{ "recipe": "opus-subagents-search-heavy", "claudeCodeVersion": "2.1.312", "model": "claude-sonnet-5-5", "startedAt": "2026-11-04T20:09:20.012Z", "prompt": null, "steps": [ "A user of this library reports: \"We create new Agent({ maxResponseSize: 1024 * 1024 }) and use it as the dispatcher for request(). A response body over 1 MB that arrives in one go is rejected with ResponseExceededMaxSizeError, as expected. But when the server streams a bigger body in many small chunks, the whole thing gets through.\"\n\nDo three things.\n\n1. Trace how the maxResponseSize option travels from new Agent({ maxResponseSize }) to the code that enforces it, for a plain HTTP/1.1 request with default settings: each file it passes through, in order, with one line on what that file does with it.\n\n2. Check the other ways people set it: on a BalancedPool, on a RetryAgent wrapping an Agent, on a ProxyAgent, on an H2CClient, and on a Client with the Milo HTTP/1 parser turned on. For each, say whether the limit is passed down and enforced on the whole body, and name the file(s) and line(s) that show it.\n\nWrite the answers to 1 and 2 in TRACE.md (paths from the repo root).\n\n3. Find the cause of the reported bug, fix it, add a regression test, and run the relevant tests. The full test suite is very large: run individual test files with node --test instead." ], "variants": [ { "name": "sonnet-alone-1", "model": "claude-sonnet-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 0.2242327, "resultSubtype": "success", "isError": false, "turns": 25, "durationMs": 194220, "inputTokens": 590753, "outputTokens": 8920, "firstContextTokens": 18698, "peakMainContextTokens": 44693 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": true } ], "resultSubtype": "success", "isError": null, "costUsd": 0.2242327, "costByModel": { "claude-sonnet-5-5": { "costUsd": 0.2242327, "inputTokens": 34, "cacheReadTokens": 559097, "cacheWriteTokens": 31622, "outputTokens": 8920 } }, "modelsCalled": [ "claude-sonnet-5-5" ], "turns": 25, "durationMs": 194220, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 24, "inSubagents": 0, "byName": { "Grep": 1, "Bash": 16, "Edit": 5, "TaskStop": 1, "Write": 1 } }, "sessionLogSubagents": [], "permissionDenials": 5, "finalMessage": "I fixed the reported bug and wrote the trace and the dispatcher check to `TRACE.md`. `node --test test/max-response-size.js` passes 7 of 7. I couldn't run it with `UNDICI_USE_MILO=1` because the sandbox blocked that command.\n\n**The bug.** The default llhttp parser's `onBody` in `lib/dispatcher/client-h1.js:770` compared each chunk to the limit on its own (`buf.length > maxResponseSize`). It never added the bytes already received, so a body sent in small chunks never hit the limit. A single large chunk did. The Milo parser and the HTTP/2 path already compared the running total. The fix is `this.bytesRead + buf.length > maxResponseSize`.\n\n**Regression test.** The new test in `test/max-response-size.js` calls `request()` with `Agent({ maxResponseSize: 25 })` against a server that sends four 10-byte chunks. With the fix it gets `ResponseExceededMaxSizeError`. With the fix reverted it hangs, because the body is never rejected.\n\n**Trace of the option.** `Agent` → `Pool` → `Client` → llhttp `Parser` → `onBody`. `TRACE.md` has the files and line numbers.\n\n**Other ways of setting it:**\n- **`BalancedPool`:** the limit is passed down and enforced on the whole body.\n- **`RetryAgent`:** it takes no `maxResponseSize`, so set it on the wrapped `Agent`. The count restarts on each retry, so the limit applies per attempt.\n- **`H2CClient`:** the limit is passed down and enforced on the running total.\n- **`Client` with Milo:** the limit is enforced on the running total in both of the parser's body paths.\n- **`ProxyAgent`, tunnelled requests:** these enforce the limit.\n- **`ProxyAgent`, plain HTTP through a proxy without tunnelling:** `Http1ProxyWrapper` builds its client with only `{ connect }` (`proxy-agent.js:58-61`), so the limit is silently ignored. This is a separate bug that I did not fix.", "diffstat": "TRACE.md | 37 +++++++++++++++++++++++++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 35 ++++++++++++++++++++++++++++++++++-\n 3 files changed, 72 insertions(+), 2 deletions(-)", "sourceRunDir": "2026-11-04T20-09-20-012Z" }, { "name": "sonnet-alone-2", "model": "claude-sonnet-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 0.2548458, "resultSubtype": "success", "isError": false, "turns": 39, "durationMs": 76288, "inputTokens": 641942, "outputTokens": 9557, "firstContextTokens": 18691, "peakMainContextTokens": 52663 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": true } ], "resultSubtype": "success", "isError": null, "costUsd": 0.2548458, "costByModel": { "claude-sonnet-5-5": { "costUsd": 0.2548458, "inputTokens": 32, "cacheReadTokens": 602318, "cacheWriteTokens": 39592, "outputTokens": 9557 } }, "modelsCalled": [ "claude-sonnet-5-5" ], "turns": 39, "durationMs": 76288, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 38, "inSubagents": 0, "byName": { "Grep": 12, "Bash": 6, "Read": 13, "Edit": 6, "Write": 1 } }, "sessionLogSubagents": [], "permissionDenials": 3, "finalMessage": "I found the cause and fixed it. The new regression test fails without the fix and passes with it. `node --test test/max-response-size.js` passes 7 of 7. I didn't run the rest of the suite.\n\n**Cause:** the default HTTP/1.1 parser, llhttp, compared only the current chunk against the limit, at `lib/dispatcher/client-h1.js:770`:\n\n```js\nif (maxResponseSize > -1 && buf.length > maxResponseSize) {\n```\n\nIt added each chunk to `this.bytesRead` but never used that running total in the check. A single big chunk was rejected, but a body streamed in small chunks was never compared as a whole. The Milo parser and the HTTP/2 path already checked the running total. The fix is `this.bytesRead + buf.length > maxResponseSize`.\n\n**Regression test:** `test/max-response-size.js` now has \"should throw an error if a streamed response exceeds the limit in total\". It streams 20 chunks of 10 bytes through `new Agent({ maxResponseSize: 50 })` using `request()`.\n\n`TRACE.md` has the full trace and the per-setup table. In short:\n\n- **Agent path:** `agent.js` → `pool.js` → `client.js` → `client-h1.js`, where the parser checks the limit in `Parser.onBody`.\n- **`BalancedPool`:** passes the option down to its Pools, so the fix covers it.\n- **`RetryAgent`:** takes an already-built dispatcher, so it uses that dispatcher's limit. The count restarts on each retry, so the limit applies per attempt, not across attempts.\n- **`ProxyAgent` with a tunnel:** passes the option down.\n- **`H2CClient`:** passes the option down and enforces it on the whole body.\n- **`Client` with Milo:** enforces it on the whole body.\n\n**Unfixed gap:** `ProxyAgent` has no limit on plain `http:` requests that are forwarded without a tunnel. `Http1ProxyWrapper` builds its inner client with only `{ connect }` (`lib/dispatcher/proxy-agent.js:49-62`), so `maxResponseSize` is dropped. The SOCKS5 branch (`proxy-agent.js:157-167`) also passes no size option. I left both alone because they are outside the reported bug. Say if you want them fixed too.", "diffstat": "TRACE.md | 37 +++++++++++++++++++++++++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 39 ++++++++++++++++++++++++++++++++++++++-\n 3 files changed, 76 insertions(+), 2 deletions(-)", "sourceRunDir": "2026-11-04T20-09-23-624Z" }, { "name": "sonnet-alone-3", "model": "claude-sonnet-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 0.2555597, "resultSubtype": "success", "isError": false, "turns": 35, "durationMs": 91587, "inputTokens": 591337, "outputTokens": 10475, "firstContextTokens": 18695, "peakMainContextTokens": 51244 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": false } ], "resultSubtype": "success", "isError": null, "costUsd": 0.2555597, "costByModel": { "claude-sonnet-5-5": { "costUsd": 0.2555597, "inputTokens": 32, "cacheReadTokens": 553132, "cacheWriteTokens": 38173, "outputTokens": 10475 } }, "modelsCalled": [ "claude-sonnet-5-5" ], "turns": 35, "durationMs": 91587, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 34, "inSubagents": 0, "byName": { "Grep": 12, "Bash": 7, "Edit": 5, "Read": 9, "Write": 1 } }, "sessionLogSubagents": [], "permissionDenials": 4, "finalMessage": "Fixed. The bug was in the default llhttp parser. `onBody` in `lib/dispatcher/client-h1.js:770` compared each chunk's size to the limit, not the running total. A body streamed in small chunks therefore never tripped it. The fix is `this.bytesRead + buf.length > maxResponseSize`. The Milo parser and the HTTP/2 path already checked the running total.\n\nI added a regression test in `test/max-response-size.js`: `new Agent({ maxResponseSize: 50 })` plus `request()` against a server writing twenty 10-byte chunks. It fails without the fix and passes with it, and all 7 tests in that file pass with the fix. I ran only that file, not the full suite.\n\nI wrote the trace and the checks of the other settings to `TRACE.md` from reading the code. I didn't run the BalancedPool, RetryAgent, ProxyAgent, H2CClient or Milo cases.\n\n- **BalancedPool, H2CClient, Milo (`useMilo`):** the limit is passed down and enforced on the whole body.\n- **RetryAgent:** it has no limit of its own. The limit comes from the wrapped Agent and applies to each attempt, not to the total across retries.\n- **ProxyAgent, tunnelled** (https target or `proxyTunnel: true`): the limit is enforced.\n- **ProxyAgent, plain `http:` target without `proxyTunnel`, or SOCKS5:** the limit is silently dropped. `Http1ProxyWrapper` (`proxy-agent.js:59,61,180`) and `Socks5ProxyAgent` (`proxy-agent.js:158`) are built without the Agent's options. Your reporter may hit this too if they use a proxy, but I left it alone because it's outside the reported bug.", "diffstat": "TRACE.md | 36 ++++++++++++++++++++++++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 39 ++++++++++++++++++++++++++++++++++++++-\n 3 files changed, 75 insertions(+), 2 deletions(-)", "sourceRunDir": "2026-11-04T20-09-27-229Z" }, { "name": "sonnet-alone-4", "model": "claude-sonnet-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 0.2645862, "resultSubtype": "success", "isError": false, "turns": 27, "durationMs": 204140, "inputTokens": 806074, "outputTokens": 9211, "firstContextTokens": 18692, "peakMainContextTokens": 51318 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": false } ], "resultSubtype": "success", "isError": null, "costUsd": 0.2645862, "costByModel": { "claude-sonnet-5-5": { "costUsd": 0.2645862, "inputTokens": 40, "cacheReadTokens": 767787, "cacheWriteTokens": 38247, "outputTokens": 9211 } }, "modelsCalled": [ "claude-sonnet-5-5" ], "turns": 27, "durationMs": 204140, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 26, "inSubagents": 0, "byName": { "Grep": 2, "Bash": 16, "bash_placeholder": 1, "Edit": 5, "TaskStop": 1, "Write": 1 } }, "sessionLogSubagents": [], "permissionDenials": 4, "finalMessage": "I found the cause of the reported bug and fixed it. The new regression test passes with the fix, and `node --test test/max-response-size.js` passes all 8 tests. I couldn't get a clean fail-without-fix result. With the fix reverted, the test run didn't finish within the 120 s timeout, so I stopped it. I didn't run eslint or any other test files.\n\n**Cause:** `Parser.onBody` in `lib/dispatcher/client-h1.js` (line 770) compared only the size of the current chunk against the limit: `buf.length > maxResponseSize`. A single oversized chunk was rejected, but a body streamed in many small chunks never tripped it. The fix compares the running total instead: `this.bytesRead + buf.length > maxResponseSize`. The Milo parser and the HTTP/2 path already counted the running total.\n\n**Regression test:** it's in `test/max-response-size.js`. It streams 20 chunks of 10 bytes against a 50-byte limit through `new Agent(...)` and `request()`. It runs once with the default parser and once with `useMilo: true`, and expects `ResponseExceededMaxSizeError`.\n\n**`TRACE.md`:** it holds the 8-step trace for question 1 and a table for question 2.\n- **`BalancedPool`:** the limit is passed down and enforced on the whole body (after the fix).\n- **`H2CClient`:** passed down and enforced on the whole body.\n- **`Client` with `useMilo: true`:** passed down and enforced on the whole body; it never had the bug.\n- **`RetryAgent`:** it has no `maxResponseSize` option of its own, so set the limit on the wrapped `Agent`. The count restarts on each retry attempt.\n- **`ProxyAgent`:** the limit is dropped for plain `http://` targets through an http proxy, and for SOCKS5 proxies. Tunnelled requests (https, or `proxyTunnel: true`) do get it. The details are in the table in `TRACE.md`.\n\nI didn't fix the `ProxyAgent` problem because it's outside the reported bug. It looks like a real gap for anyone relying on the limit behind a proxy, so say if you want it fixed too.", "diffstat": "TRACE.md | 24 ++++++++++++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 41 ++++++++++++++++++++++++++++++++++++++++-\n 3 files changed, 65 insertions(+), 2 deletions(-)", "sourceRunDir": "2026-11-04T20-09-30-841Z" }, { "name": "sonnet-alone-5", "model": "claude-sonnet-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 0.2431889, "resultSubtype": "success", "isError": false, "turns": 27, "durationMs": 199180, "inputTokens": 670333, "outputTokens": 9322, "firstContextTokens": 18691, "peakMainContextTokens": 47599 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": true } ], "resultSubtype": "success", "isError": null, "costUsd": 0.2431889, "costByModel": { "claude-sonnet-5-5": { "costUsd": 0.2431889, "inputTokens": 36, "cacheReadTokens": 635769, "cacheWriteTokens": 34528, "outputTokens": 9322 } }, "modelsCalled": [ "claude-sonnet-5-5" ], "turns": 27, "durationMs": 199180, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 26, "inSubagents": 0, "byName": { "Grep": 3, "Read": 1, "Bash": 12, "Edit": 8, "TaskStop": 1, "Write": 1 } }, "sessionLogSubagents": [], "permissionDenials": 4, "finalMessage": "I'm wrapping up. The fix and tests are done, and I just finished correcting a few line references in TRACE.md. I'll give you the summary now.\n\n**Cause:** the default (llhttp) HTTP/1.1 path in `lib/dispatcher/client-h1.js:770` compared each chunk to the limit (`buf.length > maxResponseSize`) instead of the running total. A body streamed in small chunks never tripped it. The Milo and HTTP/2 paths already used `bytesRead + len`.\n\n**Fix:** that line is now `this.bytesRead + buf.length > maxResponseSize`.\n\n**Test:** I added a regression test to `test/max-response-size.js`. It streams 10-byte chunks through an `Agent` with `maxResponseSize: 50`, once with `useMilo: false` and once with `true`. With the fix, `node --test test/max-response-size.js` passes 8 of 8. With the fix reverted, the run hung until it timed out, so I stopped it. I didn't capture a clean failure message for the unfixed code.\n\n**TRACE.md** has the file-by-file trace (Agent → Pool → Client → `connectH1` → llhttp `Parser`) and the table for the other setups.\n- **Enforced on the whole body:** `BalancedPool`, `H2CClient`, `Client` with `useMilo: true`, and `ProxyAgent` in CONNECT-tunnel mode (https, or `proxyTunnel: true`).\n- **`RetryAgent`:** the option has to go on the wrapped agent. Setting it on `RetryAgent` itself does nothing. I expect the limit to apply per attempt but didn't test that.\n- **Silently dropped:** plain-`http:` `ProxyAgent` without a tunnel (`Http1ProxyWrapper` creates its client with only `{ connect }`, `proxy-agent.js:47-62`) and SOCKS5 proxies (`socks5-proxy-agent.js:235-237`). Responses through those proxies have no size limit. I didn't fix these because you didn't ask for it, but I can.", "diffstat": "TRACE.md | 27 +++++++++++++++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 39 +++++++++++++++++++++++++++++++++++++--\n 3 files changed, 65 insertions(+), 3 deletions(-)", "sourceRunDir": "2026-11-04T20-09-34-457Z" }, { "name": "opus-no-subagents-1", "model": "claude-opus-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 1.1117869999999999, "resultSubtype": "success", "isError": false, "turns": 64, "durationMs": 605079, "inputTokens": 2172233, "outputTokens": 19627, "firstContextTokens": 16395, "peakMainContextTokens": 71621 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": true } ], "resultSubtype": "success", "isError": null, "costUsd": 1.1117869999999999, "costByModel": { "claude-opus-5-5": { "costUsd": 1.1117869999999999, "inputTokens": 94, "cacheReadTokens": 2112880, "cacheWriteTokens": 59259, "outputTokens": 19627 } }, "modelsCalled": [ "claude-opus-5-5" ], "turns": 64, "durationMs": 605079, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 63, "inSubagents": 0, "byName": { "Grep": 4, "Read": 9, "Bash": 31, "Edit": 12, "ToolSearch": 1, "TaskStop": 3, "Write": 3 } }, "sessionLogSubagents": [], "permissionDenials": 10, "finalMessage": "I found and fixed the bug, added a regression test, and wrote both traces into `TRACE.md`. Checking the other setups also turned up a second bug in `ProxyAgent`, which I have not fixed.\n\n**Cause:** for HTTP/1.1 with the default parser, the size check in `lib/dispatcher/client-h1.js:770` compared each chunk to the limit on its own (`buf.length > maxResponseSize`). It never added the bytes already received. So a 1 MB+ body in one chunk was rejected, but a body streamed in chunks each under 1 MB got through whatever its total size. The fix is one line: `this.bytesRead + buf.length > maxResponseSize`. The HTTP/2 and Milo parser paths already checked it this way.\n\n**Regression test:** added to `test/max-response-size.js`. It uses `new Agent({ maxResponseSize: 1024 })` with `request()` against a server that streams 10 × 200-byte chunks, and runs once with each parser (default and Milo).\n- **Without the fix**, the default-parser case fails: all 2000 bytes arrive and no error is raised.\n- **With the fix**, both cases pass.\n- **Related test files:** I ran 9 with `node --test` (max-response-size, client, agent, balanced-pool, retry-agent, proxy-agent, h2c-client, milo, content-length): 159 passed, 0 failed, 1 skipped. I didn't run eslint because the command needed approval.\n\n**1. Path for a plain HTTP/1.1 request** (line-by-line detail is in `TRACE.md`):\n1. `lib/dispatcher/agent.js` keeps the option in its stored options and hands them to the `Pool` it creates for each origin.\n2. `lib/dispatcher/pool.js` stores the options and passes them on to each `Client` it creates.\n3. `lib/dispatcher/client.js` checks the value and stores it (`-1` means no limit).\n4. `lib/dispatcher/client-h1.js` copies it into the parser, whose `onBody` enforces it.\n\n**2. Other setups:**\n\n| Setup | Limit applied to the whole body? |\n|---|---|\n| `BalancedPool` | Yes, now. It goes through the same `Pool` → `Client` path, so it had the same bug before the fix. |\n| `RetryAgent` wrapping an `Agent` | Yes, now, when set on the inner `Agent`. A size error is not retried. Set on the `RetryAgent` itself, it is silently ignored: that argument is only retry options. |\n| `ProxyAgent` | **Only partly.** It works when the request is tunnelled (`https:` targets, or `proxyTunnel: true`). For an `http:` target with default settings, and for SOCKS proxies, the option is dropped and there is no limit at all (`proxy-agent.js:58-61`, `180-187`; `socks5-proxy-agent.js:235`). |\n| `H2CClient` | Yes; this path was already correct (`client-h2.js:1141`, `1455`). |\n| `Client` with Milo | Yes; this path was already correct (`parser-h1.js:433`, `932`). |\n\nI confirmed the `ProxyAgent`, `BalancedPool` and `RetryAgent` results with a throwaway script in `/tmp/diag` (outside the repo). It sent a 5000-byte response with a 1024 limit: the default `ProxyAgent` to an `http:` origin let it through, while the tunnelled one rejected it.\n\n**Decision for you:** whether to fix the `ProxyAgent` case. That means passing the agent's options into the forwarding client and the SOCKS pool. I left it out because it isn't what was reported and it changes how options flow to the proxy-side client; I can do it next if you want.\n\nNothing is committed.", "diffstat": "TRACE.md | 31 ++++++++++++++++++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 46 ++++++++++++++++++++++++++++++++++++++++++++-\n 3 files changed, 77 insertions(+), 2 deletions(-)", "sourceRunDir": "2026-11-04T20-09-21-226Z" }, { "name": "opus-no-subagents-2", "model": "claude-opus-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 0.9153298, "resultSubtype": "success", "isError": false, "turns": 49, "durationMs": 592552, "inputTokens": 1651971, "outputTokens": 17645, "firstContextTokens": 16396, "peakMainContextTokens": 60202 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": true } ], "resultSubtype": "success", "isError": null, "costUsd": 0.9153298, "costByModel": { "claude-opus-5-5": { "costUsd": 0.9153298, "inputTokens": 78, "cacheReadTokens": 1603614, "cacheWriteTokens": 48279, "outputTokens": 17645 } }, "modelsCalled": [ "claude-opus-5-5" ], "turns": 49, "durationMs": 592552, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 48, "inSubagents": 0, "byName": { "Grep": 1, "Read": 4, "Bash": 31, "Edit": 7, "Write": 2, "Glob": 1, "ToolSearch": 1, "TaskStop": 1 } }, "sessionLogSubagents": [], "permissionDenials": 9, "finalMessage": "I found and fixed the bug. The new tests pass, and the llhttp one fails on the old code as it should. All three parts are done, and TRACE.md is written.\n\n## Cause and fix (part 3)\nWith default settings, HTTP/1.1 bodies go through the llhttp parser. Its `Parser.onBody` checked the size of each chunk, not the running total:\n\n```js\n// lib/dispatcher/client-h1.js:770\n- if (maxResponseSize > -1 && buf.length > maxResponseSize) {\n+ if (maxResponseSize > -1 && this.bytesRead + buf.length > maxResponseSize) {\n```\n\nA 1 MB+ body that arrived in one read was over the limit and got rejected. A body sent in small chunks never had a single chunk over the limit, so the whole thing got through. `bytesRead` was already being counted (line 775) and reset for each response (line 806), so this one-line change is the whole fix. The Milo parser and the HTTP/2 code already checked the running total.\n\n## Regression test\nI added two tests to `test/max-response-size.js` that copy the report: `request()` through `new Agent({ maxResponseSize: 1024 })`, with the server sending 64 × 64-byte chunks on separate timers. One test uses the default llhttp parser and one uses Milo.\n\n- **With the fix:** all 8 tests in the file pass.\n- **On the old code:** the llhttp test fails (no error, all 4096 bytes received) and the Milo test passes. After that failure the test process hangs until killed rather than exiting. This happens only when the assertion fails and seems to come from how the file's existing tests are set up.\n- **Related files** (`content-length`, `client-request`, `client-pipelining`, `client-keep-alive`, `retry-agent`): 112 of 112 pass.\n\nI couldn't run eslint because the command needed approval.\n\n## Trace (parts 1 and 2, in TRACE.md)\nThe path from `new Agent()` is `agent.js` → `pool.js` → `client.js` (stores the limit at line 323, then calls `connectH1`) → `client-h1.js` (llhttp `Parser`, which enforces the limit at line 770).\n\n| Setup | Limit passed down? | Whole body enforced? |\n|---|---|---|\n| BalancedPool | yes, through its Pool | yes, now that the bug is fixed |\n| RetryAgent wrapping an Agent | yes, through the inner Agent | yes, now that the bug is fixed (see notes) |\n| ProxyAgent | only for tunnelled requests | tunnelled: yes, now fixed; plain `http:` targets: **no** |\n| H2CClient | yes | yes, already (`client-h2.js:1455`) |\n| Client with Milo | yes | yes, already (`parser-h1.js:433`, `:932`) |\n\nTwo things in TRACE.md that I didn't fix, since they're separate from the report:\n- **ProxyAgent:** for plain `http:` targets with the default `proxyTunnel`, `Http1ProxyWrapper` creates its client with only `{ connect }` (`proxy-agent.js:58-62`). The limit is dropped completely there. This one is a real gap and probably worth fixing.\n- **RetryAgent:**\n - Passing `maxResponseSize` to RetryAgent itself does nothing; only the inner Agent's setting counts.\n - If a download is retried and resumed with a Range request, each attempt is counted separately. The total the caller receives can then exceed the limit.\n\n## Leftovers\nI left `/tmp/maxresp-scratch/repro.js` (a standalone repro I couldn't run without approval). Nothing is committed.", "diffstat": "TRACE.md | 24 ++++++++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 53 ++++++++++++++++++++++++++++++++++++++++++++-\n 3 files changed, 77 insertions(+), 2 deletions(-)", "sourceRunDir": "2026-11-04T20-09-24-817Z" }, { "name": "opus-no-subagents-3", "model": "claude-opus-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 1.1249466000000001, "resultSubtype": "success", "isError": false, "turns": 70, "durationMs": 698543, "inputTokens": 1990439, "outputTokens": 23074, "firstContextTokens": 16399, "peakMainContextTokens": 67314 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": true } ], "resultSubtype": "success", "isError": null, "costUsd": 1.1249466000000001, "costByModel": { "claude-opus-5-5": { "costUsd": 1.1249466000000001, "inputTokens": 90, "cacheReadTokens": 1935133, "cacheWriteTokens": 55216, "outputTokens": 23074 } }, "modelsCalled": [ "claude-opus-5-5" ], "turns": 70, "durationMs": 698543, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 69, "inSubagents": 0, "byName": { "Grep": 4, "Read": 7, "Bash": 30, "Edit": 21, "ToolSearch": 1, "TaskStop": 1, "Write": 3, "Glob": 2 } }, "sessionLogSubagents": [], "permissionDenials": 9, "finalMessage": "I found the cause and fixed it with a one-line change. The answers to parts 1 and 2 are in `TRACE.md`. I haven't committed anything.\n\n## Cause and fix\nOn a plain HTTP/1.1 request with default settings, the limit is checked in `onBody()` at `lib/dispatcher/client-h1.js:770`. That check compared each chunk to the limit (`buf.length > maxResponseSize`) instead of the total received so far. A 1.1 MB body arriving in one read was rejected, but the same body in many smaller chunks never was. The parser was already keeping a running total in `this.bytesRead` and resetting it for each response; the check just didn't use it. It now reads `this.bytesRead + buf.length > maxResponseSize`, the same rule the Milo and HTTP/2 code already uses.\n\n## Regression tests (`test/max-response-size.js`)\nI added four tests, each run once with the default parser (llhttp) and once with Milo:\n- **Your user's case:** `Agent({ maxResponseSize: 1000 })` with `request()`, against a server that streams 2000 bytes in 100-byte chunks. It must fail with `ResponseExceededMaxSizeError` after at most 1000 bytes.\n- **Per-response limit:** two 600-byte responses on the same kept-alive connection both succeed, so the count starts over for each response.\n\nResults:\n- **Without the fix:** only the llhttp streaming test fails (\"got null after 2000 bytes\"). Milo was already correct.\n- **With the fix:** `node --test` on `max-response-size.js`, `client.js`, `request.js` and `client-pipelining.js` gives 113 passed, 0 failed, 1 skipped. Another 48 tests (parser, content-length, Milo, agent, balanced-pool, retry-agent) all pass.\n- The new tests use plain `node:assert` instead of the file's usual tspl helper. With tspl, the failing test made the whole run hang instead of failing.\n- I didn't run eslint, because the command needed approval.\n\n## Part 2\nI checked each setup in the code and also ran it against a streaming server.\n\n| Setup | Limit applied to the whole body? |\n|---|---|\n| BalancedPool | Yes, now. It goes through the same code that had the bug. |\n| RetryAgent wrapping an Agent | Yes, now, if the option is set on the inner Agent. Each retry gets its own limit. |\n| H2CClient | Yes. This path already checked the total. |\n| Client with Milo on | Yes. Both of its body paths already checked the total. |\n| ProxyAgent | Only when tunnelling (`https:` targets or `proxyTunnel: true`). |\n\n## Two more gaps I didn't fix\n- **ProxyAgent with a plain `http:` target:** by default this request goes straight to the proxy without tunnelling. That path builds its own `Client(proxyUrl, { connect })` (`lib/dispatcher/proxy-agent.js:58-62`), which drops `maxResponseSize`, so no limit applies at all. In my run, a 100-byte body got through a 50-byte limit. SOCKS proxies drop it too. Fixing this means passing the option into those wrappers.\n- **`new RetryAgent(agent, { maxResponseSize })`:** setting the option on the RetryAgent itself does nothing, because those options only control retries.\n\nThe check scripts I used are in `/tmp/dbg-maxsize/`, outside the repo.", "diffstat": "TRACE.md | 44 ++++++++++++++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 76 ++++++++++++++++++++++++++++++++++++++++++++-\n 3 files changed, 120 insertions(+), 2 deletions(-)", "sourceRunDir": "2026-11-04T20-09-28-446Z" }, { "name": "opus-no-subagents-4", "model": "claude-opus-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 0.6671025999999999, "resultSubtype": "success", "isError": false, "turns": 35, "durationMs": 390540, "inputTokens": 1069169, "outputTokens": 11943, "firstContextTokens": 16396, "peakMainContextTokens": 55954 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": true } ], "resultSubtype": "success", "isError": null, "costUsd": 0.6671025999999999, "costByModel": { "claude-opus-5-5": { "costUsd": 0.6671025999999999, "inputTokens": 60, "cacheReadTokens": 1024488, "cacheWriteTokens": 44621, "outputTokens": 11943 } }, "modelsCalled": [ "claude-opus-5-5" ], "turns": 35, "durationMs": 390540, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 33, "inSubagents": 0, "byName": { "Grep": 2, "Bash": 22, "Read": 1, "Edit": 5, "ToolSearch": 1, "TaskStop": 1, "Write": 1 } }, "sessionLogSubagents": [], "permissionDenials": 4, "finalMessage": "I've fixed the bug, added a regression test, and written the trace and dispatcher check (parts 1 and 2) to `TRACE.md`. Nothing is committed.\n\n**Cause:** Plain HTTP/1.1 uses the default llhttp parser. It compared each chunk against the limit on its own instead of adding chunks up (`lib/dispatcher/client-h1.js:770`):\n\n```js\nif (maxResponseSize > -1 && buf.length > maxResponseSize) {\n```\n\nA body that arrives in one piece is one big chunk, so it was caught. A body streamed in small chunks never had a single chunk over 1 MB, so it got through. The code already kept a running byte count (`this.bytesRead`, reset for each response) but didn't use it in this check. The fix is `this.bytesRead + buf.length > maxResponseSize`. That matches how the Milo parser (`parser-h1.js:433`, `:932`) and HTTP/2 (`client-h2.js:1455`) already did it.\n\n**Regression test:** in `test/max-response-size.js`, run once with the default parser and once with Milo. The server streams 20 × 10-byte chunks through `request()` with `new Agent({ maxResponseSize: 50 })`. The test expects `ResponseExceededMaxSizeError` and no more than 50 bytes delivered.\n- **Without the fix:** the default-parser version fails and the Milo version passes, which confirms only the default parser was affected. After the failure the test run hung until my 30-second timeout killed it.\n- **With the fix:** `node --test test/max-response-size.js test/client-request.js test/agent.js test/pool.js test/content-length.js` gives 121 passed, 0 failed.\n- **Not done:** running eslint needed approval it didn't get, so the changed files haven't been linted.\n\n**Part 1:** the path is `request()` → `agent.js` → `pool.js` → `client.js` → `client-h1.js`. `TRACE.md` has file and line references for each step.\n\n**Part 2:**\n- **BalancedPool:** the option is passed down. It had the same chunk-by-chunk bug and is fixed by the same change.\n- **RetryAgent:** only the wrapped Agent's setting counts; a `maxResponseSize` given to RetryAgent itself is ignored. Each attempt is limited, and a size error isn't retried. One gap: if a download is cut off and resumed with a `Range` request, counting starts again from 0. So the limit covers each attempt, not the total across attempts.\n- **ProxyAgent:** the limit is enforced for tunneled requests (`https:` targets, or `proxyTunnel: true`). For `http:` targets without `proxyTunnel: true`, the request goes through `Http1ProxyWrapper`, which creates its Client with only `{ connect }` (`proxy-agent.js:59-61`). The limit is not applied at all there. That's a separate bug that this change doesn't fix. I can fix it if you'd like.\n- **H2CClient:** enforced on the whole body; it already counted correctly.\n- **Client with Milo:** enforced on the whole body; it already counted correctly.", "diffstat": "TRACE.md | 22 ++++++++++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 46 ++++++++++++++++++++++++++++++++++++++++++++-\n 3 files changed, 68 insertions(+), 2 deletions(-)", "sourceRunDir": "2026-11-04T20-09-32-031Z" }, { "name": "opus-no-subagents-5", "model": "claude-opus-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 0.9358943999999998, "resultSubtype": "success", "isError": false, "turns": 50, "durationMs": 416442, "inputTokens": 2006522, "outputTokens": 14044, "firstContextTokens": 16397, "peakMainContextTokens": 64118 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": true } ], "resultSubtype": "success", "isError": null, "costUsd": 0.9358943999999998, "costByModel": { "claude-opus-5-5": { "costUsd": 0.9358943999999998, "inputTokens": 90, "cacheReadTokens": 1953647, "cacheWriteTokens": 52785, "outputTokens": 14044 } }, "modelsCalled": [ "claude-opus-5-5" ], "turns": 50, "durationMs": 416442, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 49, "inSubagents": 0, "byName": { "Grep": 2, "Read": 5, "Bash": 31, "Edit": 6, "ToolSearch": 2, "TaskStop": 2, "Write": 1 } }, "sessionLogSubagents": [], "permissionDenials": 7, "finalMessage": "I found and fixed the bug, added a regression test that fails without the fix, and wrote the trace and the per-setup check into `TRACE.md`. One more gap turned up and is not fixed: a ProxyAgent sending plain `http:` requests drops the limit entirely.\n\n**The bug.** The default HTTP/1.1 parser checked each body chunk on its own against the limit instead of adding up the whole body (`lib/dispatcher/client-h1.js:770`):\n```js\nif (maxResponseSize > -1 && buf.length > maxResponseSize) // before\nif (maxResponseSize > -1 && this.bytesRead + buf.length > maxResponseSize) // after\n```\nA single 2 MB chunk failed the check, but 2,000 chunks of 1 KB each passed. The running count `bytesRead` already existed and is reset for each response. The Milo parser and the HTTP/2 code already checked the running total.\n\n**Regression test** (`test/max-response-size.js`): it uses `new Agent({ maxResponseSize: 1024 })` with `request()`. The server sends 4 KB as 64 writes of 64 bytes, with a short pause between them. It runs four ways: llhttp and Milo, each with chunked and content-length bodies.\n- **With the fix:** all four pass.\n- **Without the fix:** both llhttp versions fail and both Milo versions pass, which matches the cause. On that failing run the test process didn't exit after reporting and I had to stop it, probably because of open keep-alive connections. With the fix in place it exits normally.\n\n**Tests run:** `max-response-size`, `client`, `content-length`, `client-pipelining`, `client-request`, `client-stream`, `parser-issues`, `milo`, `pool`, `retry-agent` and `h2c-client`. 256 passed, 0 failed, and 1 test was skipped by the suite itself. ESLint on the two changed files wasn't approved, so lint hasn't been run.\n\n**Results for the other setups:**\n- **BalancedPool:** the limit is passed down to each Pool and Client. It had the same chunk bug, which this fixes.\n- **H2CClient:** passed down, and it checks the whole body. Going over the limit resets only that stream, not the connection.\n- **Client with Milo:** passed down, and both of its body paths check the whole body.\n- **RetryAgent:** the limit applies to each attempt on the wrapped Agent, not across attempts. If a connection drops and the request resumes with a `Range` request, the count starts again at zero. The total delivered across attempts can then go over the limit.\n- **ProxyAgent:** the limit only applies when the request is tunnelled (an `https:` target, or `proxyTunnel: true`). For an `http:` target with default settings, requests go through `Http1ProxyWrapper`. It builds its client with only `{ connect }` (`lib/dispatcher/proxy-agent.js:58-62`), so there is no limit at all. The SOCKS5 path also drops it.\n\n**Decision for you:** the ProxyAgent fix would mean passing the user's options through to `Http1ProxyWrapper` and the SOCKS5 agent. That changes proxy behaviour beyond the reported bug, so I didn't make it. I can do it if you want.\n\nNothing is committed yet.", "diffstat": "TRACE.md | 24 ++++++++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 55 ++++++++++++++++++++++++++++++++++++++++++++-\n 3 files changed, 79 insertions(+), 2 deletions(-)", "sourceRunDir": "2026-11-04T20-09-35-634Z" }, { "name": "opus-subagents-default-1", "model": "claude-opus-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 0.7439078000000001, "resultSubtype": "success", "isError": false, "turns": 38, "durationMs": 582510, "inputTokens": 1322311, "outputTokens": 13672, "firstContextTokens": 18685, "peakMainContextTokens": 55935 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": true } ], "resultSubtype": "success", "isError": null, "costUsd": 0.7439078000000001, "costByModel": { "claude-opus-5-5": { "costUsd": 0.7439078000000001, "inputTokens": 68, "cacheReadTokens": 1279379, "cacheWriteTokens": 42864, "outputTokens": 13672 } }, "modelsCalled": [ "claude-opus-5-5" ], "turns": 38, "durationMs": 582510, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 37, "inSubagents": 0, "byName": { "Grep": 2, "Read": 5, "Bash": 22, "Edit": 5, "ToolSearch": 1, "TaskStop": 1, "Write": 1 } }, "sessionLogSubagents": [], "permissionDenials": 4, "finalMessage": "I fixed the bug and added regression tests, which pass. Sections 1 and 2 are written up in `TRACE.md`.\n\n## Cause and fix\nThe limit was checked against each body chunk, not the running total. `lib/dispatcher/client-h1.js:770` (in the default llhttp parser) compared `buf.length > maxResponseSize`, even though it was already counting bytes in `this.bytesRead`. A 2 MB body arriving in one chunk was rejected. A body sent as many chunks, each under 1 MB, got through whatever its total size.\n\nThe fix is one line: `this.bytesRead + buf.length > maxResponseSize`. That is the same check the Milo parser and the HTTP/2 path already make. The count is reset for each response, so separate responses on a kept-alive connection don't add up.\n\n## 1. The path for a default `Agent`\n`agent.js` keeps the option in its stored options and builds a `Pool`. `pool.js` keeps it and builds a `Client`. `client.js` validates it and saves it on the client. `client-h1.js` hands it to the llhttp parser, which checks it each time a piece of the body arrives. That check is where the bug was.\n\n## 2. Other ways of setting it\n- **BalancedPool:** passed down through Pool → Client, and enforced on the whole body now that the fix is in.\n- **RetryAgent wrapping an Agent:** enforced, because the wrapped Agent does the work. Two things to know:\n - Putting `maxResponseSize` in the RetryAgent's own options does nothing; it's treated as a retry option.\n - The size error isn't on the default list of errors to retry, so a retry won't hide it.\n- **ProxyAgent:** only partly passed down. It works for tunnelled requests (https targets, or `proxyTunnel: true`). For plain `http://` targets without tunnelling, the client is built with only `{ connect }` (`proxy-agent.js` lines 59, 61 and 170–188), so there is **no limit at all**. SOCKS proxies drop it too (`socks5-proxy-agent.js` lines 235–237). I wrote this up but didn't fix it. Tell me if you want it fixed.\n- **H2CClient:** passed down, and the HTTP/2 code checks the whole body (`client-h2.js` lines 1141 and 1455). Going over the limit resets only that stream.\n- **Client with Milo:** passed down, and it already checked the whole body before this fix (`parser-h1.js` lines 433, 932 and 648).\n\n## Tests\n- I added four tests to `test/max-response-size.js`. They use `request()` through `new Agent({ maxResponseSize: 1024 })`, with both llhttp and Milo:\n - A chunked body of 64 × 64 bytes must be rejected, and no more than 1024 bytes may reach the caller.\n - Two responses of exactly 1024 bytes on one connection must both succeed. This checks the boundary and that the count resets per response.\n- With the old line put back, the llhttp \"exceeds\" test failed and the Milo tests passed, which matches the trace. When that test fails, the file then hangs until the runner's timeout; it doesn't fail quickly.\n- With the fix, `node --test test/max-response-size.js` passes 10 of 10.\n- `test/client.js`, `test/content-length.js`, `test/agent.js` and `test/pool.js` pass 129, with 1 skipped already and none failing.\n\nI didn't run the linter, because the command needed approval. Nothing is committed.", "diffstat": "TRACE.md | 38 +++++++++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 83 ++++++++++++++++++++++++++++++++++++++++++++-\n 3 files changed, 121 insertions(+), 2 deletions(-)", "sourceRunDir": "2026-11-04T20-09-22-419Z" }, { "name": "opus-subagents-default-2", "model": "claude-opus-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 0.6890354, "resultSubtype": "success", "isError": false, "turns": 39, "durationMs": 159834, "inputTokens": 1137191, "outputTokens": 13603, "firstContextTokens": 18687, "peakMainContextTokens": 52512 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": true } ], "resultSubtype": "success", "isError": null, "costUsd": 0.6890354, "costByModel": { "claude-opus-5-5": { "costUsd": 0.6890354, "inputTokens": 58, "cacheReadTokens": 1097692, "cacheWriteTokens": 39441, "outputTokens": 13603 } }, "modelsCalled": [ "claude-opus-5-5" ], "turns": 39, "durationMs": 159834, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 38, "inSubagents": 0, "byName": { "Grep": 3, "Read": 5, "Edit": 8, "Bash": 21, "Write": 1 } }, "sessionLogSubagents": [], "permissionDenials": 4, "finalMessage": "I fixed the bug and added a regression test. Both tracing answers are in `TRACE.md`, and I didn't commit anything.\n\n**Cause:** with the default llhttp parser, the size check looked at each chunk alone and ignored the bytes already received for that response. In `lib/dispatcher/client-h1.js:770` it tested `buf.length > maxResponseSize`, so a body arriving as many chunks, each under 1 MB, was never rejected. A body arriving in one go was rejected because that single chunk was over the limit. The fix is one line: it now tests `this.bytesRead + buf.length > maxResponseSize`, which is how the Milo parser and HTTP/2 already count. `bytesRead` goes back to 0 after each response, so earlier responses on a kept-alive connection don't count against later ones.\n\n**Test:** I added one test to `test/max-response-size.js` and run it twice, once with Milo off and once with it on. It matches the report: `new Agent({ maxResponseSize: 10 })` with `request()`, and a server sending 20 chunks of 5 bytes. It first checks that a small chunked body still gets through on the same Agent, then that the big one is rejected with `ResponseExceededMaxSizeError`.\n- With the old line put back, only the Milo-off version fails, which confirms the cause.\n- With the fix, `node --test test/max-response-size.js` passes all 8 tests.\n- I also ran `test/client.js`, `test/content-length.js`, `test/pool.js`, `test/proxy-agent.js` and `test/retry-agent.js`: 175 pass, 0 fail, and 1 test is marked skip in the code.\n- ESLint needed an approval that wasn't given, so lint hasn't been run.\n\n**1. How the option travels (Agent, plain HTTP/1.1, default settings):**\n1. `lib/dispatcher/agent.js` saves it with the Agent's options and hands them to a new `Pool` for each origin.\n2. `lib/dispatcher/pool.js` saves it the same way and hands it to each `Client` it creates.\n3. `lib/dispatcher/client.js` checks it and stores it as `kMaxResponseSize`, then uses `client-h1.js` for an HTTP/1.1 connection.\n4. `lib/dispatcher/client-h1.js` gives it to the llhttp `Parser`, and `onBody` enforces it (this is where the bug was).\n\n**2. Other ways to set it:**\n\n| Setup | Passed down? | Whole body checked? | Where it shows |\n|---|---|---|---|\n| BalancedPool | Yes | Yes, now that the bug is fixed | `balanced-pool.js` L62 and L91, then the same Pool → Client path |\n| RetryAgent wrapping an Agent | Yes, through the inner Agent | Yes, now fixed, per attempt | `retry-agent.js` L18-27 |\n| ProxyAgent | Only for tunnelled requests | See below | `proxy-agent.js` |\n| H2CClient | Yes | Yes, already correct | `client-h2.js` L1141 and L1455 |\n| Client with `useMilo: true` | Yes | Yes, already correct | `parser-h1.js` L173, L433 and L932 |\n\nFor RetryAgent, setting `maxResponseSize` on the RetryAgent itself does nothing; it only works on the Agent inside it.\n\n**One more gap I didn't fix:** `ProxyAgent` drops the limit in some cases.\n- **Where it works:** HTTPS targets, or any target when `proxyTunnel: true`, go through an Agent that keeps the option, so the limit applies.\n- **Where it's lost:** a plain `http:` target with the default `proxyTunnel` goes through `Http1ProxyWrapper`. That wrapper builds its connection to the proxy from only `{ connect }` (`proxy-agent.js` L58-61), so there is no limit at all.\n- **SOCKS proxies** drop it too (`proxy-agent.js` L158-167 and `socks5-proxy-agent.js` L235-238).\n\nFixing it means passing the size option through those constructors. Should I do that as well?", "diffstat": "TRACE.md | 22 ++++++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 55 ++++++++++++++++++++++++++++++++++++++++++++-\n 3 files changed, 77 insertions(+), 2 deletions(-)", "sourceRunDir": "2026-11-04T20-09-26-030Z" }, { "name": "opus-subagents-default-3", "model": "claude-opus-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 0.8479944000000001, "resultSubtype": "success", "isError": false, "turns": 44, "durationMs": 497897, "inputTokens": 1576546, "outputTokens": 15633, "firstContextTokens": 18688, "peakMainContextTokens": 59066 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": true } ], "resultSubtype": "success", "isError": null, "costUsd": 0.8479944000000001, "costByModel": { "claude-opus-5-5": { "costUsd": 0.8479944000000001, "inputTokens": 74, "cacheReadTokens": 1530692, "cacheWriteTokens": 45780, "outputTokens": 15633 } }, "modelsCalled": [ "claude-opus-5-5" ], "turns": 44, "durationMs": 497897, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 43, "inSubagents": 0, "byName": { "Grep": 5, "Read": 6, "Bash": 22, "Edit": 7, "ToolSearch": 1, "TaskStop": 1, "Write": 1 } }, "sessionLogSubagents": [], "permissionDenials": 6, "finalMessage": "I found and fixed the bug, added a regression test, and wrote `TRACE.md` with parts 1 and 2.\n\n**Cause:** the size check for the default HTTP/1.1 parser (llhttp) looked at each chunk by itself. In `lib/dispatcher/client-h1.js:770` it compared `buf.length > maxResponseSize`, so a body sent as many chunks, each under the limit, got through however large it was. Only a body arriving in one big piece was caught, which is what the user saw. The fix compares the running total instead:\n\n```js\nif (maxResponseSize > -1 && this.bytesRead + buf.length > maxResponseSize) {\n```\n\nThe parser already kept that total (`this.bytesRead`) and reset it for each response; the check just wasn't using it. The Milo parser and HTTP/2 paths already checked the total.\n\n**Regression tests**, added to `test/max-response-size.js`:\n- `new Agent({ maxResponseSize: 10 })` used with `request()`, and a server that sends 20 chunks of 2 bytes. The test expects `ResponseExceededMaxSizeError` and at most 10 bytes delivered. It runs once with llhttp and once with Milo.\n- A body streamed in chunks that totals exactly the limit is still accepted.\n\n**Test results:**\n- With the old line put back, the llhttp test fails and the Milo one passes, as expected. The failing run then hangs until the test runner times out, because the test helper waits for an assertion that never runs; this only happens while the bug is present.\n- With the fix, all 9 tests in `test/max-response-size.js` pass.\n- `test/client-request.js`, `test/milo.js`, `test/h2c-client.js`, `test/retry-agent.js`, `test/proxy-agent.js`, `test/content-length.js`, `test/node-test/agent.js` and `test/node-test/balanced-pool.js` all pass (207 tests including the file above, 0 failures).\n- I did not run eslint, because the command needed an approval that wasn't given.\n\n**What `TRACE.md` covers:**\n- **Part 1:** the route from `index.js` to `api-request.js`, `agent.js`, `pool.js`, `client.js` and `client-h1.js`, where the check happens, with file and line numbers.\n- **Part 2:** BalancedPool, an Agent wrapped in RetryAgent, H2CClient and Milo all pass the limit down. BalancedPool and RetryAgent go through the same llhttp code, so they only check the whole body now that it's fixed; H2CClient and Milo already did. Two other findings, which I left unchanged:\n - **ProxyAgent drops the limit** for plain `http:` targets when `proxyTunnel` isn't set, which is the default for `http:`. Those requests go through a `Client` built with only `{ connect }` (`proxy-agent.js:58-61`). SOCKS proxies drop it the same way (`socks5-proxy-agent.js:235-238`). Only tunneled requests are limited.\n - **On RetryAgent, the option only works on the inner Agent.** Set on the RetryAgent itself, it's treated as a retry setting and does nothing. Going over the limit isn't retried.\n\nShould I fix the ProxyAgent and SOCKS gaps too?", "diffstat": "TRACE.md | 29 ++++++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 75 ++++++++++++++++++++++++++++++++++++++++++++-\n 3 files changed, 104 insertions(+), 2 deletions(-)", "sourceRunDir": "2026-11-04T20-09-29-642Z" }, { "name": "opus-subagents-default-4", "model": "claude-opus-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 0.6814701999999999, "resultSubtype": "success", "isError": false, "turns": 38, "durationMs": 144360, "inputTokens": 1183317, "outputTokens": 13098, "firstContextTokens": 18690, "peakMainContextTokens": 51115 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": true } ], "resultSubtype": "success", "isError": null, "costUsd": 0.6814701999999999, "costByModel": { "claude-opus-5-5": { "costUsd": 0.6814701999999999, "inputTokens": 62, "cacheReadTokens": 1145211, "cacheWriteTokens": 38044, "outputTokens": 13098 } }, "modelsCalled": [ "claude-opus-5-5" ], "turns": 38, "durationMs": 144360, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 37, "inSubagents": 0, "byName": { "Grep": 3, "Read": 3, "Bash": 23, "Edit": 6, "Write": 2 } }, "sessionLogSubagents": [], "permissionDenials": 6, "finalMessage": "I fixed the bug, added a regression test, and wrote parts 1 and 2 to `TRACE.md`.\n\n**Cause:** In `lib/dispatcher/client-h1.js:770`, the default (llhttp) HTTP/1.1 parser checked each chunk against the limit on its own (`buf.length > maxResponseSize`). It ignored the running total in `this.bytesRead`. A body that arrives in one piece trips the check, but a body streamed in chunks smaller than 1 MB never does. The fix is one line: `this.bytesRead + buf.length > maxResponseSize`. The Milo parser and HTTP/2 already checked the total this way. The count goes back to zero for each new response, so keep-alive connections aren't affected.\n\n**1. Path for a default HTTP/1.1 request:**\n1. `agent.js` stores the option and passes it to the factory, which builds a `Pool`.\n2. `pool.js` stores it again and builds a `Client`.\n3. `client.js` validates it and saves it on the client.\n4. `client-h1.js` copies it into the llhttp parser, and `onBody()` enforces it there. This is where the bug was.\n\n**2. Other setups** (file and line references are in `TRACE.md`):\n\n| Setup | Passed down and enforced? |\n|---|---|\n| BalancedPool | Yes. It hands the option to its Pools and Clients. It had the same chunking bug, now fixed. |\n| RetryAgent wrapping an Agent | Yes, through the wrapped Agent. Setting it in RetryAgent's own options does nothing. If a body is resumed across retries, the limit applies to each attempt, not to the total. |\n| ProxyAgent | Only when tunnelling (`proxyTunnel: true`, or a non-`http:` target). By default, `http:` targets go through a forward-proxy wrapper that builds its Client with only `{ connect }`, so **there is no limit at all**. I didn't fix this. |\n| H2CClient | Yes. The HTTP/2 path already checked the whole body. |\n| Client with Milo | Yes. Both of Milo's body-handling paths already checked the whole body. |\n\n**Tests:** I added four cases to `test/max-response-size.js`, run with both parsers. Each uses `new Agent({ maxResponseSize })` with `request()` and a server that streams small chunks:\n- a body over the limit must be rejected with `ResponseExceededMaxSizeError`;\n- a body exactly at the limit must get through.\n\nWithout the fix, the llhttp \"over the limit\" case fails; with it, all of `test/max-response-size.js` passes (10/10). I also ran it together with `test/client.js`, `test/client-pipelining.js`, `test/agent.js` and `test/balanced-pool.js`: 93 tests, 92 passed and 0 failed. The one that didn't pass was probably skipped, but I didn't check.\n\n**Not done:**\n- ESLint needed an approval I didn't have, so it hasn't been run.\n- I wrote a script in `/tmp/mrs-check/` to check the ProxyAgent, RetryAgent and BalancedPool claims against live servers, but running it also needed approval. Those findings come from reading the code only.\n\nShould I also fix the ProxyAgent gap by passing the option through to the forward-proxy wrapper's Client?", "diffstat": "TRACE.md | 22 +++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 67 ++++++++++++++++++++++++++++++++++++++++++++-\n 3 files changed, 89 insertions(+), 2 deletions(-)", "sourceRunDir": "2026-11-04T20-09-33-237Z" }, { "name": "opus-subagents-default-5", "model": "claude-opus-5-5", "steps": [ { "step": 1, "permissionMode": "acceptEdits", "exitCode": 0, "signal": null, "spawnError": null, "costUsd": 0.9177420000000001, "resultSubtype": "success", "isError": false, "turns": 54, "durationMs": 573171, "inputTokens": 1733738, "outputTokens": 16026, "firstContextTokens": 18687, "peakMainContextTokens": 65193 } ], "exitCode": 0, "signal": null, "spawnError": null, "checks": [ { "name": "chunked overflow rejected via Agent, Pool and Client (hidden test, 7 cases)", "pass": true }, { "name": "existing test/max-response-size.js passes", "pass": true }, { "name": "TRACE.md names the default path: agent.js, pool.js, client.js, client-h1.js (hidden check)", "pass": true }, { "name": "TRACE.md names the other paths: balanced-pool.js, retry-agent.js, proxy-agent.js, h2c-client.js, client-h2.js, parser-h1.js (hidden check)", "pass": true }, { "name": "added or changed a test that uses maxResponseSize", "pass": true }, { "name": "ran the tests after the last code edit (TRACE.md edits don't count)", "pass": true } ], "resultSubtype": "success", "isError": null, "costUsd": 0.9177420000000001, "costByModel": { "claude-opus-5-5": { "costUsd": 0.9177420000000001, "inputTokens": 76, "cacheReadTokens": 1681540, "cacheWriteTokens": 52122, "outputTokens": 16026 } }, "modelsCalled": [ "claude-opus-5-5" ], "turns": 54, "durationMs": 573171, "subagentCalls": 0, "subagentCallDetails": [], "toolCalls": { "main": 53, "inSubagents": 0, "byName": { "Grep": 2, "Read": 13, "Bash": 29, "Edit": 5, "ToolSearch": 1, "TaskStop": 1, "Write": 2 } }, "sessionLogSubagents": [], "permissionDenials": 9, "finalMessage": "I found the bug, fixed it, added a regression test, and wrote parts 1 and 2 to `TRACE.md`. The new test fails without the fix and passes with it.\n\n**The cause:** with the default parser (llhttp), the size check in `lib/dispatcher/client-h1.js:770` compared only the current chunk with the limit (`buf.length > maxResponseSize`). It never added what had already been received. A 1 MB+ body that arrives in one go fails that check, but a body sent in many small chunks gets through at any size. The fix is one line: `this.bytesRead + buf.length > maxResponseSize`. That's how the Milo parser and the HTTP/2 code already do it.\n\n**1. Path from `new Agent({ maxResponseSize })` to the check:** `agent.js` → `pool.js` → `pool-base.js` → `client.js` (stores it as `kMaxResponseSize`) → `client-h1.js`. There the parser copies it (line 261) and checks it on each body chunk. `TRACE.md` has line numbers and what each file does with it.\n\n**2. Other setups:**\n\n| Setup | Passed down? | Limit on the whole body? |\n|---|---|---|\n| BalancedPool | Yes | Yes, now that this fix is in |\n| RetryAgent wrapping an Agent | Yes, if set on the inner Agent | Yes, now that this fix is in |\n| ProxyAgent, https target or `proxyTunnel: true` | Yes | Yes, now that this fix is in |\n| ProxyAgent, plain `http:` target (the default) | **No** | **No, not enforced at all** |\n| H2CClient | Yes | Yes, already correct |\n| Client with `useMilo: true` | Yes | Yes, already correct |\n\n- **ProxyAgent with a plain `http:` target:** `Http1ProxyWrapper` builds its client from `{ connect }` only (`lib/dispatcher/proxy-agent.js:58-62`), so `maxResponseSize` is dropped. This comes from reading the code: the script I wrote to check it was blocked by an approval prompt, so it never ran. I didn't fix it because it's a separate bug from the one reported; it's yours to decide whether to take it on.\n- **RetryAgent:** `new RetryAgent(agent, { maxResponseSize })` does nothing. The second argument only holds retry options.\n\n**The test:** I added a case to `test/max-response-size.js`. It uses `new Agent({ maxResponseSize: 1024 })` with `request()` against a server that sends 4 KiB as 64 separate 64-byte writes, and runs once with each parser.\n- Without the fix, the llhttp run fails with \"Missing expected rejection\" and the Milo run passes. The test file then hung for about 40 seconds before the run ended; once the fix was back in, it finished cleanly.\n- With the fix, all 153 tests pass across these files: `max-response-size`, `client-request`, `client-keep-alive`, `client-pipelining`, `milo`, `agent-connection-management`, `retry-agent`, `proxy-agent` and `balanced-pool`.\n\nI couldn't run eslint because it also needed approval. Nothing is committed.", "diffstat": "TRACE.md | 37 ++++++++++++++++++++++++++++++++++\n lib/dispatcher/client-h1.js | 2 +-\n test/max-response-size.js | 49 ++++++++++++++++++++++++++++++++++++++++++++-\n 3 files changed, 86 insertions(+), 2 deletions(-)", "sourceRunDir": "2026-11-04T20-09-36-882Z" } ], "finishedAt": "2026-11-04T20:22:10.991Z", "mergedFrom": [ "2026-11-04T20-09-20-012Z", "2026-11-04T20-09-21-226Z", "2026-11-04T20-09-22-419Z", "2026-11-04T20-09-23-624Z", "2026-11-04T20-09-24-817Z", "2026-11-04T20-09-26-030Z", "2026-11-04T20-09-27-229Z", "2026-11-04T20-09-28-446Z", "2026-11-04T20-09-29-642Z", "2026-11-04T20-09-30-841Z", "2026-11-04T20-09-32-031Z", "2026-11-04T20-09-33-237Z", "2026-11-04T20-09-34-457Z", "2026-11-04T20-09-35-634Z", "2026-11-04T20-09-36-882Z" ], "aggregates": [ { "setup": "sonnet-alone", "model": "claude-sonnet-5-5", "runs": 5, "errors": 0, "hiddenTestPassed": 5, "existingTestPassed": 5, "traceDefaultPathNamed": 5, "traceOtherPathsNamed": 5, "addedTest": 5, "ranTestsAfterLastCodeEdit": 3, "allChecksPassed": 3, "subagentCallsTotal": 0, "subagentCallsPerRun": [ 0, 0, 0, 0, 0 ], "runsThatDelegated": 0, "subagentTypes": {}, "sessionLogSubagentsTotal": 0, "toolCallsInSubagentsTotal": 0, "avgToolCallsMain": 29.6, "avgToolCallsInSubagents": 0, "avgCostUsd": 0.248483, "minCostUsd": 0.224233, "maxCostUsd": 0.264586, "avgCostByModelUsd": { "claude-sonnet-5-5": 0.248483 }, "avgInputTokens": 660088, "avgOutputTokens": 9497, "avgTotalTokens": 669585, "avgPeakMainContextTokens": 49503, "avgTurns": 30.6, "avgDurationSec": 153.083, "totalCostUsd": 1.242413, "runsOfferedSubagentTool": 5, "avgFirstContextTokens": 18693 }, { "setup": "opus-no-subagents", "model": "claude-opus-5-5", "runs": 5, "errors": 0, "hiddenTestPassed": 5, "existingTestPassed": 5, "traceDefaultPathNamed": 5, "traceOtherPathsNamed": 5, "addedTest": 5, "ranTestsAfterLastCodeEdit": 5, "allChecksPassed": 5, "subagentCallsTotal": 0, "subagentCallsPerRun": [ 0, 0, 0, 0, 0 ], "runsThatDelegated": 0, "subagentTypes": {}, "sessionLogSubagentsTotal": 0, "toolCallsInSubagentsTotal": 0, "avgToolCallsMain": 52.4, "avgToolCallsInSubagents": 0, "avgCostUsd": 0.951012, "minCostUsd": 0.667103, "maxCostUsd": 1.124947, "avgCostByModelUsd": { "claude-opus-5-5": 0.951012 }, "avgInputTokens": 1778067, "avgOutputTokens": 17267, "avgTotalTokens": 1795333, "avgPeakMainContextTokens": 63842, "avgTurns": 53.6, "avgDurationSec": 540.6312, "totalCostUsd": 4.75506, "runsOfferedSubagentTool": 0, "avgFirstContextTokens": 16397 }, { "setup": "opus-subagents-default", "model": "claude-opus-5-5", "runs": 5, "errors": 0, "hiddenTestPassed": 5, "existingTestPassed": 5, "traceDefaultPathNamed": 5, "traceOtherPathsNamed": 5, "addedTest": 5, "ranTestsAfterLastCodeEdit": 5, "allChecksPassed": 5, "subagentCallsTotal": 0, "subagentCallsPerRun": [ 0, 0, 0, 0, 0 ], "runsThatDelegated": 0, "subagentTypes": {}, "sessionLogSubagentsTotal": 0, "toolCallsInSubagentsTotal": 0, "avgToolCallsMain": 41.6, "avgToolCallsInSubagents": 0, "avgCostUsd": 0.77603, "minCostUsd": 0.68147, "maxCostUsd": 0.917742, "avgCostByModelUsd": { "claude-opus-5-5": 0.77603 }, "avgInputTokens": 1390621, "avgOutputTokens": 14406, "avgTotalTokens": 1405027, "avgPeakMainContextTokens": 56764, "avgTurns": 42.6, "avgDurationSec": 391.5544, "totalCostUsd": 3.88015, "runsOfferedSubagentTool": 5, "avgFirstContextTokens": 18687 } ], "totalCostUsd": 9.877623, "slotSpendUsd": { "smokeV1": 0.791506, "smokeV1Runs": [ "2026-11-04T19-57-19-804Z", "2026-11-04T19-57-23-803Z", "2026-11-04T19-57-43-258Z" ], "smoke": 2.373645, "smokeRuns": [ "2026-11-04T20-03-28-613Z", "2026-11-04T20-03-29-975Z", "2026-11-04T20-03-31-494Z" ], "scored": 9.877623, "total": 13.042774 } }