Sounds

SFXMint MCP Server

Free CC0 sound effects — describe a sound to find it, preview, and download MP3 (WAV comes with the download pack). Free to try with no signup or API key, no attribution. Agents can ask by role, take one of 18 sets, or search the library, and get permanent hotlinkable URLs. When nothing in the library fits, the agent tells the user which sound is missing; SFXMint no longer makes new sounds, and new ones join the library from what people search for.

Free use has a daily allowance: without a key, 20 lookups and tool calls and 5 different sound downloads a day per network (a second format or a retry of the same sound is not counted again); a free account's API key gives 100 calls and 20 downloads a day (300 a month); a download pack removes the limits and adds WAV for 30 days, and file URLs returned to its keyed requests carry a signed g= good for 48 hours. Past a limit the answer is 429 download_limit or call_limit with a message to pass on to the user. Listening in a browser is never counted. Keep page_url in SOUNDS.md, never a URL with g=.

• Endpoint (Streamable HTTP): https://sfxmint.com/mcp
• Docs: https://sfxmint.com/api/docs
• Registry: published as com.sfxmint/sounds on 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.

Quick start

Claude Code, as a plugin (the MCP server plus the skill below):

/plugin install sfxmint --marketplace sfxmint/sfxmint-mcp

On Claude Code before 2.1.275, run /plugin marketplace add sfxmint/sfxmint-mcp, then /plugin install sfxmint@sfxmint. Or add only the MCP server:

claude mcp add --transport http sfxmint "https://sfxmint.com/mcp?ref=github-readme"

Gemini CLI, as an extension (the MCP server, a context file and the skill):

gemini extensions install https://github.com/sfxmint/sfxmint-mcp

Codex CLI, as a plugin (the MCP server plus the skill):

codex plugin marketplace add sfxmint/sfxmint-mcp

codex plugin add sfxmint@sfxmint

Cursor / generic mcpServers config:

{ "mcpServers": { "sfxmint": { "url": "https://sfxmint.com/mcp?ref=github-readme" } } }

With a free account's API key (higher daily limits; a download pack lifts them for the key's account):

claude mcp add --transport http sfxmint "https://sfxmint.com/mcp?ref=github-readme" --header "Authorization: Bearer $SFXMINT_API_KEY"

{ "mcpServers": { "sfxmint": { "url": "https://sfxmint.com/mcp?ref=github-readme", "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 sfxmint/sfxmint-mcp -y

The 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 hit

It writes the audio plus a sounds.json manifest recording each file's source URL, SHA-256 and license, and a SOUNDS.md table linking each sound's page, and ships a small Web Audio runtime (createSoundboard) for first-gesture unlock, overlapping cues and a persisted mute. Source: sfxmint/sfxmint-npm.

Tutorials

• [Add sound effects to a Remotion video with SFXMint MCP](examples/remotion/README.md) — an 18-second runnable example with four timed cues, a finished video, a copy-and-paste agent prompt, and a read-only MCP check. 中文教程.

Tools

When nothing fits, pass user_message on to the user and list the sound under a Missing heading in SOUNDS.md. The four library tools are all there is for new users: SFXMint no longer makes new sounds. An account that already has credits or a plan still sees generate_sound and get_generation with its API key. Game kits (projects of many sounds) closed on 2026-10-20; their tools answer tool_retired. get_job and POST /api/v1/generate stay retired.

Requirements, processing and acceptance

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. When nothing matches every word, closest lists the nearest sounds that meet every hard requirement, each with missing_terms, and library_fit says how well the library covers the request. 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.

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. Other sources and local synthesis remain separate, task-authorized choices.

Use URLs returned by the live API, without inventing or rewriting them. See the API docs, Phaser guide, React guide, and download example.

Rate limits & fair use

• Without a key: 20 lookups and tool calls and 5 sound downloads a day per network; a free account's API key: 100 calls and 20 downloads a day
• Hotlinking is allowed and encouraged; files are served with long-lived immutable caching

Contact

hello@sfxmint.com · https://sfxmint.com