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error_max_turns — a budget, arriving dressed as an outage

error_max_turns

If you pasted that into a search box, something you launched came back with a result whose subtype said this and whose text probably said less. The word error in it is misleading: nothing broke. A counter reached its limit and the run was stopped, mid-work, with whatever it had. The expensive part is not the stop — it is that the stop is easy to mistake for a failure of the service, and easy to blame on a cap other than the one actually in force. Both of those are documented on the vendor’s own repositories, and this page quotes them with their addresses; both of those pages were fetched on 7 October 2026.

What the field is, and the three it sits beside

A documentation issue opened on 31 March 2026, anthropics/claude-code #41265, quotes the TypeScript reference’s result shape. That quotation is the authoritative part, so here it is as the issue gives it:

subtype: | "error_max_turns" | "error_during_execution" | "error_max_budget_usd" | "error_max_structured_output_retries"; ... is_error: boolean; ... errors: string[];

Four endings, and they are four different problems. Read them side by side and the shape of the whole design appears: three of the four are budgets — turns, dollars, retries — and only one, error_during_execution, is a thing going wrong. Which means that if you are branching on “did it error”, you are collapsing three resource ceilings and one fault into a single bucket, and they want four different responses from you. A budget ending means give it more room or less work. A fault means look at the fault.

The same issue quotes the Python side, where the envelope is a class with subtype: str, is_error: bool, and result: str | None = None. Note the None: the human-readable result is optional, and on a cap-stop you may have the subtype and nothing else to print.

The counter: this one was fixed late, and the issue is quoted saying so

The part of #41265 worth your attention if you wrote error handling against an older release is a changelog line it reproduces, for version 2.1.88:

Fixed SDK error result messages (error_during_execution, error_max_turns) to correctly set is_error: true with descriptive messages

Take the implication seriously, because it changes what your own logs mean. If a fix was needed to make these two subtypes “correctly set is_error: true”, then before that version there were runs that ended on a turn cap and did not announce themselves as errors. Any dashboard you built on is_error alone, over a period that includes an older release, undercounts cap-stops — and a cap-stop looks exactly like a success that just didn’t say much. The fix is cheap and it is the same one in every direction: branch on subtype, which has always carried the truth, rather than on is_error, which has not always.

That issue is also, on the copy we read on 7 October 2026, carrying a stale label — so if you are waiting for prose that explains these payloads, do not plan around it arriving soon. The field names above are enough to write the handler yourself.

What it looks like from the outside, which is the real problem

The most useful record this page found is not a bug report but a commit message, referenced from anthropics/claude-code-action issue #1177 and dated 6 September 2026. A developer describes what a turn cap did to their continuous-integration reviews, verbatim:

Both requests during the docs reorganization (#1148, #1149 - 53 and 31 files) died with `error_max_turns` after ~1m45s, having spent the entire budget gathering context and posted nothing but a half-ticked todo list. The action surfaces this as a generic "Claude encountered an error", so it reads like an outage rather than a budget, which is why it went undiagnosed.

Three separate things to take from that, and each of them is a thing to check in your own setup. It died fast — about a minute and three quarters — so speed is not evidence that you hit a timeout rather than a cap; a cap can be reached long before any clock runs out. It spent the budget on input, gathering context, and then had no turns left for the work it was launched to do. And it was relabelled on the way out: a generic failure string reached the human, which is why, in that writer’s own account, the cause went undiagnosed.

Their remedy is recorded in the same message and is worth copying because of how it splits the two budgets: “`--max-turns 20` is too low to read a PR and write a review. Raised to 60. The job’s `timeout-minutes: 30` remains the real backstop”. The turn cap sized for the work; a wall clock as the thing that actually guarantees termination. Those are two instruments and using one as the other is how you get surprised.

The cap that stopped you may not be the cap you set

Before you raise a number, confirm the number you already set is the one in force. Issue #1177, opened 5 April 2026 and labelled a bug, documents a path in which it was not. Its description:

maxTurns is never wired through to the SDK in src/entrypoints/run.ts, causing all runs to hit the SDK's default limit of 10 turns regardless of configuration.

And the part that defeats the obvious workaround:

Passing --max-turns 50 via claude_args puts the value into extraArgs["max-turns"], which is passed through to the CLI subprocess. However, the SDK enforces its own turn counter from sdkOptions.maxTurns (which is undefined, so 10), so the CLI never gets a chance to process more than 10 turns.

That is a specific report about a specific entry point, and whether it still holds where you are is for you to test rather than for this page to assert. But the general lesson survives any version: a cap can be enforced at more than one layer, and the one that stops you is the innermost one that has a value. Passing a bigger number to an outer layer changes nothing if an inner layer is still holding its default.

Four checks, all on your own run

None of these depends on a claim about anybody’s internals, which is deliberate — a procedure that only reads your own output cannot be wrong about someone else’s release.

• Print the whole result envelope once, not just the text. You want subtype, is_error, the turn count and the errors list in your log for every run, from today onward. One line, and it ends the entire class of “was that an outage” question for good.
• Measure the cap instead of reading it. Launch a task you know needs more turns than your configured limit and see where it stops. If it stops at ten and you configured fifty, you have the #1177 shape: an inner default is winning, and raising the outer number again will not help.
• Ask where the budget went. In the 6 September record the entire allowance was spent gathering context. Count how many of your turns happen before the real work starts; if reading the inputs costs most of the cap, the fix is to hand the inputs over directly rather than to let the run go and find them.
• Keep the partial work. That same run “posted nothing but a half-ticked todo list” — the work up to the cap existed and was discarded. Write intermediate output somewhere durable as it is produced, and a cap-stop costs you the remainder rather than the whole run.

The fix is two numbers and one branch

Branch on the subtype. Treat error_max_turns, error_max_budget_usd and error_max_structured_output_retries as “ran out of room” and error_during_execution as “went wrong”, because retrying the second may work and retrying the first identically will produce the identical stop. Never surface a cap-stop to a human as a generic error; say which budget, and say what it had done when it ran out.

Then size the turn cap to the work and let a clock be the backstop. A turn cap is not a safety device — it is an estimate of how many steps the task needs, and if you set it low to feel safe you are buying truncated work rather than safety. The thing that guarantees you get your machine back is a wall-clock limit at the layer above. Set the turns for the task; set the timeout for your own protection.

The thing worth keeping even if you never see this string again: every autonomous loop has at least two independent budgets — steps and time, and often money and retries beside them — and whichever is tightest is the one that will stop you, usually not the one you were thinking about when you chose the numbers. Decide what each one is for, write down which you expect to bind, and make the run say which one actually did. That last part is the whole difference between this string being a diagnosis and being an outage.

The sibling walls this is not

If the ceiling you hit raised an exception rather than arriving in a field, it is a different harness: Max turns (10) exceeded is the OpenAI Agents SDK, which does raise, and carries the finished work on the exception. If your loop ran out of graph steps instead, that is Recursion limit of 25 reached without hitting a stop condition. And if you are not yet sure whether what stopped you was turns, a clock or a context window, start at max turns vs timeout vs context, because those three produce different endings and only one of them is fixed by a bigger number.

What is behind this site

The short version: error_max_turns is one of four subtype values on the result envelope, quoted on anthropics/claude-code #41265 alongside error_during_execution, error_max_budget_usd and error_max_structured_output_retries — three budgets and one fault. The same issue reproduces a changelog line about making these subtypes “correctly set is_error: true”, so branch on subtype rather than on is_error. A record of 6 September 2026 referenced from claude-code-action #1177 shows runs dying on this after about 1m45s and being surfaced as a generic error, which is why it “went undiagnosed”; #1177 itself documents a cap of ten being enforced regardless of configuration. So: measure the cap rather than reading it, size turns to the task, and use a clock as the backstop.

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