useSignal

Measured conclusion: Deep-tested. L2 outcome: tools_ok.

QR codes, JSON diff/format, hashes, JWT, cron, timestamps, placeholders, flowcharts, forms, regex.

Add to your agent

Copy this into your MCP client config:

{
  "mcpServers": {
    "useSignal": {
      "url": "https://www.usesignal.dev/mcp",
      "transport": "streamable-http"
    }
  }
}

Measured tools (12)

• usesignal_generate_form read-only

  Generate an editable form from a JSON object. Returns nested field paths, JSON Schema, HTML, React JSX and config exports. Arrays and nulls use JSON textareas. Values are processed in memory; avoid secrets. To show an interactive preview, call usesignal_open_workbench with this result input.

  Parameters:

  • json (required) — string
  • title — string
  • overrides — array

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• usesignal_generate_colors read-only

  Generate light and dark semantic color tokens from a six-digit hex brand color. Returns a shade scale, measured text contrast checks and CSS, JSON and Tailwind exports. This measures listed color pairs only, not whole-page accessibility. Call usesignal_open_workbench with the result input to preview.

  Parameters:

  • baseColor (required) — string

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• usesignal_test_regex read-only

  Execute a JavaScript regular expression against text and expected match/non-match test cases. Returns indexed matches and capture groups. Flags use JavaScript semantics. Execution times out after 500ms. Call usesignal_open_workbench with result input to highlight matches.

  Parameters:

  • pattern (required) — string
  • text (required) — string
  • flags — string
  • tests — array

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• usesignal_generate_qr read-only

  Generate a scannable QR code for a link, text, Wi-Fi network, contact card (vCard), email, SMS, phone number, WhatsApp chat or UPI payment. Returns the encoded payload, an SVG file and a PNG preview image. values by type: url{url}; text{text}; wifi{ssid,password,security:WPA|WEP|nopass,hidden}; vcard{firstName,lastName,phone,email,org,title,website,address}; email{to,subject,body}; sms{phone,message}; phone{phone}; whatsapp{phone,message}; upi{vpa,name,amount,note}.

  Parameters:

  • type (required) — string
  • values (required) — object
  • dark — string
  • light
  • margin — integer
  • moduleStyle — string
  • errorCorrection — string

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• usesignal_encode_decode read-only

  Exact text transforms: Base64 encode/decode (UTF-8), URL encode/decode, decode a JWT header and payload with readable exp/iat/nbf dates (the signature is not verified), or hash text with MD5, SHA-1, SHA-256 and SHA-512. Use this instead of computing hashes or Base64 by hand.

  Parameters:

  • operation (required) — string
  • text (required) — string

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• usesignal_explain_cron read-only

  Explain a standard 5-field cron expression (minute hour day-of-month month day-of-week) in plain English and list its next run times in a given time zone, handling daylight saving time.

  Parameters:

  • expression (required) — string
  • count — integer
  • timeZone — string — IANA time zone, e.g. Asia/Kolkata or America/New_York

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• usesignal_convert_timestamp read-only

  Convert a Unix timestamp (seconds or milliseconds) or an ISO 8601 date into ISO, UTC, epoch seconds/milliseconds, a relative time and the local time in a given time zone.

  Parameters:

  • value (required) — string
  • timeZone — string — IANA time zone, e.g. Asia/Kolkata or America/New_York

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• usesignal_diff_json read-only

  Compare two JSON documents structurally and list every added, removed and changed value with its JSONPath. Numbers compare exactly. Arrays match by content by default, so an inserted item shows as one addition; use arrays:"position" to compare index by index.

  Parameters:

  • left (required) — string
  • right (required) — string
  • arrays — string

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• usesignal_format_json read-only

  Validate, pretty-print or minify JSON, optionally sorting keys. Invalid JSON reports the exact line and column; with repair (default on) it fixes common problems such as trailing commas, single quotes, comments and unquoted keys, and lists each fix.

  Parameters:

  • json (required) — string
  • mode — string
  • indent — string
  • repair — boolean
  • sortKeys — boolean

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• usesignal_placeholder_image read-only

  Create a placeholder image URL (served by usesignal.dev) plus HTML, Markdown and CSS snippets, for mockups, prototypes, seed data and layouts. Width and height up to 4000 px.

  Parameters:

  • width (required) — integer
  • height (required) — integer
  • text — string
  • color
  • style — string
  • radius — integer
  • pattern — string
  • background — string

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• usesignal_flowchart read-only

  Turn JavaScript/TypeScript code, arrow steps or Mermaid-style arrows into a flowchart, returned as Mermaid source and an SVG diagram. Steps mode uses one flow per line: "Start -> Validate -> Save" and branches like "Validate -- No --> Show error".

  Parameters:

  • mode (required) — string
  • input (required) — string
  • direction — string

  Hints: read-only yes · destructive no · idempotent yes · open-world no

• usesignal_open_workbench read-only

  Show the editable useSignal UI. First call a useSignal data tool, then pass its returned input and matching tool name. Recomputes from validated inputs; no shared state.

  Parameters:

  • tool (required) — string
  • input (required) — object

  Hints: read-only yes · destructive no · idempotent yes · open-world no

Publisher website Repository

Measured by MCPYP probing. Untested fields are omitted, never estimated. Listing is always free; MCPYP never proxies calls or stores user tokens.