pi-ds-anchor.ts

A developer released pi-ds-anchor.ts, an extension for the Pi coding agent that adds two commands—/new-ds-anchored-session and /ds-anchor—to send a tool-free 'who are you' probe with a minimal system prompt to DeepSeek models. The extension restricts the probe to DeepSeek v4 flash and pro models, rewrites the provider payload to strip tools, and stores anchoring state as a custom session entry for persistence.

| / | | | DS Anchored Session Extensions | | | | | | Provides two commands that send a single "who are you" probe with: | | | - a minimal system prompt "You are a helpful software engineer assistant" | | | - no tools in the provider payload | | | | | | /new-ds-anchored-session | | | Creates a new session, then runs the anchored probe as its first message. | | | | | | /ds-anchor | | | Runs the anchored probe in the current session. Fails if the session | | | already has conversation history or the current model is not supported. | | | | | | The anchoring state is stored as a custom session entry so it survives | | | session persistence; before provider request rewrites only the probe turn. | | | / | | | import type { | | | ExtensionAPI, | | | ExtensionCommandContext, | | | ExtensionContext, | | | SessionEntry, | | | } from "@earendil-works/pi-coding-agent"; | | | const ALLOWED PROVIDER = "deepseek"; | | | const ALLOWED MODEL IDS = new Set "deepseek-v4-flash", "deepseek-v4-pro" ; | | | const SINGLE SYSTEM PROMPT = "You are a helpful software engineer assistant"; | | | const ANCHOR CUSTOM TYPE = "ds-anchored-session"; | | | const ANCHOR WIDGET ID = "ds-anchored-session"; | | | interface AnchorState { | | | phase: "anchoring" | "done"; | | | } | | | interface ModelIdentity { | | | provider: string; | | | id: string; | | | } | | | function isAllowedModel model: ModelIdentity | undefined | null : boolean { | | | return | | | model == undefined && | | | model == null && | | | model.provider === ALLOWED PROVIDER && | | | ALLOWED MODEL IDS.has model.id | | | ; | | | } | | | function modelLabel model: ModelIdentity : string { | | | return ${model.provider}/${model.id} ; | | | } | | | function findLatestAnchorEntry entries: SessionEntry : AnchorState | undefined { | | | for let i = entries.length - 1; i = 0; i-- { | | | const entry = entries i ; | | | if entry.type === "custom" && entry.customType === ANCHOR CUSTOM TYPE { | | | return entry.data as AnchorState; | | | } | | | } | | | return undefined; | | | } | | | function hasConversationHistory entries: SessionEntry : boolean { | | | return entries.some entry = entry.type === "message" || entry.type === "compaction" ; | | | } | | | function isAnchoring entries: SessionEntry : boolean { | | | return findLatestAnchorEntry entries ?.phase === "anchoring"; | | | } | | | function rewritePayloadForAnchoring payload: unknown : unknown { | | | if typeof payload == "object" || payload === null { | | | return payload; | | | } | | | const request = payload as Record<string, unknown ; | | | const messages = request.messages; | | | if Array.isArray messages { | | | const firstMessage = messages 0 as Record<string, unknown | undefined; | | | if | | | firstMessage == undefined && | | | firstMessage.role === "system" || firstMessage.role === "developer" | | | { | | | firstMessage.content = SINGLE SYSTEM PROMPT; | | | } else { | | | messages.unshift { role: "system", content: SINGLE SYSTEM PROMPT } ; | | | } | | | } | | | // DeepSeek uses the OpenAI-compatible chat completions format. | | | delete request.tools; | | | delete request.tool choice; | | | return request; | | | } | | | export default function pi: ExtensionAPI { | | | // Set by /new-ds-anchored-session before ctx.newSession and consumed by | | | // the replacement session's session start handler. Plain module state is | | | // safe to carry across the session replacement lifecycle. | | | let pendingNewSessionAnchor = false; | | | pi.registerCommand "ds-anchor", { | | | description: | | | "Send a tool-free 'who are you' probe with a minimal system prompt in the current session", | | | handler: async args: string, ctx: ExtensionCommandContext = { | | | if ctx.model === undefined || isAllowedModel ctx.model { | | | ctx.ui.notify | | | ds-anchor requires model ${ALLOWED PROVIDER}/ ${ ...ALLOWED MODEL IDS .join ", " } , current: ${ctx.model ? modelLabel ctx.model : "none"} , | | | "error", | | | ; | | | return; | | | } | | | if ctx.modelRegistry.hasConfiguredAuth ctx.model { | | | ctx.ui.notify ds-anchor: no API key configured for ${modelLabel ctx.model } , "error" ; | | | return; | | | } | | | if hasConversationHistory ctx.sessionManager.getEntries { | | | ctx.ui.notify "ds-anchor requires a session without conversation history", "error" ; | | | return; | | | } | | | pi.appendEntry ANCHOR CUSTOM TYPE, { phase: "anchoring" } ; | | | ctx.ui.setWidget ANCHOR WIDGET ID, "Anchoring" ; | | | pi.sendUserMessage "who are you" ; | | | }, | | | } ; | | | pi.registerCommand "new-ds-anchored-session", { | | | description: | | | "Create a new session and send a tool-free 'who are you' probe with a minimal system prompt", | | | handler: async args: string, ctx: ExtensionCommandContext = { | | | pendingNewSessionAnchor = true; | | | const result = await ctx.newSession { | | | withSession: async newCtx = { | | | // session start already wrote the anchoring state when the | | | // replacement model is supported; this is the final check. | | | if newCtx.model === undefined || isAllowedModel newCtx.model { | | | newCtx.ui.notify | | | new-ds-anchored-session requires model ${ALLOWED PROVIDER}/ ${ ...ALLOWED MODEL IDS .join ", " } , current: ${newCtx.model ? modelLabel newCtx.model : "none"} , | | | "error", | | | ; | | | return; | | | } | | | if newCtx.modelRegistry.hasConfiguredAuth newCtx.model { | | | newCtx.ui.notify | | | new-ds-anchored-session: no API key configured for ${modelLabel newCtx.model } , | | | "error", | | | ; | | | return; | | | } | | | await newCtx.sendUserMessage "who are you" ; | | | }, | | | } ; | | | if result.cancelled { | | | pendingNewSessionAnchor = false; | | | } | | | }, | | | } ; | | | pi.on "session start", event, ctx: ExtensionContext = { | | | if event.reason == "new" || pendingNewSessionAnchor { | | | return; | | | } | | | pendingNewSessionAnchor = false; | | | // Only write the anchoring state when the replacement session is usable. | | | if ctx.model === undefined || isAllowedModel ctx.model { | | | return; | | | } | | | if ctx.modelRegistry.hasConfiguredAuth ctx.model { | | | return; | | | } | | | pi.appendEntry ANCHOR CUSTOM TYPE, { phase: "anchoring" } ; | | | ctx.ui.setWidget ANCHOR WIDGET ID, "Anchoring" ; | | | } ; | | | pi.on "before provider request", event, ctx: ExtensionContext = { | | | if isAnchoring ctx.sessionManager.getEntries { | | | return undefined; | | | } | | | // Safety net: never rewrite payloads for models outside the supported set. | | | if isAllowedModel ctx.model { | | | return undefined; | | | } | | | return rewritePayloadForAnchoring event.payload ; | | | } ; | | | pi.on "agent settled", event, ctx: ExtensionContext = { | | | if isAnchoring ctx.sessionManager.getEntries { | | | return; | | | } | | | pi.appendEntry ANCHOR CUSTOM TYPE, { phase: "done" } ; | | | ctx.ui.setWidget ANCHOR WIDGET ID, "Anchored" ; | | | } ; | | | } |