Pi Updates & Release Notes

Breaking Changes

Removed the openai-responses compat.sendSessionIdHeader flag from models.json. Session-affinity behavior is now controlled by compat.sessionAffinityFormat ("openai", "openai-nosession", or "openrouter"). Replace sendSessionIdHeader: false with sessionAffinityFormat: "openai-nosession" (#6496 by @petrroll).

New Features

Cache-friendly dynamic tool loading - Extensions can add tools during execution while supported Anthropic and OpenAI Responses models preserve prompt-cache prefixes. See Dynamic Tool Loading.

Message copy shortcut - Ctrl+X copies the last assistant message in the transcript or the selected message in /tree, making older and branched messages directly copyable. See Display and Message Queue.

Fable 5 xhigh and max thinking - Native xhigh and max thinking levels are available across generated provider catalogs. See Model Options.

Added

Added cache-friendly dynamic tool loading for extension tools activated by tool results. Supported Anthropic and OpenAI Responses models load definitions where they become available, preserving the cached prompt prefix. See Dynamic Tool Loading (#6474).

Added inherited native xhigh and max thinking levels for Claude Fable 5 across all generated provider catalogs (#6490 by @davidbrai).

Added Ctrl+X to copy the last assistant message, or the selected message in /tree.

Added inherited toolChoice support for OpenAI and Codex Responses, including required and named tool selection (#6588 by @xl0).

Fixed

Fixed inherited OpenRouter model context windows to use the top provider's actual context length (#6481 by @davidbrai).

Fixed inherited OpenRouter OpenAI-compatible session IDs to use the x-session-id header instead of OpenAI-specific session-affinity fields (#6496 by @petrroll).

Fixed Ctrl+V to paste clipboard text when the pasteboard does not contain an image.

Fixed /login amazon-bedrock to prompt for and save a Bedrock API key instead of only displaying ambient AWS credential setup instructions.

Fixed inherited Amazon Bedrock ambient AWS credentials to keep using SigV4 authentication, including for custom model IDs (#6532 by @ribelo).

Fixed inherited Cloudflare Workers AI and AI Gateway authentication to use ambient account and gateway IDs when stored credentials contain only an API key (#6292 by @markphelps).

Fixed inherited legacy terminal decoding for Alt+symbol key combinations such as Alt+, and Alt+. (#6523 by @ribelo).

Fixed the GitHub Copilot mai-code-1-flash-picker model to route through the /responses endpoint (#6544 by @petrroll).

Fixed branch summaries to work with providers that use ambient authentication instead of API keys (#6595 by @davidbrai).

Fixed inherited Amazon Bedrock errors to report unhandled provider stop reasons instead of only An unknown error occurred (#6598 by @davidbrai).

Fixed npm package removal when installed packages have conflicting peer dependencies (#6604 by @davidbrai).

Fixed inherited Azure OpenAI Responses reasoning replay when encrypted_content appears only in the terminal response event (#6608 by @davidbrai).

Fixed inherited Anthropic-compatible proxies that omit usage from message_delta events (#6611 by @davidbrai).

Fixed inherited OpenCode OpenAI Responses models to omit the unsupported session-id header while preserving other cache-affinity data (#6645 by @davidbrai).

Fixed system prompt cache invalidation across dates by removing the current date from the default prompt (#6621).

New Features

max thinking level - New opt-in thinking level above xhigh, natively supported on GPT-5.6 and adaptive Claude models, available across CLI (--thinking max), SDK, RPC, and model selection. Custom themes can define thinkingMax. See CLI Reference.

Input-based pricing tiers - Request-wide input-token pricing tiers for accurate long-context cost accounting (e.g. GPT-5.4/5.5/5.6 long-context rates), also configurable for custom models in models.json and modelOverrides. See Model Configuration.

Added

Added the opt-in max thinking level across CLI, SDK, RPC, model selection, and themes. Custom themes can define thinkingMax; existing themes fall back to thinkingXhigh.

Added request-wide input-token pricing tiers to custom model costs in models.json, modelOverrides, and extension-registered providers.

Added ~ (home directory) expansion for the shellPath setting (#6470 by @aaronkyriesenbach).

Fixed

Fixed inherited post-compaction output-token budgeting to ignore stale assistant usage from before the compaction boundary (#6464).

Fixed inherited GPT-5.4 and GPT-5.5 long-context cost accounting while retaining the intentional 272K default context limit for models that require an explicit override.

Fixed inherited GPT-5.6 metadata to keep direct OpenAI requests in the 272K short-context tier while exposing the Codex backend's 372K context window with long-context pricing, and removed the nonexistent bare gpt-5.6 alias.

Fixed inherited Anthropic message conversion to preserve thinking blocks with empty thinking text but a valid signature instead of dropping them, avoiding thinking-block errors on newer Claude models (#6457 by @davidbrai).

New Features

Anthropic Claude Sonnet 5 support - Claude Sonnet 5 is available through inherited Anthropic-compatible and Bedrock provider catalogs with adaptive thinking enabled. See Providers and Model Options.

Configurable output spacing - outputPad controls horizontal padding for user messages, assistant messages, and thinking blocks. See Settings.

External editor configuration - externalEditor lets Ctrl+G use a configured editor before $VISUAL/$EDITOR fallbacks. See Settings and Keybindings.

Richer RPC session tree access - RPC clients can inspect session entries and tree snapshots with get_entries and get_tree. See get_entries and get_tree.

Extension session metadata updates - Extensions can observe session name changes through session_info_changed. See session_info_changed.

Modern Azure Foundry endpoint support - Azure OpenAI Responses provider setup supports current Microsoft Foundry endpoint URLs. See Azure OpenAI.

Added

Added inherited Anthropic Claude Sonnet 5 model support.

Added get_entries and get_tree RPC commands for reading session entries and tree snapshots over RPC (#6078 by @geraschenko).

Added a package ./rpc-entry export for launching Pi directly in RPC mode.

Added session-name change events for extensions (#6175 by @xl0).

Added inherited Azure OpenAI Responses support for modern Microsoft Foundry endpoint URLs (#6004 by @gukoff).

Added inherited Usage.reasoning token counts for providers that report reasoning/thinking token usage (#6057).

Added an externalEditor settings.json override for Ctrl+G external editor commands, with default fallbacks to Notepad on Windows and nano elsewhere (#6122).

Added an outputPad setting for user message, assistant message, and thinking horizontal padding (#6168).

Changed

Changed the default OpenAI model to gpt-5.5.

Changed inherited OpenAI Codex Responses SSE response-header waits to use the configured HTTP timeout instead of the previous fixed 20 second timeout, reducing false timeouts on slow connections (#4945).

Fixed

Fixed inherited Claude Sonnet 5 metadata to use adaptive thinking payloads for Anthropic-compatible and Bedrock requests.

Fixed inherited generated Xiaomi MiMo model pricing to match current pay-as-you-go pricing from models.dev (#6138).

Fixed inherited provider HTTP errors to include response bodies instead of opaque SDK messages (#5832 by @stephanmck).

Fixed inherited streamSimple() max-token caps so providers that count input and output against one context window do not reject long requests (#5595).

Fixed inherited OpenAI Responses streams to preserve reasoning replay state when output items finish out of order (#6009).

Fixed inherited Z.AI preserved thinking requests to send thinking.clear_thinking: false when thinking is enabled, allowing replayed reasoning_content to participate in provider caching (#6083).

Fixed pre-prompt compaction to stop after compaction instead of continuing immediately (#6074 by @yzhg1983).

Fixed resource notifications to stay before messages when resuming sessions (#6048 by @haoqixu).

Fixed startup benchmark timing output to print after TUI shutdown, preserve extension timings, and drain terminal-query replies before stopping benchmark mode (#6030 by @xl0, #6063 by @xl0).

Fixed extension tool changes to apply before the next provider request in the same agent run without dropping before_agent_start system-prompt overrides (#6162).

Fixed a crash when undici emits an internal client error while terminating a mid-stream HTTP response (#6133).

Fixed the compaction event regression test to cover status indicator cleanup and keep CI passing.

Fixed interactive status indicators so ending work, retry, compaction, or branch-summary indicators no longer shrink the TUI when clear-on-shrink is enabled (#6026).

Fixed --session and SessionManager.open() to reject non-empty invalid session files without overwriting them (#6002).

Fixed user-message transcript rendering to keep visible backslashes in Markdown escape sequences such as " (#6105).

Fixed assistant messages stopped by output length to show a visible incomplete-response error (#4290).

Fixed --no-session --session-id so ephemeral CLI runs can use deterministic session IDs for provider cache affinity (#6070).

Fixed disk BMP image files to be detected, converted to PNG, and attached through read and CLI @file inputs (#6047).

Fixed auto-retry for provider stream errors that explicitly tell callers to retry the request (#6019).

Changed

Changed inherited pi-ai ApiKeyCredential to use the auth.json-compatible discriminator type: "api_key" and provider-scoped env values instead of type: "api-key" and metadata.

Renamed the inherited agent-core public harness shell execution options type from ExecutionEnvExecOptions to ShellExecOptions.

Fixed

Fixed inherited Anthropic-compatible custom models to use explicit compatibility metadata instead of provider-name heuristics for session-affinity headers and unsupported tool-field omissions.

Fixed inherited request-scoped apiKey and env values to participate in provider auth resolution, so providers such as Cloudflare can derive request-specific base URLs from explicit call options (#6021).

Restored inherited temporary legacy per-API stream aliases such as streamSimpleOpenAICompletions on the pi-ai compat entrypoint (#6016, #6017).

Restored inherited runtime detectCompat fallback in openai-completions for models without explicit compat metadata (#6020).

Changed

Added Ctrl+J as a default newline keybinding alongside Shift+Enter.

Renamed the displayed zai provider label to ZAI Coding Plan (Global) for clarity (#5965).

pi-ai's old global API (stream/complete/completeSimple, getModel/getModels/getProviders, registerApiProvider, getEnvApiKey, ...) moved off the @earendil-works/pi-ai root entrypoint to @earendil-works/pi-ai/compat. Extensions are not affected at runtime: the extension loader resolves the pi-ai root to the compat entrypoint (a strict superset), so existing extensions keep working unchanged. Extension sources that typecheck against pi-ai's published types should switch those imports to @earendil-works/pi-ai/compat (or migrate to the new createModels()/provider-factory API). The compat entrypoint and the loader alias will be removed in a future release with a migration guide.

Fixed

Fixed session names to normalize newline characters before storing or displaying labels (#5999 by @haoqixu).

Fixed the session selector to order threaded session trees by the latest activity anywhere in each subtree (#5784 by @Perlence).

Fixed extension-related crash and startup-failure reporting to suggest restarting with pi -ne.

Fixed inherited OpenAI Responses streams to fail before missing terminal events and fixed context usage and compaction estimates to ignore malformed all-zero assistant usage after truncated responses (#5526 by @dmmulroy).

Fixed inherited OpenAI Codex Responses WebSocket sessions to reconnect once when OpenAI's connection limit is reached before output starts (#5973).

Fixed inherited Amazon Bedrock endpoint resolution to honor scoped AWS_PROFILE values.

Fixed inherited Cloudflare providers to require account/gateway configuration and route built-in compat calls through provider auth.

Fixed provider-scoped auth environment values to reach inherited Models/ImagesModels API calls and compat API-key injection.

Fixed inherited OpenCode Go GLM-5.2 metadata to expose xhigh reasoning and send the provider's max reasoning effort (#5967).

Fixed pi --resume to load user package themes and resolve automatic light/dark theme settings.

Fixed models.json custom providers so stored credentials can satisfy auth without a redundant provider-level apiKey (#5953).

Removed

Removed inherited selective-provider @earendil-works/pi-ai/base and @earendil-works/pi-agent-core/base entrypoints; use the root packages with explicit Models provider factories instead.

New Features

Extension compaction event context - Extension session_before_compact and session_compact events now include reason and willRetry, so extensions can distinguish manual /compact, threshold auto-compaction, and overflow retry flows. See session_before_compact / session_compact and Custom Summarization via Extensions.

Safer update flow - pi update installs the exact checked Pi version, and update notices show the changelog URL, making upgrades more predictable. See Install and Manage.

Added

Added reason and willRetry metadata to extension session_before_compact and session_compact events so extensions can distinguish manual, threshold, and overflow compaction flows (#5962 by @PizzaMarinara).

Fixed

Fixed the find tool to respect nested git repository boundaries when parent .gitignore rules ignore the nested repo (#5960).

Fixed the usage docs slash command table to include /trust and /import (#5959).

Fixed inherited OpenAI-compatible streaming to preserve encrypted reasoning_details that arrive before matching tool call deltas (#5114).

Fixed broken TUI documentation links to the plan-mode extension example (#5957).

Fixed transient extension UI and session-start messages emitted during session replacement or reload so they remain visible, and kept reload input blocked until reload completes (#5943).

Fixed the plan-mode example to preserve active custom tools, skip the action prompt when no plan is found, and queue refinement/execution follow-ups correctly from agent_end (#5940).

Fixed pi update to install the exact version returned by the Pi update check, make --force reinstall that checked version, fail instead of falling back to an unversioned reinstall when no version is available, and report both the old and updated versions.

Fixed update notifications to display the actual changelog URL as the hyperlink text.

New Features

Chat-template thinking compatibility - OpenAI-compatible custom providers can map Pi thinking levels into chat_template_kwargs, enabling vLLM/Hugging Face chat-template models such as DeepSeek to use provider-native thinking controls. See Custom Provider API Types and OpenAI Compatibility.

GLM-5.2 provider improvements - GLM-5.2 now has corrected Fireworks OpenAI-compatible routing and OpenRouter xhigh thinking support, improving /model behavior and high-effort reasoning for GLM-5.2 users. See Model Options.

Added

Added inherited configurable chat-template thinking support for OpenAI-compatible providers that use chat_template_kwargs, such as DeepSeek models behind vLLM (#5673).

Fixed

Fixed inherited Fireworks GLM-5.2 metadata to use the OpenAI-compatible Chat Completions endpoint with reasoning_effort support (#5923).

Fixed same-directory session switches to reuse imported extension modules while preserving fresh extension instances and lifecycle events (#5905).

Fixed deep session branches taking quadratic time to build context or branch paths (#5909).

Fixed inherited OpenRouter GLM-5.2 metadata to expose xhigh reasoning and send OpenRouter's native xhigh effort (#5770).

Fixed inherited Markdown streaming code fence rendering so partial closing fences no longer make code blocks shrink or flicker while content streams (#5846 by @xl0).

Fixed fuzzy edit matches to preserve untouched line blocks instead of rewriting the whole file through normalized content (#5899).

Fixed bash commands through legacy WSL bash.exe to pass scripts over stdin so shell variables expand in the target bash (#5893).

Fixed /model to hide GitHub Copilot models that are unavailable to the authenticated account (#5897).

Fixed /model selector search to rank exact provider-prefixed matches before proxy-provider model ID matches (#5892).

New Features

Selective provider base entry points - SDK users can pair @earendil-works/pi-ai/base and @earendil-works/pi-agent-core/base with explicit provider registration to keep bundled applications from including unused provider transports. See pi-ai Base Entry Point and pi-agent-core Base Entry Point.

Mistral prompt caching - Mistral sessions now use provider-side prompt caching with session affinity and cached-token usage/cost accounting. See API Keys and Environment Variables.

Post-compaction token estimates - Compact results and compaction events now include estimated post-compaction token counts so clients can show the approximate context reduction. See RPC compact and compaction events.

OpenRouter Fusion alias - openrouter/fusion is available as a built-in OpenRouter model alias. See API Keys.

Added

Added inherited @earendil-works/pi-ai/base and @earendil-works/pi-agent-core/base entry points for selective provider registration in bundled applications (#5348 by @FredKSchott).

Added inherited Mistral prompt caching using the pi session ID as prompt_cache_key, including cached-token usage and cost accounting (#5854).

Added estimated post-compaction token counts to compact results and compaction events (#5877).

Added the inherited OpenRouter Fusion alias as openrouter/fusion (#5866 by @dannote).

Fixed

Updated vulnerable runtime dependencies, including undici and the packaged protobufjs transitive dependency.

Fixed compaction to refuse sessions with no eligible messages instead of producing empty summaries (#4811).

Fixed successful overflow-triggered auto-compaction to avoid retrying completed assistant responses (#5720).

New Features

• Automatic theme mode - /settings can choose separate light and dark themes and follow terminal color-scheme changes. See Selecting a Theme.
• Self-only updates by default - pi update now updates pi only, with pi update --all for updating pi and packages together. See Install and Manage.
• Extension API helpers - extensions can use CONFIG_DIR_NAME for project config paths and import edit diff helpers for edit-style diffs. See ctx.cwd and SDK Exports.
• Warp inline images - Warp terminals now get inline image rendering through Kitty graphics detection. See Image.

Added

• Added automatic theme mode so /settings can use separate light and dark themes and follow terminal color-scheme changes (#5874).
• Added inherited Warp terminal image capability detection so inline images render through Warp's Kitty graphics support (#5841 by @dodiego).
• Exported CONFIG_DIR_NAME from the coding-agent public API so extensions can resolve project config paths without hardcoding .pi (#5869 by @xl0).
• Exported edit diff helpers (generateDiffString, generateUnifiedPatch, and EditDiffResult) from the public API for extensions that need edit-style diffs (#5756 by @xl0).

Changed

• Changed bare pi update to update only pi, added pi update --all for updating pi and extensions together, and clarified extension update prompts.
• Reserved / in theme names for automatic light/dark theme settings.
• Updated extension docs, examples, runtime help, trust prompts, and config labels to use the configured project config directory instead of hardcoded .pi paths.

Fixed

• Fixed RPC unknown-command errors to include the request id so clients do not hang waiting for a response (#5868).
• Fixed /model autocomplete and model selection searches to match provider/model queries regardless of whether the provider or model token is typed first.
• Fixed the tree navigator to horizontally pan deep entries so the selected item remains readable (#5830).

New Features

Provider-scoped API key environments - auth.json API key entries can now include env overrides for provider-specific Cloudflare, Azure OpenAI, Google Vertex, Amazon Bedrock, cache retention, and proxy settings without changing the project shell. See Auth File.

Global HTTP proxy setting - Configure httpProxy once in global settings to apply HTTP_PROXY and HTTPS_PROXY to Pi-managed HTTP clients. See Network.

Vercel AI Gateway attribution - Vercel AI Gateway requests now include Pi attribution headers by default. See API Keys.

Added

• Added Vercel AI Gateway request attribution headers (http-referer and x-title) for Vercel AI Gateway models (#5798 by @rwachtler).
• Added an xp footer marker when experimental features are enabled.
• Added a global httpProxy setting that applies as HTTP_PROXY and HTTPS_PROXY for Pi-managed HTTP clients (#5790).
• Added auth.json API key env values so provider-specific environment overrides can be scoped to Pi and propagated to inherited provider configuration (#5728).

Changed

Updated the vendored Markdown parser used by HTML session exports to marked 18.0.5.

Fixed

• Fixed inherited OpenAI Responses streaming to tolerate null message content from OpenAI-compatible servers before tool calls (#5819).
• Fixed inherited OpenCode DeepSeek V4 thinking requests to avoid sending both thinking and reasoning_effort (#5818).
• Fixed device-code login to stop opening the browser automatically.
• Fixed inherited editor Cursor Up handling so non-empty drafts jump to the start of the line before browsing input history (#5789 by @4h9fbZ).
• Fixed inherited Z.AI GLM-5.2 thinking requests to send reasoning_effort with the provider's high/max effort mapping (#5770).
• Fixed successful pi update on Windows to exit naturally instead of calling process.exit(0), avoiding a Node.js/libuv assertion after version-check network requests (#5805).
• Fixed inherited Google and google-vertex Gemini model metadata to map latest aliases to the current models, add Gemini 3.5 Flash for Vertex, correct Gemini 2.5 Flash Vertex cache pricing, and remove shut-down Vertex preview models (#5761).
• Fixed the session selector to stay open and show the all-sessions empty state when both current-folder and all-scope session lists are empty (#5747).
• Fixed inherited Moonshot AI China model metadata to include Kimi K2.7 Code, and omitted unsupported thinking-off payloads for Kimi K2.7 Code models (#5760).

New Features

Automatic first-run theme selection - pi detects the terminal background on first run and defaults to the dark or light theme. See Selecting a Theme.

Standalone binary integrity checksums - GitHub release assets now include SHA256SUMS files for verifying standalone binary downloads. See Quickstart Install.

Added

Added SHA256SUMS integrity files to standalone binary GitHub release assets (#5739).

Added first-run interactive theme detection from the terminal background (#5385 by @vegarsti).

Fixed

Fixed bash tool output collection to keep draining stdout/stderr after the child exits while descendants still write, avoiding truncated late output (#5753 by @Mearman).

Fixed /tree help rendering to show compact wrapped controls instead of truncating them on narrow terminals (#5055).

Fixed SIGTERM/SIGHUP interactive shutdown to keep signal handlers installed until terminal cleanup completes, preventing signal-exit from re-sending the signal and leaving the terminal in raw/Kitty keyboard mode (#5724).

Fixed extensions documentation to clarify that pi.getActiveTools() returns active tool names while pi.getAllTools() returns tool metadata (#5729).

Fixed question and questionnaire extension examples to wrap long prompt, option, and help text instead of truncating it (#5708 by @xl0).

Fixed package commands such as pi list, pi install, and pi update to terminate after completing even if an extension leaves background handles open (#5687).

Fixed pi update for pnpm global installs whose configured global-bin-dir no longer matches the active pnpm home (#5689).

Fixed npm package specs that use ranges or tags (for example @^1.2.7) so installed package resources still load instead of being treated as mismatched exact pins (#5695).

Fixed inherited Anthropic 1-hour prompt-cache write cost accounting to price 1-hour cache writes at 2x input instead of the 5-minute cache-write rate (#5738 by @theBucky).

Fixed inherited GitHub Copilot Claude adaptive-thinking effort metadata to match manually checked Copilot model capabilities (#4637).

Fixed inherited OpenCode/OpenCode Go completion model metadata to omit long-retention cache fields for routes that reject prompt_cache_retention (#5702).

Fixed inherited overlay compositing over CJK wide characters so borders stay aligned when an overlay starts inside a full-width cell (#5297).

Fixed inherited WezTerm inline Kitty image rendering during full redraw fallbacks so image padding rows are reserved before the placement is drawn without regressing tall-image placement (#5618, #4415).

Fixed custom provider config so plain uppercase API key and header values remain literals instead of being treated as legacy environment references; use explicit $ENV_VAR syntax for environment variables (#5661).