking blocks. ([#302](https://github.com/badlogic/pi-mono/pull/302) by [@nicobailon](https://github.com/nicobailon))

## [0.25.1] - 2025-12-21

### Added

- **xhigh thinking level support**: Added `supportsXhigh()` function to check if a model supports xhigh reasoning level. Also clamps xhigh to high for OpenAI models that don't support it. ([#236](https://github.com/badlogic/pi-mono/pull/236) by [@theBucky](https://github.com/theBucky))

### Fixed

- **Gemini multimodal tool results**: Fixed images in tool results causing flaky/broken responses with Gemini models. For Gemini 3, images are now nested inside `functionResponse.parts` per the [docs](https://ai.google.dev/gemini-api/docs/function-calling#multimodal). For older models (which don't support multimodal function responses), images are sent in a separate user message.

- **Queued message steering**: When `getQueuedMessages` is provided, the agent loop now checks for queued user messages after each tool call and skips remaining tool calls in the current assistant message when a queued message arrives (emitting error tool results).

- **Double API version path in Google provider URL**: Fixed Gemini API calls returning 404 after baseUrl support was added. The SDK was appending its default apiVersion to baseUrl which already included the version path. ([#251](https://github.com/badlogic/pi-mono/pull/251) by [@shellfyred](https://github.com/shellfyred))

- **Anthropic SDK retries disabled**: Re-enabled SDK-level retries (default 2) for transient HTTP failures. ([#252](https://github.com/badlogic/pi-mono/issues/252))

## [0.23.5] - 2025-12-19

### Added

- **Gemini 3 Flash thinking support**: Extended thinking level support for Gemini 3 Flash models (MINIMAL, LOW, MEDIUM, HIGH) to match Pro models' capabilities. ([#212](https://github.com/badlogic/pi-mono/pull/212) by [@markusylisiurunen](https://github.com/markusylisiurunen))

- **GitHub Copilot thinking models**: Added thinking support for additional Copilot models (o3-mini, o1-mini, o1-preview). ([#234](https://github.com/badlogic/pi-mono/pull/234) by [@aadishv](https://github.com/aadishv))

### Fixed

- **Gemini tool result format**: Fixed tool result format for Gemini 3 Flash Preview which strictly requires `{ output: value }` for success and `{ error: value }` for errors. Previous format using `{ result, isError }` was rejected by newer Gemini models. Also improved type safety by removing `as any` casts. ([#213](https://github.com/badlogic/pi-mono/issues/213), [#220](https://github.com/badlogic/pi-mono/pull/220))

- **Google baseUrl configuration**: Google provider now respects `baseUrl` configuration for custom endpoints or API proxies. ([#216](https://github.com/badlogic/pi-mono/issues/216), [#221](https://github.com/badlogic/pi-mono/pull/221) by [@theBucky](https://github.com/theBucky))

- **GitHub Copilot vision requests**: Added `Copilot-Vision-Request` header when sending images to GitHub Copilot models. ([#222](https://github.com/badlogic/pi-mono/issues/222))

- **GitHub Copilot X-Initiator header**: Fixed X-Initiator logic to check last message role instead of any message in history. This ensures proper billing when users send follow-up messages. ([#209](https://github.com/badlogic/pi-mono/issues/209))

## [0.22.3] - 2025-12-16

### Added

- **Image limits test suite**: Added comprehensive tests for provider-specific image limitations (max images, max size, max dimensions). Discovered actual limits: Anthropic (100 images, 5MB, 8000px), OpenAI (500 images, ≥25MB), Gemini (~2500 images, ≥40MB), Mistral (8 images, ~15MB), OpenRouter (~40 images context-limited, ~15MB). ([#120](https://github.com/badlogic/pi-mono/pull/120))

- **Tool result streaming**: Added `tool_execution_update` event and optional `onUpdate` callback to `AgentTool.execute()` for streaming tool output during execution. Tools can now emit partial results (e.g., bash stdout) that are forwarded to subscribers. ([#44](https://github.com/badlogic/pi-mono/issues/44))

- **X-Initiator header for GitHub Copilot**: Added X-Initiator header handling for GitHub Copilot provider to ensure correct call accounting (agent calls are not deducted from quota). Sets initiator based on last message role. ([#200](https://github.com/badlogic/pi-mono/pull/200) by [@kim0](https://github.com/kim0))

### Changed

- **Normalized tool_execution_end result**: `tool_execution_end` event now always contains `AgentToolResult` (no longer `AgentToolResult | string`). Errors are wrapped in the standard result format.

### Fixed

- **Reasoning disabled by default**: When `reasoning` option is not specified, thinking is now explicitly disabled for all providers. Previously, some providers like Gemini with "dynamic thinking" would use their default (thinking ON), causing unexpected token usage. This was the original intended behavior. ([#180](https://github.com/badlogic/pi-mono/pull/180) by [@markusylisiurunen](https://github.com/markusylisiurunen))

## [0.22.2] - 2025-12-15

### Added

- **Interleaved thinking for Anthropic**: Added `interleavedThinking` option to `AnthropicOptions`. When enabled, Claude 4 models can think between tool calls and reason after receiving tool results. Enabled by default (no extra token cost, just unlocks the capability). Set `interleavedThinking: false` to disable.

## [0.22.1] - 2025-12-15

_Dedicated to Peter's shoulder ([@steipete](https://twitter.com/steipete))_

### Added

- **Interleaved thinking for Anthropic**: Enabled interleaved thinking in the Anthropic provider, allowing Claude models to output thinking blocks interspersed with text responses.

## [0.22.0] - 2025-12-15

### Added

- **GitHub Copilot provider**: Added `github-copilot` as a known provider with models sourced from models.dev. Includes Claude, GPT, Gemini, Grok, and other models available through GitHub Copilot. ([#191](https://github.com/badlogic/pi-mono/pull/191) by [@cau1k](https://github.com/cau1k))

### Fixed

- **GitHub Copilot gpt-5 models**: Fixed API selection for gpt-5 models to use `openai-responses` instead of `openai-completions` (gpt-5 models are not accessible via completions endpoint)

- **GitHub Copilot cross-model context handoff**: Fixed context handoff failing when switching between GitHub Copilot models using different APIs (e.g., gpt-5 to claude-sonnet-4). Tool call IDs from OpenAI Responses API were incompatible with other models. ([#198](https://github.com/badlogic/pi-mono/issues/198))

- **Gemini 3 Pro thinking levels**: Thinking level configuration now works correctly for Gemini 3 Pro models. Previously all levels mapped to -1 (minimal thinking). Now LOW/MEDIUM/HIGH properly control test-time computation. ([#176](https://github.com/badlogic/pi-mono/pull/176) by [@markusylisiurunen](https://github.com/markusylisiurunen))

## [0.18.2] - 2025-12-11

### Changed

- **Anthropic SDK retries disabled**: Set `maxRetries: 0` on Anthropic client to allow application-level retry handling. The SDK's built-in retries were interfering with coding-agent's retry logic. ([#157](https://github.com/badlogic/pi-mono/issues/157))

## [0.18.1] - 2025-12-10

### Added

- **Mistral provider**: Added support for Mistral AI models via the OpenAI-compatible API. Includes automatic handling of Mistral-specific requirements (tool call ID format). Set `MISTRAL_API_KEY` environment variable to use.

### Fixed

- Fixed Mistral 400 errors after aborted assistant messages by skipping empty assistant messages (no content, no tool calls) ([#165](https://github.com/badlogic/pi-mono/issues/165))

- Removed synthetic assistant bridge message after tool results for Mistral (no longer required as of Dec 2025) ([#165](https://github.com/badlogic/pi-mono/issues/165))

- Fixed bug where `ANTHROPIC_API_KEY` environment variable was deleted globally after first OAuth token usage, causing subsequent prompts to fail ([#164](https://github.com/badlogic/pi-mono/pull/164))

## [0.17.0] - 2025-12-09

### Added

- **`agentLoopContinue` function**: Continue an agent loop from existing context without adding a new user message. Validates that the last message is `user` or `toolResult`. Useful for retry after context overflow or resuming from manually-added tool results.

### Breaking Changes

- Removed provider-level tool argument validation. Validation now happens in `agentLoop` via `executeToolCalls`, allowing models to retry on validation errors. For manual tool execution, use `validateToolCall(tools, toolCall)` or `validateToolArguments(tool, toolCall)`.

### Added

- Added `validateToolCall(tools, toolCall)` helper that finds the tool by name and validates arguments.

- **OpenAI compatibility overrides**: Added `compat` field to `Model` for `openai-completions` API, allowing explicit configuration of provider quirks (`supportsStore`, `supportsDeveloperRole`, `supportsReasoningEffort`, `maxTokensField`). Falls back to URL-based detection if not set. Useful for LiteLLM, custom proxies, and other non-standard endpoints. ([#133](https://github.com/badlogic/pi-mono/issues/133), thanks @fink-andreas for the initial idea and PR)

- **xhigh reasoning level**: Added `xhigh` to `ReasoningEffort` type for OpenAI codex-max models. For non-OpenAI providers (Anthropic, Google), `xhigh` is automatically mapped to `high`. ([#143](https://github.com/badlogic/pi-mono/issues/143))

### Changed

- **Updated SDK versions**: OpenAI SDK 5.21.0 → 6.10.0, Anthropic SDK 0.61.0 → 0.71.2, Google GenAI SDK 1.30.0 → 1.31.0

## [0.13.0] - 2025-12-06

### Breaking Changes

- **Added `totalTokens` field to `Usage` type**: All code that constructs `Usage` objects must now include the `totalTokens` field. This field represents the total tokens processed by the LLM (input + output + cache). For OpenAI and Google, this uses native API values (`total_tokens`, `totalTokenCount`). For Anthropic, it's computed as `input + output + cacheRead + cacheWrite`.

## [0.12.10] - 2025-12-04

### Added

- Added `gpt-5.1-codex-max` model support

### Fixed

- **OpenAI Token Counting**: Fixed `usage.input` to exclude cached tokens for OpenAI providers. Previously, `input` included cached tokens, causing double-counting when calculating total context size via `input + cacheRead`. Now `input` represents non-cached input tokens across all providers, making `input + output + cacheRead + cacheWrite` the correct formula for total context size.

- **Fixed Claude Opus 4.5 cache pricing** (was 3x too expensive)
  - Corrected cache_read: $1.50 → $0.50 per MTok
  - Corrected cache_write: $18.75 → $6.25 per MTok
  - Added manual override in `scripts/generate-models.ts` until upstream fix is merged
  - Submitted PR to models.dev: https://github.com/sst/models.dev/pull/439

## [0.9.4] - 2025-11-26

Initial release with multi-provider LLM support.
