feat(analyst): answer_commit renders the final answer deterministically

packages/core/src/v1/session.ts

@@ -484,6 +484,9 @@ export const Assistant = Schema.Struct({
   structured: Schema.optional(Schema.Any),
   variant: Schema.optional(Schema.String),
   finish: Schema.optional(Schema.String),
+  // altimate_change start — preserve committed-answer echo diagnostics across Effect message events
+  metadata: Schema.optional(Schema.Record(Schema.String, Schema.Unknown)),
+  // altimate_change end
 }).annotate({ identifier: "AssistantMessage" })
 export type Assistant = Omit<Types.DeepMutable<Schema.Schema.Type<typeof Assistant>>, "error"> & {
   error?: AssistantError

packages/opencode/package.json

@@ -48,6 +48,7 @@
     "@types/turndown": "5.0.5",
     "@types/yargs": "17.0.33",
     "@typescript/native-preview": "catalog:",
+    "ajv": "8.20.0",
     "drizzle-orm": "catalog:",
     "playwright-core": "1.59.1",
     "prettier": "3.6.2",

packages/opencode/src/acp/event.ts

@@ -40,6 +40,9 @@ export class Subscription {
   private readonly abort = new AbortController()
   private readonly shellSnapshots = new Map<string, string>()
   private readonly toolStarts = new Set<string>()
+  // altimate_change start — ACP chunks cannot retract provisional compaction text
+  private readonly summaryMessages = new Set<string>()
+  // altimate_change end
   private readonly permission: ACPPermission.Handler
   private started = false
 
@@ -67,6 +70,15 @@ export class Subscription {
 
   async handle(event: Event) {
     switch (event.type) {
+      // altimate_change start — recovery clears summary before publishing its authoritative answer
+      case "message.updated": {
+        const message = event.properties.info
+        if (message.role !== "assistant") return
+        if (message.summary) this.summaryMessages.add(message.id)
+        else this.summaryMessages.delete(message.id)
+        return
+      }
+      // altimate_change end
       case "permission.asked":
         this.permission.handle(event)
         return
@@ -169,6 +181,9 @@ export class Subscription {
         : await this.fetchPartMetadata(session.id, session.cwd, props.messageID, props.partID)
     if (metadata?.role !== "assistant") return
     if (metadata.partType === "text" && props.field === "text" && metadata.ignored !== true) {
+      // altimate_change start — internal summaries may be removed or replaced after streaming
+      if (this.summaryMessages.has(props.messageID)) return
+      // altimate_change end
       await this.input.connection.sessionUpdate({
         sessionId: session.id,
         update: {
@@ -218,6 +233,9 @@ export class Subscription {
   }
 
   private async recordFetchedPart(sessionId: string, message: SessionMessageResponse, part: Part) {
+    // altimate_change start — cover subscriptions that join after the initial message update
+    if (message.info.role === "assistant" && message.info.summary) this.summaryMessages.add(message.info.id)
+    // altimate_change end
     return await Effect.runPromise(
       this.input.session.recordPartMetadata({
         sessionId,

packages/opencode/src/agent/agent.ts

@@ -328,6 +328,7 @@ export const layer = Layer.effect(
               Permission.fromConfig({
                 "*": "deny",
                 ...readOnlyDataPermission,
+                answer_commit: "allow",
                 webfetch: "allow",
                 websearch: "allow",
                 question: "allow",

packages/opencode/src/altimate/prompts/analyst.txt

@@ -18,4 +18,6 @@ You are a trainable AI teammate. Check the "Teammate Training" section in your s
 If the user corrects your behavior, offer to save it as a rule using `training_save`.
 Use `training_list` to review learned knowledge. Skills: /teach, /train, /training-status.
 
-Finish with a delimited answer: one or two sentences of basis (population, grain, caveats), then the final line `**Answer:** <requested value(s), with units>`. The final message is the deliverable: keep working notes in earlier turns, and never list candidates you excluded or alternative answers under other interpretations — pick one and state it. When the request asks for only the answer or a specific format, the final message is exactly that, with no basis. A top-N with a tie at the boundary still returns N concrete rows (note the tie briefly). If unresolved, use `**Answer:** unable to determine — <why>`; never guess.
+When the request supplies an output JSON schema (the `StructuredOutput` tool is available), finish with `StructuredOutput` instead of `answer_commit` or a plain-text reply; follow that schema. The text finalization rules below apply when no output schema is supplied.
+
+Finish by calling `answer_commit` with the single chosen value(s) with one field per item the request asks for, a one-or-two-sentence basis (population, grain, source object/column), or `unresolved` with the reason, then reply with exactly the text it returns and nothing else. Always supply `basis`, even when unresolved; it is never shown when the request asks for only the answer. Never list excluded candidates or alternative answers; a top-N with a tie at the boundary still returns N concrete rows (note the tie briefly in `rows.note`); when the request asks for only the answer or a specific format, set `answer_only`. If `answer_commit` is unavailable, finish with one or two sentences of basis and a final line `**Answer:** <requested value(s), with units>`, or `**Answer:** unable to determine — <why>`; when the request asks for only the answer or a specific format, the final message is exactly the requested value(s) or table in the requested format, with no label and no basis (or `unable to determine — <why>` if unresolved); never guess.

packages/opencode/src/altimate/run-budget.ts

@@ -4,6 +4,13 @@ import z from "zod"
 
 const generations = new Map<string, () => void>()
 
+/** A harness deadline stops generation but may still deliver an already committed answer. */
+export class HarnessDeadline extends DOMException {
+  constructor() {
+    super("Run time budget hard deadline reached", "AbortError")
+  }
+}
+
 /** Register only the active provider request; disposing cannot remove a newer request. */
 export function registerGeneration(sessionID: string, interrupt: () => void): () => void {
   generations.set(sessionID, interrupt)