fix: preserve tool results when call IDs are reused

README.md

@@ -49,6 +49,8 @@ In `range` mode, when a new compression overlaps an earlier one, the earlier sum
 
 Identifies repeated tool calls (same tool, same arguments) and keeps only the most recent output. Recalculated when the compress tool runs, so prompt cache is only impacted alongside compression.
 
+When a provider reuses a tool call ID, DCP retains those calls instead of automatically pruning or sweeping an ambiguous ID. Unique IDs keep the normal pruning behavior. Original provider call/result IDs are preserved.
+
 ### Purge Errors
 
 Prunes inputs from errored tool calls after a configurable number of turns. Error messages are preserved; only the potentially large input content is removed. Recalculated on compress tool use.

lib/commands/sweep.ts

@@ -19,6 +19,7 @@ import { saveSessionState } from "../state/persistence"
 import { isMessageCompacted } from "../state/utils"
 import { isToolProtected } from "../protected-patterns"
 import { syncToolCache } from "../state/tool-cache"
+import { getAmbiguousToolIds } from "../tool-ids"
 
 export interface SweepCommandContext {
     client: any
@@ -164,8 +165,9 @@ export async function handleSweepCommand(ctx: SweepCommandContext): Promise<void
     }
 
     // Filter out already-pruned tools, protected tools, and protected file paths
+    const ambiguousIds = getAmbiguousToolIds(messages)
     const newToolIds = toolIdsToSweep.filter((id) => {
-        if (state.prune.tools.has(id)) {
+        if (state.prune.tools.has(id) || ambiguousIds.has(id)) {
             return false
         }
         const entry = state.toolParameters.get(id)

lib/compress/protected-content.ts

@@ -8,6 +8,7 @@ import {
 } from "../subagents/subagent-results"
 import { fetchSessionMessages } from "./search"
 import type { SearchContext, SelectionResolution } from "./types"
+import { toolOccurrenceKey } from "../tool-ids"
 
 export function appendProtectedUserMessages(
     summary: string,
@@ -152,7 +153,8 @@ export async function appendProtectedTools(
                         part.state?.status === "completed" &&
                         typeof part.state?.output === "string"
                     ) {
-                        const cachedSubAgentResult = state.subAgentResultCache.get(part.callID)
+                        const cacheKey = toolOccurrenceKey(message, part)
+                        const cachedSubAgentResult = state.subAgentResultCache.get(cacheKey)
 
                         if (cachedSubAgentResult !== undefined) {
                             if (cachedSubAgentResult) {
@@ -176,7 +178,7 @@ export async function appendProtectedTools(
                                 }
 
                                 if (subAgentResultText) {
-                                    state.subAgentResultCache.set(part.callID, subAgentResultText)
+                                    state.subAgentResultCache.set(cacheKey, subAgentResultText)
                                     output = mergeSubagentResult(
                                         part.state.output,
                                         subAgentResultText,

lib/messages/inject/subagent-results.ts

@@ -7,6 +7,7 @@ import {
     mergeSubagentResult,
 } from "../../subagents/subagent-results"
 import { stripHallucinationsFromString } from "../utils"
+import { toolOccurrenceKey } from "../../tool-ids"
 
 async function fetchSubAgentMessages(client: any, sessionId: string): Promise<WithParts[]> {
     const response = await client.session.messages({
@@ -41,7 +42,8 @@ export const injectExtendedSubAgentResults = async (
                 continue
             }
 
-            const cachedResult = state.subAgentResultCache.get(part.callID)
+            const cacheKey = toolOccurrenceKey(message, part)
+            const cachedResult = state.subAgentResultCache.get(cacheKey)
             if (cachedResult !== undefined) {
                 if (cachedResult) {
                     part.state.output = stripHallucinationsFromString(
@@ -74,7 +76,7 @@ export const injectExtendedSubAgentResults = async (
                 continue
             }
 
-            state.subAgentResultCache.set(part.callID, subAgentResultText)
+            state.subAgentResultCache.set(cacheKey, subAgentResultText)
             part.state.output = stripHallucinationsFromString(
                 mergeSubagentResult(part.state.output, subAgentResultText),
                 state.idFormat,

lib/messages/prune.ts

@@ -6,6 +6,7 @@ import { createSyntheticUserMessage, replaceBlockIdsWithBlocked } from "./utils"
 import { getLastUserMessage } from "./query"
 import type { UserMessage } from "@opencode-ai/sdk/v2"
 import { formatBlockRef } from "../message-ids"
+import { getAmbiguousToolIds } from "../tool-ids"
 
 const PRUNED_TOOL_OUTPUT_REPLACEMENT =
     "[Output removed to save context - information superseded or no longer needed]"
@@ -19,6 +20,8 @@ export const prune = (
     messages: WithParts[],
     summaryBase?: WithParts,
 ): void => {
+    // Legacy persisted call IDs must not remove multiple tool occurrences.
+    for (const id of getAmbiguousToolIds(messages)) state.prune.tools.delete(id)
     filterCompressedRanges(state, logger, config, messages, summaryBase)
     // pruneFullTool(state, logger, messages)
     pruneToolOutputs(state, logger, messages)

lib/state/tool-cache.ts

@@ -3,6 +3,7 @@ import type { Logger } from "../logger"
 import { PluginConfig } from "../config"
 import { isMessageCompacted } from "./utils"
 import { countToolTokens } from "../token-utils"
+import { getAmbiguousToolIds } from "../tool-ids"
 
 const MAX_TOOL_CACHE_SIZE = 1000
 
@@ -18,6 +19,12 @@ export function syncToolCache(
     try {
         logger.info("Syncing tool parameters from OpenCode messages")
 
+        const ambiguousIds = getAmbiguousToolIds(messages)
+        for (const id of ambiguousIds) {
+            state.toolParameters.delete(id)
+            state.prune.tools.delete(id)
+        }
+
         let turnCounter = 0
 
         for (const msg of messages) {
@@ -32,7 +39,7 @@ export function syncToolCache(
                     continue
                 }
 
-                if (part.type !== "tool" || !part.callID) {
+                if (part.type !== "tool" || !part.callID || ambiguousIds.has(part.callID)) {
                     continue
                 }
 

lib/strategies/deduplication.ts

@@ -3,6 +3,7 @@ import { Logger } from "../logger"
 import type { SessionState, WithParts } from "../state"
 import { isToolProtected } from "../protected-patterns"
 import { getTotalToolTokens } from "../token-utils"
+import { getAmbiguousToolIds } from "../tool-ids"
 
 /**
  * Deduplication strategy - prunes older tool calls that have identical
@@ -29,7 +30,10 @@ export const deduplicate = (
     }
 
     // Filter out IDs already pruned
-    const unprunedIds = allToolIds.filter((id) => !state.prune.tools.has(id))
+    const ambiguousIds = getAmbiguousToolIds(messages)
+    const unprunedIds = allToolIds.filter(
+        (id) => !state.prune.tools.has(id) && !ambiguousIds.has(id),
+    )
 
     if (unprunedIds.length === 0) {
         return

lib/strategies/purge-errors.ts

@@ -3,6 +3,7 @@ import { Logger } from "../logger"
 import type { SessionState, WithParts } from "../state"
 import { isToolProtected } from "../protected-patterns"
 import { getTotalToolTokens } from "../token-utils"
+import { getAmbiguousToolIds } from "../tool-ids"
 
 /**
  * Purge Errors strategy - prunes tool inputs for tools that errored
@@ -32,7 +33,10 @@ export const purgeErrors = (
     }
 
     // Filter out IDs already pruned
-    const unprunedIds = allToolIds.filter((id) => !state.prune.tools.has(id))
+    const ambiguousIds = getAmbiguousToolIds(messages)
+    const unprunedIds = allToolIds.filter(
+        (id) => !state.prune.tools.has(id) && !ambiguousIds.has(id),
+    )
 
     if (unprunedIds.length === 0) {
         return

lib/tool-ids.ts

@@ -0,0 +1,21 @@
+import type { WithParts } from "./state"
+
+type ToolPart = Extract<WithParts["parts"][number], { type: "tool" }>
+
+export function getAmbiguousToolIds(messages: WithParts[]): Set<string> {
+    const seen = new Set<string>()
+    const ambiguous = new Set<string>()
+    for (const message of messages) {
+        const parts = Array.isArray(message.parts) ? message.parts : []
+        for (const part of parts) {
+            if (part.type !== "tool" || !part.callID) continue
+            if (seen.has(part.callID)) ambiguous.add(part.callID)
+            seen.add(part.callID)
+        }
+    }
+    return ambiguous
+}
+
+export function toolOccurrenceKey(message: WithParts, part: ToolPart): string {
+    return JSON.stringify([message.info.id, part.id ?? part.callID])
+}

lib/v2/messages.ts

@@ -90,15 +90,22 @@ function output(content: ReadonlyArray<{ type: string; text?: string }>): unknow
 
 export function project(native: Message[], entries: History, session: Session) {
     const byID = new Map(entries.map((entry) => [entry.id, entry]))
-    const results = new Map<string, ToolResultPart>()
-    const owners = new Map<string, string>()
+    const calls = new Map<string, { part: ContentPart; messageId?: string }>()
+    const results = new Map<ContentPart, ToolResultPart>()
+    const owners = new Map<ToolResultPart, string>()
     const links = new Map<ContentPart, Part>()
     const originals = new Map<string, WithParts>()
     const messages: WithParts[] = []
     for (const message of native)
         for (const part of message.content) {
-            if (part.type === "tool-result") results.set(part.id, part)
-            if (part.type === "tool-call" && message.id) owners.set(part.id, message.id)
+            if (part.type === "tool-call") calls.set(part.id, { part, messageId: message.id })
+            if (part.type === "tool-result") {
+                const call = calls.get(part.id)
+                if (!call) continue
+                results.set(call.part, part)
+                if (call.messageId) owners.set(part, call.messageId)
+                calls.delete(part.id)
+            }
         }
     for (const message of native) {
         if (!message.id || !["user", "assistant"].includes(message.role)) continue
@@ -121,7 +128,7 @@ export function project(native: Message[], entries: History, session: Session) {
                     url: typeof part.data === "string" ? part.data : "",
                 }
             if (part.type === "tool-call") {
-                const result = results.get(part.id)
+                const result = results.get(part)
                 const entry = byID.get(message.id)
                 const durable =
                     entry?.type === "assistant"
@@ -205,8 +212,8 @@ export function project(native: Message[], entries: History, session: Session) {
                 if (part.type === "tool-call") content.push(...added.splice(0))
                 if (
                     part.type === "tool-result" &&
-                    originals.has(owners.get(part.id)!) &&
-                    !retained.has(owners.get(part.id)!)
+                    originals.has(owners.get(part)!) &&
+                    !retained.has(owners.get(part)!)
                 )
                     continue
                 const edit = links.get(part)