# Delta Signal (remote · signal.daxfoundation.org)

Audio steganography & watermarking. Encode/decode hidden messages that survive YouTube re-encoding.

- Trust score: 20/100 (low)
- Change this week: −40
- Registry status: active
- Liveness: live
- Owner verified: no
- Last scored: 2026-11-05

## Components

- remote · `signal.daxfoundation.org`: 20/100 (this document), [markdown](https://verifymcp.io/servers/org-daxfoundation-signal-delta-signal/signal.md), [page](https://verifymcp.io/servers/org-daxfoundation-signal-delta-signal/signal)

## Channel facts

- Endpoint: `https://signal.daxfoundation.org/mcp`
- Transports: `streamable-http`
- Auth: `none`
- Version: `0.1.0`

## Trust breakdown

How this component scores in each security and reliability category. Every signal is checked automatically against the live server, and we only credit what we can confirm. Scores are 0–100 per category. Scoring method: https://verifymcp.io/docs/scoring (what has changed: https://verifymcp.io/docs/scoring/changelog)

Scored 2026-11-05.

- **Endpoint Security**: 49/100
  - The endpoint's TLS certificate is valid, in date, and uses a strong key.
  - Authorisation not yet verified: we couldn't confirm whether this endpoint requires it.
  - HTTPS enforcement could not be verified: the plaintext port answered with HTTP 503, which proves neither a plaintext path nor enforcement.
  - HSTS check failed: the Strict-Transport-Security header is absent.
  - DNSSEC is configured correctly; the domain's records validate against the full chain to the root.
- **Transport & Reachability**: 0/100
  - Transport check failed: declared streamable-http, but the endpoint returned HTTP 503.
- **Schema Quality & AI Usability**: 0/100
  - Schema not yet verified: we couldn't read the endpoint's schema, or could read only part of its tool list.
- **Stability & Change Management**: 0/100
  - Stability not yet verified: not enough scan history yet (needs a 30-day window).
- **Tool Coverage**: 0/100
  - Tool coverage not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.
- **Tool Safety**: 0/100
  - Tool safety not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.
- **Capabilities**: 0/100
  - Capabilities not yet verified: we couldn't read the endpoint's capabilities.

**Unverified: 5 categories.** Categories scored 0 because we could not verify them: authentication we do not have, an unreachable endpoint, or not enough scan history. We only credit what we can confirm.

## Install

### How do I install the Delta Signal MCP server?

Delta Signal is a hosted endpoint at https://signal.daxfoundation.org/mcp, so there is nothing to install locally. Ready-made configuration for Claude, Cursor, VS Code, Codex and 5 more is on this page, copied from each client's own documentation.

### Claude

```bash
claude mcp add --transport http org-daxfoundation-signal-delta-signal 'https://signal.daxfoundation.org/mcp'
```

### Cursor

```json
{
  "mcpServers": {
    "org-daxfoundation-signal-delta-signal": {
      "url": "https://signal.daxfoundation.org/mcp"
    }
  }
}
```

### VS Code

```json
{
  "servers": {
    "org-daxfoundation-signal-delta-signal": {
      "type": "http",
      "url": "https://signal.daxfoundation.org/mcp"
    }
  }
}
```

### Codex

```toml
[mcp_servers.org-daxfoundation-signal-delta-signal]
url = "https://signal.daxfoundation.org/mcp"
```

### opencode

```json
{
  "$schema": "https://opencode.ai/config.json",
  "mcp": {
    "org-daxfoundation-signal-delta-signal": {
      "type": "remote",
      "url": "https://signal.daxfoundation.org/mcp",
      "enabled": true
    }
  }
}
```

### OpenClaw

```bash
openclaw mcp add org-daxfoundation-signal-delta-signal --url 'https://signal.daxfoundation.org/mcp' --transport streamable-http
```

### Hermes

```yaml
mcp_servers:
  org-daxfoundation-signal-delta-signal:
    url: "https://signal.daxfoundation.org/mcp"
```

### Netclaw

```json
{
  "McpServers": {
    "org-daxfoundation-signal-delta-signal": {
      "Transport": "http",
      "Url": "https://signal.daxfoundation.org/mcp"
    }
  }
}
```

### Vellum

```bash
assistant mcp add org-daxfoundation-signal-delta-signal -t streamable-http -u 'https://signal.daxfoundation.org/mcp'
```

### Other

```json
{
  "mcpServers": {
    "org-daxfoundation-signal-delta-signal": {
      "type": "http",
      "url": "https://signal.daxfoundation.org/mcp"
    }
  }
}
```

The mcpServers block is a cross-client convention. Remote transports vary, so check your client's docs.

## Changelog

Every change recorded for this component, newest first. Days that predate change tracking, or that we cannot explain, say so: "we were watching and nothing happened" and "we were not watching" are different claims.

### 2026-11-05 (score 20, −45)

- [security regression] Endpoint reachability: reachable → not serving MCP
- [security regression] Stability: 0.23 → unverified
- [security regression] Tool safety: pass → unverified
- [security regression] Transport: pass → fail
- [security] Authorization: Authorisation not yet verified: we couldn't confirm whether this endpoint requires it.
- [functional regression] Schema quality: 100 → unverified
- [functional regression] Capabilities: pass → unverified
- [functional regression] Tool coverage: 100 → unverified

### 2026-11-04 (score 65, +1)

No change was recorded against any check on this day. Stability & Change Management went from 20 to 23. That category is still filling its 30-day observation window: 6 days of observed history at the previous scan, 7 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-11-03 (score 64, +6)

- [security improvement] Judged manipulation: unverified → pass
- [functional improvement] Schema quality: unverified → good

### 2026-11-02 (score 58, −4)

- [security regression] Judged manipulation: pass → unverified
- [security] Tool “describe_engine” rewrote its description, which is the text the model reads
- [functional regression] Schema quality: 472 → 542
- [functional regression] Schema quality: good → unverified
- [functional] The server now declares the “resources” capability
- [functional] First check of Schema quality: 100
- [functional] New resource “presets”
- [cosmetic] “render_signature” added an optional parameter “preset”

### 2026-11-01 (score 62, +1)

No change was recorded against any check on this day. Stability & Change Management went from 10 to 13. That category is still filling its 30-day observation window: 3 days of observed history at the previous scan, 4 at this one. The score rises as the window fills, whether or not the server changes.

### 2026-10-30 (score 61, +1)

- [security] Tool “decode_audio” rewrote its description, which is the text the model reads
- [cosmetic] “decode_audio” reworded the description of “url”

### 2026-10-29 (score 60, 0)

- [functional improvement] Stability: unverified → 0.03

### 2026-10-28 (score 60)

First indexed and scored.

## MCP tools (5)

### `describe_engine` (~27 tokens)

Free. Describe Delta Signal: layers, stings, defaults, limits, presets and prices.

### `preview_card` (~46 tokens)

Free. Render the SSTV signature card image for a message (PNG) so you can see what the picture sting will carry.

Input parameters:

- `text` (string, required): Up to 38 characters

### `render_signature` (~197 tokens)

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.

Input parameters:

- `duration` (number): Seconds of signature body (default 60)
- `layers` (object): Per-layer options: bed, heartbeat, primes, glyph {band: mid|hi}, watermark {payload}
- `message` (string, required): Printable ASCII, up to 32 characters
- `preset` (string): Named preset: expands to a layer + sting bundle. Explicit options override the preset.
- `seed` (string): Watermark key; keep it to verify later
- `stings` (array)

### `decode_audio` (~107 tokens)

Decode every Delta Signal layer from a WAV, MP3 or M4A (AAC) 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).

Input parameters:

- `layers` (array)
- `seed` (string)
- `url` (string, required): https URL of a WAV, MP3 or M4A (AAC) file (convert other formats first)

### `verify_signature` (~120 tokens)

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.

Input parameters:

- `expected_message` (string): Message you expect to find; omit to discover what is present
- `seed` (string): Watermark key used when the signature was rendered
- `url` (string, required): https URL of a WAV file

## Diagnostics

Captured diagnostic sections: TLS, DNSSEC, Authorisation, Transports. The full working is on the page: https://verifymcp.io/servers/org-daxfoundation-signal-delta-signal/signal#diagnostics

## Score history

- 2026-11-05: 20
- 2026-11-04: 65
- 2026-11-03: 64
- 2026-11-02: 58
- 2026-11-01: 62
- 2026-10-31: 61
- 2026-10-30: 61
- 2026-10-29: 60
- 2026-10-28: 60

## Common questions

### What is the Delta Signal MCP server?

Delta Signal is an MCP server listed in the public MCP registry as org.daxfoundation.signal/delta-signal. Audio steganography & watermarking. Encode/decode hidden messages that survive YouTube re-encoding. This page covers its hosted endpoint (https://signal.daxfoundation.org/mcp).

### Is the Delta Signal MCP server safe to use?

Delta Signal scores 20 out of 100 on VerifyMCP. That is a record of what we were able to check automatically, not an endorsement. The category breakdown on this page shows every signal behind the number, including the ones we could not confirm.

### What tools does the Delta Signal MCP server expose?

Delta Signal exposes 5 tools: describe_engine, preview_card, render_signature, decode_audio, verify_signature. Their descriptions and schemas cost roughly 497 tokens of context every time the server is loaded.

### Does the Delta Signal MCP server require authentication?

Its publisher declares no required credentials for Delta Signal. We have not been able to confirm that against the live endpoint, and a server can require authorisation without declaring it here.

### Is the Delta Signal MCP server still maintained?

Delta Signal is still listed as active in the MCP registry. We last reached this channel on 5 November 2026. Those dates come from our own scans of the registry and the channel itself, not from anything the publisher announced.

### What did VerifyMCP test on the Delta Signal MCP server?

VerifyMCP ran 4 checks on Delta Signal, covering TLS certificate, HSTS header, DNSSEC and Transport. 7 items could not be completed, a gap on our side rather than a finding about Delta Signal: Authorization, HTTPS, Schema quality, Stability and 3 more. 5 categories score 0 for that reason, because we only credit what we can confirm. Supply Chain Security and Provenance & Transparency do not apply to a hosted endpoint, so they were not tested. The score does not measure everything, and the scoring documentation lists what it leaves out.

## Links

- Remote endpoint: https://signal.daxfoundation.org/mcp
- Website: https://signal.daxfoundation.org/
- Changelog RSS feed: https://verifymcp.io/servers/org-daxfoundation-signal-delta-signal/signal.xml
- Changelog JSON feed: https://verifymcp.io/servers/org-daxfoundation-signal-delta-signal/signal/changelog.json
- Trust report (JSON): https://verifymcp.io/servers/org-daxfoundation-signal-delta-signal/signal.json
- HTML version of this page: https://verifymcp.io/servers/org-daxfoundation-signal-delta-signal/signal