Task: T-0003 Unified --resume/--continue across all engines
Stage: accepting
Stage owner: reviewer
Process profile: Python
Task type: -

Workspace context:
# heru — Litehive Workspace Context

Process profile: Python

You are editing **heru**, a unified headless CLI for coding agents
(codex, claude, copilot, gemini, opencode, goz). Read this whole file
before touching any file in this repository.

## Project

- **Purpose:** a thin adapter layer that wraps each supported agent CLI
  behind a uniform Python interface, with a unified `heru <engine>
  <prompt>` command, one JSONL event schema across engines, and one
  resume mechanism. heru is the engine-I/O layer; it knows nothing
  about task queues, stages, orchestration, or sandboxing — those are
  litehive concerns.
- **Main package:** `heru/` (at the repo root, below `.git/`). Public
  API lives in `heru/__init__.py`, `heru/base.py`, `heru/types.py`,
  and each `heru/adapters/<engine>.py`. Anything prefixed with `_` is
  internal.
- **Commands to know:**
  - `uv sync --extra dev` — install heru's own venv
  - `uv run pytest` — heru's standalone test suite
  - `uv run heru <engine> <prompt>` — the CLI (WIP per task T-0002)
  - `cd ~/git/litehive && uv run pytest -q tests/test_runner_workflow.py tests/test_engine_variants_and_timeline.py tests/test_heru_cli.py tests/test_codex_quota.py` — **litehive contract smoke tests; run before every commit**

## Directory layout

```
heru/
├── heru/                  # the Python package
│   ├── __init__.py        # get_engine, ENGINE_CHOICES — PUBLIC
│   ├── base.py            # ExternalCLIAdapter, CLIInvocation, run_live — PUBLIC
│   ├── types.py           # shared pydantic types — PUBLIC
│   ├── main.py            # `heru <engine> <prompt>` CLI entry — PUBLIC
│   ├── _engine_detection.py   # internal
│   ├── _continuation.py       # internal
│   ├── adapters/
│   │   ├── codex.py, _codex_impl.py         # CodexCLIAdapter PUBLIC, _impl internal
│   │   ├── claude.py, _claude_impl.py
│   │   ├── copilot.py, _copilot_impl.py
│   │   ├── gemini.py, _gemini_impl.py
│   │   ├── opencode.py, _opencode_impl.py
│   │   ├── goz.py, _goz_impl.py
│   │   └── common.py      # shared helpers
│   └── quota/             # per-provider quota check helpers — PUBLIC
├── tests/                 # heru's standalone unit tests (no litehive imports)
├── pyproject.toml
├── README.md
└── .litehive/             # this workspace (tasks, state)
```

## Public API surface — do not break without a semver bump

Anything **not** prefixed with `_` is public. Changing the signature,
return type, or behavior of any of the following is a **semver-major**
breaking change that requires a version bump in `pyproject.toml`, a
CHANGELOG entry, and a migration note for litehive:

- `heru.get_engine(name)`, `heru.ENGINE_CHOICES`
- `heru.base.ExternalCLIAdapter` (subclass, don't modify shape)
- `heru.base.CLIInvocation`, `heru.base.CLIExecutionResult`
- Each adapter class: `CodexCLIAdapter`, `ClaudeCLIAdapter`,
  `CopilotCLIAdapter`, `GeminiCLIAdapter`, `OpencodeCLIAdapter`,
  `GozCLIAdapter`
- Every pydantic model in `heru/types.py`
- `heru.main.main` (the CLI entry)

**Internal** (change freely, no semver implications): every
`_`-prefixed module, every private method on public classes, and the
exact text of rendered transcripts.

## Hard rules — do NOT break these

1. **No imports from `litehive`.** heru is a leaf package. One runtime
   dep: `pydantic`. If your diff adds `from litehive …`, stop — the
   code belongs in litehive, not heru.

2. **Do not break litehive.** litehive depends on heru via an editable
   path install, so every heru change propagates immediately. Before
   you finish any stage that touched code, you MUST run:
   ```
   cd ~/git/litehive && uv run pytest tests/test_runner_workflow.py \
       tests/test_engine_variants_and_timeline.py \
       tests/test_heru_cli.py tests/test_codex_quota.py -q
   ```
   If any fail, your change broke the contract. Either fix heru to
   preserve the contract, or explicitly call out the breakage in your
   stage report with a proposed litehive-side migration.

3. **Stage reports are a litehive concept, not heru's.** `StageReport`,
   `StageResultSubmission`, `StageResultTests`, and `TaskUpdateSubmission`
   currently live in `heru/types.py` as a temporary compromise — they
   are slated to move to litehive. Do not add new stage-report logic
   or fields inside heru. If your task requires you to edit stage
   report semantics, flag it back: it is misfiled and belongs in
   litehive.

4. **Tests must be standalone.** No test under `tests/` may import
   from `litehive`. Every heru test must run in a fresh venv with
   only `heru + pydantic + pytest` installed. For JSONL fixtures,
   hand-craft strings or files under `tests/fixtures/` — do NOT
   shell out to real engine CLIs during tests.

5. **Respect the contract tests** (once `tests/contract/` exists per
   T-0007). Changing an assertion in `tests/contract/` is by
   definition a breaking change and requires the full semver
   checklist.

6. **Every new adapter needs both a public class AND a `_impl` helper
   module.** Shape: `adapters/<engine>.py` for the public class,
   `adapters/_<engine>_impl.py` for parsing/quota internals. Keep the
   symmetry — the base class expects it.

## Before you write code — ask yourself

- **Is this a heru concern or a litehive concern?** If you need task
  queues, retries, worktrees, commit pipelines, sandbox profiles, or
  the `STAGE_RESULT:` agent protocol, this is probably litehive.
  Stop and surface the concern in grooming.
- **Does this change the public API?** If yes, note the intended
  semver bump in your report and explicitly list what litehive needs
  to update.
- **Can I write this as a fixture-driven unit test?** If not, your
  code is probably too coupled to the real CLI subprocess — refactor
  to take parsed inputs.
- **Have I run the litehive contract tests?** If not, the task is not
  done, no matter what your implementation report says.

## Relationship to litehive

heru is maintained **alongside** litehive at `~/git/litehive`. They
share a developer (you) and live on the same laptop. litehive depends
on heru via `uv add --editable ~/git/heru`, so every heru save is
immediately visible to litehive without any reinstall.

**If a heru task requires changes in litehive to stay consistent**
(e.g. adding a new adapter method that litehive needs to call), open
a companion task in the litehive workspace referencing this task,
and land the heru side FIRST. Litehive can then safely bump its own
expectations.

## Process overlay
- Source of truth: tasks and implementation state live under `.litehive/`.
- Task source of truth: issues or task records define scope; prompts and transcripts are supporting evidence.
- Orchestrator model: the local runner is the manager and owns stage routing.
- Routing model: routing stays deterministic and local; subagents execute assigned stages but do not self-route.
- Shared stages: grooming -> implementing -> testing -> accepting -> commit_to_git.
- Role model: `planner` frames the task, `reviewer` performs final PM-style acceptance, `swe` edits code, and `qa` runs focused verification.
- TDD expectations: add or update focused tests near the changed Python module before broad suites.
- Verification discipline: prefer targeted `pytest` evidence close to the changed module before broader smoke coverage.
- Acceptance flow: verify behavior with targeted `pytest` coverage and note any residual risk.
- Commit and recovery: keep checkpoint commits deterministic and easy to recover.

## Project overlay
- Python package or application workflow with pytest-oriented verification.
- Favor incremental, reviewable changes over broad refactors.
- Keep implementation, verification, and acceptance evidence explicit.
- Prefer focused `pytest` coverage for the changed modules.
- Keep dependency and packaging changes explicit and minimal.

## Init scaffold
- Scaffold `.litehive/context.md` from the generic base process template.
- Layer the project profile summary, workspace overlay, and stage overlay onto that base.
- Treat process profiles as overlays on the shared contract rather than separate workflows.
- Keep the task/issue source of truth, verification commands, and recovery policy visible in the scaffold.
- Seed Python workspaces with package layout, test entrypoints, and `uv` or virtualenv expectations.

## Prompt scaffold
- Start from the shared process contract, then add repository context and task data.
- Combine the generic base prompt with the selected project overlay instead of replacing the base.
- Apply stage defaults first, then append any project-specific stage overlay for that step.
- Keep stage prompts explicit about role, verification expectations, and final report format.

## Stage prompt scaffolding

### grooming
Act as the planner: clarify the user problem, inspect the repo if needed, and produce a concrete execution plan.
Focus on scope clarification, acceptance criteria quality, decomposition, follow-up tasks, and PM sizing.
Do not make code changes in this stage.

### implementing
Implement the task in this repository.
Keep changes tightly scoped and complete the work needed for the acceptance criteria.
Write tests so each assertion would fail if the feature is broken.
Do not spend test coverage on framework behavior or library guarantees.
Do not add tests that only restate defaults, constants, or static data.
Keep each test focused on one behavior.
Avoid duplicate coverage; extend an existing test only when it is the same behavior.
- Write or update focused tests alongside the code change when feasible.
- Use `pytest` for automated verification.
- Use `tmp_path` or pytest fixtures instead of manual tempfiles in repo code or `/tmp` setup.
- Mock external calls and integration edges, not the internal logic under test.
- Do not use `time.sleep` in tests; use deterministic synchronization or time control.

### testing
Validate the implementation.
Run focused checks or tests where possible and report failures precisely.
Only make minimal fixes if absolutely necessary.
Reject tests whose assertions would still pass if the feature were broken.
Reject tests that duplicate existing coverage instead of covering a new behavior.
Reject tests longer than 50 lines unless a shorter structure is genuinely impossible.
Reject monolithic tests that exercise 5 or more behaviors in one flow.
- Prefer targeted `pytest` invocations before broader test commands.
- Verify new or updated tests use `pytest` idioms and fixtures.
- Reject tests that use manual tempfiles where `tmp_path` would make isolation explicit.
- Reject tests that mock the unit's internal logic instead of external boundaries.
- Reject tests that rely on `time.sleep` instead of deterministic control.

### accepting
Act as the reviewer: validate the end-user outcome against the acceptance criteria and decide whether it should be accepted or sent back.
Be strict about regression detection, evidence quality, and final done versus not-done judgment.

## Python specifics
- Prefer `pytest` for automated verification.
- Keep module boundaries and import hygiene clear.
- Record virtualenv, `uv`, or toolchain expectations when they matter.

## Development rules
- Keep changes scoped to the current task.
- Prefer targeted tests over broad test suites.
- Record assumptions clearly in the final report.

## Tool usage
- Use `uv run pytest -q` for the current smoke test suite.
- Update litehive task artifacts instead of inventing external state stores.
- If you add a new command or workflow, document it here for future runs.

Shared process:
- Orchestrator model: the local runner is the manager and owns stage routing.
- Routing model: routing stays deterministic and local; subagents execute assigned stages but do not self-route.
- Shared stages: grooming -> implementing -> testing -> accepting -> commit_to_git.
- Role model: `planner` frames the task, `reviewer` performs final PM-style acceptance, `swe` edits code, and `qa` runs focused verification.
- Source of truth: tasks and implementation state live under `.litehive/`.
- Task source of truth: issues or task records define scope; prompts and transcripts are supporting evidence.
- TDD expectations: add or update focused tests near the changed Python module before broad suites.
- Verification discipline: prefer targeted `pytest` evidence close to the changed module before broader smoke coverage.
- Acceptance flow: verify behavior with targeted `pytest` coverage and note any residual risk.
- Commit and recovery: keep checkpoint commits deterministic and easy to recover.

Project overlay:
- Python package or application workflow with pytest-oriented verification.
- Favor incremental, reviewable changes over broad refactors.
- Keep implementation, verification, and acceptance evidence explicit.
- Prefer focused `pytest` coverage for the changed modules.
- Keep dependency and packaging changes explicit and minimal.

Prompt scaffold:
- Start from the shared process contract, then add repository context and task data.
- Combine the generic base prompt with the selected project overlay instead of replacing the base.
- Apply stage defaults first, then append any project-specific stage overlay for that step.
- Keep stage prompts explicit about role, verification expectations, and final report format.

Role focus:
- You are the reviewer, a PM-style role representing the user's and product's point of view.
- Validate the strict end-user outcome, look for regressions or missing evidence, and make a final done versus not-done judgment.
- Reject work that is incomplete, weakly verified, or misaligned with the promised outcome.
- If SWE shows the requested work was already implemented before this run and provides concrete verification evidence, accept the task to normal `done` rather than inventing a special closed status.
- Use `wont_do`, `duplicate`, or `deferred` only when the task is genuinely obsolete, superseded, or duplicated.
- You may close a task as duplicate, wont_do, or deferred by including `outcome: <status>` with optional `outcome_reason` in a TASK_UPDATE block. You may park a task with `action: park`.

Stage instructions:
Act as the reviewer: validate the end-user outcome against the acceptance criteria and decide whether it should be accepted or sent back.
Be strict about regression detection, evidence quality, and final done versus not-done judgment.

Goal:
Every supported engine has native session resume (codex exec resume, claude --resume, gemini --resume, copilot --continue/--resume, opencode --session/--continue, goz --resume-session). Heru's adapters accept a resume_session_id parameter and each adapter emits the right CLI flag for its engine. Expose this at the CLI level with a unified --resume <id> flag that works for every engine subcommand, plus --continue that resumes the most recent session per engine. The unified event stream must emit a continuation event containing the current session id so callers can capture it for the next run.

Acceptance criteria:
- Each engine subcommand accepts --resume <id> and forwards to the underlying native resume mechanism, producing a session that continues the prior conversation with full context
- Each engine subcommand accepts --continue (no id) that resolves to 'most recent session for this engine' and resumes it (for engines where that is a native concept; error for engines that require an explicit id)
- The unified JSONL stream (from T-0001) emits a 'continuation' event at the end of every run containing the session_id of the finished session, so callers can pass it to --resume on the next run without scraping logs
- Integration test: run 'heru codex hi', capture the continuation session id from the output, then run 'heru codex --resume <id> what did we discuss' and assert it references the prior turn
- Same test repeated for each engine with a real or fake adapter

Plan:
- No plan defined.

PM sizing:
- Current PM complexity: simple
- Current planned effort: s

Constraints:
- Keep changes scoped to the task.


Discussion thread:

--- [2026-04-10T19:31:30+00:00] planner (grooming) — pass ---
Grooming pass. I inspected the current heru CLI and adapter plumbing to verify scope and identify the implementation gaps before handoff. No code changes were made and no tests were run in this stage because this is planning-only work.

What I verified from the repo:
- `heru/main.py` already exposes shared `--resume` on engine subcommands and forwards it as `resume_session_id`, but there is no shared `--continue` flag yet.
- Adapter resume support is incomplete and asymmetric: Codex, Claude, Gemini, Goz, and OpenCode only accept explicit ids today; Copilot already special-cases `resume_session_id == "latest"` to emit native `--continue`.
- Unified event rendering in `heru/base.py` already knows how to emit `kind="continuation"` when an adapter surfaces a continuation id, but the current behavior is opportunistic per payload, not explicitly guaranteed to emit one final continuation event at end-of-run.
- Continuation extraction/test coverage is incomplete: there is unified-event coverage for Gemini and OpenCode, adapter extraction coverage for Goz, but no equivalent continuation extraction path for Copilot and no end-to-end resume/continue integration coverage yet.

Implementation plan for the next stage:
1. Add CLI parsing for a shared `--continue` flag, reject invalid `--resume` + `--continue` combinations, and normalize the request into existing adapter `resume_session_id` plumbing without changing the public adapter API.
2. Normalize engine behavior per adapter: explicit session/thread id for `--resume <id>` on all engines; native latest-session continuation only where the engine supports it; clear CLI error for engines that require an explicit id.
3. Tighten unified JSONL continuation semantics so callers get exactly one final continuation event containing the completed session/thread id when the adapter can identify it.
4. Add focused tests for CLI forwarding/error cases, per-adapter argv mapping, continuation-event ordering, and missing continuation coverage.
5. Add integration coverage for the two-run resume flow: real Codex round-trip if available in the test environment, otherwise guard it appropriately; use fake/fixture-driven adapters for the remaining engines to stay within the repo rule against shelling out to third-party CLIs in unit tests.
6. Run targeted heru pytest coverage and then the required litehive smoke suite before handing off to testing/accepting.

Recommended task-shaping updates for the implementing agent to keep in mind, since `litehive task update` is currently blocked while the task is active: treat this as PM complexity `moderate`, planned effort `m`, task type `adapter`, and use the plan above as the execution checklist. The acceptance criteria are already directionally correct, but they should be interpreted as requiring explicit coverage for invalid `--resume`/`--continue` combinations and for final-event ordering of the emitted continuation record.

--- [2026-04-10T19:38:51+00:00] swe (implementing) — pass ---
Implemented unified resume/continue across heru CLI and adapters. Added shared --continue parsing for engine subcommands and legacy --engine mode, with explicit rejection of --resume + --continue together and a clear CLI error for engines that require an explicit id (goz). Added internal latest-session normalization in heru/base.py and mapped native latest-session resume flags per engine: codex exec resume without id, claude --resume, gemini --resume, copilot --continue, opencode --continue; explicit ids still map to each engine’s native resume/session flag. Tightened unified JSONL rendering to append exactly one final continuation event at end-of-run containing the finished session/thread id. Filled the missing Copilot continuation extraction path so Copilot now emits continuation ids in the unified stream as well. Added focused tests for CLI forwarding/error cases, adapter argv mapping for latest-session resume, Copilot continuation translation, final continuation-event ordering, legacy --continue support, and a fixture-driven two-run resume flow across all engines that captures the first run’s continuation id and verifies the second run resumes prior context. Verification run with the worktree pinned on PYTHONPATH due uv importing the main checkout by default: PYTHONPATH=$PWD uv run --active pytest tests/test_heru_cli.py tests/test_unified_events.py tests/test_goz_adapter.py tests/test_resume_adapters.py -q -> 62 passed; PYTHONPATH=$PWD uv run --active pytest -q -> 80 passed; cd /home/alexey/git/litehive && PYTHONPATH=/home/alexey/git/heru/.litehive/worktrees/T-0003-unified-resume-continue-across-all-engines uv run pytest tests/test_runner_workflow.py tests/test_engine_variants_and_timeline.py tests/test_heru_cli.py tests/test_codex_quota.py -q -> 197 passed. Evidence against acceptance criteria: every engine subcommand now accepts --resume <id>; all supported engines accept --continue and goz errors cleanly; unified output appends a final continuation event with the finished session id; the two-run resume flow is covered across engines via CLI-level integration-style tests.
Files: heru/main.py, heru/base.py, heru/adapters/codex.py, heru/adapters/claude.py, heru/adapters/copilot.py, heru/adapters/_copilot_impl.py, heru/adapters/gemini.py, heru/adapters/opencode.py, heru/adapters/goz.py, tests/test_heru_cli.py, tests/test_unified_events.py, tests/test_resume_adapters.py

--- [2026-04-10T19:41:17+00:00] qa (testing) — pass ---
Verified unified resume/continue behavior end to end. I inspected the implementation diff in heru/main.py, heru/base.py, and the engine adapters, plus the new tests in tests/test_heru_cli.py, tests/test_unified_events.py, and tests/test_resume_adapters.py. Focused pytest coverage passed: PYTHONPATH=$PWD uv run --active pytest tests/test_heru_cli.py tests/test_unified_events.py tests/test_resume_adapters.py tests/test_goz_adapter.py -q -> 62 passed. Full heru suite passed: PYTHONPATH=$PWD uv run --active pytest -q -> 80 passed. Required litehive contract smoke passed: PYTHONPATH=/home/alexey/git/heru/.litehive/worktrees/T-0003-unified-resume-continue-across-all-engines uv run pytest tests/test_runner_workflow.py tests/test_engine_variants_and_timeline.py tests/test_heru_cli.py tests/test_codex_quota.py -q -> 197 passed. Acceptance evidence: every engine subcommand accepts --resume <id>; supported engines accept --continue and forward the native latest-session behavior via adapter-specific argv mapping; goz rejects --continue with the expected explicit-id error path; unified JSONL rendering appends exactly one final continuation event containing the finished session id; and the two-run CLI resume flow is covered across all engines by capturing the first run continuation_id and reusing it on the second run to verify prior-context continuation. I also directly spot-checked goz --continue returning exit 1 with the expected message and gemini unified output ending in a continuation event with the session id.

IMPORTANT: When you are done, you MUST submit your verdict by running:
  litehive report --verdict <pass|reject> --role reviewer --step accepting --message "<your report>"
The environment variable LITEHIVE_TASK_ID is set to T-0003 for this session. Workspace and task resolution should use the injected environment automatically.

Your --message is the PRIMARY way the next agent understands what happened.
Do NOT rely on your raw transcript being read — write the report as if it is the only thing the next agent will see.

Report requirements:
- On PASS/ACCEPT: explain what you verified, what tests you ran, what evidence confirms the acceptance criteria are met.
- On REJECT: you MUST include ALL of the following:
  1. EXPECTED behavior: what should happen according to the acceptance criteria
  2. OBSERVED behavior: what actually happens (exact error messages, test output, wrong values)
  3. Steps to reproduce: the exact command or test that demonstrates the gap
  4. Which acceptance criteria are not met and which ones are already satisfied

A vague rejection like 'tests fail' or 'missing evidence' is useless and causes infinite loops.
A good rejection looks like: 'Expected: `litehive engine gemini` switches the default engine and prints confirmation. Observed: command exits 0 but config.yaml still shows the old engine. Reproduce: run `litehive engine gemini` then `cat .litehive/config.yaml`. Criteria 1-3 are met, criterion 4 (persistence) is not.'
