Free CC0 sound effects — describe a sound to find it, preview, and download WAV/MP3. No signup, no API key, no attribution. Agents can ask by role, take one of 18 sets, or search the library, and get permanent hotlinkable URLs. With an API key, they can also generate a sound the library lacks.
- Endpoint (Streamable HTTP):
https://sfxmint.com/mcp - Docs: https://sfxmint.com/api/docs
- Registry: published as
com.sfxmint/soundson the official MCP Registry - License of all audio: CC0 1.0 — public domain, commercial use welcome, no attribution required
Sounds are AI-generated or procedurally synthesized and offered under CC0. Audio URLs are immutable, CORS-enabled and free to hotlink. Download files into the project when offline playback is required; preview suitability in the actual app or game.
Claude Code:
claude mcp add --transport http sfxmint https://sfxmint.com/mcpCursor / generic mcpServers config:
{ "mcpServers": { "sfxmint": { "url": "https://sfxmint.com/mcp" } } }To let the agent generate sounds too, add your API key (only generate_sound and get_generation use it):
claude mcp add --transport http sfxmint https://sfxmint.com/mcp --header "Authorization: Bearer $SFXMINT_API_KEY"{ "mcpServers": { "sfxmint": { "url": "https://sfxmint.com/mcp", "headers": { "Authorization": "Bearer sfx_live_…" } } } }Prefer a skill over a server? This repo also ships an Agent Skill that uses the plain HTTP API — no MCP server required:
npx skills add flreey/sfxmint-mcp -yThe agent chooses a role for one event, a set for several events, or structured search for a description or gap. These are task branches, not a required sequence. Library files, other permitted sources and local synthesis can be mixed. The skill includes React / Phaser / plain-HTML integration examples. Source: skills/sfxmint/SKILL.md.
No agent involved? The sfxmint CLI puts the same files in a project directly:
npx sfxmint add coin jump hitIt writes the audio plus a sounds.json manifest recording each file's source URL, SHA-256 and license, and ships a small Web Audio runtime (createSoundboard) for first-gesture unlock, overlapping cues and a persisted mute. Source: flreey/sfxmint-npm.
| Tool | What it does |
|---|---|
get_role_sound |
Ask by event — button-click, purchase-success, error, coin, notification. Returns a file-checked candidate plus alternates; plain-English aliases work |
get_sound_set |
Candidates grouped by event and style (18 sets: ui-crisp, retro-game, checkout, platformer, ai-coding-tool, …) |
search_sounds |
Free-text retrieval with explicit duration, loop and format requirements; hard constraints can produce no candidates |
get_sound |
Full metadata for one sound (incl. a short description, measured acoustics, license) |
generate_sound |
Make a new sound from a description when the library has nothing suitable. Needs an API key; one credit per generation of up to four CC0 WAV takes, given back if none can be made |
get_generation |
Status of a generation and fresh download links for its takes |
The four library tools never need a key. Generation needs an SFXMint API key in the Authorization header (a free account comes with free credits); without one, generate_sound answers api_key_required with isError. Ask the user before spending credits, and let them listen to the takes. The same generation is available over REST as POST https://sfxmint.com/api/v1/orders (docs). get_job and POST /api/v1/generate stay retired; existing job records remain readable at GET /api/v1/jobs/{job_id}.
Use REST structured search (response=structured&limit=3) or the matching MCP parameters to pass required duration, loop and format explicitly. Check returned requirements; do not substitute near_matches. Scores and match types describe ranking, not listening confidence. Legacy loopable does not prove a seamless loop.
Sets accept format=wav|mp3: download_urls follows the requested format, legacy urls stays MP3, and missing_roles identifies incomplete sets. File decoding and hashes do not certify scene suitability. content_check is scoped to the exact scene, event, format and SHA256; unknown content is not accepted.
Task-permitted trimming, filtering and level changes are allowed. Retain originals, source URLs, license, processing recipes and new file hashes; re-measure requirements and preview the result. Changed bytes and new scenes do not inherit the original acceptance. The API and MCP server have no generation path; generating on the website, local synthesis or an external service remains a separate, task-authorized choice.
Use URLs returned by the live API, without inventing or rewriting them. See the API docs, Phaser guide, React guide, and download example.
- Search/metadata: no auth, generous limits
- Hotlinking is allowed and encouraged; files are served with long-lived immutable caching