agentic-dev-loop

An opinionated library for building stage-gated autonomous dev pipelines. A pipeline is a YAML file of steps; each step runs an OpenHands agent (with a file-artifact verdict protocol), a deterministic Python action, or a mechanical shell command (exit code = verdict); LangGraph drives routing, retries, checkpoints and resume. The fixed policies — artifact hygiene, attempt-bounded retries, fail-fast on empty context, a single gated commit point — are the product.

Publicly depends on OpenHands SDK for agent execution and LangGraph (+ langgraph-checkpoint-sqlite) for the state graph.

Install & test

pip install agentic-dev-loop  # published release
pip install -e .              # from this repo (development)
python -m pytest tests/ -q

Requires Python ≥ 3.12.

Quick start

export OPENAI_API_KEY=...   # whatever env var your pipeline's api_key_env names
agentic-dev-loop agentic-dev-loop/pipeline.yaml --plan plan.md
agentic-dev-loop agentic-dev-loop/pipeline.yaml --ai-dlc-unit U2
agentic-dev-loop agentic-dev-loop/pipeline.yaml --resume <thread-id> --max-attempts 5
./trigger-agentic-dev-loop.sh --plan plan.md   # same thing, from the repo root

Exit code is 0 on pipeline success, 1 otherwise. Each run prints its thread id; --resume continues the latest checkpoint of a previous thread (crash, Ctrl-C, exhaustion) with all accumulated notes intact. A live graph view is served on localhost by default (browser auto-opens; --viz-port sets a preferred port, default 8321) — pass --no-viz to suppress it. A stale viz server from a crashed run of the same repo is swept automatically at startup; if another repo's run holds the port, the engine prints a notice and serves on a free port. The sidebar nests each stage's console output (ANSI colours preserved) under a collapsible section: completed stages auto-collapse, the running stage stays expanded and live-tails its console. To eyeball the viz page without running a pipeline, .venv/bin/python viz_demo.py serves the real topology and replays a scripted run (every node state, verdict badges, retry cycle).

--ai-dlc-unit accepts any unambiguous spelling of a unit number — U2, 2, U002, 002 — or the full unit slug (U002-custom-configuration). If multiple unit directories match one id, the run fails loudly naming every candidate; pass the full slug to disambiguate.

What a run looks like

The shipped self-loop example (agentic-dev-loop/, launched from the repo root so the pipeline constructs this library itself) is:

dev ──▶ test ──▶ review ──▶ qa ──▶ commit
▲          │         │         │
└──────────┴─────────┴─────────┘   fail verdicts / a failing test gate
                                   retry to dev (attempt-bounded)

1. dev runs the dev agent with full context (selected docs + additional_files: + auto-generated expected-output paths). Its writes are untracked; the pipeline only cares about declared produces: files.
2. test is a mechanical command step: it runs the suite (.venv/bin/python -m pytest tests/ -q) in the workspace shell. Exit 0 passes and moves on; anything else (including no exit by timeout) fails and rewinds to dev with the failing output in the retry note.
3. review / qa are verdict agents: each must write its declared artifact (e.g. .pr/qa-report.md) whose last VERDICT: <word> line decides routing. pass follows on_pass, fail follows on_fail — here {goto: dev, retry: true}, which consumes an attempt and feeds the artifact back to the dev agent as a retry note.
4. commit is the single commit point: git add -A + templated message, but only when the worktree was clean at run start (your in-progress edits are never swept into a loop commit).
5. Attempts are bounded by max_attempts (YAML or --max-attempts). Exhaustion or a failure route ends the run; success commits and exits.

Every stage boundary is checkpointed to <state_dir>/loop-checkpoints.sqlite — resume loses nothing but the in-flight stage.

pipeline.yaml reference

Verbatim from agentic-dev-loop/pipeline.yaml (comments added):

name: agentic-dev-loop-construction
extensions:
  - agentic_dev_loop.extensions.aidlc:AidlcExtension
additional_files:
  - ../README.md                     # shared context for every agent step

llm:
  model: openai/deepseek-v4-pro
  base_url: https://api.deepseek.com
  api_key_env: OPENAI_API_KEY        # missing env var → run fails fast, naming it
  # timeout: null                    # default = no client timeout (long agent runs)

state_dir: .pr                        # artifacts + checkpoints live here
max_attempts: 10                      # retries across the whole graph
agents_dir: sdk_agents                # consumer-owned <name>.agent.md files

steps:
  - name: dev
    agent: dev                        # → sdk_agents/dev.agent.md
    produces: implementation-summary.md  # written under state_dir (str or list)
    on_pass: test                     # explicit; omitted → next step in order

  - name: test
    command: .venv/bin/python -m pytest tests/ -q   # mechanical: exit code is the verdict
    timeout: 600                                     # seconds; SIGKILLs the process group
    on_pass: review
    on_fail: {goto: dev, retry: true}

  - name: review
    agent: review
    artifact: review-findings.md
    verdicts: {pass: APPROVED, fail: NEEDS CHANGES}
    on_pass: qa
    on_fail: {goto: dev, retry: true}

  - name: qa
    agent: qa
    artifact: qa-report.md
    max_iterations: 200               # per-run agent iteration cap
    verdicts: {pass: PASS, fail: FAIL}
    on_pass: commit
    on_fail: {goto: dev, retry: true}

  - name: commit
    action: commit                    # built-in action
    on_pass: success                  # terminal (also the default for the last step)
    params:
      message: "feat: construct {subject} (agent dev loop)"  # {subject} templated

Step types

How a step behaves is determined solely by which of three mutually-exclusive keys it carries — exactly one of agent:, command:, or action: is required, an empty value does not count, and zero or several keys fail to load. Graph-building dispatches on this kind (see StepConfig.kind in config.py).

• agent: <name> — an agent step: loads sdk_agents/<name>.agent.md and runs it via the OpenHands SDK against the accumulated context. May declare produces: (hygiene-tracked outputs, no verdict parsing) or artifact: + verdicts: (verdict-parsed routing). max_iterations caps the agent's own loop.

• command: <shell> — a command step: mechanical, never an LLM call. The command runs in the workspace shell; exit 0 passes, anything else (including no exit by timeout) fails. timeout: is its only extra field.

• action: <name> — an action step: invokes a registered node-shaped function (state, params) -> state update with the step's params:. The built-in is commit; extensions register more via registry.add_action. Unknown action names fail at graph build time, not mid-run.

• agent, action, and command are mutually exclusive; exactly one is required — an empty value does not count.

Step semantics

• A command step is mechanical — the command runs in the workspace shell; exit 0 passes, anything else (including no exit by timeout, default 600s) fails and follows on_fail with the output tail in the retry note. The kind is the command: key, never the step's name.
• artifact + verdicts mark a verdict step. on_pass/on_fail may be a step name, the terminal success/failure, or {goto: X, retry: true}. on_pass omitted → next step in list order. on_fail omitted → failure. No loops happen unless you write them.
• A verdict agent that writes nothing, or writes an artifact with no parseable verdict, triggers an attempt-bounded retry with a note — verdicts are never silently routable, and the last verdict line wins (markdown decoration like **VERDICT: PASS** is tolerated).
• produces: / artifact files are deleted at every attempt start, so a retry can never re-read a stale artifact from the previous attempt.
• params on the commit action support {subject} templating (e.g. "feat: {subject} (agent dev loop)").

Extension points

Extensions are plain Python classes referenced by extensions: entries as module:Class (the module must be importable — e.g. on PYTHONPATH):

class MyExtension:
    name = "mine"
    def register(self, registry) -> None:
        registry.add_action("run_conformance", run_conformance)   # step actions
        registry.add_tool("figma", FigmaTool)                     # OpenHands tools
        registry.add_document_loader(MyLoader())                  # context sources

Working samples of all three kinds ship as the test fixture tests/sample_ext.py (actions, tools, a document loader — plus constructor- failure coverage).

Actions receive (state, params); returning continues the pipeline, raising fails the run. Actions have no verdict channel — for retry-driven fixing, prefer a verdict agent step.

Document loaders decide which docs enter the run context:

class MyLoader:
    name = "wiki"
    defaultable = False                     # may autodetect when no flag is given?
    def add_cli_args(self, parser):         # flag defaults MUST be None
        parser.add_argument("--wiki-page", default=None)
    def resolve(self, args):                # -> (docs: dict[str, str], subject: str)
        return fetch_docs(args.wiki_page), f"wiki {args.wiki_page}"

Loader-selection flow: a loader's flag in argv selects it; flags from two loaders in one invocation error out; with no flag, the sole defaultable loader autoruns (the bundled ai-dlc loader autodetects the current unit from aidlc-docs/aidlc-state.md), otherwise the run proceeds with no injected docs and the pipeline name: as subject. Unit ids resolve by exact directory name or by numeric prefix (unit-004-preset-management answers to 4, 004, U4, U004, or its full slug); ambiguous ids fail loud listing all matches. A selected loader that yields zero docs fails fast — context is never silently degraded. Duplicate CLI option strings across loaders are a load-time error naming both.

Fixed policies (intentionally not configurable)

• Fail fast on missing config/secrets — no silent fallbacks.
• Verdicts are file artifacts under state_dir; the last decoration-tolerant VERDICT: X line wins.
• Attempt-bounded retries with full retry-note accumulation.
• Per-attempt artifact hygiene — stale artifacts are deleted, never re-parsed.
• Single commit point, gated on a clean-at-start worktree; the commit action no-ops rather than sweep up your unrelated edits.
• Unclear verdicts are never routable — always an attempt-bounded retry.
• Command steps are mechanical — never an LLM call; the exit code is the verdict; a timeout kills the process group.
• Port sweeps are explicit actions with required port, optional match substring filter — the startup sweep of the engine's own viz server (cwd-scoped, best-effort) is the one built-in exception.
• No client-side LLM timeout by default (timeout: null) — agent runs are long; set timeout if your provider needs one.
• Crash-safe resume — every stage boundary is a checkpoint.

The example consumer

agentic-dev-loop/ is a complete, runnable consumer that turns the library on its own repo: the pipeline above, its three agent definitions (sdk_agents/), and this README wired in as shared context. Run it from the repo root with ./trigger-agentic-dev-loop.sh --plan plan.md. The e2e suite (tests/test_e2e_fixtures.py) replays historical failure fixtures against it — markdown-decorated verdicts, stale-artifact hygiene, verdict-first truncation, unclear-verdict retry, dirty-worktree commit skip, and empty-context fail-fast.

AI-DLC

The development lifecycle workflow lives in .aidlc/aidlc-rules/aws-aidlc-rules/core-workflow.md (the entry point; phase details under aws-aidlc-rule-details/). Working docs — plans, user stories, units of work, state — live in aidlc-docs/, created as the workflow runs. The bundled ai-dlc document loader (see Extension points) wires the pipeline's --ai-dlc-unit flag to those docs.

OpenCode commands over the workflow: /epic-status, /ticket-details, /unit-status, /update-subtask (ticket boards over aidlc-docs/), /apply-aidlc-patches (numbered .patch files under .aidlc/aidlc-patches/, applied by apply-patches.sh), /load-backend-rules (coding-standards-ddd.yaml), /software-selection, /postmortem, /figma, and /export-opencode-tools-to-claude (syncs commands and skills into .claude-local/ for the Claude CLI).

Skills: brainstorming, hypothesis-generation, writing-plans.