Delta Signal
org.daxfoundation.signal/delta-signalsignal.daxfoundation.orgstreamable-httpv0.1.0Scanned
Audio steganography & watermarking. Encode/decode hidden messages that survive YouTube re-encoding.
5 tools: 3 change things and 2 only read.
- Reads private data · 0
- Reads text others write · 2
- Can send data out · 2
- No findings
Anlyon alternative
3 of these tools change something. Run those as governed actions.
Declare what an action changes, and Anlyon puts it under a shared limit, binds every approval to the exact request, and grades the outcome. It works on any HTTPS API you can describe as an action.
Anlyon does not run, proxy or govern this MCP server. A tool your own code calls directly is not routed through Anlyon and is not governed by it.
Import an OpenAPI spec →Tools
Grouped by what each tool does, most consequential first. Open one for its reasons and full description; descriptions are the publisher's own words.
5 tools
Changes things 3Claude Code: ask
decode_audioDecode every Delta Signal layer from a WAV or MP3 file at an https URL: heartbeat cipher, spectral glyph, prime count, watermark (needs the seed used to render), ggwave, modem text…Reads text others writeCan send data outNo findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
What it can reach
- untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
- outboundThe input takes a URL (input.url): a request to a URL can carry data to whoever runs it.
Description, as the server wrote it Decode every Delta Signal layer from a WAV or MP3 file at an https URL: heartbeat cipher, spectral glyph, prime count, watermark (needs the seed used to render), ggwave, modem text and SSTV pictures (returned as PNG).
Annotations the server declares
- title: Decode audio
- readOnlyHint: true
- openWorldHint: true
render_signatureRender a Delta Signal audio signature (WAV, 48 kHz) that hides your message: in the heartbeat rhythm, as text in the spectrogram, as an inaudible watermark, and optionally as an SS…No findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
Description, as the server wrote it Render a Delta Signal audio signature (WAV, 48 kHz) that hides your message: in the heartbeat rhythm, as text in the spectrogram, as an inaudible watermark, and optionally as an SSTV picture, a ggwave data chirp or modem tones. Returns a download link (kept 7 days) and a manifest. Survives YouTube-grade AAC/Opus.
Annotations the server declares
- title: Render signature
- readOnlyHint: false
- openWorldHint: false
verify_signatureVerify a Delta Signal audio signature at an https WAV URL: returns which hidden layers are present (found_layers) and whether the audio matches an expected message (matches: true/f…Reads text others writeCan send data outNo findings
Why it is in this group
- Nothing in its name or description says what it does, so it is counted as a write.
- The server marks it read-only (readOnlyHint: true), but an annotation never lowers a class.
What it can reach
- untrusted-inputThe server marks it openWorldHint: true: it reaches things outside the server's own data.
- outboundThe input takes a URL (input.url): a request to a URL can carry data to whoever runs it.
Description, as the server wrote it Verify a Delta Signal audio signature at an https WAV URL: returns which hidden layers are present (found_layers) and whether the audio matches an expected message (matches: true/false, or null if no expected_message given). Cheaper than full decode — use it when you only need to confirm presence or identity.
Annotations the server declares
- title: Verify signature
- readOnlyHint: true
- openWorldHint: true
Only reads 2Show 2 read-only tools
describe_engineFree.No findings
Why it is in this group
- The name "describe_engine" says "describe": a word for reading.
Description, as the server wrote it Free. Describe Delta Signal: layers, stings, defaults, limits and prices.
Annotations the server declares
- readOnlyHint: true
preview_cardFree.No findings
Why it is in this group
- The name "preview_card" says "preview": a word for reading.
Description, as the server wrote it Free. Render the SSTV signature card image for a message (PNG) so you can see what the picture sting will carry.
Annotations the server declares
- readOnlyHint: true
This is not a safety rating, and no finding is not a safety guarantee. The groups and findings come from fixed checks of the tool definitions the server returned on the date shown, not from its code or what it does when called. How the checks work.
Exfil surface
Which tools read private data, which read text someone else can write, and which can send data out. One of each is a path a prompt injection can use.
No private-data, untrusted-input, outbound path in this server alone: no tool is tagged private-data.
- Reads private data0
- Reads files, mail, messages, databases, secrets, calendars or repositories.
- Reads text others write2
- Brings in text someone else can write: web pages, inbound email, messages, issues and comments.
- Can send data out2
- Can carry data to people or systems: it sends, posts or publishes, or takes a recipient, channel or URL.
Other servers in the same agent add their own tools to these paths. Audit your whole setup to see them together.
Findings
Matches of fixed checks, with the text they matched.
No check matched anything in these tool definitions. That is not a safety guarantee.
History
Changes to its tool definitions and to its remote endpoint, newest first.
No change seen yet. Its tools are rescanned every day, and a remote endpoint is looked at once a week.
Install
Pinned to version 0.1.0. Values in angle brackets are yours to fill in.
claude mcp add --transport http delta-signal https://signal.daxfoundation.org/mcpclaude mcp add --transport http delta-signal https://signal.daxfoundation.org/mcpRun in a terminal.
Claude Code permissions
Allow the reads, ask before a change or a way out, deny the deletes. Paste into .claude/settings.json.
{
"permissions": {
"allow": [
"mcp__delta-signal__describe_engine",
"mcp__delta-signal__preview_card"
],
"ask": [
"mcp__delta-signal__render_signature",
"mcp__delta-signal__decode_audio",
"mcp__delta-signal__verify_signature"
],
"deny": []
}
}Tools that only read are allowed, tools that change things ask first, tools that delete or cancel are denied. A read that can send data out (it takes a URL, say) asks first too. It assumes the server is installed as delta-signal. Review it before you use it.
Capability tags behind 2 rules
- mcp__delta-signal__decode_audio untrusted-input, outbound
- mcp__delta-signal__verify_signature untrusted-input, outbound
Pin
Keep the decision: fail CI when the tools change, follow every change, or show a badge.
Pin in CI
Fail a build when the tools you reviewed are not the tools the server serves today.
curl -s "https://anlyon.dev/api/v1/servers/org.daxfoundation.signal/delta-signal/verify?hash=8781a2cf79589ce0db9bfb9e4d3e5b54823aae734fc00cc9fabbd67f92428709" | jq -e '.changed == false'Pinned hash 8781a2cf7958, from Oct 28, 2026, 21:18 UTC.
Watch
Get told when its tools change: a new tool, a new description, a new class.
https://anlyon.dev/servers/org.daxfoundation.signal/delta-signal/changes.xmlAn Atom feed. Works in any feed reader or Slack's RSS app.
Badge
[](https://anlyon.dev/servers/org.daxfoundation.signal/delta-signal)Source: MCP Registry. Synced Oct 28, 2026, 21:18 UTC.