Delta Signal
REMOTE · SIGNAL.DAXFOUNDATION.ORG
Audio steganography & watermarking. Encode/decode hidden messages that survive YouTube re-encoding.
Available components
Last scanned (11 hours ago)
Scores higher than 7% of remote servers
Reachable. Last reached 5 Nov 2026.
Category Design and Media
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. How we score → Why this is hard to score →
Endpoint Security49
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- Authorisation not yet verified: we couldn't confirm whether this endpoint requires it. View diagnostics → Unverified
- HTTPS enforcement could not be verified: the plaintext port answered with HTTP 503, which proves neither a plaintext path nor enforcement. View diagnostics → Unverified
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC is configured correctly; the domain's records validate against the full chain to the root. View diagnostics → Pass
Transport & Reachability0
- Transport check failed: declared streamable-http, but the endpoint returned HTTP 503. See how to fix → View diagnostics → Fail
Schema Quality & AI Usability0
- Schema not yet verified: we couldn't read the endpoint's schema, or could read only part of its tool list.Unverified
Stability & Change Management0
- Stability not yet verified: not enough scan history yet (needs a 30-day window).Unverified
Tool Coverage0
- Tool coverage not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.Unverified
Tool Safety0
- Tool safety not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.Unverified
Capabilities0
- Capabilities not yet verified: we couldn't read the endpoint's capabilities.Unverified
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.
Checks we ran (4)
- TLS certificate
- HSTS header
- DNSSEC
- Transport
Checks we could not complete (7)
These are gaps on our side, not findings about this hosted endpoint. We only credit what we can confirm, so a category made up entirely of them scores 0.
- Authorization in Endpoint SecurityAuthorisation not yet verified: we couldn't confirm whether this endpoint requires it.
- HTTPS in Endpoint SecurityHTTPS enforcement could not be verified: the plaintext port answered with HTTP 503, which proves neither a plaintext path nor enforcement.
- Schema quality in Schema Quality & AI Usability (scores 0 for this)Schema not yet verified: we couldn't read the endpoint's schema, or could read only part of its tool list.
- Stability in Stability & Change Management (scores 0 for this)Stability not yet verified: not enough scan history yet (needs a 30-day window).
- Tool coverage in Tool Coverage (scores 0 for this)Tool coverage not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.
- Tool safety in Tool Safety (scores 0 for this)Tool safety not yet verified: we couldn't read the endpoint's tools, or could read only part of the list.
- Capabilities in Capabilities (scores 0 for this)Capabilities not yet verified: we couldn't read the endpoint's capabilities.
Does not apply to this hosted endpoint (2)
- Supply Chain SecurityScored on package channels only. This is a hosted endpoint, so there is nothing to install or inspect.
- Provenance & TransparencyScored on package channels only. This is a hosted endpoint, so there is nothing to install or inspect.
The score does not measure everything. What the score does not measure →
Every change we have recorded for this component, newest first. Security-relevant changes are always shown. ▲ marks a change for the better, ▼ a change for the worse; unmarked changes are neutral.
- 5 Nov 26 −45
- Endpoint reachability: reachable → not serving MCP ▼ security
- Stability: 0.23 → unverified ▼ security
- Tool safety: pass → unverified ▼ security
- Transport: pass → fail ▼ security
- Authorization: Authorisation not yet verified: we couldn't confirm whether this endpoint requires it. security
- Schema quality: 100 → unverified ▼ functional
- Capabilities: pass → unverified ▼ functional
- Tool coverage: 100 → unverified ▼ functional
- 4 Nov 26 +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.
- 3 Nov 26 +6
- Judged manipulation: unverified → pass ▲ security
- Schema quality: unverified → good ▲ functional
- 2 Nov 26 −4
- Judged manipulation: pass → unverified ▼ security
- Tool “describe_engine” rewrote its description, which is the text the model reads security
- Schema quality: 472 → 542 ▼ functional
- Schema quality: good → unverified ▼ functional
- The server now declares the “resources” capability functional
- First check of Schema quality: 100 functional
- New resource “presets” functional
- “render_signature” added an optional parameter “preset” cosmetic
- 1 Nov 26 +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.
- 30 Oct 26 +1
- Tool “decode_audio” rewrote its description, which is the text the model reads security
- “decode_audio” reworded the description of “url” cosmetic
- 29 Oct 26 0
- Stability: unverified → 0.03 ▲ functional
- 28 Oct 26 60
First indexed and scored.
Diagnostic detail from the automated scan of this channel: what the scanner observed at each step, so you can see exactly where a check passed or failed. It is informational only and never changes the trust score.
Captured 5 Nov 2026 · Probed https://signal.daxfoundation.org/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=daxfoundation.org | CN=WE1,O=Google Trust Services,C=US | 27 Oct 2026 | 25 Jan 2027 | ECDSA 256 | ECDSA-SHA256 | 8b79b5127ce53876133e568b54facbdb |
| SANs: daxfoundation.org, signal.daxfoundation.org, *.signal.daxfoundation.org | ||||||
| CN=WE1,O=Google Trust Services,C=US (CA) | CN=GTS Root R4,O=Google Trust Services LLC,C=US | 13 Dec 2023 | 20 Feb 2029 | ECDSA 256 | ECDSA-SHA384 | 7ff31977972c224a76155d13b6d685e3 |
| CN=GTS Root R4,O=Google Trust Services LLC,C=US (CA) | CN=GlobalSign Root CA,OU=Root CA,O=GlobalSign nv-sa,C=BE | 15 Nov 2023 | 28 Jan 2028 | ECDSA 384 | SHA256-RSA | 7fe530bf331343bedd821610493d8a1b |
Background: What to check on a remote MCP endpoint →
DNSSEC secure
Validation of signal.daxfoundation.org. — Secure
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | Trust anchor | 20326, 38696 | 8, 8 | Verified |
| org. | DS published | 725, 26974 | 8, 8 | Verified |
| daxfoundation.org. | DS published | 2371 | 13 | Verified |
| signal.daxfoundation.org. | Verified address RRset verified with the apex keys |
Authentication Inconclusive
We could not reach the endpoint well enough to judge its authorisation posture.
| Result | Inconclusive |
|---|---|
| HTTP status | 503 |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://signal.daxfoundation.org/mcp | HTTP error | 503 | |
| http (plaintext) | http://signal.daxfoundation.org/mcp | Inconclusive | 503 |
The tools this component advertises to a client, with an estimated token cost for each. Expand a tool to see its parameters and schema. The per-tool counts are indicative and are not scored directly; the schema's total context footprint is one signal in Schema Quality & AI Usability. A tool's description is untrusted text the model reads on every call, which is what makes this list a security surface and not just an inventory: how tool poisoning works →
decode_audio ~107
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).
| Name | Type | Req | Description |
|---|---|---|---|
| layers | array | – | – |
| seed | string | – | – |
| url | string | yes | https URL of a WAV, MP3 or M4A (AAC) file (convert other formats first) |
No output schema declared.
No examples provided.
describe_engine ~27
Free. Describe Delta Signal: layers, stings, defaults, limits, presets and prices.
Input schema present but exposes no named parameters.
No output schema declared.
No examples provided.
preview_card ~46
Free. Render the SSTV signature card image for a message (PNG) so you can see what the picture sting will carry.
| Name | Type | Req | Description |
|---|---|---|---|
| text | string | yes | Up to 38 characters |
No output schema declared.
No examples provided.
render_signature ~197
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.
| Name | Type | Req | Description |
|---|---|---|---|
| duration | number | – | Seconds of signature body (default 60) |
| layers | object | – | Per-layer options: bed, heartbeat, primes, glyph {band: mid|hi}, watermark {payload} |
| message | string | yes | 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 | – | – |
No output schema declared.
No examples provided.
verify_signature ~120
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.
| Name | Type | Req | Description |
|---|---|---|---|
| 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 | yes | https URL of a WAV file |
No output schema declared.
No examples provided.
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.
remote · signal.daxfoundation.org
claude mcp add --transport http org-daxfoundation-signal-delta-signal 'https://signal.daxfoundation.org/mcp'
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.