io.github.lonniev/excalibur-mcp
REMOTE · EXCALIBUR-MCP.FASTMCP.APP
FastMCP server for posting formatted content to X (Twitter) — Tollbooth-monetized, DPYC-native
Available components
Last scanned (8 hours ago)
Scores higher than 19% of remote servers
Reachable. Last reached 5 Nov 2026.
Category Marketing and SEO
Recent critical change
Authorization (15 Oct 2026). See the changelog before you install this server.
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 Security89
- The endpoint's TLS certificate is valid, in date, and uses a strong key. View diagnostics → Pass
- The endpoint enforces authorisation, advertised via RFC 9728 protected-resource metadata. View diagnostics → Pass
- HTTPS is enforced; there's no plaintext access path. View diagnostics → Pass
- HSTS check failed: the Strict-Transport-Security header is absent. See how to fix → View diagnostics → Fail
- DNSSEC check failed: this domain isn't protected by DNSSEC. See how to fix → View diagnostics → Fail
- The authorisation server offers only Dynamic Client Registration (RFC 7591), which MCP 2026-07-28 deprecated in favour of Client ID Metadata Documents. View diagnostics → Partial
Transport & Reachability0
- Transport blocked by authentication: the endpoint requires auth we don't have to verify streamable-http. See how to fix → View diagnostics → Unverified
Schema Quality & AI Usability0
- Schema blocked by authentication: the endpoint requires auth we don't have to read it. See how to fix → Unverified
Stability & Change Management0
- Stability not yet verified: not enough scan history yet (needs a 30-day window).Unverified
Tool Coverage0
- Tool coverage blocked by authentication: the endpoint requires auth we don't have to read its tools.Unverified
Tool Safety0
- Tool safety blocked by authentication: the endpoint requires auth we don't have to read its tools.Unverified
Capabilities0
- Capabilities blocked by authentication: the endpoint requires auth we don't have to read them. See how to fix → Unverified
Unverified: 6 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. Claim this server and supply a read-only token to verify it and lift the score.
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.
- 18 Oct 26 −40
- Endpoint reachability: reachable → behind authorisation ▼ security
- Stability: pass → unverified ▼ security
- Tool safety: pass → unverified ▼ security
- Transport: pass → unverified ▼ security
- Authorization: fail → pass ▲ security
- First check of Authorization: partial security
- Capabilities: pass → unverified ▼ functional
- Tool coverage: 100 → unverified ▼ functional
- First check of Schema quality: unverified functional
- 15 Oct 26 +3
- Authorization: unverified → fail ▼ critical
- Schema quality: 179 → 237 ▼ functional
- Tool coverage: 52% → 100% ▲ functional
- Schema quality: good → excellent functional
- Destructive annotations: All 12 tool(s) whose name or description implies an irreversible operation declare an MCP destructiveHint annotation. functional
- 13 Oct 26 0
- New tool “excalibur_request_echo” functional
- 10 Oct 26 +1
- Judged manipulation: unverified → pass ▲ security
- 6 Oct 26 −2
- Judged manipulation: pass → unverified ▼ security
- Tool coverage: 58% → 52% ▼ functional
- 30 Sept 26 0
- Tool “excalibur_check_proof_status” rewrote its description, which is the text the model reads security
- Tool “excalibur_receive_npub_proof” rewrote its description, which is the text the model reads security
- Tool “excalibur_request_npub_proof” rewrote its description, which is the text the model reads security
- “excalibur_check_proof_status” reworded the description of “dpop_token” cosmetic
- 29 Sept 26 0
- Tool “excalibur_restore_neon_schema” rewrote its description, which is the text the model reads security
- 28 Sept 26 0
- We updated how we score, so this day's move reflects our rubric, not a change to the server See what changed → functional
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://excalibur-mcp.fastmcp.app/mcp
TLS valid
Negotiated TLS 1.3 with TLS_AES_128_GCM_SHA256 .
| Subject | Issuer | Valid from | Valid until | Key | Signature | Serial |
|---|---|---|---|---|---|---|
| CN=*.fastmcp.app | CN=Amazon RSA 2048 M04,O=Amazon,C=US | 17 Jun 2026 | 31 Dec 2026 | RSA 2048 | SHA256-RSA | a1583bafd89c7b58780ef1a0a0d2ad7 |
| SANs: *.fastmcp.app | ||||||
| CN=Amazon RSA 2048 M04,O=Amazon,C=US (CA) | CN=Amazon Root CA 1,O=Amazon,C=US | 23 Aug 2022 | 23 Aug 2030 | RSA 2048 | SHA256-RSA | 773124f2a952e3ed18a58bdb85d1bc0ce5f27 |
| CN=Amazon Root CA 1,O=Amazon,C=US (CA) | CN=Starfield Services Root Certificate Authority - G2,O=Starfield Technologies\, Inc.,L=Scottsdale,ST=Arizona,C=US | 25 May 2015 | 31 Dec 2037 | RSA 2048 | SHA256-RSA | 67f944a2a27cdf3fac2ae2b01f908eeb9c4c6 |
Background: What to check on a remote MCP endpoint →
DNSSEC insecure
Validation of excalibur-mcp.fastmcp.app. — Not signed
| Zone | DS | Keys | Algorithms | Outcome |
|---|---|---|---|---|
| . | trust_anchor | 20326, 38696 | 8, 8 | Verified |
| app. | present | 23684 | 8 | Verified |
| fastmcp.app. | absent | Unsigned (proven) parent-signed NSEC/NSEC3 proves an unsigned delegation |
Authentication Enforced and verified
The endpoint asked for a token and published valid RFC 9728 metadata describing how to get one.
| Result | Enforced and verified |
|---|---|
| Enforced | On connection |
| HTTP status | 401 |
WWW-Authenticate challenge Bearer resource_metadata="https://excalibur-mcp.fastmcp.app/.well-known/oauth-protected-resource/mcp"
Bearer resource_metadata="https://excalibur-mcp.fastmcp.app/.well-known/oauth-protected-resource/mcp" | Header | Value |
|---|---|
| www-authenticate | Bearer resource_metadata="https://excalibur-mcp.fastmcp.app/.well-known/oauth-protected-resource/mcp" |
Protected resource metadata
| Document | https://excalibur-mcp.fastmcp.app/.well-known/oauth-protected-resource/mcp |
|---|---|
| Retrieved | Yes |
| Resource | https://excalibur-mcp.fastmcp.app/mcp |
| Authorisation server | https://excalibur-mcp.fastmcp.app/ |
Background: How OAuth 2.1 works in the 2026 MCP spec →
Transports 2 probes
| Transport | URL | Outcome | Status | Location |
|---|---|---|---|---|
| streamable-http | https://excalibur-mcp.fastmcp.app/mcp | Auth required | 401 | |
| http (plaintext) | http://excalibur-mcp.fastmcp.app/mcp | HTTPS enforced | 301 | https://excalibur-mcp.fastmcp.app/mcp |
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 →
excalibur_post_nostr_message Post a Nostr note ~399
Publish a public Nostr note (kind 1) authored by your proven npub. eXcalibur cannot sign a note *as* you — a Nostr event must be signed by the key it claims to come from, and eXcalibur never holds your nsec. So for this one note it mints a fresh, ephemeral "scribe" keypair, signs with it, and ``p``-tags YOUR npub as the author. The p-tag renders the note as a real mention and places it in your own Nostr mentions, so you can see — and disown — anything published in your name. The author is always your **proven** npub from this session (the same npub you pass for billing); it is never a free-form argument, so no caller can scribe as anyone else. The note publishes to the DPYC relay set. The call **succeeds if at least one** relay accepts it; the response lists every relay's accept/reject and the accepted/attempted counts so you can see the note's real reach — a one-relay publish never reads as a clean broadcast.
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| message | string | yes | The note text to publish. You (the proven npub) are recorded as its author. |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_post_performance Post performance ~209
Patron: derived reach scores across your harvested post corpus. Computes escape velocity (t+15m vs rolling median), breakout ratio (final reach ÷ rolling-median final reach; suppressed below 5 posts), link-placement cohort medians, and snippet/voice attribution from the durable snapshot store — signals that come from owning the curve, not proxying a single X endpoint.
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_post_performance_infographic Post performance infographic ~178
Patron: SVG infographic of post performance (gold-steel theme). Mirrors ``account_statement_infographic`` — a dark-themed SVG of corpus size, median t+15m impressions, top posts, and link-placement cohorts.
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_post_tweet Post a tweet ~218
Post a text tweet with markdown formatting converted to Unicode rich text. Accepts standard markdown inline formatting and converts it to Unicode Mathematical Alphanumeric Symbols that render as styled text on X: **bold** -> bold *italic* -> italic ***bold italic*** -> bold italic `monospace` -> monospace
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
| text | string | yes | Tweet content with optional markdown formatting. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_post_tweet_image Post a tweet with an image ~226
Post a tweet with a hero banner image to X/Twitter. Provide either an image_url (fetched and attached) or banner_svg (rendered to PNG and attached). Text supports the same markdown formatting as post_tweet.
| Name | Type | Req | Description |
|---|---|---|---|
| banner_svg | string | – | Self-contained SVG markup string, converted to PNG. |
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| image_url | string | – | URL of an image to attach to the tweet. |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
| text | string | yes | Tweet content with optional markdown formatting. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_process_scheduled_posts Publish due posts ~290
Launch a publisher for every due post (operator-only). Selects ``scheduled`` posts whose ``publish_at`` has arrived, claims each atomically, and starts one background publisher per post. It does NOT publish: composing content, billing the owner, posting to X and recording the outcome all belong to the publisher, which runs on the async job queue and so may take the minutes a dynamic block needs. This call returns as soon as the work is dispatched — expect it to be fast even when the publishing itself is slow, and read per-post outcomes from ``get_scheduler_log`` or the post rows. Requires the operator's npub proof; the trigger itself is free. Returns ``{kind: "tick", processed, launched, contended}``.
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_publish_nostr_profile Publish Nostr profile ~151
Publish a CLIENT-SIGNED kind-0 profile to relays for an npub. The wheel never holds a patron nsec. The frontend signs the kind-0 metadata event with the patron's session key or a NIP-07 extension and passes the signed event (JSON) here; the wheel verifies the signature matches the npub, then relays it to public relays. The signature is the authorization — no proof token, no key custody. Free.
| Name | Type | Req | Description |
|---|---|---|---|
| npub | string | – | The patron's Nostr public key the event must be signed by. |
| signed_event | string | – | A JSON-encoded, client-signed kind-0 event. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_purchase_credits Buy credits ~158
Buy credits via Bitcoin Lightning. Creates a Lightning invoice. Pay it with any Lightning wallet, then call check_payment to confirm. Proof of npub ownership is required so credits land in the correct ledger. Free — no credits required to call.
| Name | Type | Req | Description |
|---|---|---|---|
| amount_sats | integer | – | Satoshis to purchase (default 1000). |
| dpop_token | string | yes | Proof that the caller holds npub: the grant envelope from receive_npub_proof, or the raw JSON of a kind-27235 Nostr event signed by npub whose `u` tag is this tool's name. |
| npub | string | yes | The Nostr public key (npub1...) the credits will fund. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_receive_credentials Receive credentials ~355
Pick up credentials from the Secure Courier. Completes the CREDENTIAL-DELIVERY flow (the ownership-proof counterpart is ``receive_npub_proof``). **Call this only after the user confirms they have replied.** Deterministic, one-shot retrieval: name the response you want with ``(sender_npub, service, dpop_token)`` and the tool drains ONLY the rendezvous relay that channel was pinned to. Every popped DM with the wrong session phrase is deleted and its sender is NACK'd; the first DM with the matching phrase is accepted (ACK'd) and the scan stops. If none match, the queue is drained and a ``courier_not_found`` result is returned. Do NOT poll, loop, or retry. If a credential_card (ncred1...) is provided, it is redeemed directly without any relay access (dpop_token not required for that path). On success, the payment processor client is reinitialized from the new credentials — no server restart needed.
| Name | Type | Req | Description |
|---|---|---|---|
| credential_card | string | – | Optional. An ncred1... card to redeem directly (bypasses the relay drain; dpop_token not needed). |
| dpop_token | string | – | Proof that the caller holds npub: the grant envelope from receive_npub_proof, or the raw JSON of a kind-27235 Nostr event signed by npub whose `u` tag is this tool's name. |
| sender_npub | string | – | Required. The npub that sent the credentials. |
| service | string | – | Required. The credential service name (must match the service used in request_credential_channel). |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_receive_npub_proof Receive npub proof ~364
Receive npub ownership confirmation from a patron. Completes the npub-OWNERSHIP-PROOF flow (the credential-delivery counterpart is ``receive_credentials``). **Call this only after the user confirms they have replied.** Deterministic, one-shot retrieval: name the response with ``(patron_npub, dpop_token)`` — the ``dpop_token`` being the value returned by ``request_npub_proof``. The tool drains ONLY the pinned rendezvous relay that challenge was published on, stopping at the DM whose phrase matches. Mismatched DMs are deleted and NACK'd (without revealing the expected phrase). If called before the user replies, their message will never be found. Do NOT poll, loop, or retry. The signed DM itself proves npub ownership (the patron's nsec signed it). On success, returns a new ``dpop_token``: an Operator-signed **proof grant envelope** ``{"grant": …, "nonce": …}`` bound to the patron, this challenge, and the duration the patron named. The calling application MUST remember that whole string and pass it as ``dpop_token`` on every subsequent paid tool call. The grant is self-verifying; nothing about it is stored here. Free.
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | – | Proof that the caller holds npub: the grant envelope from receive_npub_proof, or the raw JSON of a kind-27235 Nostr event signed by npub whose `u` tag is this tool's name. |
| patron_npub | string | – | Required. The patron's npub to receive proof from. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_redeem_coupon Redeem coupon ~200
Claim a coupon by its name (the code the operator shared). Looks up the operator's coupon by ``code``, validates the window and total cap, and records a per-patron redemption row. Subsequent paid tool calls on this MCP auto-apply the discount until ``uses_per_patron`` is exhausted. Free — no credits required. Requires proof of ``npub``. Idempotent: redeeming the same code twice returns the existing redemption.
| Name | Type | Req | Description |
|---|---|---|---|
| code | string | yes | The coupon code the operator shared. |
| dpop_token | string | – | Proof that the caller holds npub: the grant envelope from receive_npub_proof, or the raw JSON of a kind-27235 Nostr event signed by npub whose `u` tag is this tool's name. |
| npub | string | yes | The patron's Nostr public key (npub1...). |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_refine_post_region Refine a post region ~338
Refine a flagged region of a post with an LLM — server-side. The operator's LLM key stays in the vault and never leaves the server. Send the flagged ``region``, the surrounding ``full_text``, an optional ``instruction`` (what to change), and the editor's ``voice`` profile + ``bans`` (JSON array or comma list of banned constructions). Returns ``{"success": true, "suggestions": [...3 strings...]}``. Paid: the AI cost is metered as a tollbooth fare. The fare is refunded if no LLM key is configured or the upstream call returns nothing.
| Name | Type | Req | Description |
|---|---|---|---|
| bans | string | – | Banned constructions — JSON array or comma-separated (optional). |
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| full_text | string | – | The whole tweet, for context. |
| instruction | string | – | What the editor wants changed (optional). |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
| region | string | yes | The flagged span to rewrite. |
| voice | string | – | Voice-profile text fed to the model (optional). |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_reply_to_conversation Reply to a conversation ~290
Post your reply into one of your leads' threads on X (``conversation_id`` is the row id from ``list_conversations``). ``text`` is up to 280 characters; markdown inline formatting is converted the same way ``post_tweet`` does it. Posted with your own X token as a reply to the lead's post; on X's confirmation the lead is marked ``engaged`` and remembers the reply. A refused post changes nothing and refunds the fare. Returns ``{reply:{tweet_id,url}, conversation}``.
| Name | Type | Req | Description |
|---|---|---|---|
| conversation_id | string | yes | The lead's row UUID (``id`` from ``list_conversations``). |
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
| text | string | yes | Your reply, 1..280 characters, with optional markdown inline formatting. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_report_issue Report an issue ~307
File a field report about this service as a GitHub issue on the operator's repo. Found a tool's metadata or response wrong or confusing? Report it where the tool lives. The **author of record is your npub** — no npub / no proof, no issue — and it is stamped into the issue so the report is attributed to you, not the operator. Costs a small fee (a free write to an issue tracker would be abused). The report is PUBLIC and goes to the maintainers' normal triage; nothing is verified here. Returns the filed issue's repo, number, and url. If this operator has not enabled field reports, returns an "issue reporting not configured" situation and you are not charged.
| Name | Type | Req | Description |
|---|---|---|---|
| body | string | yes | The details — which tool, what was wrong, what you expected. |
| dpop_token | string | yes | Proof that the caller holds npub: the grant envelope from receive_npub_proof, or the raw JSON of a kind-27235 Nostr event signed by npub whose `u` tag is this tool's name. |
| npub | string | yes | Your Nostr public key (npub1...); the report's author of record. |
| title | string | yes | One-line summary of the problem. |
| tool_name | string | – | Optional: the specific tool the report is about (e.g. "schwab_get_option_chain"). |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_request_adoption Request adoption ~227
Ask a chosen Authority to adopt this operator (deferred courtship). RESTRICTED to the operator — requires proof the caller controls this operator's npub. Resolves the Authority's MCP endpoint from the community registry, mints an inline ownership proof with this operator's nsec, and delivers the request MCP-to-MCP. The Authority records it as pending; its owner approves on their own time. Poll ``adoption_status`` for progress; the operator flips to ``ready`` once the Authority provisions it.
| Name | Type | Req | Description |
|---|---|---|---|
| authority_npub | string | yes | npub of the Authority to request adoption from. |
| dpop_token | string | – | Proof that the caller holds npub: the grant envelope from receive_npub_proof, or the raw JSON of a kind-27235 Nostr event signed by npub whose `u` tag is this tool's name. |
| note | string | – | optional message for the Authority owner. |
| service_url | string | – | this operator's MCP endpoint (advertised to the Authority). |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_request_credential_channel Open credential channel ~252
Open a Secure Courier channel for credential delivery. This is the CREDENTIAL-DELIVERY flow — use it to hand over a service secret (API keys, tokens). To merely prove you control an npub (the usual answer to a ``proof_required`` error), use ``request_npub_proof`` instead. Note: dynamic/OAuth2 services (e.g. Schwab) need NO couriered secret — check ``service_status`` first. Sends a welcome DM with a credential template. The recipient must read the DM in their Nostr client, fill in the fields, and reply manually. **This is a human-in-the-loop flow.** After calling this tool, STOP and tell the user what to do. Wait for the user to confirm they have replied before calling ``receive_credentials``. Do NOT poll or retry — each ``receive_credentials`` call destructively drains the relay mailbox.
| Name | Type | Req | Description |
|---|---|---|---|
| sender_npub | string | – | Required. The npub to send the template to. |
| service | string | – | Required. The credential service name (e.g., from get_operator_onboarding_status or get_patron_onboarding_status). |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_request_echo Request echo ~94
Echo what the client sent with this request. Free. Reports the URL path and query, the headers, the cookies and the MCP request ``_meta``. Values are SHA-256 fingerprints, so nothing a client sends is repeated back; equal fingerprints mean equal values. Call it from two conversations and compare: a value that stays the same within one and changes between them identifies the conversation.
Input schema present but exposes no named parameters.
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_request_npub_proof Request npub proof ~503
Request npub ownership proof from a patron via Nostr DM. This is the npub-OWNERSHIP-PROOF flow — use it when a call returns ``proof_required``. It proves the caller controls an npub; it does NOT deliver any service secret. To hand an operator its API keys or OAuth secrets, use ``request_credential_channel`` instead. Sends a challenge DM that the patron must sign and reply to using their Nostr client. **This is a human-in-the-loop flow.** After calling this tool, STOP and tell the user to check their Nostr client and reply to the challenge. Wait for the user to confirm they have replied before calling ``receive_npub_proof``. Do NOT poll or retry — each ``receive_npub_proof`` call destructively drains the relay mailbox. **Returns** a ``dpop_token`` — the one-time challenge nonce shown in the DM. Pass it to ``receive_npub_proof`` to collect the reply. It is a matching token, not a credential: on its own it authorizes nothing. **Lifecycle:** ``receive_npub_proof`` returns the proof grant, which expires after the duration the patron named in their reply. When it expires, call ``request_npub_proof`` again for a fresh challenge, then wait for the user, then call ``receive_npub_proof``. Free.
| Name | Type | Req | Description |
|---|---|---|---|
| patron_npub | string | – | Required. The patron's npub to request proof from. |
| reason | string | – | Optional. A human-readable purpose for the request ("I'm working on your request XYZ and need the Operator to do ABC for you"). Signed into the provenance attestation and shown in the DM, so the reci… |
| verify_at | string | – | Optional. A free-form statement of WHERE you (the initiating agent) already showed this proof's one-time code to the user — a URL, or "your Claude.ai conversation", "the Grok session". The OAuth 2.0… |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_reset_pricing_model Reset pricing model ~133
Erase all pricing models and restore a viable default. Deletes every stored model, then self-initializes a fresh one from the tool registry — all tools at 0 sats with proper UUIDs. Returns the new model. RESTRICTED to operator — requires proof (nsec-signed).
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | – | Proof that the caller holds the operator's npub: the grant envelope from receive_npub_proof, or the raw JSON of a kind-27235 Nostr event signed by the operator whose `u` tag is this tool's name. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_resolve_dynamic_block Resolve a dynamic block ~539
Start resolving a dynamic post block with an LLM — returns a CLAIM CHECK. A dynamic block's ``prompt`` is run by the model (with web search + web fetch for live data) and woven into the surrounding post ``context`` in the author's ``voice``. The author's instruction governs length — there is no character cap (X supports long-form posts). The operator's LLM key stays in the vault and never leaves the server. Because that work (paginated fetches + generation) can outlast a client timeout, this returns immediately with a **claim check** instead of the text: ``{"success": true, "claim_check": "...", "status": "pending", "poll_after_seconds": N}``. Redeem it with the free companion ``fetch_dynamic_block(claim_check)`` until ``status == "done"`` (then read ``result.text``). (The scheduler resolves blocks directly server-side at fire time and does not use this tool.) Paid: the AI cost is metered as a tollbooth fare on THIS start call, refunded if no LLM key is configured or the job ultimately fails.
| Name | Type | Req | Description |
|---|---|---|---|
| allowed_domains | string | – | Author allowlist for web_fetch — JSON array or comma-separated. Blank = fetch any URL the prompt references. |
| bans | string | – | Banned constructions — JSON array or comma-separated (optional). |
| context | string | – | The surrounding composed post (may contain the ⟨HERE⟩ marker). |
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| max_fetches | integer | – | Author budget for web lookups (search + fetch), 1..25. |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
| prompt | string | yes | The dynamic block's prompt to run. |
| runtime_limit_seconds | integer | – | Author's time budget for this block in seconds (60–1800). Bounds how long the job may run AND sets the poll cadence; the operator may price it ad valorem. |
| voice | string | – | Voice-profile text fed to the model (optional). |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_restore_credits Restore credits ~257
Credit a patron's ledger from a BTCPay-settled invoice. **RESTRICTED to the operator** — the operator owns the books and is the only party who can issue a manual credit grant. Patrons who believe they paid but never got credits must escalate to the operator's support, who then invokes this tool on their behalf. Use cases: cold-start vault races during check_payment, ncred delivery hiccups, patrons closing Top-Off sheets before settle, any infrastructure incident that left an invoice settled at BTCPay but uncredited on the operator's ledger. Idempotent — if the invoice is already credited (in the patron's ``credited_invoices``), returns success with credits_granted=0.
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | yes | Proof that the caller holds npub: the grant envelope from receive_npub_proof, or the raw JSON of a kind-27235 Nostr event signed by npub whose `u` tag is this tool's name. |
| invoice_id | string | yes | The BTCPay invoice ID to verify and credit. |
| patron_npub | string | yes | The patron's npub whose ledger receives the grant. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_restore_neon_schema Restore database schema ~167
Prepare this operator's database schema again, ignoring the breadcrumb. Diagnostic / recovery tool for when Neon keeps answering 4xx and the operator suspects a table or grant is missing. Every statement is idempotent, so a clean re-run is harmless; the breadcrumb is rewritten at the end. Returns one step per concern, with Neon's own error text inline for any that failed. RESTRICTED to operator — requires proof (nsec-signed).
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | – | Proof that the caller holds the operator's npub: the grant envelope from receive_npub_proof, or the raw JSON of a kind-27235 Nostr event signed by the operator whose `u` tag is this tool's name. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_save_conversation_query Save a conversation query ~426
Save a named X search clause to run with ``find_conversations``. Omit ``query_id`` to create; pass it to update in place — only the fields you pass change, and a changed ``query`` resets the last-run watermark. ``weights`` holds only the scoring values you override. At most 50 saved queries per npub; names are unique per npub. Free and owner-scoped. Returns ``{"success": true, "query": …}``.
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| name | string | – | The query's name, up to 120 characters and unique among your queries. Required on create; blank on update keeps it. |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
| query | string | – | The X search clause, up to 438 characters, with no ``?`` operator. Required on create; blank on update keeps it. |
| query_id | string | – | UUID of the query to update; blank creates a new one. |
| safe_defaults | – | – | ``true`` appends X's safe-default filters when the query runs; null keeps the current value (and means ``true`` on create). |
| weights | – | – | Scoring overrides to store, an object whose keys are any of ``need``, ``replies``, ``band``, ``spam``, ``reply``, ``replies_min``, ``followers_min``, ``followers_max``, ``decay_hours`` with integer v… |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_save_snippet Save a snippet ~393
Save a reusable post snippet (opening/footer/CTA). Omit ``snippet_id`` to create a new one; pass it to update an existing snippet in place (name/text/ favorite/doc). On update only the fields you pass change — omit ``favorite`` (leave it null) to keep it as-is, so a doc-only patch (e.g. toggling a snippet dynamic) doesn't reset it. ``doc`` is the same block/flag document a post carries, so the editor is identical for both. Free and owner-scoped. Returns ``{"success": true, "snippet": …}``.
| Name | Type | Req | Description |
|---|---|---|---|
| doc | – | – | The block/flag document (same shape as a post's ``doc``), or null. |
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| favorite | – | – | ``true`` pins it as a one-click chiclet; null keeps the current value on update (and means ``false`` on create). |
| name | string | – | The snippet's label, up to 120 characters. Required on create; blank on update keeps the current name. |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
| snippet_id | string | – | UUID of the snippet to update; blank creates a new one. |
| text | string | – | The snippet body, up to 8000 characters. Required on create; blank on update keeps the current body. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_save_voice Save your Voice ~296
Save your writing Voice (replaces the previous one — it is a per-npub singleton). ``profile`` is free text. ``bans`` is a list of ``{text, on}`` objects: ``text`` is the construction to avoid, ``on`` whether it is an active constraint. Blank/duplicate entries are dropped server-side. Owner-scoped; priced by the operator's pricing model (use ``check_price``). Returns ``{"success": true, "voice": {...}}``.
| Name | Type | Req | Description |
|---|---|---|---|
| bans | – | – | Up to 200 ``{"text": str, "on": bool}`` objects, each ``text`` up to 200 characters; null saves an empty list. |
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
| profile | string | – | Free-text description of your writing voice, up to 4000 characters. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_scheduler_check_now Run the scheduler now ~335
Ask the scheduler to run one tick now (free; any proven patron). Pokes the Worker's ``/tick`` — the same work the ~30-minute cron does: it claims a pending proof reply (completing the operator's authorization) and fires any due posts. Use it right after the operator approves in Studio so nobody waits for the next tick. Deliberately NOT operator-only. Approving is the operator's act; noticing that they approved is anyone's, and a patron watching a parked scheduler is often the one who notices first. The poke carries no authority — it cannot approve anything, only ask the Worker to look. The challenge phrase stays operator-gated (``scheduler_pending``). The Worker runs the tick in the background and returns immediately; re-read ``scheduler_status`` a few seconds later to see the phase flip. Returns ``{started: true}`` or ``{started: false}`` if the Worker couldn't be reached.
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_scheduler_pending Scheduler pending request ~308
What is the scheduled-post cron Worker waiting on? (operator-only). When the Worker's authorization lapses it DMs the operator a challenge phrase and parks. This returns that pending phrase so the operator can match it against the DM before approving in Studio — the Device-Grant second surface for a headless actor. The phrase lives only in the Worker's KV (an impostor can't inject it); we read it AS the operator (a kind-27235 signed with the operator key), so the human never signs anything in the browser. ``restricted``: gated to the operator npub, free. Never returns the active session token. Returns ``{phase, code, reason, requestedAt}`` — ``phase`` is ``pending`` / ``active`` / ``idle``, or ``unavailable`` if the Worker can't be reached.
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_scheduler_reissue Reissue the scheduler request ~286
Send the scheduler's proof request again, now (operator-only). For a pending request that is not going to complete — the reply went to an older DM, or ``scheduler_pending`` shows a last check that says the request was replaced or expired. The Worker drops it and DMs a fresh one straight away instead of waiting out its hour. Approve the NEWEST DM in Studio, then ``scheduler_check_now``. Signed as the operator with a sentinel ``u``-tag the Worker checks literally, like ``scheduler_pending``, so the browser signs nothing. An already-authorized scheduler is left alone. ``restricted``: gated to the operator npub, free. Returns ``{success, phase, requestedAt, message}``.
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_scheduler_status Scheduler status ~251
The scheduler's configuration and current status (free; any proven patron). Relays the cron Worker's public ``/status`` — cadence, version, renewal window, and current authorization phase (``pending`` / ``active`` / ``idle``, no challenge phrase) — and adds the operator npub it acts for. No secrets: the pending phrase (operator-only) is ``scheduler_pending``; the per-tick traffic log is ``get_scheduler_log``. Returns the merged config, or ``{worker: "unavailable"}`` merged in if the Worker can't be reached.
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_service_status Service status ~22
Check the health and configuration of this service. Free.
Input schema present but exposes no named parameters.
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_session_status Session status ~312
Check operator readiness. Returns the operator lifecycle state and clear guidance on what to do next. Free. Lifecycle states: - ready: Vault AND pricing model verified on this call. Proceed with tool calls — this is the answer the moment the vault is up. - warming_up: Persistence could not be reached on this call (a transient failure, seen, not assumed). Retry; the next call completes the bootstrap. Never reported on a clock. - misconfigured: Persistence rejected a query with a permanent SQL error (permission denied, missing relation). Paid tools will fail until the operator repairs the database — retrying does not help. - quota_exceeded: The persistence provider (Neon) answered HTTP 402 — the operator's database has exhausted its compute/storage quota, so the books are locked for billing. Paid tools fail; retrying does NOT help. The operator's Authority must restore capacity (upgrade the plan or wait for the quota reset). Free tools remain available. - not_registered: Operator has no Authority relationship yet. Call register_operator first. - no_identity: Operator nsec is not configured. Deployment issue.
| Name | Type | Req | Description |
|---|---|---|---|
| patron_npub | string | – | Optional. If supplied, the response includes an ``upstream_oauth`` block with the patron's stored OAuth token expiry (runtime-derived from vault state) so a client can refresh proactively rather than… |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_set_conversation_status Set a conversation's status ~239
Mark one of your leads ``new|seen|engaged|dismissed`` by its row id (the ``id`` from ``list_conversations``, not X's conversation id). A re-run of the search never changes a status you set. Free and owner-scoped.
| Name | Type | Req | Description |
|---|---|---|---|
| conversation_id | string | yes | The lead's row UUID (``id`` from ``list_conversations``). |
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
| status | string | yes | One of ``new``, ``seen``, ``engaged``, ``dismissed``. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_set_pricing_model Set pricing model ~136
Set the active pricing model. RESTRICTED to operator. Requires a valid proof (Schnorr-signed kind-27235 event) proving the caller holds the operator's nsec.
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | – | Proof that the caller holds the operator's npub: the grant envelope from receive_npub_proof, or the raw JSON of a kind-27235 Nostr event signed by the operator whose `u` tag is this tool's name. |
| model_json | string | yes | The complete pricing model as a JSON object; it replaces the active model. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_update_coupon Update coupon ~373
Patch a coupon's editable fields. Pass only the fields you want to change. To set a cap to unlimited (NULL in the schema), pass ``clear_uses_per_patron=true`` or ``clear_total_uses=true``. Renaming the code is allowed — existing patron redemption rows survive (they key on coupon id). ``tool_ids`` replaces the coupon's binding — tool ids or MCP tool names, ``["*"]`` for every paid tool, ``[]`` to unbind it. RESTRICTED to operator — requires proof.
| Name | Type | Req | Description |
|---|---|---|---|
| clear_total_uses | boolean | – | True makes total redemptions unlimited. |
| clear_uses_per_patron | boolean | – | True makes discounted calls per patron unlimited. |
| coupon_id | string | yes | The id of the coupon to change (from list_coupons). |
| discount_percent | – | – | A new percentage off the base price (0-100). |
| dpop_token | string | – | Proof that the caller holds the operator's npub: the grant envelope from receive_npub_proof, or the raw JSON of a kind-27235 Nostr event signed by the operator whose `u` tag is this tool's name. |
| name | – | – | A new code for patrons to type. |
| tool_ids | – | – | The tools the coupon discounts: tool ids or MCP tool names, ["*"] for every paid tool, [] to unbind it. |
| total_uses | – | – | A new number of redemptions across all patrons. |
| uses_per_patron | – | – | A new number of discounted calls per patron. |
| valid_from | – | – | A new ISO-8601 datetime when the coupon becomes active. |
| valid_until | – | – | A new ISO-8601 datetime when the coupon expires. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_update_operator_credential Update operator credential ~223
Add or update a single operator secret field. Merges into the operator's stored credentials without touching the others — the field-level counterpart to re-delivering the whole bundle over Secure Courier. Use it to rotate one secret (a reissued ``btcpay_api_key``, say) without restating the six you did not change, where any field omitted from a courier reply is destroyed. The value is never echoed back. RESTRICTED to the operator — requires the operator's proof (a kind-27235 event or a proof grant); patron proofs are rejected.
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | yes | Proof that the caller holds npub: the grant envelope from receive_npub_proof, or the raw JSON of a kind-27235 Nostr event signed by npub whose `u` tag is this tool's name. |
| field | string | yes | The operator credential field to set. Must be declared in the operator's credential template. |
| value | string | yes | The value to store. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_update_patron_credential Update patron credential ~177
Add or update a single patron credential field. Merges into existing stored credentials without affecting other fields. Useful for setting an account identifier after OAuth, changing a default brain, etc. Free. Proof of npub ownership is required — this is a write to the patron's sensitive credential vault.
| Name | Type | Req | Description |
|---|---|---|---|
| dpop_token | string | yes | Proof that the caller holds npub: the grant envelope from receive_npub_proof, or the raw JSON of a kind-27235 Nostr event signed by npub whose `u` tag is this tool's name. |
| field | string | yes | The credential field name to set. |
| npub | string | yes | The patron's Nostr public key (npub1...). |
| value | string | yes | The value to store. |
Structured output declared, but exposes no named fields.
No examples provided.
excalibur_update_post Update a post ~356
Patch a stored post. ``patch`` may set ``doc, publish_at, recurrence, cease_at, status`` (omit a field to leave it unchanged). ``text_cache`` is written when supplied (alongside a doc change). ``client_req_id`` dedupes debounced autosave retries — a repeat is a no-op with no second charge.
| Name | Type | Req | Description |
|---|---|---|---|
| client_req_id | string | – | Idempotency key for this edit; resending the last applied id changes nothing and charges nothing. |
| dpop_token | string | – | Proof that the caller holds npub. Either the grant envelope that receive_npub_proof returned, or the raw JSON of a kind-27235 Nostr event signed by npub: content "", a `u` tag holding this tool's exa… |
| npub | string | – | The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it. |
| patch | object | yes | Object of the fields to change, any of ``doc``, ``publish_at``, ``recurrence``, ``cease_at``, ``status`` (``draft``, ``scheduled``, ``archived``, ``sent``), ``tweet_url``, ``title``. Each value has t… |
| post_id | string | yes | The post's UUID. |
| text_cache | string | – | Composed text (blocks joined) to store with a ``doc`` change; blank leaves the stored text as it is. |
Structured output declared, but exposes no named fields.
No examples provided.
How do I install the io.github.lonniev/excalibur-mcp server?
io.github.lonniev/excalibur-mcp is a hosted endpoint at https://excalibur-mcp.fastmcp.app/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 · excalibur-mcp.fastmcp.app
claude mcp add --transport http lonniev-excalibur-mcp 'https://excalibur-mcp.fastmcp.app/mcp'
What is the io.github.lonniev/excalibur-mcp server?
io.github.lonniev/excalibur-mcp is listed in the public MCP registry as io.github.lonniev/excalibur-mcp. FastMCP server for posting formatted content to X (Twitter), Tollbooth-monetized, DPYC-native. This page covers its hosted endpoint (https://excalibur-mcp.fastmcp.app/mcp).
Is the io.github.lonniev/excalibur-mcp server safe to use?
io.github.lonniev/excalibur-mcp scores 36 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 io.github.lonniev/excalibur-mcp server expose?
io.github.lonniev/excalibur-mcp exposes 87 tools: excalibur_check_balance, excalibur_purchase_credits, excalibur_check_payment, excalibur_restore_credits, excalibur_account_statement, and 82 more. Their descriptions and schemas cost roughly 19,998 tokens of context every time the server is loaded.
Does the io.github.lonniev/excalibur-mcp server require authentication?
Yes. io.github.lonniev/excalibur-mcp asked us for credentials when we connected, so you will need to authorise it in your MCP client before it can do anything.
Is the io.github.lonniev/excalibur-mcp server still maintained?
io.github.lonniev/excalibur-mcp 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.