[Agent]: Add support for Devin for Terminal CLI

[ivishalgandhi]

Agent Name

Devin for Terminal

Official Website

https://cli.devin.ai/docs

Agent Type

CLI tool (command-line interface)

CLI Command (if applicable)

devin

Installation Method

curl -fsSL https://cli.devin.ai/install.sh | bash (macOS / Linux / WSL) — Windows via irm https://static.devin.ai/cli/setup.ps1 | iex. Also bundled with Windsurf Enterprise via the Install Devin for Terminal command palette action.

Command/Workflow Structure

Devin's user-extensible commands are called Skills (see https://cli.devin.ai/docs/extensibility/skills/overview).

Format: Markdown with YAML frontmatter.
Directory (project-scoped): .devin/skills//SKILL.md
Directory (user-scoped): ~/.config/devin/skills//SKILL.md
Invocation: / slash command inside an interactive devin session.
Frontmatter fields: name, description, allowed-tools, triggers (user and/or model).

Example (from Devin docs):

---
name: review
description: Review code changes before committing
allowed-tools:
  - read
  - grep
  - glob
  - exec
---
Review the current git diff and provide feedback:
1. Run `git diff --staged` (or `git diff` if nothing is staged)
2. Check for logic errors, missing error handling, security issues, style inconsistencies
3. Summarize findings and suggest improvements

Invoked as /review in the Devin terminal.

This maps cleanly to Spec Kit's existing SkillsIntegration base class (same shape as Codex CLI). Proposed Spec Kit layout:

.devin/skills/speckit.specify/SKILL.md
.devin/skills/speckit.plan/SKILL.md
.devin/skills/speckit.tasks/SKILL.md (etc.)
Context / rules file: AGENTS.md at project root (Devin reads it natively — see https://cli.devin.ai/docs/extensibility/rules).

Argument Passing Pattern

Skills receive the user's free-text arguments appended after the slash command (/review fix the auth flow). There is no special placeholder token in Devin skill bodies; the prompt body is treated as the skill's instructions and any arguments the user types are added to the conversation context. Proposed registrar placeholder for Spec Kit: $ARGUMENTS (same convention already used by Codex and Claude SkillsIntegrations).

Popularity/Usage

Widely used (thousands+ of users)

Documentation Links

Quickstart: https://cli.devin.ai/docs
Essential commands: https://cli.devin.ai/docs/essential-commands
Commands & flags reference: https://cli.devin.ai/docs/reference/commands
Skills (extensibility): https://cli.devin.ai/docs/extensibility/skills/overview
Creating skills: https://cli.devin.ai/docs/extensibility/skills/creating-skills
Rules & AGENTS.md: https://cli.devin.ai/docs/extensibility/rules

Use Case

I use Devin for Terminal as my primary CLI coding agent and want to drive Spec-Driven Development workflows (/speckit.specify, /speckit.plan, /speckit.tasks, /speckit.implement) through it without maintaining a parallel fork of the templates. Devin's Skills system is a near-perfect match for Spec Kit's slash-command model, and AGENTS.md support means the project context file requires zero new convention.

Relationship to the existing windsurf integration

Spec Kit already supports Windsurf (the IDE) via src/specify_cli/integrations/windsurf/. Cognition AI acquired Windsurf in July 2025, and Devin for Terminal is now distributed under that combined org (with a "Windsurf Enterprise" install path via the Windsurf command palette). Despite the shared parent company, the two are distinct products with different on-disk conventions, and the existing integration does not cover Devin:

	windsurf (existing)	devin (proposed)
Product	Windsurf IDE	Devin for Terminal CLI
requires_cli	False	True (binary: devin)
Base class	MarkdownIntegration	SkillsIntegration
Commands path	.windsurf/workflows/<name>.md	.devin/skills/<name>/SKILL.md
File format	Flat markdown	Markdown with YAML frontmatter (name, description, allowed-tools, triggers)
Context file	.windsurf/rules/specify-rules.md	AGENTS.md
Invocation	/workflow-name in Windsurf chat	/skill-name in devin terminal

Devin can also read skills from .windsurf/skills/<name>/SKILL.md, but that is a different directory from the existing integration's .windsurf/workflows/, so there is no overlap to reuse. Recommending a separate devin integration, mirroring the codex SkillsIntegration shape.

Example Command File

Proposed .devin/skills/speckit.specify/SKILL.md generated by Spec Kit from the existing templates/commands/speckit.specify.md template (Spec Kit frontmatter translated to Devin's Skill frontmatter; body kept intact so $ARGUMENTS continues to work via the registrar_config.args substitution):

---
name: speckit.specify
description: Create or update a feature specification from a natural-language description
triggers:
  - user
allowed-tools:
  - read
  - write
  - grep
  - glob
  - exec
---

## User Input

```text
$ARGUMENTS
```

Given the feature description above:

1. **Create the feature branch** by running the script:
   - Bash: `.specify/scripts/bash/create-new-feature.sh --json --short-name "<short-name>" "<description>"`
   - The JSON output contains BRANCH_NAME and SPEC_FILE paths.

2. **Read the spec-template** to see the sections you need to fill.

3. **Write the specification** to SPEC_FILE, replacing the placeholders in each section (Overview, Requirements, Acceptance Criteria) with details from the user's description.

Invoked from the Devin terminal as /speckit.specify add OAuth login to the admin panel — Devin appends the free-text arguments into the skill body at the $ARGUMENTS placeholder and runs the skill with the declared allowed-tools.

Contribution

• I can help test the integration
• I can provide example command files
• I can help with documentation
• I can submit a pull request for the integration

Additional Context

• Devin for Terminal launched in 2025 from Cognition AI and is bundled with Windsurf Enterprise (Cognition acquired Windsurf in July 2025). Parent product Devin has a large user base; the terminal CLI is newer.
• Proposed implementation approach (for maintainer sanity-check before coding):
  • New subpackage src/specify_cli/integrations/devin/ subclassing SkillsIntegration (mirrors codex/).
  • key = "devin" (matches shutil.which("devin") for requires_cli: True).
  • config.folder = ".devin/", commands_subdir = "skills", install_url = "https://cli.devin.ai/docs".
  • registrar_config: dir = ".devin/skills", format = "markdown", args = "$ARGUMENTS", extension = "/SKILL.md".
  • context_file = "AGENTS.md".
  • Wire into src/specify_cli/integrations/__init__.py::_register_builtins(), scripts/bash/update-agent-context.sh, scripts/powershell/update-agent-context.ps1, and integrations/catalog.json.
  • Add tests/integrations/test_integration_devin.py mirroring test_integration_codex.py.
• AI assistance disclosure: this issue text and the proposed integration design were drafted with help from an AI pair-programming assistant (Windsurf / Claude); I have personally read the Devin CLI docs linked above and verified the mapping to Spec Kit's SkillsIntegration base class. Implementation and manual testing will be done by me.

[mnriem]

Feel free to create a PR. We would love the contribution!