fix: preserve unexpected provider finish reasons

packages/opencode/src/kilocode/session/processor.ts

@@ -10,7 +10,7 @@ import * as Log from "@opencode-ai/core/util/log"
 import { Cause, Effect, Exit } from "effect"
 import { Flag } from "@opencode-ai/core/flag/flag"
 import { EffectBridge } from "@/effect/bridge"
-import type { LLMEvent, Usage } from "@opencode-ai/llm"
+import type { LLMEvent, ProviderMetadata, Usage } from "@opencode-ai/llm"
 import type { ProviderV2 } from "@opencode-ai/core/provider"
 import { SessionRetry } from "@/session/retry"
 import { computeMetrics as computeMetricsHelper, type TokenRates } from "@/kilocode/session/metrics"
@@ -137,6 +137,14 @@ export namespace KiloSessionProcessor {
   /** Returned shape for downstream consumers that prefer the namespace. */
   export type Metrics = TokenRates
 
+  export function generationID(meta: ProviderMetadata | undefined) {
+    const value = meta?.gateway?.generationId
+    if (typeof value !== "string") return
+    const id = value.trim()
+    if (!/^gen_[A-Za-z0-9_-]{1,200}$/.test(id)) return
+    return id
+  }
+
   /**
    * Effect-based offline handler for the retry schedule.
    * Shows offline status, waits for network reconnection or user rejection.

packages/opencode/src/session/processor.ts

@@ -869,6 +869,7 @@ export const layer = Layer.effect(
               modelID: ctx.model.id,
               selected: ctx.assistantMessage.modelID,
             })
+            const generationID = KiloSessionProcessor.generationID(value.providerMetadata)
             // kilocode_change end
             // kilocode_change start - guard against finish-step without start-step:
             // ctx.stepStart is 0 until `start-step` fires, which would feed a
@@ -922,6 +923,7 @@ export const layer = Layer.effect(
               type: "step-finish",
               time: { start: startDate, end: endDate, elapsed: elapsedMs }, // kilocode_change
               ...(model ? { model } : {}), // kilocode_change
+              ...(generationID ? { generationID } : {}), // kilocode_change
               ...(metrics ? { metrics } : {}), // kilocode_change
               tokens: usage.tokens,
               cost: usage.cost,

packages/opencode/test/kilocode/session-generation-id.test.ts

@@ -0,0 +1,23 @@
+import { describe, expect, test } from "bun:test"
+import { KiloSessionProcessor } from "../../src/kilocode/session/processor"
+
+describe("session generation id", () => {
+  test("extracts a bounded Gateway generation id", () => {
+    expect(
+      KiloSessionProcessor.generationID({
+        gateway: {
+          generationId: " gen_test-123 ",
+          routing: { finalProvider: "novita" },
+          marketCost: "0.1",
+        },
+      }),
+    ).toBe("gen_test-123")
+  })
+
+  test("rejects arbitrary or oversized metadata values", () => {
+    expect(KiloSessionProcessor.generationID({ gateway: { generationId: "request-secret" } })).toBeUndefined()
+    expect(KiloSessionProcessor.generationID({ gateway: { generationId: `gen_${"a".repeat(201)}` } })).toBeUndefined()
+    expect(KiloSessionProcessor.generationID({ gateway: { generationId: 42 } })).toBeUndefined()
+    expect(KiloSessionProcessor.generationID({ openai: { responseId: "gen_response" } })).toBeUndefined()
+  })
+})

packages/opencode/test/kilocode/session-processor-empty-tool-calls.test.ts

@@ -577,7 +577,14 @@ describe("session processor empty tool-calls", () => {
               index: 0,
               reason: "stop",
               usage: usage(),
-              providerMetadata: { kilocode: { routedModelID: "openai/gpt-5.5-20260423" } },
+              providerMetadata: {
+                kilocode: { routedModelID: "openai/gpt-5.5-20260423" },
+                gateway: {
+                  generationId: "gen_test",
+                  routing: { finalProvider: "openai" },
+                  marketCost: "0.1",
+                },
+              },
             }),
             LLMEvent.finish({ reason: "stop", usage: usage() }),
           )
@@ -632,6 +639,9 @@ describe("session processor empty tool-calls", () => {
             providerID: selection.providerID,
             modelID: ModelV2.ID.make("openai/gpt-5.5-20260423"),
           })
+          expect(part?.generationID).toBe("gen_test")
+          expect(part).not.toHaveProperty("providerMetadata")
+          expect(part).not.toHaveProperty("gateway")
         }),
       { git: true },
     ),

packages/opencode/test/session/llm.test.ts

@@ -281,7 +281,7 @@ describe("session.llm.ai-sdk adapter", () => {
       {
         type: "step-finish",
         index: 0,
-        reason: "unknown",
+        reason: "other", // kilocode_change
         usage: {
           inputTokens: 10,
           outputTokens: 5,
@@ -294,7 +294,7 @@ describe("session.llm.ai-sdk adapter", () => {
       },
       {
         type: "finish",
-        reason: "unknown",
+        reason: "other", // kilocode_change
         usage: {
           inputTokens: 11,
           outputTokens: 6,