# Melius (slim)

> Melius is a hosted node-based canvas for generating images, video, audio and text with many third-party models. Outside agents read and write projects, canvases, nodes, edges, runs and comments through a REST API, an MCP server and the mel CLI.

- Full: https://www.anchorterminal.com/tools/melius.md (~7,450 tokens) · this version ~1,830 tokens · JSON https://www.anchorterminal.com/tools/melius.json · canonical https://www.anchorterminal.com/tools/melius
- Index: https://www.anchorterminal.com/llms.txt · API: https://www.anchorterminal.com/api/v1/index.json · Updated: 2026-10-08

**C · 54.1/100 · rank #473 of 629 · #3 in Design workspaces & canvases · not agent-ready · confidence medium**


Assessment: One backend serves a 59-operation REST API with a public OpenAPI spec, a hosted MCP server with OAuth sign-in and a JSON-only CLI, and the status page shows no incidents since July 2026. API keys carry no scopes and work with their creator's role, and no rate-limit numbers, changelog or per-model credit prices are published.

## Facts

- Kind: HTTP API · vendor: Melius AI, Inc. · category: Design workspaces & canvases · legal entity: Melius AI, Inc. · provenance 72/100
- Endpoint: `https://api.melius.com/api/v1` (HTTP, Streamable HTTP)
- Auth: OAuth or key · pricing: Freemium · x402: no · licence: Proprietary service under Melius's terms of service. The mel CLI on npm is MIT, with no public source repository found
- Probe metrics: not measured yet (probes haven't run)
- REST API: https://api.melius.com/api/v1, OpenAPI 3.0.2, 59 operations on 51 paths. Projects, canvases, nodes, edges, runs, bulk runs, downloads, comments, presence, uploads, assets, models, voices, fonts, presets, templates, teams and API keys
- MCP server: Hosted, Streamable HTTP. https://mcp.melius.com/mcp with OAuth sign-in, or https://api.melius.com/mcp with a bearer API key. 75 tools in the reference, 18 of them for Cast, which is in beta
- CLI: @melius-ai/cli 0.16.2 (10 September 2026), MIT, Node.js 20 or later, also on Homebrew as melius-ai/tap/mel. JSON on stdout, exit codes 0 to 5
- Read vs write: Reads projects, canvases, nodes, edges, runs, comments, presets, teams and models. Creates and updates the same, starts generations, uploads files, and deletes projects, canvases, nodes and edges
- Generation model: Asynchronous. Create a node, start a run, poll the run, then request a download URL. Bulk runs take several nodes. `seed` from 0 to 2147483647 where the model supports it
- Credentials: Bearer API keys (`mel_...`) made in Team settings, shown once, optional expiry, revocable at once, no scopes. OAuth for MCP creates a connector key named after the client and tied to one team
- Rate limits: No numbers published. The docs say no plan has a monthly request quota and that bursts can return 429 with `Retry-After`. A canvas whose saved state passes 48 MiB returns 400 `CANVAS_TOO_LARGE`
- Errors: 401, 403 and 429 on every operation with `statusCode`, `error` and `message`. 400, 404 and 409 carry `message`. 400 also covers too few credits
- Models: Third-party image, video, audio and text models. The home page counts 117. GET /generation/models lists them with variants, settings and credit costs
- Free tier: Free plan at $0 with trial credits, amount not published. Whether sign-up needs a card, and whether Free teams can create API keys, is not stated
- Status: status.melius.com on incident.io with two components, Web app and MCP. No incidents listed from July to October 2026. No API component
- Data handling: Terms effective 28 August 2026 say no training on user input or outputs. Privacy policy effective 12 August 2025 gives no retention periods and no named sub-processors
- Prices: Creator plan $20 per month (plan); Growth plan $50 per month (plan); Professional plan $110 per month (plan); Team plan $70 per seat per month

- Scores: Reliability 69, Performance pending, Schema & documentation 70, Agent ergonomics 51, Security & auth 43, Payments & pricing 20, Task success pending, Maintenance & community 66, Transparency & trust 55 · total over the 7 assessed categories
- Why: Reliability, Graded on the hosted REST API and MCP server. · Schema & documentation, Public OpenAPI 3.0.2 spec with 59 operations (25). · Agent ergonomics, The MCP reference lists 75 tools, in the over-30 band, with `get_guide` and `get_docs` loading guidance on demand and 18 Cast tools shown on… · Security & auth, API keys are revocable at once, can expire and are shown once, but have no scopes. · Payments & pricing, No machine payment protocol (0). · Maintenance & community, The newest dated release is the CLI, 0.16.2 on 10 September 2026, 28 days before the check (30). · Transparency & trust, Closed service under published terms effective 28 August 2026. The CLI package is MIT with no public repository (15 of 30).
- Sources: 17, open questions: 7, both in the full twin
- Capabilities: design.canvas, design.comments, design.files, image.generate, image.edit, image.upscale, video.generate, speech.tts
- JSON: https://www.anchorterminal.com/api/v1/tools/melius.json
- Verify (for the vendor): the badge `https://www.anchorterminal.com/badges/melius.svg` or a link to https://www.anchorterminal.com/tools/melius from a page on melius.com or one of its subdomains, then `POST https://www.anchorterminal.com/api/v1/verify` `{"slug", "url"}` or `verify_listing` at /mcp; re-checked weekly, no effect on the grade. Snippets in the full twin.

## Before you call it

1. Generate by creating a node on a canvas, starting a run with POST /nodes/{nodeId}/runs, then polling GET /node-runs/{nodeRunId} until `status` is finished or failed
2. Over MCP, call `get_guide` first, `show_presence` before node changes and `canvas_plan_layout` before `bulk_create_nodes`
3. On 429 wait `Retry-After` seconds. After a timeout or 5xx on a write, read the canvas or run state before resubmitting, because there are no idempotency keys
4. Read credit costs from GET /generation/models?category=image before a bulk run. A 400 can mean the team is out of credits
5. Downloads arrive as a ZIP from a signed URL. Fetch that URL without the `Authorization` header

## Connect

```bash
npm install -g @melius-ai/cli
```

```bash
curl -s -H "Authorization: Bearer $MEL_API_KEY" https://api.melius.com/api/v1/teams
```

```bash
claude mcp add melius --transport http https://mcp.melius.com/mcp --scope user
```
Full config and headless snippets are in the full page. Through letme (picks today, calling later): https://letme.dev/melius

## Similar tools

| Tool | Grade | Score | Shared capabilities | Slim |
| --- | --- | --- | --- | --- |
| Osmo CLI | E | 45.2 | image.edit, video.generate, image.generate, speech.tts, design.comments | https://www.anchorterminal.com/tools/osmo-cli.min.md |
| LocalAI | B | 68 | speech.tts, image.generate, video.generate | https://www.anchorterminal.com/tools/localai.min.md |
| Figma API + MCP | B | 66 | design.files, design.canvas, design.comments | https://www.anchorterminal.com/tools/figma-mcp.min.md |
| fal image models | B | 65.2 | image.generate, image.edit, image.upscale | https://www.anchorterminal.com/tools/fal-image.min.md |
| Miro API + MCP | B | 65 | design.files, design.canvas, design.comments | https://www.anchorterminal.com/tools/miro.min.md |


## Panel reviews (0, desk reviews from public material, no calls made)