diff --git a/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/fixtures/background-child-session.jsonl b/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/fixtures/background-child-session.jsonl
new file mode 100644
index 0000000000..ed668e807f
--- /dev/null
+++ b/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/fixtures/background-child-session.jsonl
@@ -0,0 +1,8 @@
+{"type": "session", "version": 3, "id": "e56a0006-f421-45be-9aef-e4019db1cf24", "timestamp": "2026-10-21T13:05:57.384Z", "cwd": "/tmp/paseo-edxeth-fixture/lean/workspace", "name": "[marker] Fixture marker verification", "parentSession": "/tmp/paseo-edxeth-fixture/lean/sessions/2026-10-21T13-05-53-085Z_01a15e91-73bd-7282-82c6-d3974711a941.jsonl"}
+{"type": "custom", "customType": "pi-subagents_launch_metadata", "data": {"version": 1, "timestamp": "2026-10-21T13:05:57.385Z", "name": "fixture-marker", "title": "Fixture marker verification", "sessionTitle": "[marker] Fixture marker verification", "agent": "marker", "mode": "background", "sessionMode": "lineage-only", "autoExit": true, "parentClosePolicy": "terminate", "reportContextUsage": true, "async": true, "model": "openai-codex/gpt-5.6-sol", "thinking": "high", "modelRef": "openai-codex/gpt-5.6-sol:high", "definitionModel": "openai-codex/gpt-5.6-sol", "definitionThinking": "high", "allowModelOverride": true, "modelSource": "agent", "tools": "read", "denyTools": ["subagent", "subagent_resume", "subagent_kill"], "spawnableAgents": [], "spawnBudget": null, "extensions": [], "noContextFiles": false, "inheritAppendSystem": false, "noSession": false, "trustProject": false, "agentConfigDir": "/tmp/paseo-edxeth-fixture/lean/agent", "cwd": "/tmp/paseo-edxeth-fixture/lean/workspace", "boundarySystemPrompt": false}, "id": "57355eeb", "parentId": null, "timestamp": "2026-10-21T13:05:57.386Z"}
+{"type": "session_info", "id": "847415e4", "parentId": "57355eeb", "timestamp": "2026-10-21T13:05:57.566Z", "name": "[marker] Fixture marker verification"}
+{"type": "model_change", "id": "d4ad59be", "parentId": "847415e4", "timestamp": "2026-10-21T13:05:57.672Z", "provider": "openai-codex", "modelId": "gpt-5.6-sol"}
+{"type": "thinking_level_change", "id": "7f6bf9d2", "parentId": "d4ad59be", "timestamp": "2026-10-21T13:05:57.672Z", "thinkingLevel": "high"}
+{"type": "message", "id": "737b762e", "parentId": "6b436446", "timestamp": "2026-10-21T13:05:57.679Z", "message": {"role": "user", "content": [{"type": "text", "text": "\n\n\nReturn only the exact marker supplied by the user. Do not use tools.\n\nComplete your task autonomously.\n\nReturn only PASEO_EDXETH_LEAN_OK\n\nYour FINAL assistant message should summarize what you accomplished.\n\n"}], "timestamp": 1792587957678}}
+{"type": "message", "id": "100b110d", "parentId": "737b762e", "timestamp": "2026-10-21T13:06:02.050Z", "message": {"role": "assistant", "content": [{"type": "text", "text": "PASEO_EDXETH_LEAN_OK"}], "api": "openai-codex-responses", "provider": "openai-codex", "model": "gpt-5.6-sol", "usage": {"input": 1713, "output": 13, "cacheRead": 0, "cacheWrite": 0, "reasoning": 0, "totalTokens": 1726, "cost": {"input": 0.006852, "output": 0.00026000000000000003, "cacheRead": 0, "cacheWrite": 0, "total": 0.007111999999999999}}, "stopReason": "stop", "timestamp": 1792587957684, "responseId": "resp_0bc8bfaee079148a016ad8b8b7edb08191924676ed8dcfd447", "rawStopReason": "completed"}}
+{"type": "custom", "customType": "pi-subagent-completion", "data": {"reason": "normal"}, "id": "80bbd3bb", "parentId": "100b110d", "timestamp": "2026-10-21T13:06:02.054Z"}
diff --git a/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/fixtures/background.json b/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/fixtures/background.json
new file mode 100644
index 0000000000..fe4913f6b6
--- /dev/null
+++ b/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/fixtures/background.json
@@ -0,0 +1,263 @@
+{
+ "provenance": {
+ "package": "Zeno2019/pi-subagents-lean",
+ "version": "2.9.2-lean.1",
+ "sourceCommit": "e10fe855808abcae193a205ea98f8ccd70d25620",
+ "piVersion": "0.87.1",
+ "captureDate": "2026-10-21"
+ },
+ "events": [
+ {
+ "type": "tool_execution_start",
+ "toolCallId": "call_f28b261de3c6440b953f0f56c3fec7d0|fc_0d35cf51b3ed48b9016ad8b8b4a63c81918a55903d0a4f12cb",
+ "toolName": "subagent",
+ "args": {
+ "agent": "marker",
+ "name": "fixture-marker",
+ "title": "Fixture marker verification",
+ "task": "Return only PASEO_EDXETH_LEAN_OK"
+ }
+ },
+ {
+ "type": "tool_execution_end",
+ "toolCallId": "call_f28b261de3c6440b953f0f56c3fec7d0|fc_0d35cf51b3ed48b9016ad8b8b4a63c81918a55903d0a4f12cb",
+ "toolName": "subagent",
+ "result": {
+ "content": [
+ {
+ "type": "text",
+ "text": "Sub-agent \"fixture-marker\" launched async with id 1bfdf3b3. Results will be delivered automatically as a steer message when it finishes. Use this exact id if you need to resume or stop this child.\n\nActivity: /home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/activity.jsonl\nRun evidence: /home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/result.json\nRead these on demand for progress or failure diagnosis; activity is evidence, not a completion verdict."
+ }
+ ],
+ "details": {
+ "evidence": {
+ "runId": "1bfdf3b3",
+ "cwd": "/tmp/paseo-edxeth-fixture/lean/workspace",
+ "activityFile": "/home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/activity.jsonl",
+ "resultFile": "/home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/result.json"
+ },
+ "id": "1bfdf3b3",
+ "name": "fixture-marker",
+ "title": "Fixture marker verification",
+ "task": "Return only PASEO_EDXETH_LEAN_OK",
+ "agent": "marker",
+ "sessionFile": "/tmp/paseo-edxeth-fixture/background/child-session.jsonl",
+ "noSession": false,
+ "status": "started",
+ "mode": "background",
+ "deliveryState": "detached",
+ "parentClosePolicy": "terminate",
+ "async": true,
+ "autoExit": true
+ }
+ },
+ "isError": false
+ },
+ {
+ "type": "message_end",
+ "message": {
+ "role": "custom",
+ "customType": "subagent_result",
+ "content": "Sub-agent \"fixture-marker\" completed (7s).\n\nPASEO_EDXETH_LEAN_OK\n\nSession: /tmp/paseo-edxeth-fixture/background/child-session.jsonl\nResume: pi --session /tmp/paseo-edxeth-fixture/background/child-session.jsonl\n\nSub-agent context: 2K/372K tokens (0%) used at finish.\n\nActivity: /home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/activity.jsonl\nRun evidence: /home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/result.json\nRead these on demand for progress or failure diagnosis; activity is evidence, not a completion verdict.",
+ "display": true,
+ "details": {
+ "evidence": {
+ "runId": "1bfdf3b3",
+ "cwd": "/tmp/paseo-edxeth-fixture/lean/workspace",
+ "activityFile": "/home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/activity.jsonl",
+ "resultFile": "/home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/result.json",
+ "finalized": true
+ },
+ "id": "1bfdf3b3",
+ "name": "fixture-marker",
+ "task": "Return only PASEO_EDXETH_LEAN_OK",
+ "agent": "marker",
+ "mode": "background",
+ "status": "completed",
+ "deliveryState": "detached",
+ "parentClosePolicy": "terminate",
+ "async": true,
+ "exitCode": 0,
+ "elapsed": 7,
+ "outputTokens": 13,
+ "contextTokens": 1775,
+ "contextWindow": 372000,
+ "sessionFile": "/tmp/paseo-edxeth-fixture/background/child-session.jsonl"
+ },
+ "timestamp": 1792587964414
+ }
+ }
+ ],
+ "messages": [
+ {
+ "role": "assistant",
+ "content": [
+ {
+ "type": "toolCall",
+ "id": "call_f28b261de3c6440b953f0f56c3fec7d0|fc_0d35cf51b3ed48b9016ad8b8b4a63c81918a55903d0a4f12cb",
+ "name": "subagent",
+ "arguments": {
+ "agent": "marker",
+ "name": "fixture-marker",
+ "title": "Fixture marker verification",
+ "task": "Return only PASEO_EDXETH_LEAN_OK"
+ }
+ }
+ ],
+ "api": "openai-codex-responses",
+ "provider": "openai-codex",
+ "model": "gpt-5.6-sol",
+ "usage": {
+ "input": 2020,
+ "output": 43,
+ "cacheRead": 0,
+ "cacheWrite": 0,
+ "reasoning": 0,
+ "totalTokens": 2063,
+ "cost": {
+ "input": 0.00808,
+ "output": 0.0008600000000000001,
+ "cacheRead": 0,
+ "cacheWrite": 0,
+ "total": 0.00894
+ }
+ },
+ "stopReason": "toolUse",
+ "timestamp": 1792587953256,
+ "responseId": "resp_0d35cf51b3ed48b9016ad8b8b3698481918f82962b6eaf2788",
+ "rawStopReason": "completed"
+ },
+ {
+ "role": "toolResult",
+ "toolCallId": "call_f28b261de3c6440b953f0f56c3fec7d0|fc_0d35cf51b3ed48b9016ad8b8b4a63c81918a55903d0a4f12cb",
+ "toolName": "subagent",
+ "content": [
+ {
+ "type": "text",
+ "text": "Sub-agent \"fixture-marker\" launched async with id 1bfdf3b3. Results will be delivered automatically as a steer message when it finishes. Use this exact id if you need to resume or stop this child.\n\nActivity: /home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/activity.jsonl\nRun evidence: /home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/result.json\nRead these on demand for progress or failure diagnosis; activity is evidence, not a completion verdict."
+ }
+ ],
+ "details": {
+ "evidence": {
+ "runId": "1bfdf3b3",
+ "cwd": "/tmp/paseo-edxeth-fixture/lean/workspace",
+ "activityFile": "/home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/activity.jsonl",
+ "resultFile": "/home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/result.json",
+ "finalized": true
+ },
+ "id": "1bfdf3b3",
+ "name": "fixture-marker",
+ "title": "Fixture marker verification",
+ "task": "Return only PASEO_EDXETH_LEAN_OK",
+ "agent": "marker",
+ "sessionFile": "/tmp/paseo-edxeth-fixture/background/child-session.jsonl",
+ "noSession": false,
+ "status": "started",
+ "mode": "background",
+ "deliveryState": "detached",
+ "parentClosePolicy": "terminate",
+ "async": true,
+ "autoExit": true
+ },
+ "isError": false,
+ "timestamp": 1792587957399
+ },
+ {
+ "role": "assistant",
+ "content": [
+ {
+ "type": "thinking",
+ "thinking": "**Identifying need for await keyword**"
+ },
+ {
+ "type": "text",
+ "text": "DONE"
+ }
+ ],
+ "api": "openai-codex-responses",
+ "provider": "openai-codex",
+ "model": "gpt-5.6-sol",
+ "usage": {
+ "input": 2258,
+ "output": 18,
+ "cacheRead": 0,
+ "cacheWrite": 0,
+ "reasoning": 11,
+ "totalTokens": 2276,
+ "cost": {
+ "input": 0.009032,
+ "output": 0.00036,
+ "cacheRead": 0,
+ "cacheWrite": 0,
+ "total": 0.009392
+ }
+ },
+ "stopReason": "stop",
+ "timestamp": 1792587957402,
+ "responseId": "resp_0d35cf51b3ed48b9016ad8b8b602108191a8e8f7fd77fbe5b5",
+ "rawStopReason": "completed"
+ },
+ {
+ "role": "custom",
+ "customType": "subagent_result",
+ "content": "Sub-agent \"fixture-marker\" completed (7s).\n\nPASEO_EDXETH_LEAN_OK\n\nSession: /tmp/paseo-edxeth-fixture/background/child-session.jsonl\nResume: pi --session /tmp/paseo-edxeth-fixture/background/child-session.jsonl\n\nSub-agent context: 2K/372K tokens (0%) used at finish.\n\nActivity: /home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/activity.jsonl\nRun evidence: /home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/result.json\nRead these on demand for progress or failure diagnosis; activity is evidence, not a completion verdict.",
+ "display": true,
+ "details": {
+ "evidence": {
+ "runId": "1bfdf3b3",
+ "cwd": "/tmp/paseo-edxeth-fixture/lean/workspace",
+ "activityFile": "/home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/activity.jsonl",
+ "resultFile": "/home/pi-user/.pi/history/workspace/artifacts/2026-10-21T13-05-57-380Z_db802a71-7bb32177-573971ee-535c/subagents/1bfdf3b3/result.json",
+ "finalized": true
+ },
+ "id": "1bfdf3b3",
+ "name": "fixture-marker",
+ "task": "Return only PASEO_EDXETH_LEAN_OK",
+ "agent": "marker",
+ "mode": "background",
+ "status": "completed",
+ "deliveryState": "detached",
+ "parentClosePolicy": "terminate",
+ "async": true,
+ "exitCode": 0,
+ "elapsed": 7,
+ "outputTokens": 13,
+ "contextTokens": 1775,
+ "contextWindow": 372000,
+ "sessionFile": "/tmp/paseo-edxeth-fixture/background/child-session.jsonl"
+ },
+ "timestamp": 1792587964414
+ },
+ {
+ "role": "assistant",
+ "content": [
+ {
+ "type": "text",
+ "text": "DONE"
+ }
+ ],
+ "api": "openai-codex-responses",
+ "provider": "openai-codex",
+ "model": "gpt-5.6-sol",
+ "usage": {
+ "input": 389,
+ "output": 5,
+ "cacheRead": 2176,
+ "cacheWrite": 0,
+ "reasoning": 0,
+ "totalTokens": 2570,
+ "cost": {
+ "input": 0.0015559999999999999,
+ "output": 0.0001,
+ "cacheRead": 0.0008704000000000001,
+ "cacheWrite": 0,
+ "total": 0.0025264
+ }
+ },
+ "stopReason": "stop",
+ "timestamp": 1792587964417,
+ "responseId": "resp_0d35cf51b3ed48b9016ad8b8bd0c548191bddd1fe3410a1c82",
+ "rawStopReason": "completed"
+ }
+ ]
+}
diff --git a/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/fixtures/foreground-child-session.jsonl b/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/fixtures/foreground-child-session.jsonl
new file mode 100644
index 0000000000..a607a1032d
--- /dev/null
+++ b/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/fixtures/foreground-child-session.jsonl
@@ -0,0 +1,8 @@
+{"type": "session", "version": 3, "id": "afbea6e0-7858-4ecf-8ef1-e26af9b7d6e0", "timestamp": "2026-10-21T13:05:17.628Z", "cwd": "/tmp/paseo-edxeth-fixture/upstream/workspace", "name": "[marker] Fixture marker verification", "parentSession": "/tmp/paseo-edxeth-fixture/upstream/sessions/2026-10-21T13-05-12-212Z_01a15e90-d414-7243-a701-4eb4b0bec880.jsonl"}
+{"type": "custom", "customType": "pi-subagents_launch_metadata", "data": {"version": 1, "timestamp": "2026-10-21T13:05:17.628Z", "name": "fixture-marker", "title": "Fixture marker verification", "sessionTitle": "[marker] Fixture marker verification", "agent": "marker", "mode": "background", "sessionMode": "lineage-only", "autoExit": true, "parentClosePolicy": "terminate", "reportContextUsage": true, "async": false, "model": "openai-codex/gpt-5.6-sol", "thinking": "high", "modelRef": "openai-codex/gpt-5.6-sol:high", "definitionModel": "openai-codex/gpt-5.6-sol", "definitionThinking": "high", "allowModelOverride": true, "modelSource": "agent", "tools": "read", "denyTools": ["subagent", "subagent_resume", "subagent_kill"], "spawnableAgents": [], "spawnBudget": null, "extensions": [], "noContextFiles": false, "inheritAppendSystem": false, "noSession": false, "trustProject": false, "agentConfigDir": "/tmp/paseo-edxeth-fixture/upstream/agent", "cwd": "/tmp/paseo-edxeth-fixture/upstream/workspace", "boundarySystemPrompt": false}, "id": "3f7d3c3f", "parentId": null, "timestamp": "2026-10-21T13:05:17.629Z"}
+{"type": "session_info", "id": "6e198450", "parentId": "3f7d3c3f", "timestamp": "2026-10-21T13:05:17.825Z", "name": "[marker] Fixture marker verification"}
+{"type": "model_change", "id": "94bf4c0b", "parentId": "6e198450", "timestamp": "2026-10-21T13:05:17.962Z", "provider": "openai-codex", "modelId": "gpt-5.6-sol"}
+{"type": "thinking_level_change", "id": "57cc6428", "parentId": "94bf4c0b", "timestamp": "2026-10-21T13:05:17.962Z", "thinkingLevel": "high"}
+{"type": "message", "id": "a9e47f08", "parentId": "8c186624", "timestamp": "2026-10-21T13:05:17.970Z", "message": {"role": "user", "content": [{"type": "text", "text": "\n\n\nReturn only the exact marker supplied by the user. Do not use tools.\n\nComplete your task autonomously.\n\nReturn only PASEO_EDXETH_UPSTREAM_OK\n\nYour FINAL assistant message should summarize what you accomplished.\n\n"}], "timestamp": 1792587917968}}
+{"type": "message", "id": "bc221a13", "parentId": "a9e47f08", "timestamp": "2026-10-21T13:05:23.476Z", "message": {"role": "assistant", "content": [{"type": "thinking", "thinking": "**Following user file marker exactly**"}, {"type": "text", "text": "PASEO_EDXETH_UPSTREAM_OK"}], "api": "openai-codex-responses", "provider": "openai-codex", "model": "gpt-5.6-sol", "usage": {"input": 1673, "output": 49, "cacheRead": 0, "cacheWrite": 0, "reasoning": 34, "totalTokens": 1722, "cost": {"input": 0.006692, "output": 0.0009800000000000002, "cacheRead": 0, "cacheWrite": 0, "total": 0.007672}}, "stopReason": "stop", "timestamp": 1792587917974, "responseId": "resp_09445c1733d532e7016ad8b8909c908191ba803c059497945e", "rawStopReason": "completed"}}
+{"type": "custom", "customType": "pi-subagent-completion", "data": {"reason": "normal"}, "id": "832fc8c9", "parentId": "bc221a13", "timestamp": "2026-10-21T13:05:23.477Z"}
diff --git a/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/fixtures/foreground.json b/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/fixtures/foreground.json
new file mode 100644
index 0000000000..c8df8eb5c2
--- /dev/null
+++ b/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/fixtures/foreground.json
@@ -0,0 +1,156 @@
+{
+ "provenance": {
+ "package": "edxeth/pi-subagents",
+ "version": "2.9.2",
+ "sourceCommit": "cf6dbf41c17986f3882e6804a68e8fb8282d25e6",
+ "piVersion": "0.87.1",
+ "captureDate": "2026-10-21"
+ },
+ "events": [
+ {
+ "type": "tool_execution_start",
+ "toolCallId": "call_0bc6fc2213cd49aa92950947bde5dd8a|fc_0a0ca4aa78cd296a016ad8b88d018481919eadbf09eb191a1a",
+ "toolName": "subagent",
+ "args": {
+ "agent": "marker",
+ "name": "fixture-marker",
+ "title": "Fixture marker verification",
+ "task": "Return only PASEO_EDXETH_UPSTREAM_OK"
+ }
+ },
+ {
+ "type": "tool_execution_end",
+ "toolCallId": "call_0bc6fc2213cd49aa92950947bde5dd8a|fc_0a0ca4aa78cd296a016ad8b88d018481919eadbf09eb191a1a",
+ "toolName": "subagent",
+ "result": {
+ "content": [
+ {
+ "type": "text",
+ "text": "Sub-agent \"fixture-marker\" completed (7s).\n\nPASEO_EDXETH_UPSTREAM_OK\n\nSession: /tmp/paseo-edxeth-fixture/foreground/child-session.jsonl\nResume: pi --session /tmp/paseo-edxeth-fixture/foreground/child-session.jsonl\n\nSub-agent context: 2K/372K tokens (0%) used at finish."
+ }
+ ],
+ "details": {
+ "id": "dd7f94e8",
+ "name": "fixture-marker",
+ "agent": "marker",
+ "status": "completed",
+ "mode": "background",
+ "parentClosePolicy": "terminate",
+ "deliveryState": "awaited",
+ "async": false,
+ "autoExit": true,
+ "exitCode": 0,
+ "elapsed": 7,
+ "outputTokens": 49,
+ "contextTokens": 1777,
+ "contextWindow": 372000,
+ "summary": "PASEO_EDXETH_UPSTREAM_OK",
+ "sessionFile": "/tmp/paseo-edxeth-fixture/foreground/child-session.jsonl"
+ }
+ },
+ "isError": false
+ }
+ ],
+ "messages": [
+ {
+ "role": "assistant",
+ "content": [
+ {
+ "type": "toolCall",
+ "id": "call_0bc6fc2213cd49aa92950947bde5dd8a|fc_0a0ca4aa78cd296a016ad8b88d018481919eadbf09eb191a1a",
+ "name": "subagent",
+ "arguments": {
+ "agent": "marker",
+ "name": "fixture-marker",
+ "title": "Fixture marker verification",
+ "task": "Return only PASEO_EDXETH_UPSTREAM_OK"
+ }
+ }
+ ],
+ "api": "openai-codex-responses",
+ "provider": "openai-codex",
+ "model": "gpt-5.6-sol",
+ "usage": {
+ "input": 3256,
+ "output": 43,
+ "cacheRead": 0,
+ "cacheWrite": 0,
+ "reasoning": 0,
+ "totalTokens": 3299,
+ "cost": {
+ "input": 0.013023999999999999,
+ "output": 0.0008600000000000001,
+ "cacheRead": 0,
+ "cacheWrite": 0,
+ "total": 0.013883999999999999
+ }
+ },
+ "stopReason": "toolUse",
+ "timestamp": 1792587912428,
+ "responseId": "resp_0a0ca4aa78cd296a016ad8b88bd52881918cbb9b8326b3060a",
+ "rawStopReason": "completed"
+ },
+ {
+ "role": "toolResult",
+ "toolCallId": "call_0bc6fc2213cd49aa92950947bde5dd8a|fc_0a0ca4aa78cd296a016ad8b88d018481919eadbf09eb191a1a",
+ "toolName": "subagent",
+ "content": [
+ {
+ "type": "text",
+ "text": "Sub-agent \"fixture-marker\" completed (7s).\n\nPASEO_EDXETH_UPSTREAM_OK\n\nSession: /tmp/paseo-edxeth-fixture/foreground/child-session.jsonl\nResume: pi --session /tmp/paseo-edxeth-fixture/foreground/child-session.jsonl\n\nSub-agent context: 2K/372K tokens (0%) used at finish."
+ }
+ ],
+ "details": {
+ "id": "dd7f94e8",
+ "name": "fixture-marker",
+ "agent": "marker",
+ "status": "completed",
+ "mode": "background",
+ "parentClosePolicy": "terminate",
+ "deliveryState": "awaited",
+ "async": false,
+ "autoExit": true,
+ "exitCode": 0,
+ "elapsed": 7,
+ "outputTokens": 49,
+ "contextTokens": 1777,
+ "contextWindow": 372000,
+ "summary": "PASEO_EDXETH_UPSTREAM_OK",
+ "sessionFile": "/tmp/paseo-edxeth-fixture/foreground/child-session.jsonl"
+ },
+ "isError": false,
+ "timestamp": 1792587924671
+ },
+ {
+ "role": "assistant",
+ "content": [
+ {
+ "type": "text",
+ "text": "DONE"
+ }
+ ],
+ "api": "openai-codex-responses",
+ "provider": "openai-codex",
+ "model": "gpt-5.6-sol",
+ "usage": {
+ "input": 388,
+ "output": 5,
+ "cacheRead": 3072,
+ "cacheWrite": 0,
+ "reasoning": 0,
+ "totalTokens": 3465,
+ "cost": {
+ "input": 0.001552,
+ "output": 0.0001,
+ "cacheRead": 0.0012288000000000002,
+ "cacheWrite": 0,
+ "total": 0.0028808
+ }
+ },
+ "stopReason": "stop",
+ "timestamp": 1792587924675,
+ "responseId": "resp_0a0ca4aa78cd296a016ad8b896af2c81919c0ef586dd50f2f0",
+ "rawStopReason": "completed"
+ }
+ ]
+}
diff --git a/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/index.test.ts b/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/index.test.ts
new file mode 100644
index 0000000000..86692ab32e
--- /dev/null
+++ b/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/index.test.ts
@@ -0,0 +1,336 @@
+import { describe, expect, test } from "vitest";
+import { fileURLToPath } from "node:url";
+import { createPiExtensionHost } from "../index.js";
+import { readSubagentFixture, verifySubagentFixture } from "../subagent-fixture-test.js";
+import { mkdtemp, rm, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { edxethPiSubagents } from "./index.js";
+import { streamPiHistory } from "../../history-mapper.js";
+import { ProviderSubagentStore } from "../../../../provider-subagents/store.js";
+
+const args = {
+ agent: "scout",
+ name: "status-scout",
+ title: "Check child status",
+ task: "Return the completion marker",
+};
+
+describe("edxeth/pi-subagents adapter", () => {
+ test.each(["tool", "notification"])("ends a child that requested help via %s", (delivery) => {
+ const host = createPiExtensionHost();
+ const call = { callId: "spawn-1", toolName: "subagent", args, status: "completed" as const };
+ host.mapToolCall({
+ ...call,
+ result: { details: { id: "run-1", name: args.name, status: "started" } },
+ });
+ const details = { id: "run-1", name: args.name, message: "Please clarify the task" };
+ const result =
+ delivery === "tool"
+ ? host.mapToolCall({ ...call, result: { details: { ...details, status: "pinged" } } })
+ : host.mapCustomMessage({
+ role: "custom",
+ customType: "subagent_ping",
+ content: "Child requested help and exited",
+ details,
+ });
+ expect(result?.subagents).toEqual([
+ expect.objectContaining({
+ type: "upsert",
+ id: "spawn-1",
+ status: "canceled",
+ subtitle: "Needs help",
+ }),
+ ]);
+ });
+
+ test("leaves unrelated tools and other subagent protocols to their adapters", () => {
+ const host = createPiExtensionHost(undefined, [edxethPiSubagents]);
+ const call = { callId: "other", toolName: "subagent", args, status: "completed" as const };
+ for (const details of [null, {}, { mode: "single", results: [] }, { id: "run-1" }]) {
+ expect(host.mapToolCall({ ...call, result: { details } })).toBeUndefined();
+ }
+ expect(
+ host.mapToolCall({
+ ...call,
+ toolName: "unrelated",
+ result: { details: { id: "run-1", name: args.name, status: "completed" } },
+ }),
+ ).toBeUndefined();
+ for (const details of [{ id: "run-1" }, { id: "run-1", status: "unknown" }]) {
+ expect(
+ host.mapCustomMessage({
+ role: "custom",
+ customType: "subagent_result",
+ content: "Unrecognized result",
+ details,
+ }),
+ ).toBeUndefined();
+ }
+ });
+
+ test("waits for cancellation after a kill acknowledgement reports stopping", () => {
+ const host = createPiExtensionHost();
+ host.mapToolCall({
+ callId: "spawn-1",
+ toolName: "subagent",
+ args,
+ status: "completed",
+ result: { details: { id: "run-1", name: args.name, status: "started" } },
+ });
+ const stopping = host.mapToolCall({
+ callId: "kill-1",
+ toolName: "subagent_kill",
+ args: { id: "run-1" },
+ status: "completed",
+ result: { details: { id: "run-1", name: args.name, status: "stopping" } },
+ });
+ expect(stopping?.subagents ?? []).toEqual([]);
+ expect(
+ host.mapCustomMessage({
+ role: "custom",
+ customType: "subagent_result",
+ content: "Cancelled",
+ details: { id: "run-1", status: "cancelled" },
+ })?.subagents,
+ ).toEqual([{ type: "upsert", id: "spawn-1", status: "canceled" }]);
+ });
+
+ test("preserves a completion that arrives before its launch acknowledgement", () => {
+ const host = createPiExtensionHost();
+ const early = host.mapCustomMessage({
+ role: "custom",
+ customType: "subagent_result",
+ content: "Already done",
+ details: { id: "fast-run", status: "completed" },
+ });
+ expect(early?.subagents ?? []).toEqual([]);
+ const started = host.mapToolCall({
+ callId: "fast-call",
+ toolName: "subagent",
+ args,
+ status: "completed",
+ result: {
+ details: { id: "fast-run", name: args.name, agent: args.agent, status: "started" },
+ },
+ });
+ expect(started?.subagents).toEqual([
+ {
+ type: "upsert",
+ id: "fast-call",
+ title: "scout",
+ description: args.task,
+ toolCallId: "fast-call",
+ status: "completed",
+ },
+ ]);
+ });
+
+ test.each([
+ { details: { status: "completed" }, expected: "completed" },
+ { details: { status: "failed" }, expected: "failed" },
+ { details: { status: "cancelled" }, expected: "canceled" },
+ { details: { error: "Child watcher exited unexpectedly" }, expected: "failed" },
+ ])("maps completion $details to $expected", ({ details, expected }) => {
+ const host = createPiExtensionHost();
+ host.mapToolCall({
+ callId: "spawn-1",
+ toolName: "subagent",
+ args,
+ status: "completed",
+ result: { details: { id: "run-1", name: args.name, status: "started" } },
+ });
+ expect(
+ host.mapCustomMessage({
+ role: "custom",
+ customType: "subagent_result",
+ content: "Child result",
+ details: { id: "run-1", ...details },
+ })?.subagents,
+ ).toEqual([{ type: "upsert", id: "spawn-1", status: expected }]);
+ });
+
+ test("a resume gets its own run and reads the retained child session", async () => {
+ const dir = await mkdtemp(join(tmpdir(), "paseo-edxeth-resume-"));
+ const file = join(dir, "child.jsonl");
+ const host = createPiExtensionHost();
+ try {
+ await writeFile(
+ file,
+ JSON.stringify({
+ type: "message",
+ message: { role: "assistant", content: [{ type: "text", text: "RESUMED" }] },
+ }) + "\n",
+ );
+ const original = host.mapToolCall({
+ callId: "spawn-1",
+ toolName: "subagent",
+ args,
+ status: "completed",
+ result: {
+ details: { id: "run-1", name: args.name, status: "completed", sessionFile: file },
+ },
+ });
+ await original?.hydration;
+ const resumed = host.mapToolCall({
+ callId: "resume-1",
+ toolName: "subagent_resume",
+ args: { sessionFile: file, task: "Continue" },
+ status: "completed",
+ result: {
+ details: { id: "run-2", name: args.name, status: "started", sessionFile: file },
+ },
+ });
+ expect(resumed?.childSessions).toEqual([{ id: "resume-1", file }]);
+ expect(await resumed?.hydration).toEqual([
+ {
+ type: "provider_subagent",
+ provider: "pi",
+ event: {
+ type: "timeline",
+ id: "resume-1",
+ item: expect.objectContaining({ type: "assistant_message", text: "RESUMED" }),
+ },
+ },
+ ]);
+ expect(
+ host.mapCustomMessage({
+ role: "custom",
+ customType: "subagent_result",
+ content: "Resumed run complete",
+ details: { id: "run-2", status: "completed", sessionFile: file },
+ })?.subagents,
+ ).toEqual([{ type: "upsert", id: "resume-1", status: "completed" }]);
+ } finally {
+ host.close();
+ await rm(dir, { recursive: true, force: true });
+ }
+ });
+
+ test("settles each batched child by run id without creating a parent-call card", () => {
+ const host = createPiExtensionHost();
+ const result = host.mapToolCall({
+ callId: "batch-1",
+ toolName: "subagent",
+ args: { children: [args, { ...args, agent: "reviewer", name: "status-reviewer" }] },
+ status: "completed",
+ result: {
+ details: {
+ status: "batch",
+ children: [
+ { id: "run-1", ...args, mode: "background", status: "completed" },
+ { id: "run-2", name: "status-reviewer", agent: "reviewer", status: "started" },
+ ],
+ },
+ },
+ });
+ expect(result?.subagents).toEqual([
+ {
+ type: "upsert",
+ id: "batch-1:0",
+ title: "scout",
+ description: args.task,
+ toolCallId: "batch-1",
+ status: "completed",
+ },
+ {
+ type: "upsert",
+ id: "batch-1:1",
+ title: "reviewer",
+ description: undefined,
+ toolCallId: "batch-1",
+ status: "running",
+ },
+ ]);
+ expect(
+ host.mapCustomMessage({
+ role: "custom",
+ customType: "subagent_result",
+ content: "Done",
+ details: { id: "run-2", status: "completed" },
+ })?.subagents,
+ ).toEqual([{ type: "upsert", id: "batch-1:1", status: "completed" }]);
+ });
+
+ test.each([
+ { mode: "foreground", statuses: ["running", "completed"] },
+ { mode: "background", statuses: ["running", "running", "completed"] },
+ ])("settles the captured $mode run live and on replay", async ({ mode, statuses }) => {
+ const fixture = readSubagentFixture(new URL(`./fixtures/${mode}.json`, import.meta.url), {
+ from: `/tmp/paseo-edxeth-fixture/${mode}/child-session.jsonl`,
+ to: fileURLToPath(new URL(`./fixtures/${mode}-child-session.jsonl`, import.meta.url)),
+ });
+ const events = await verifySubagentFixture(fixture);
+ const updates = events.flatMap(({ event }) => (event.type === "upsert" ? [event] : []));
+ expect(updates.map((event) => event.status)).toEqual(statuses);
+ expect(new Set(updates.map((event) => event.id)).size).toBe(1);
+ expect(events.some(({ event }) => event.type === "timeline")).toBe(true);
+ });
+
+ test.each(["foreground", "background"])(
+ "restores a completed %s child and its transcript to the consumer store",
+ async (mode) => {
+ const fixture = readSubagentFixture(new URL(`./fixtures/${mode}.json`, import.meta.url), {
+ from: `/tmp/paseo-edxeth-fixture/${mode}/child-session.jsonl`,
+ to: fileURLToPath(new URL(`./fixtures/${mode}-child-session.jsonl`, import.meta.url)),
+ });
+ const store = new ProviderSubagentStore();
+ for await (const event of streamPiHistory("pi", fixture.messages)) {
+ if (event.type === "provider_subagent") store.apply("parent", "pi", event.event);
+ }
+ const children = store.list("parent");
+ expect(children).toEqual([expect.objectContaining({ status: "completed", title: "marker" })]);
+ const transcript = store.fetchTimeline("parent", children[0]!.id);
+ expect(transcript.rows).toContainEqual(
+ expect.objectContaining({
+ item: expect.objectContaining({
+ type: "assistant_message",
+ text: mode === "foreground" ? "PASEO_EDXETH_UPSTREAM_OK" : "PASEO_EDXETH_LEAN_OK",
+ }),
+ }),
+ );
+ },
+ );
+
+ test("settles a synchronous result on the card created when the tool started", () => {
+ const host = createPiExtensionHost();
+ const call = { callId: "spawn-1", toolName: "subagent", args };
+ const start = host.mapToolCall({ ...call, status: "running", result: null });
+ expect(start?.subagents).toEqual([
+ {
+ type: "upsert",
+ id: "spawn-1",
+ title: "scout",
+ description: args.task,
+ toolCallId: "spawn-1",
+ status: "running",
+ },
+ ]);
+ const end = host.mapToolCall({
+ ...call,
+ status: "completed",
+ result: {
+ content: [{ type: "text", text: "DONE" }],
+ details: {
+ id: "run-1",
+ name: args.name,
+ agent: args.agent,
+ mode: "background",
+ status: "completed",
+ deliveryState: "awaited",
+ exitCode: 0,
+ },
+ },
+ });
+ expect(end?.subagents).toEqual([
+ {
+ type: "upsert",
+ id: "spawn-1",
+ title: "scout",
+ description: args.task,
+ toolCallId: "spawn-1",
+ status: "completed",
+ },
+ ]);
+ });
+});
diff --git a/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/index.ts b/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/index.ts
new file mode 100644
index 0000000000..c00e39aaad
--- /dev/null
+++ b/packages/server/src/server/agent/providers/pi/extensions/edxeth-pi-subagents/index.ts
@@ -0,0 +1,119 @@
+import { z } from "zod";
+import { extractTextFromToolResult } from "../../tool-call-mapper.js";
+import type { PiChildSessionFile, PiExtension } from "../contract.js";
+import type { ProviderSubagentInputEvent } from "../../../../provider-subagents/store.js";
+
+const Run = z
+ .object({
+ id: z.string().trim().min(1),
+ name: z.string().trim().min(1),
+ agent: z.string().trim().min(1).optional(),
+ task: z.string().optional(),
+ status: z.enum(["started", "completed", "failed", "cancelled", "pinged"]),
+ sessionFile: z.string().trim().min(1).optional(),
+ })
+ .passthrough();
+const Args = z.object({ task: z.string().optional() }).passthrough();
+const Batch = z.object({ status: z.enum(["started", "batch"]), children: z.array(Run).min(1) });
+const Completion = z
+ .object({
+ id: z.string().trim().min(1),
+ status: z.enum(["completed", "failed", "cancelled", "pinged"]).optional(),
+ error: z.string().optional(),
+ sessionFile: z.string().trim().min(1).optional(),
+ })
+ .passthrough();
+const Ping = Completion.extend({ message: z.string() });
+
+function childStatus(status: z.infer["status"]) {
+ if (status === "started") return "running";
+ // A ping ends the child process and needs a new resume run. It is not success.
+ if (status === "cancelled" || status === "pinged") return "canceled";
+ return status;
+}
+
+export const edxethPiSubagents: PiExtension = {
+ id: "edxeth/pi-subagents",
+ createSession: () => {
+ const callsByRun = new Map();
+ const completions = new Map>();
+ const readSessions = new Map();
+ const childSession = (id: string, file: string | undefined): PiChildSessionFile[] => {
+ if (!file || readSessions.get(id) === file) return [];
+ readSessions.set(id, file);
+ return [{ id, file }];
+ };
+ const completeRun = (result: z.infer) => {
+ const status = result.status ?? (result.error === undefined ? undefined : "failed");
+ if (!status) return undefined;
+ // A fast child can finish before the tool returns its run id. Keep the
+ // terminal outcome so a later "started" acknowledgement cannot regress it.
+ completions.set(result.id, { ...result, status });
+ const id = callsByRun.get(result.id);
+ if (!id) return undefined;
+ const subagents: ProviderSubagentInputEvent[] = [
+ {
+ type: "upsert",
+ id,
+ status: childStatus(status),
+ ...(status === "pinged" ? { subtitle: "Needs help" } : {}),
+ },
+ ];
+ return { subagents, childSessions: childSession(id, result.sessionFile) };
+ };
+ return {
+ mapToolCall(call) {
+ const isLaunch = call.toolName === "subagent" || call.toolName === "subagent_resume";
+ if (!isLaunch || call.status === "running") return undefined;
+ const details = typeof call.result === "object" ? call.result?.details : null;
+ const single = Run.safeParse(details);
+ let runs: z.infer[];
+ if (single.success) {
+ runs = [single.data];
+ } else {
+ const batch = Batch.safeParse(details);
+ if (!batch.success) return undefined;
+ runs = batch.data.children;
+ }
+ const args = Args.safeParse(call.args);
+ const description = args.success ? args.data.task : undefined;
+ const subagents: ProviderSubagentInputEvent[] = [];
+ const childSessions: PiChildSessionFile[] = [];
+ for (const [index, run] of runs.entries()) {
+ const id = runs.length === 1 ? call.callId : `${call.callId}:${index}`;
+ const completion = completions.get(run.id);
+ const status = completion?.status ?? run.status;
+ callsByRun.set(run.id, id);
+ subagents.push({
+ type: "upsert",
+ id,
+ title: run.agent ?? run.name,
+ description: run.task ?? description,
+ toolCallId: call.callId,
+ status: childStatus(status),
+ ...(status === "pinged" ? { subtitle: "Needs help" } : {}),
+ });
+ childSessions.push(...childSession(id, completion?.sessionFile ?? run.sessionFile));
+ }
+ return {
+ detail: {
+ type: "sub_agent",
+ description,
+ log: extractTextFromToolResult(call.result)?.trim() ?? "",
+ },
+ subagents,
+ childSessions,
+ };
+ },
+ mapCustomMessage(message) {
+ if (message.customType === "subagent_ping") {
+ const ping = Ping.safeParse(message.details);
+ return ping.success ? completeRun({ ...ping.data, status: "pinged" }) : undefined;
+ }
+ if (message.customType !== "subagent_result") return undefined;
+ const parsed = Completion.safeParse(message.details);
+ return parsed.success ? completeRun(parsed.data) : undefined;
+ },
+ };
+ },
+};
diff --git a/packages/server/src/server/agent/providers/pi/extensions/registry.ts b/packages/server/src/server/agent/providers/pi/extensions/registry.ts
index c66fabad80..ca273b83bb 100644
--- a/packages/server/src/server/agent/providers/pi/extensions/registry.ts
+++ b/packages/server/src/server/agent/providers/pi/extensions/registry.ts
@@ -1,5 +1,6 @@
import { piAskUser } from "./pi-ask-user/index.js";
import { piSubagents } from "./pi-subagents/index.js";
+import { edxethPiSubagents } from "./edxeth-pi-subagents/index.js";
import { piMcpAdapter } from "./pi-mcp-adapter/index.js";
import { rpivTodo } from "./rpiv-todo/index.js";
import { piExampleTodo } from "./pi-example-todo/index.js";
@@ -10,6 +11,7 @@ import { rpivAskUserQuestion } from "./rpiv-ask-user-question/index.js";
export const piExtensions = [
piAskUser, // Dialog correlation
+ edxethPiSubagents, // Structured results before the generic subagent tool matcher
piSubagents, // Delegation calls
tintinwebPiSubagents,
gotgenesPiSubagents,