The eval agent() helper used `agent_type`/`return_handle` (snake_case) in
Python/Ruby/Julia and `agentType`/`returnHandle` (camelCase) in JS, forcing
the prelude docs to repeat every option twice ("JS same but camelcased").
Both are now single lowercase words identical across all four runtimes, and
`agent` matches the `task` tool's existing agent-selection parameter.
- Renamed across py/js/rb/jl preludes (signatures, forwarding, docstrings).
- Renamed the `__agent__` bridge wire protocol + `EvalAgentArgs` (`agentType`
→ `agent`, `returnHandle` → `handle`) so no prelude-side remap is needed.
- Updated prompt docs (workflow-notice.md, tools/eval.md), repo docs
(docs/tools/eval.md, docs/python-repl.md), and all bridge/prelude tests.
- CHANGELOG: Breaking Changes entry under [Unreleased].
Branch-mode isolation can capture nested repository changes without creating a root branch. Eval agent() with apply=false previously treated that shape as no captured changes and returned no recoverable nested patch payload after the isolation worktree was removed.
Expose captured nested patches in EvalAgentResult details and copy them onto JS/Python returnHandle nodes (nestedPatches / nested_patches). Document the return_handle escape hatch and add regression coverage for branch-mode nested-only apply=false runs.
Fixes#3196
When agent() ran with schema and apply=false, the bridge correctly returned the captured patch/branch in details, but the preludes only forwarded id/agent/handle/data on the returnHandle node. Structured workflows had no way to recover the artifact for a manual apply.
Both runtimes now copy isolated, patchPath/branchName, changesApplied, and isolationSummary onto the returnHandle node (snake_case in Python, camelCase in JS), keeping null changesApplied so apply=false stays distinguishable from a successful apply. Updated the workflow notice and the Python agent() docstring to point callers at return_handle as the artifact escape hatch for isolated+apply=false runs. Added prelude tests locking the new node shape in both runtimes.
Fixes#3196
- Updated `packages/coding-agent/src/eval/py/prelude.py` to accept positional `offset` and `limit` in `read()`.
- Added regression coverage in `packages/coding-agent/src/eval/py/__tests__/prelude.test.ts` for positional read signatures.