Track OpenCode child sessions under root sessions

CHANGELOG.md

@@ -28,6 +28,13 @@
   `Shell`, `ReadFile`, and `WriteFile`, and maps hidden managed Kimi Code
   model aliases to priced Kimi K2 entries.
 
+### Fixed (CLI)
+- **OpenCode child sessions are attributed to their root session.** The
+  OpenCode parser now walks the unarchived `session.parent_id` subtree so
+  child and grandchild agent sessions contribute token and tool usage under
+  the discovered root session while still excluding child sessions from
+  top-level discovery to avoid double counting.
+
 ## 0.9.9 - 2026-05-15
 
 ### Added (CLI)

docs/providers/opencode.md

@@ -26,6 +26,10 @@ Per `<sessionId>:<messageId>`.
 
 - **Schema validation is loud.** When a required table is missing, the parser logs an actionable warning telling the user which table is gone and what version of OpenCode it expects. This is the right behavior; do not silently swallow these.
 - Source paths are encoded as `<dbPath>:<sessionId>`.
+- Discovery only emits root sessions (`parent_id IS NULL`) to avoid double
+  counting. Parsing a root session walks the unarchived `session.parent_id`
+  subtree, so child and grandchild agent sessions contribute their message,
+  token, and tool usage back to the root session.
 - Each message's `parts` are indexed; preserving the order matters for reasoning-token correctness.
 - Tokens are reported across `input`, `output`, `reasoning`, `cache.read`, and `cache.write`. Anthropic semantics.
 - External MCP tools are stored as `<server>_<tool>` names (for example

src/providers/opencode.ts

@@ -13,6 +13,7 @@ import type {
 } from './types.js'
 
 type MessageRow = {
+  session_id: string
   id: string
   time_created: number
   data: Uint8Array | string
@@ -189,12 +190,34 @@ function createParser(
         }
 
         const messages = db.query<MessageRow>(
-          'SELECT id, time_created, CAST(data AS BLOB) AS data FROM message WHERE session_id = ? ORDER BY time_created ASC',
+          `WITH RECURSIVE session_tree(id) AS (
+            SELECT id FROM session WHERE id = ?
+            UNION
+            SELECT child.id
+            FROM session child
+            JOIN session_tree parent ON child.parent_id = parent.id
+            WHERE child.time_archived IS NULL
+          )
+          SELECT session_id, id, time_created, CAST(data AS BLOB) AS data
+          FROM message
+          WHERE session_id IN (SELECT id FROM session_tree)
+          ORDER BY time_created ASC, id ASC`,
           [sessionId],
         )
 
         const parts = db.query<PartRow>(
-          'SELECT message_id, CAST(data AS BLOB) AS data FROM part WHERE session_id = ? ORDER BY message_id, id',
+          `WITH RECURSIVE session_tree(id) AS (
+            SELECT id FROM session WHERE id = ?
+            UNION
+            SELECT child.id
+            FROM session child
+            JOIN session_tree parent ON child.parent_id = parent.id
+            WHERE child.time_archived IS NULL
+          )
+          SELECT message_id, CAST(data AS BLOB) AS data
+          FROM part
+          WHERE session_id IN (SELECT id FROM session_tree)
+          ORDER BY message_id, id`,
           [sessionId],
         )
 
@@ -210,7 +233,7 @@ function createParser(
           }
         }
 
-        let currentUserMessage = ''
+        const currentUserMessageBySession = new Map<string, string>()
 
         for (const msg of messages) {
           let data: MessageData
@@ -226,7 +249,7 @@ function createParser(
               .map((p) => p.text ?? '')
               .filter(Boolean)
             if (textParts.length > 0) {
-              currentUserMessage = textParts.join(' ')
+              currentUserMessageBySession.set(msg.session_id, textParts.join(' '))
             }
             continue
           }
@@ -259,7 +282,7 @@ function createParser(
             .filter((p) => p.tool === 'bash' && typeof p.state?.input?.command === 'string')
             .flatMap((p) => extractBashCommands(p.state!.input!.command!))
 
-          const dedupKey = `opencode:${sessionId}:${msg.id}`
+          const dedupKey = `opencode:${msg.session_id}:${msg.id}`
           if (seenKeys.has(dedupKey)) continue
           seenKeys.add(dedupKey)
 
@@ -293,7 +316,7 @@ function createParser(
             timestamp: parseTimestamp(msg.time_created),
             speed: 'standard',
             deduplicationKey: dedupKey,
-            userMessage: currentUserMessage,
+            userMessage: currentUserMessageBySession.get(msg.session_id) ?? '',
             sessionId,
           }
         }

tests/providers/opencode.test.ts

@@ -643,6 +643,103 @@ skipUnlessSqlite('opencode provider - session parsing', () => {
     expect(calls[1]!.userMessage).toBe('second question')
   })
 
+  it('attributes child and grandchild session calls back to the root session', async () => {
+    const dbPath = createTestDb(tmpDir)
+    withTestDb(dbPath, (db) => {
+      insertSession(db, 'root')
+      insertSession(db, 'child', { parentId: 'root' })
+      insertSession(db, 'grandchild', { parentId: 'child' })
+
+      insertMessage(db, 'msg-root-user', 'root', 1700000000000, { role: 'user' })
+      insertPart(db, 'part-root-user', 'msg-root-user', 'root', { type: 'text', text: 'root prompt' })
+      insertMessage(db, 'msg-root-assistant', 'root', 1700000001000, {
+        role: 'assistant',
+        modelID: 'claude-opus-4-6',
+        cost: 0.01,
+        tokens: { input: 10, output: 20, reasoning: 0, cache: { read: 0, write: 0 } },
+      })
+      insertPart(db, 'part-root-tool', 'msg-root-assistant', 'root', {
+        type: 'tool',
+        tool: 'read',
+        state: { status: 'completed', input: {} },
+      })
+
+      insertMessage(db, 'msg-child-user', 'child', 1700000002000, { role: 'user' })
+      insertPart(db, 'part-child-user', 'msg-child-user', 'child', { type: 'text', text: 'child prompt' })
+      insertMessage(db, 'msg-child-assistant', 'child', 1700000003000, {
+        role: 'assistant',
+        modelID: 'claude-opus-4-6',
+        cost: 0.02,
+        tokens: { input: 30, output: 40, reasoning: 5, cache: { read: 0, write: 0 } },
+      })
+      insertPart(db, 'part-child-tool', 'msg-child-assistant', 'child', {
+        type: 'tool',
+        tool: 'task',
+        state: { status: 'completed', input: {} },
+      })
+
+      insertMessage(db, 'msg-grand-user', 'grandchild', 1700000004000, { role: 'user' })
+      insertPart(db, 'part-grand-user', 'msg-grand-user', 'grandchild', { type: 'text', text: 'grandchild prompt' })
+      insertMessage(db, 'msg-grand-assistant', 'grandchild', 1700000005000, {
+        role: 'assistant',
+        modelID: 'claude-opus-4-6',
+        cost: 0.03,
+        tokens: { input: 50, output: 60, reasoning: 0, cache: { read: 0, write: 0 } },
+      })
+      insertPart(db, 'part-grand-tool', 'msg-grand-assistant', 'grandchild', {
+        type: 'tool',
+        tool: 'bash',
+        state: { status: 'completed', input: { command: 'npm test' } },
+      })
+    })
+
+    const calls = await collectCalls(createOpenCodeProvider(tmpDir), dbPath, 'root')
+
+    expect(calls).toHaveLength(3)
+    expect(calls.map(call => call.sessionId)).toEqual(['root', 'root', 'root'])
+    expect(calls.map(call => call.deduplicationKey)).toEqual([
+      'opencode:root:msg-root-assistant',
+      'opencode:child:msg-child-assistant',
+      'opencode:grandchild:msg-grand-assistant',
+    ])
+    expect(calls.map(call => call.userMessage)).toEqual([
+      'root prompt',
+      'child prompt',
+      'grandchild prompt',
+    ])
+    expect(calls[0]!.tools).toEqual(['Read'])
+    expect(calls[1]!.tools).toEqual(['Agent'])
+    expect(calls[2]!.tools).toEqual(['Bash'])
+    expect(calls[2]!.bashCommands).toEqual(['npm'])
+  })
+
+  it('does not include archived child sessions in the root subtree', async () => {
+    const dbPath = createTestDb(tmpDir)
+    withTestDb(dbPath, (db) => {
+      insertSession(db, 'root')
+      insertSession(db, 'archived-child', { parentId: 'root', archived: 1700000002500 })
+
+      insertMessage(db, 'msg-root-assistant', 'root', 1700000001000, {
+        role: 'assistant',
+        modelID: 'claude-opus-4-6',
+        cost: 0.01,
+        tokens: { input: 10, output: 20, reasoning: 0, cache: { read: 0, write: 0 } },
+      })
+
+      insertMessage(db, 'msg-child-assistant', 'archived-child', 1700000003000, {
+        role: 'assistant',
+        modelID: 'claude-opus-4-6',
+        cost: 0.02,
+        tokens: { input: 30, output: 40, reasoning: 0, cache: { read: 0, write: 0 } },
+      })
+    })
+
+    const calls = await collectCalls(createOpenCodeProvider(tmpDir), dbPath, 'root')
+
+    expect(calls).toHaveLength(1)
+    expect(calls[0]!.deduplicationKey).toBe('opencode:root:msg-root-assistant')
+  })
+
   it('joins multiple text parts in user messages', async () => {
     const dbPath = createTestDb(tmpDir)
     withTestDb(dbPath, (db) => {