feat(adapters): added LangGraph and DeepAgents export adapters

CONTRIBUTING.md

@@ -133,6 +133,12 @@ Add your adapter to the switch statement that dispatches on `-a <adapter>`.
 
 If your framework has a config file format, add an exporter in `commands/export.ts` or `src/adapters/`.
 
+If your example directory commits an `expected_output.py` (or similar) snapshot, regenerate it whenever you change the adapter so it does not drift:
+
+```bash
+opengap export --dir examples/<name> --format <name> --output examples/<name>/expected_output.py
+```
+
 ### 4. Document what's lossy
 
 Every adapter loses something — that's expected. Please document it clearly:

README.md

@@ -371,6 +371,7 @@ Adapters are used by both `export` and `run`. Available adapters:
 | `codex` | OpenAI Codex CLI instructions (export only) |
 | `kiro` | Kiro agent format (export only) |
 | `gitclaw` | GitClaw agent format |
+| `deepagents` | LangChain DeepAgents harness (`create_deep_agent(...)`) — skills, tools, sub-agents |
 
 ```bash
 # Export to system prompt

examples/deepagents/README.md

@@ -0,0 +1,37 @@
+# DeepAgents example
+
+A research agent with a fact-checker sub-agent, demonstrating the DeepAgents adapter:
+
+- `agent.yaml` — manifest (model, skills, tools, sub-agent declaration)
+- `SOUL.md` — agent identity, embedded in the generated `system_prompt`
+- `skills/web-research/`, `skills/summarize/` — passed via a `skills=` path resolved next to the generated module (`Path(__file__).parent / "skills"`), so discovery works from any working directory; DeepAgents loads each `SKILL.md` natively
+- `tools/web-search.yaml` — emitted as a `@tool` function bound into `tools=[...]`
+- `agents/fact-checker/` — emitted as a `SubAgent` dict in `subagents=[...]`. By default a sub-agent inherits the full parent `TOOLS` list; add a `tools:` list to the sub-agent's own `agent.yaml` to narrow it to a subset.
+- `expected_output.py` — the Python module the adapter produces
+
+DeepAgents is a filesystem-shaped harness — there is no graph wiring. The
+agent directory maps straight onto `create_deep_agent(...)`, and the model
+decides at runtime when to plan, when to delegate to sub-agents, and when to
+call tools. Nothing here needs a step graph, which is why this is the only
+LangChain-family adapter opengap ships.
+
+## Regenerate
+
+```bash
+opengap export --dir examples/deepagents --format deepagents --output examples/deepagents/expected_output.py
+```
+
+## Run the generated agent
+
+```bash
+pip install deepagents langchain-anthropic
+python examples/deepagents/expected_output.py
+```
+
+Or let gitagent generate and run it for you (pass an initial message with `-p`, read from `GITAGENT_PROMPT`):
+
+```bash
+opengap run --dir examples/deepagents --adapter deepagents -p "Who won the 2022 World Cup?"
+```
+
+The generated file leaves tool implementations as `NotImplementedError` stubs — replace them with your own logic before invoking.

examples/deepagents/SOUL.md

@@ -0,0 +1,5 @@
+# Research Assistant
+
+You are a research assistant. Find authoritative sources, extract the relevant
+facts, and summarize them honestly. Delegate to the `fact-checker` sub-agent
+whenever a claim warrants independent verification. Cite every claim.

examples/deepagents/agent.yaml

@@ -0,0 +1,16 @@
+spec_version: "0.1.0"
+name: research-assistant
+version: 1.0.0
+description: Research assistant with a fact-checker sub-agent
+author: gitagent-examples
+license: MIT
+model:
+  preferred: anthropic:claude-sonnet-4-5
+skills:
+  - web-research
+  - summarize
+tools:
+  - web-search
+agents:
+  fact-checker:
+    description: Verifies factual claims against authoritative sources

examples/deepagents/agents/fact-checker/SOUL.md

@@ -0,0 +1,4 @@
+# Fact-Checker
+
+You are a pedantic fact-checker. Treat every claim as unverified until you
+locate a primary source. If a claim cannot be substantiated, say so plainly.

examples/deepagents/agents/fact-checker/agent.yaml

@@ -0,0 +1,4 @@
+spec_version: "0.1.0"
+name: fact-checker
+version: 1.0.0
+description: Verifies factual claims against authoritative sources

examples/deepagents/expected_output.py

@@ -0,0 +1,87 @@
+"""
+DeepAgents definition for research-assistant v1.0.0
+Generated by gitagent export --format deepagents
+"""
+
+from __future__ import annotations
+
+from deepagents import create_deep_agent
+from langchain_core.tools import tool
+from pathlib import Path
+
+# Agent metadata
+AGENT_NAME = "research-assistant"
+AGENT_VERSION = "1.0.0"
+MODEL = "anthropic:claude-sonnet-4-5"
+
+# System prompt (SOUL.md + RULES.md + DUTIES.md + compliance)
+SYSTEM_PROMPT = """# research-assistant
+Research assistant with a fact-checker sub-agent
+
+# Research Assistant
+
+You are a research assistant. Find authoritative sources, extract the relevant
+facts, and summarize them honestly. Delegate to the `fact-checker` sub-agent
+whenever a claim warrants independent verification. Cite every claim.
+"""
+
+# Hooks (pre_tool_use scripts run before every tool call)
+def _run_pre_tool_use_hooks(tool_name: str) -> None:
+    """No pre_tool_use hooks configured in hooks/hooks.yaml."""
+    return None
+
+# NOTE: other hook events (post_tool_use, on_session_start, etc.) have no
+# DeepAgents equivalent and are intentionally skipped.
+# NOTE: memory/ has no direct DeepAgents equivalent — wire a checkpointer if needed.
+
+# Tools (from tools/*.yaml)
+@tool
+def web_search(query: str) -> str:
+    """Search the public web for a query"""
+    _run_pre_tool_use_hooks("web-search")
+    # TODO: replace this stub with a real implementation of "web-search"
+    raise NotImplementedError("Implement tool: web-search")
+
+TOOLS = [web_search]
+
+# Skills (skills/<name>/SKILL.md — DeepAgents loads these natively)
+# Resolved relative to this file so discovery works from any working directory.
+SKILLS = [str(Path(__file__).resolve().parent / "skills")]
+
+# For reference, the skills available in this agent:
+#   - summarize: Condense the gathered sources into a faithful, cited summary
+#   - web-research: Search the web for sources relevant to the user's question
+
+# Sub-agents (agents/<name>/ → SubAgent dicts)
+fact_checker_subagent = {
+    "name": "fact-checker",
+    "description": "Verifies factual claims against authoritative sources",
+    "system_prompt": """# fact-checker
+Verifies factual claims against authoritative sources
+
+# Fact-Checker
+
+You are a pedantic fact-checker. Treat every claim as unverified until you
+locate a primary source. If a claim cannot be substantiated, say so plainly.
+""",
+    "tools": TOOLS,  # inherits the full parent toolset (default) — add `tools: [...]` to
+    # this sub-agent's agent.yaml (agents/fact-checker/agent.yaml) to narrow it
+}
+
+SUBAGENTS = [fact_checker_subagent]
+
+# Agent
+agent = create_deep_agent(
+    model=MODEL,
+    system_prompt=SYSTEM_PROMPT,
+    tools=TOOLS,
+    skills=SKILLS,
+    subagents=SUBAGENTS,
+)
+
+if __name__ == "__main__":
+    import os
+    user_input = os.environ.get("GITAGENT_PROMPT", "Hello")
+    result = agent.invoke({"messages": [{"role": "user", "content": user_input}]})
+    for message in result["messages"]:
+        print(message)

examples/deepagents/skills/summarize/SKILL.md

@@ -0,0 +1,8 @@
+---
+name: summarize
+description: Condense the gathered sources into a faithful, cited summary
+---
+
+Produce a concise summary of the gathered material. Every factual claim must
+be attributed to a specific source URL. If sources disagree, surface the
+disagreement explicitly.

examples/deepagents/skills/web-research/SKILL.md

@@ -0,0 +1,8 @@
+---
+name: web-research
+description: Search the web for sources relevant to the user's question
+allowed-tools: web-search
+---
+
+Use the `web-search` tool to find authoritative sources. Capture the URL of
+every source consulted; downstream skills will cite them.

examples/deepagents/tools/web-search.yaml

@@ -0,0 +1,10 @@
+name: web-search
+description: Search the public web for a query
+input_schema:
+  type: object
+  properties:
+    query:
+      type: string
+      description: The search query
+  required:
+    - query