Supported Harnesses

This page is the canonical 5-tier support matrix for AI coding harnesses ("agents") that Spec Kitty integrates with. Each row conforms to the HarnessEntry schema in kitty-specs/spec-kitty-3-2-docs-01KS4KSZ/data-model.md. The research procedure that backs each classification lives in docs/development/3-2-harness-research-method.md.

Access date for citations: 2026-06-03.

Tier legend

Tier	One-line definition
first_class	Installed by default; canonical UX (slash command or Agent Skill); integration-tested; current external doc citation.
supported	Installed by the standard installer; current external doc citation; may lack first-class integration tests or have a degraded mechanism.
partial	Installer touches the host but coverage is incomplete, or no current external citation could be located.
experimental	Provisional coverage that may break without notice; typically depends on another harness's installation.
archived	No longer covered by the installer, or the upstream project is deprecated; coverage (if any) lives in `docs/migration/`.

Full tier criteria and promotion rules are maintained in docs/development/3-2-harness-research-method.md §5 and §6.

Support matrix

Harness	Key	Installed surface	Mechanism	Tier	Citation (accessed 2026-06-03)	Notes
Claude Code	`claude`	`.claude/commands/`	slash_command	first_class	https://docs.claude.com/en/docs/claude-code/overview	Reference harness; integration-tested in `src/specify_cli/`.
Codex CLI	`codex`	`.agents/skills/spec-kitty.*/SKILL.md`	skill	first_class	https://github.com/openai/codex	Heaviest Agent Skills integration; canonical skill tree at `.agents/skills/`.
OpenCode	`opencode`	`.opencode/command/`	slash_command	supported	https://opencode.ai/docs	`/spec-kitty.*` command set installed via standard installer.
Cursor	`cursor`	`.cursor/commands/`	slash_command	supported	https://cursor.com/docs	`/spec-kitty.*` command set installed via standard installer.
Google Gemini CLI	`gemini`	`.gemini/commands/`	slash_command	supported	https://github.com/google-gemini/gemini-cli	`/spec-kitty.*` command set installed via standard installer.
Qwen Code	`qwen`	`.qwen/commands/`	slash_command	supported	https://github.com/QwenLM/qwen-code	`/spec-kitty.*` command set installed via standard installer.
Amazon Q CLI	`q`	`.amazonq/prompts/`	prompt	supported	https://docs.aws.amazon.com/amazonq/latest/qdeveloper-ug/	Retained as legacy alongside Kiro rebrand per `CLAUDE.md`.
GitHub Copilot	`copilot`	`.github/prompts/`	prompt	supported	https://docs.github.com/en/copilot/customizing-copilot/adding-custom-instructions-for-github-copilot	Prompt-file mechanism; `/spec-kitty.*` set installed.
Augment Code (Auggie)	`augment`	`.augment/commands/`	slash_command	supported	https://docs.augmentcode.com/auggie/overview	`/spec-kitty.*` command set installed via standard installer.
Roo Cline	`roo`	`.roo/commands/`	slash_command	supported	https://docs.roocode.com/	`/spec-kitty.*` command set installed via standard installer.
Kilo Code	`kilocode`	`.kilocode/workflows/`	workflow	supported	https://kilocode.ai/docs	Workflow mechanism; `/spec-kitty.*` set installed.
Windsurf	`windsurf`	`.windsurf/workflows/`	workflow	supported	https://docs.windsurf.com/windsurf/cascade/workflows	Workflow mechanism; `/spec-kitty.*` set installed.
Kiro	`kiro`	`.kiro/prompts/`	prompt	partial	https://kiro.dev/docs	Prompt-file surface only for Spec Kitty 3.3 plugin-install scoping; not a plugin/Powers bundle candidate until upstream exposes and verifies a package primitive.
Google Antigravity	`antigravity`	`.agent/workflows/`	workflow	partial	https://www.antigravity.google/docs/rules-workflows	Local live CLI verification was unavailable on 2026-06-03; installed surface remains documented as partial until current Antigravity CLI workflow paths are smoke-tested.
Pi TUI	`pi`	`.agents/skills/spec-kitty.*/SKILL.md`	skill	partial	https://pi.dev/docs/latest/skills	Installer-supported command-skill packages; keep partial until a real-session smoke test is recorded.
Mistral Vibe	`vibe`	`.agents/skills/` via `.vibe/config.toml` `skill_paths`	skill	experimental	https://docs.mistral.ai/mistral-vibe/terminal/quickstart	Uses the shared `.agents/skills/spec-kitty.*` packages plus a `.vibe/config.toml` `skill_paths` entry. Behaviour may change with Vibe upstream.
Letta Code	`letta`	`.agents/skills/spec-kitty.*/SKILL.md`	skill	partial	https://docs.letta.com/letta-code/skills	Installer-supported command-skill packages; keep partial until a real-session smoke test is recorded.

Cross-reference quick view

Tier	Count	Members
first_class	2	Claude Code, Codex CLI
supported	10	OpenCode, Cursor, Gemini CLI, Qwen Code, Amazon Q CLI, GitHub Copilot, Augment Code, Roo Cline, Kilo Code, Windsurf
partial	4	Kiro, Google Antigravity, Pi TUI, Letta Code
experimental	1	Mistral Vibe
archived	0
Total	17

Promotion path

A harness moves up tiers only when new evidence lands. See docs/development/3-2-harness-research-method.md §6 for the full rule. Summary:

partial → supported when (a) the installer produces a full /spec-kitty.* set, (b) a current external citation is recorded, and (c) at least one smoke test has been documented.
supported → first_class when (a) integration tests exercise the harness end-to-end, (b) the mechanism is the harness's canonical UX, (c) the per-harness page under docs/how-to/harnesses/<key>.md is non-stub, and (d) the promotion is logged in CHANGELOG.
Demotion happens when citations cannot be re-verified across two freshness audits, the upstream is deprecated, or the installer ceases to produce a valid surface.

Tier moves are recorded in this matrix's row notes and the project CHANGELOG.

Maintenance

The inventory step is re-run on every release; the citation step is re-run on every release as part of the freshness audit (WP13).
This matrix is the published artifact; the procedure that backs it is maintained at docs/development/3-2-harness-research-method.md.
Per-harness "how-to" pages live at docs/how-to/harnesses/<key>.md and are promoted under the plan's matrix-first default (decision 01KS4KTS4V300M9MMTS1AJEGXY).