Signal Messaging (via signal-cli)
OCI · GHCR.IO/JOSHUAWOWK/SIGNAL-MCP
Send Signal messages and read replies through your own signal-cli JSON-RPC daemon (unofficial).
Available components
Last scanned (11 hours ago)
Scores higher than 74% of OCI servers
Category Communication
How this component scores in each security and reliability category. Every signal is checked automatically from public evidence about the published package, including repeated runs of it in an isolated sandbox, and we only credit what we can confirm. How we score → Why this is hard to score →
Supply Chain Security0
- No malware scan is available for this kind of package: the supply-chain vendors we use do not cover it. This is a permanent gap in our coverage, not a finding about the package.Unverified
- Known CVEs could not be checked: this artifact ships no SBOM or dependency manifest, so there is no dependency list to read.Unverified
- Install-script risk not yet assessed.Unverified
- Dependency health could not be checked: this artifact ships no SBOM or dependency manifest, so there is no dependency list to read.Unverified
Provenance & Transparency48
- Source repository is publicly reachable at the declared URL. View diagnostics → Pass
- Provenance check failed: no build-provenance attestation is published. See how to fix → View diagnostics → Fail
- Clear OSI-approved license (MIT).Pass
- Actively maintained (last published 15 days ago).Pass
- Publishes a security disclosure policy (SECURITY.md).Pass
Schema Quality & AI Usability76
- AI-judged instruction clarity (excellent).Pass
- Context-footprint check failed: tool/resource definitions use about 726 tokens (~145/item across 5 items; 5 tools + 0 resources), over budget; trim descriptions and params. See how to fix → Fail
- Usage-examples check failed: none of the tools include examples. See how to fix → Fail
Stability & Change Management53
- Stability observed for 16 of 30 days with no destabilising changes; credit accrues until the full window elapses.Partial
Tool Coverage100
- 100% of tools have a non-trivial description (not blank, and not just the tool's name).Pass
- 100% of tool parameters carry a description.Pass
- Structured output schemas are declared (100% of tools); any adoption earns full credit.Pass
Tool Safety100
- No prompt-injection markers were found in the server instructions, tool names or descriptions we captured.Pass
- All 3 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation.Pass
- An AI judge read all 6 captured unit(s) of tool text and found none that tries to manipulate the model reading it.Pass
Capabilities100
- Implements a current MCP spec version (2026-07-28).Pass
Unverified: 1 category
A category scored 0 because we could not verify it: a data source with nothing on this package, evidence we could not reach, or a check we could not run. We only credit what we can confirm.
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 +1
No change was recorded against any check on this day. Stability & Change Management went from 50 to 53. That category is still filling its 30-day observation window: 15 days of observed history at the previous scan, 16 at this one. The score rises as the window fills, whether or not the server changes.
- 3 Nov 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 43 to 47. That category is still filling its 30-day observation window: 13 days of observed history at the previous scan, 14 at this one. The score rises as the window fills, whether or not the server changes.
- 1 Nov 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 37 to 40. That category is still filling its 30-day observation window: 11 days of observed history at the previous scan, 12 at this one. The score rises as the window fills, whether or not the server changes.
- 30 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 30 to 33. That category is still filling its 30-day observation window: 9 days of observed history at the previous scan, 10 at this one. The score rises as the window fills, whether or not the server changes.
- 27 Oct 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.
- 25 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 13 to 17. That category is still filling its 30-day observation window: 4 days of observed history at the previous scan, 5 at this one. The score rises as the window fills, whether or not the server changes.
- 23 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 7 to 10. That category is still filling its 30-day observation window: 2 days of observed history at the previous scan, 3 at this one. The score rises as the window fills, whether or not the server changes.
- 21 Oct 26 +1
No change was recorded against any check on this day. Stability & Change Management went from 0 to 3. That category is still filling its 30-day observation window: 0 days of observed history at the previous scan, 1 at this one. The score rises as the window fills, whether or not the server changes.
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 · Analysed oci/ghcr.io/joshuawowk/signal-mcp@1.0.1
Provenance No attestation
The registry publishes no build provenance for this version, so there is nothing to verify.
| Result | No attestation |
|---|---|
| Ecosystem | oci |
| Reason | No attestation published |
Background: How many MCP packages publish verified provenance →
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 →
signal_check_replies Signal Check Replies ~138
Return recent Signal messages received by the bot account. Reads the inbox.jsonl populated by the subscriber sidecar. Filter by `since` (ISO timestamp), `from_recipient` (E.164), and/or `session_id` (matches messages whose body contains `[session_id]`). Results are newest-first.
| Name | Type | Req | Description |
|---|---|---|---|
| from_recipient | – | – | Only return messages from this E.164 number. |
| limit | integer | – | Max messages to return (default 20). |
| session_id | – | – | Only return messages whose body contains `[session_id]`. |
| since | – | – | Only return messages received at-or-after this ISO ts. |
Structured output declared, but exposes no named fields.
No examples provided.
signal_health Signal Health ~31
Full health check for the signal-mcp server. Call this first if any other tool is misbehaving.
Input schema present but exposes no named parameters.
Structured output declared, but exposes no named fields.
No examples provided.
signal_send_message Signal Send Message ~127
Send a plain Signal DM to the user (or `recipient` if overridden). Use for task-completion pings and FYI updates that don't require a reply. Keep `text` under ~500 chars; include the task name and a one-line result. If the caller has a session_id, pass it so the user can correlate the message back to this conversation.
| Name | Type | Req | Description |
|---|---|---|---|
| recipient | – | – | Optional E.164 number to override the default. |
| session_id | – | – | Optional short tag prefixed to the message. |
| text | string | yes | The message body. Plain text. |
Structured output declared, but exposes no named fields.
No examples provided.
signal_send_permission_request Signal Send Permission Request ~155
Ask the user to approve an action before the agent proceeds. Renders as: `PERMISSION [session_id]\n<action>\n\nContext:\n<context>\n\nReply YES / NO / details.`. Use for irreversible or high-impact operations: deletions, prod changes, spending money, sending external email, anything the user would normally want to confirm.
| Name | Type | Req | Description |
|---|---|---|---|
| action | string | yes | One-line description of what the agent wants to do. |
| context | string | yes | Why, scope, and blast radius. Include enough detail that the user can decide without asking follow-ups. |
| recipient | – | – | Optional E.164 override. |
| session_id | – | – | Optional short tag for correlating the reply. |
Structured output declared, but exposes no named fields.
No examples provided.
signal_send_question Signal Send Question ~215
Send a blocking question to the user. Renders as: `QUESTION [session_id]\n<question>\n\n1) opt1\n2) opt2`. The user replies with the number or free text; poll `signal_check_replies` afterwards to read the answer. Use when the agent genuinely cannot proceed without input.
| Name | Type | Req | Description |
|---|---|---|---|
| options | – | – | Optional choices, rendered as a numbered list. Accepts a real list (["A", "B"]) OR a string the client may have serialized: a JSON array '["A","B"]', or newline- or comma-separated text ("A\nB" / "A,… |
| question | string | yes | The question text. Be specific; include enough context that the user doesn't need to open Claude to answer. |
| recipient | – | – | Optional E.164 override. |
| session_id | – | – | Optional short tag for correlating the reply. |
Structured output declared, but exposes no named fields.
No examples provided.
How do I install the Signal Messaging (via signal-cli) MCP server?
Signal Messaging (via signal-cli) runs locally as a container image, launched with docker run --rm -i -e SIGNAL_SENDER -e SIGNAL_DEFAULT_RECIPIENT -e SIGNAL_RPC_URL -e SIGNAL_TCP_HOST -e SIGNAL_TCP_PORT -e SIGNAL_INBOX_PATH -e SIGNAL_POLL_INTERVAL -e SIGNAL_INBOX_RETENTION_DAYS ghcr.io/joshuawowk/signal-mcp:1.0.1. Ready-made configuration for Claude, Cursor, VS Code, Codex and 3 more is on this page, copied from each client's own documentation.
oci · ghcr.io/joshuawowk/signal-mcp
claude mcp add joshuawowk-signal-mcp -- docker run --rm -i -e SIGNAL_SENDER -e SIGNAL_DEFAULT_RECIPIENT -e SIGNAL_RPC_URL -e SIGNAL_TCP_HOST -e SIGNAL_TCP_PORT -e SIGNAL_INBOX_PATH -e SIGNAL_POLL_INTERVAL -e SIGNAL_INBOX_RETENTION_DAYS ghcr.io/joshuawowk/signal-mcp:1.0.1
This image reads SIGNAL_SENDER, SIGNAL_DEFAULT_RECIPIENT, SIGNAL_RPC_URL, SIGNAL_TCP_HOST, SIGNAL_TCP_PORT, SIGNAL_INBOX_PATH, SIGNAL_POLL_INTERVAL and SIGNAL_INBOX_RETENTION_DAYS. Set them in your client's env block for this server; docker run -e passes each one through to the container.
What is the Signal Messaging (via signal-cli) MCP server?
Signal Messaging (via signal-cli) is an MCP server listed in the public MCP registry as io.github.joshuawowk/signal-mcp. Send Signal messages and read replies through your own signal-cli JSON-RPC daemon (unofficial). This page covers its container image (ghcr.io/joshuawowk/signal-mcp).
Is the Signal Messaging (via signal-cli) MCP server safe to use?
Signal Messaging (via signal-cli) scores 49 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 Signal Messaging (via signal-cli) MCP server expose?
Signal Messaging (via signal-cli) exposes 5 tools: signal_send_message, signal_send_question, signal_send_permission_request, signal_check_replies, signal_health. Their descriptions and schemas cost roughly 666 tokens of context every time the server is loaded.
Is the Signal Messaging (via signal-cli) MCP server still maintained?
Signal Messaging (via signal-cli) 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 licence is the Signal Messaging (via signal-cli) MCP server under?
Signal Messaging (via signal-cli) declares the MIT licence, which is OSI-approved. That covers the source only, and says nothing about the cost of any service it calls.