feat(integrations): add Devin for Terminal skills-based integration

- Register DevinIntegration as a SkillsIntegration with .devin/skills/ layout
- Add catalog entry, docs row, and supported-agents listing
- Display /speckit-<command> hyphen syntax in init "Next Steps" panel
  (matches Claude/Cursor/Copilot skills mode, since Devin invokes skills
  by directory name)

Closes #2346

Author: ivishalgandhi

.github/ISSUE_TEMPLATE/agent_request.yml

@@ -8,7 +8,7 @@ body:
       value: |
         Thanks for requesting a new agent! Before submitting, please check if the agent is already supported.
         
-        **Currently supported agents**: Claude Code, Gemini CLI, GitHub Copilot, Cursor, Qwen Code, opencode, Codex CLI, Windsurf, Kilo Code, Auggie CLI, Roo Code, CodeBuddy, Qoder CLI, Kiro CLI, Amp, SHAI, Tabnine CLI, Antigravity, IBM Bob, Mistral Vibe, Kimi Code, Trae, Pi Coding Agent, iFlow CLI
+        **Currently supported agents**: Claude Code, Gemini CLI, GitHub Copilot, Cursor, Qwen Code, opencode, Codex CLI, Windsurf, Kilo Code, Auggie CLI, Roo Code, CodeBuddy, Qoder CLI, Kiro CLI, Amp, SHAI, Tabnine CLI, Antigravity, IBM Bob, Mistral Vibe, Kimi Code, Trae, Pi Coding Agent, iFlow CLI, Devin for Terminal
 
   - type: input
     id: agent-name

docs/reference/integrations.md

@@ -13,6 +13,7 @@ The Specify CLI supports a wide range of AI coding agents. When you run `specify
 | [CodeBuddy CLI](https://www.codebuddy.ai/cli)                                        | `codebuddy`      |                                                                                                                                           |
 | [Codex CLI](https://github.com/openai/codex)                                         | `codex`          | Skills-based integration; installs skills into `.agents/skills` and invokes them as `$speckit-<command>` |
 | [Cursor](https://cursor.sh/)                                                         | `cursor-agent`   |                                                                                                                                           |
+| [Devin for Terminal](https://cli.devin.ai/docs)                                      | `devin`          | Skills-based integration; installs skills into `.devin/skills/` and invokes them as `/speckit-<command>` |
 | [Forge](https://forgecode.dev/)                                                      | `forge`          |                                                                                                                                           |
 | [Gemini CLI](https://github.com/google-gemini/gemini-cli)                            | `gemini`         |                                                                                                                                           |
 | [GitHub Copilot](https://code.visualstudio.com/)                                     | `copilot`        |                                                                                                                                           |

integrations/catalog.json

@@ -66,6 +66,15 @@
       "repository": "https://github.com/github/spec-kit",
       "tags": ["cli", "skills"]
     },
+    "devin": {
+      "id": "devin",
+      "name": "Devin for Terminal",
+      "version": "1.0.0",
+      "description": "Devin for Terminal CLI skills-based integration",
+      "author": "spec-kit-core",
+      "repository": "https://github.com/github/spec-kit",
+      "tags": ["cli", "skills"]
+    },
     "qwen": {
       "id": "qwen",
       "name": "Qwen Code",

src/specify_cli/__init__.py

@@ -1523,7 +1523,8 @@ def init(
     trae_skill_mode = selected_ai == "trae"
     cursor_agent_skill_mode = selected_ai == "cursor-agent" and (ai_skills or _is_skills_integration)
     copilot_skill_mode = selected_ai == "copilot" and _is_skills_integration
-    native_skill_mode = codex_skill_mode or claude_skill_mode or kimi_skill_mode or agy_skill_mode or trae_skill_mode or cursor_agent_skill_mode or copilot_skill_mode
+    devin_skill_mode = selected_ai == "devin"
+    native_skill_mode = codex_skill_mode or claude_skill_mode or kimi_skill_mode or agy_skill_mode or trae_skill_mode or cursor_agent_skill_mode or copilot_skill_mode or devin_skill_mode
 
     if codex_skill_mode and not ai_skills:
         # Integration path installed skills; show the helpful notice
@@ -1535,6 +1536,9 @@ def init(
     if cursor_agent_skill_mode and not ai_skills:
         steps_lines.append(f"{step_num}. Start Cursor Agent in this project directory; spec-kit skills were installed to [cyan].cursor/skills[/cyan]")
         step_num += 1
+    if devin_skill_mode:
+        steps_lines.append(f"{step_num}. Start Devin in this project directory; spec-kit skills were installed to [cyan].devin/skills[/cyan]")
+        step_num += 1
     usage_label = "skills" if native_skill_mode else "slash commands"
 
     def _display_cmd(name: str) -> str:
@@ -1544,7 +1548,7 @@ def _display_cmd(name: str) -> str:
             return f"/speckit-{name}"
         if kimi_skill_mode:
             return f"/skill:speckit-{name}"
-        if cursor_agent_skill_mode or copilot_skill_mode:
+        if cursor_agent_skill_mode or copilot_skill_mode or devin_skill_mode:
             return f"/speckit-{name}"
         return f"/speckit.{name}"
 

src/specify_cli/integrations/__init__.py

@@ -56,6 +56,7 @@ def _register_builtins() -> None:
     from .codex import CodexIntegration
     from .copilot import CopilotIntegration
     from .cursor_agent import CursorAgentIntegration
+    from .devin import DevinIntegration
     from .forge import ForgeIntegration
     from .gemini import GeminiIntegration
     from .generic import GenericIntegration
@@ -86,6 +87,7 @@ def _register_builtins() -> None:
     _register(CodexIntegration())
     _register(CopilotIntegration())
     _register(CursorAgentIntegration())
+    _register(DevinIntegration())
     _register(ForgeIntegration())
     _register(GeminiIntegration())
     _register(GenericIntegration())

src/specify_cli/integrations/devin/__init__.py

@@ -0,0 +1,44 @@
+"""Devin for Terminal integration — skills-based agent.
+
+Devin uses the ``.devin/skills/speckit-<name>/SKILL.md`` layout and
+reads project context from ``AGENTS.md`` at the repo root. The CLI
+binary is ``devin`` and skills are invoked via ``/<name>`` inside an
+interactive ``devin`` session.
+
+See: https://cli.devin.ai/docs/extensibility/skills/overview
+"""
+
+from __future__ import annotations
+
+from ..base import IntegrationOption, SkillsIntegration
+
+
+class DevinIntegration(SkillsIntegration):
+    """Integration for Cognition AI's Devin for Terminal."""
+
+    key = "devin"
+    config = {
+        "name": "Devin for Terminal",
+        "folder": ".devin/",
+        "commands_subdir": "skills",
+        "install_url": "https://cli.devin.ai/docs",
+        "requires_cli": True,
+    }
+    registrar_config = {
+        "dir": ".devin/skills",
+        "format": "markdown",
+        "args": "$ARGUMENTS",
+        "extension": "/SKILL.md",
+    }
+    context_file = "AGENTS.md"
+
+    @classmethod
+    def options(cls) -> list[IntegrationOption]:
+        return [
+            IntegrationOption(
+                "--skills",
+                is_flag=True,
+                default=True,
+                help="Install as agent skills (default for Devin)",
+            ),
+        ]

tests/integrations/test_integration_devin.py

@@ -0,0 +1,30 @@
+"""Tests for DevinIntegration."""
+
+from .test_integration_base_skills import SkillsIntegrationTests
+
+
+class TestDevinIntegration(SkillsIntegrationTests):
+    KEY = "devin"
+    FOLDER = ".devin/"
+    COMMANDS_SUBDIR = "skills"
+    REGISTRAR_DIR = ".devin/skills"
+    CONTEXT_FILE = "AGENTS.md"
+
+
+class TestDevinAutoPromote:
+    """--ai devin auto-promotes to integration path."""
+
+    def test_ai_devin_without_ai_skills_auto_promotes(self, tmp_path):
+        """--ai devin should work the same as --integration devin."""
+        from typer.testing import CliRunner
+        from specify_cli import app
+
+        runner = CliRunner()
+        target = tmp_path / "test-proj"
+        result = runner.invoke(
+            app,
+            ["init", str(target), "--ai", "devin", "--no-git", "--ignore-agent-tools", "--script", "sh"],
+        )
+
+        assert result.exit_code == 0, f"init --ai devin failed: {result.output}"
+        assert (target / ".devin" / "skills" / "speckit-plan" / "SKILL.md").exists()