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io.github.lonniev/excalibur-mcp

REMOTE · EXCALIBUR-MCP.FASTMCP.APP

FastMCP server for posting formatted content to X (Twitter) — Tollbooth-monetized, DPYC-native

0 this week 36 Trust /100

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.

Trust breakdown (7 categories)

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
Transport & Reachability0
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.

Changelog

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
Diagnostics

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
MCP tools · 87 exposed · ~19,998 tokens

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 →

Tool Tokens
excalibur_post_nostr_message ~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.

NameTypeReqDescription
dpop_tokenstring–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…
messagestringyesThe note text to publish. You (the proven npub) are recorded as its author.
npubstring–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 ~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.

NameTypeReqDescription
dpop_tokenstring–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…
npubstring–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 ~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.

NameTypeReqDescription
dpop_tokenstring–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…
npubstring–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 ~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

NameTypeReqDescription
dpop_tokenstring–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…
npubstring–The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it.
textstringyesTweet content with optional markdown formatting.

Structured output declared, but exposes no named fields.

No examples provided.

excalibur_post_tweet_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.

NameTypeReqDescription
banner_svgstring–Self-contained SVG markup string, converted to PNG.
dpop_tokenstring–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_urlstring–URL of an image to attach to the tweet.
npubstring–The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it.
textstringyesTweet content with optional markdown formatting.

Structured output declared, but exposes no named fields.

No examples provided.

excalibur_process_scheduled_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}``.

NameTypeReqDescription
dpop_tokenstring–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…
npubstring–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 ~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.

NameTypeReqDescription
npubstring–The patron's Nostr public key the event must be signed by.
signed_eventstring–A JSON-encoded, client-signed kind-0 event.

Structured output declared, but exposes no named fields.

No examples provided.

excalibur_purchase_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.

NameTypeReqDescription
amount_satsinteger–Satoshis to purchase (default 1000).
dpop_tokenstringyesProof 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.
npubstringyesThe Nostr public key (npub1...) the credits will fund.

Structured output declared, but exposes no named fields.

No examples provided.

excalibur_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.

NameTypeReqDescription
credential_cardstring–Optional. An ncred1... card to redeem directly (bypasses the relay drain; dpop_token not needed).
dpop_tokenstring–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_npubstring–Required. The npub that sent the credentials.
servicestring–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 ~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.

NameTypeReqDescription
dpop_tokenstring–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_npubstring–Required. The patron's npub to receive proof from.

Structured output declared, but exposes no named fields.

No examples provided.

excalibur_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.

NameTypeReqDescription
codestringyesThe coupon code the operator shared.
dpop_tokenstring–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.
npubstringyesThe patron's Nostr public key (npub1...).

Structured output declared, but exposes no named fields.

No examples provided.

excalibur_refine_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.

NameTypeReqDescription
bansstring–Banned constructions — JSON array or comma-separated (optional).
dpop_tokenstring–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_textstring–The whole tweet, for context.
instructionstring–What the editor wants changed (optional).
npubstring–The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it.
regionstringyesThe flagged span to rewrite.
voicestring–Voice-profile text fed to the model (optional).

Structured output declared, but exposes no named fields.

No examples provided.

excalibur_reply_to_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}``.

NameTypeReqDescription
conversation_idstringyesThe lead's row UUID (``id`` from ``list_conversations``).
dpop_tokenstring–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…
npubstring–The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it.
textstringyesYour reply, 1..280 characters, with optional markdown inline formatting.

Structured output declared, but exposes no named fields.

No examples provided.

excalibur_report_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.

NameTypeReqDescription
bodystringyesThe details — which tool, what was wrong, what you expected.
dpop_tokenstringyesProof 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.
npubstringyesYour Nostr public key (npub1...); the report's author of record.
titlestringyesOne-line summary of the problem.
tool_namestring–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 ~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.

NameTypeReqDescription
authority_npubstringyesnpub of the Authority to request adoption from.
dpop_tokenstring–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.
notestring–optional message for the Authority owner.
service_urlstring–this operator's MCP endpoint (advertised to the Authority).

Structured output declared, but exposes no named fields.

No examples provided.

excalibur_request_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.

NameTypeReqDescription
sender_npubstring–Required. The npub to send the template to.
servicestring–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 ~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 ~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.

NameTypeReqDescription
patron_npubstring–Required. The patron's npub to request proof from.
reasonstring–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_atstring–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 ~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).

NameTypeReqDescription
dpop_tokenstring–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 ~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.

NameTypeReqDescription
allowed_domainsstring–Author allowlist for web_fetch — JSON array or comma-separated. Blank = fetch any URL the prompt references.
bansstring–Banned constructions — JSON array or comma-separated (optional).
contextstring–The surrounding composed post (may contain the ⟨HERE⟩ marker).
dpop_tokenstring–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_fetchesinteger–Author budget for web lookups (search + fetch), 1..25.
npubstring–The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it.
promptstringyesThe dynamic block's prompt to run.
runtime_limit_secondsinteger–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.
voicestring–Voice-profile text fed to the model (optional).

Structured output declared, but exposes no named fields.

No examples provided.

excalibur_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.

NameTypeReqDescription
dpop_tokenstringyesProof 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_idstringyesThe BTCPay invoice ID to verify and credit.
patron_npubstringyesThe patron's npub whose ledger receives the grant.

Structured output declared, but exposes no named fields.

No examples provided.

excalibur_restore_neon_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).

NameTypeReqDescription
dpop_tokenstring–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 ~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": …}``.

NameTypeReqDescription
dpop_tokenstring–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…
namestring–The query's name, up to 120 characters and unique among your queries. Required on create; blank on update keeps it.
npubstring–The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it.
querystring–The X search clause, up to 438 characters, with no ``?`` operator. Required on create; blank on update keeps it.
query_idstring–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 ~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": …}``.

NameTypeReqDescription
doc––The block/flag document (same shape as a post's ``doc``), or null.
dpop_tokenstring–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).
namestring–The snippet's label, up to 120 characters. Required on create; blank on update keeps the current name.
npubstring–The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it.
snippet_idstring–UUID of the snippet to update; blank creates a new one.
textstring–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 ~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": {...}}``.

NameTypeReqDescription
bans––Up to 200 ``{"text": str, "on": bool}`` objects, each ``text`` up to 200 characters; null saves an empty list.
dpop_tokenstring–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…
npubstring–The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it.
profilestring–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 ~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.

NameTypeReqDescription
dpop_tokenstring–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…
npubstring–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 ~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.

NameTypeReqDescription
dpop_tokenstring–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…
npubstring–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 ~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}``.

NameTypeReqDescription
dpop_tokenstring–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…
npubstring–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 ~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.

NameTypeReqDescription
dpop_tokenstring–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…
npubstring–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 ~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 ~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.

NameTypeReqDescription
patron_npubstring–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 ~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.

NameTypeReqDescription
conversation_idstringyesThe lead's row UUID (``id`` from ``list_conversations``).
dpop_tokenstring–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…
npubstring–The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it.
statusstringyesOne of ``new``, ``seen``, ``engaged``, ``dismissed``.

Structured output declared, but exposes no named fields.

No examples provided.

excalibur_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.

NameTypeReqDescription
dpop_tokenstring–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_jsonstringyesThe 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 ~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.

NameTypeReqDescription
clear_total_usesboolean–True makes total redemptions unlimited.
clear_uses_per_patronboolean–True makes discounted calls per patron unlimited.
coupon_idstringyesThe id of the coupon to change (from list_coupons).
discount_percent––A new percentage off the base price (0-100).
dpop_tokenstring–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 ~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.

NameTypeReqDescription
dpop_tokenstringyesProof 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.
fieldstringyesThe operator credential field to set. Must be declared in the operator's credential template.
valuestringyesThe value to store.

Structured output declared, but exposes no named fields.

No examples provided.

excalibur_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.

NameTypeReqDescription
dpop_tokenstringyesProof 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.
fieldstringyesThe credential field name to set.
npubstringyesThe patron's Nostr public key (npub1...).
valuestringyesThe value to store.

Structured output declared, but exposes no named fields.

No examples provided.

excalibur_update_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.

NameTypeReqDescription
client_req_idstring–Idempotency key for this edit; resending the last applied id changes nothing and charges nothing.
dpop_tokenstring–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…
npubstring–The patron's Nostr public key (npub1...). Tool fees are paid from this patron's balance; dpop_token proves the caller holds it.
patchobjectyesObject 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_idstringyesThe post's UUID.
text_cachestring–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.

Install

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

# add to Claude Code
claude mcp add --transport http lonniev-excalibur-mcp 'https://excalibur-mcp.fastmcp.app/mcp'
Common questions

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.