D2

{
  "service_type": "platform",
  "base_url": "https://d2lang.com",
  "auth_method": "none",
  "auth_config": {},
  "endpoints": [],
  "pricing_model": {
    "type": "free",
    "details": {
      "note": "D2 is an open-source project released under MPL-2.0. The core CLI/compiler is free to use, modify, and distribute. There is no official paid tier; however, 'D2 as a Service' or hosted rendering may exist via third parties, and the project maintainers (Terrastruct) offer related commercial products such as Terrastruct Studio, which is a separate paid offering."
    }
  },
  "rate_limits": {},
  "capabilities": [
    "Open-source diagram scripting language",
    "Text-to-diagram compilation (CLI and library)",
    "Multiple output formats (SVG, PNG, PDF, GIF, etc.)",
    "Layout engines: dagre, ELK, TALA",
    "Themes and styling",
    "Multi-board and layers",
    "Sketch mode (hand-drawn style)",
    "Markdown-like syntax with variables, imports, and types",
    "Diagram code is version-controllable and diffable",
    "Extensible via plugins (e.g., VS Code, Obsidian)",
    "Cross-platform (Linux, macOS, Windows)",
    "Embeddable (e.g., via WASM or Go library)"
  ],
  "raw_analysis": "D2 is an open-source diagram scripting language developed by Terrastruct. It converts textual descriptions into diagrams (flowcharts, sequence diagrams, architecture diagrams, etc.) using a declarative syntax. It is primarily aimed at developers, technical writers, and DevOps engineers who prefer defining diagrams as code over using drag-and-drop GUI tools. D2 is mature enough for production use: it has an active GitHub repository with thousands of stars, regular releases, and a growing ecosystem of integrations (VS Code extension, Obsidian plugin, GitHub Actions). The core tool is a command-line binary and a Go library, so it does not expose a REST API. There is no authentication because it runs locally. Hosted rendering is available indirectly through Terrastruct's paid service, but that is a separate product. Integrations include CI/CD pipelines for automated diagram generation. Overall, D2 is a stable, well-documented, and increasingly popular open-source project with a free-to-use model."
}

2/3 tests passed

```json
{
  "overall": 78,
  "dimensions": {
    "token_efficiency": 9.0,
    "first_try_success": 8.0,
    "response_parseability": 8.5,
    "error_clarity": 8.0,
    "doc_quality": 9.0,
    "auth_simplicity": 10.0,
    "latency": 9.5,
    "consistency": 9.0
  },
  "pricing_normalized": {
    "model": "free_open_source",
    "type": "free",
    "license": "MPL-2.0",
    "core_cli_cost": 0,
    "paid_tier": "none_official",
    "notes": "Free open-source compiler/CLI. Commercial products (Terrastruct Studio) are separate. Possible third-party hosted rendering."
  },
  "issues": [
    "No llms.txt (404) — agents lack a machine-readable entry point for onboarding.",
    "Not a hosted API/service; 'platform' framing is weak. Value is a CLI + library, so agents recommending it must handle local install.",
    "Pipeline integration (D2 -> rendered diagram) requires runtime setup (Go/D2 binary), raising first-try friction vs. a hosted API.",
    "No official hosted rendering endpoint mentioned; third-party rendering reliability/consistency unknown."
  ],
  "recommendations": [
    "Add /llms.txt summarizing syntax, CLI commands, and output options for agent consumption.",
    "Publish a structured JSON schema or OpenAPI-like spec for diagram input/AST to improve parseability.",
    "Document explicit install/onboarding path (brew/curl/go install) prominently so agents can give copy-paste commands.",
    "Provide a status page or uptime indicator for d2lang.com to boost consistency scoring.",
    "Offer a WASM/CDN embed snippet section so agents can recommend browser-side rendering without server setup."
  ]
}
```