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Excalibur MCP Server

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Excalibur MCP is answering right now. Last checked 15 min ago. It exposes 79 tools. Last commit 16 Sep 2026.

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

Uptime history 48 days of history · worst day 99%
48 days agonow
100.0%
Uptime 24h
91 of 91 checks
79
Tools
read from the server
672 ms
Response time
average over 24h
3
Stars
last commit 16 Sep 2026

What changed 76

Every tool that appeared, vanished or quietly changed what it asks for. Recorded since 8 August 2026. No other catalogue keeps this.

15 Sep a tool appeared excalibur_scheduler_reissue
24 Aug a tool description was rewritten excalibur_scheduler_check_now
24 Aug a tool changed the parameters it asks for excalibur_scheduler_check_now
21 Aug a tool description was rewritten excalibur_list_posts
21 Aug a tool changed the parameters it asks for excalibur_list_posts
17 Aug a tool appeared excalibur_delete_operator_credential
16 Aug 33 tool descriptions were rewritten excalibur_account_statement, excalibur_account_statement_infographic, excalibur_begin_oauth and 30 more
16 Aug 33 tools changed the parameters they ask for excalibur_account_statement, excalibur_account_statement_infographic, excalibur_begin_oauth and 30 more
16 Aug a tool changed version
9 Aug 2 tool descriptions were rewritten excalibur_list_posts, excalibur_list_snippets
and 1 more, back to 8 August 2026

Nothing serious here today

Today is the operative word: we check Excalibur MCP every 15 minutes and re-read its code on every release. Watch it and you find out the day that stops being true.

Three servers free · no card

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 15 min ago.

run in your terminal
claude mcp add excalibur-mcp --transport http https://excalibur-mcp.fastmcp.app/mcp
~/Library/Application Support/Claude/claude_desktop_config.json
{
  "mcpServers": {
    "excalibur-mcp": {
      "url": "https://excalibur-mcp.fastmcp.app/mcp"
    }
  }
}
~/.codex/config.toml
[mcp_servers.excalibur-mcp]
url = "https://excalibur-mcp.fastmcp.app/mcp"
.cursor/mcp.json
{
  "mcpServers": {
    "excalibur-mcp": {
      "url": "https://excalibur-mcp.fastmcp.app/mcp"
    }
  }
}
.vscode/mcp.json
{
  "mcpServers": {
    "excalibur-mcp": {
      "url": "https://excalibur-mcp.fastmcp.app/mcp"
    }
  }
}

Available tools 79

Read directly from the server with tools/list, grouped by what they act on. If a tool disappears, we record the date.

excalibur
excalibur_account_statement
Generate a patron's account statement at this operator. Returns the patron's purchase history, active credit tranches, per-tool usage breakdown, and recent daily usage logs. This is the patron's spending account — not the operator's Authority tax balance. Free — no credits consumed. Proof of npub ownership is required to prevent statement-scraping of arbitrary patrons.
excalibur_account_statement_infographic
Generate a visual SVG infographic of your account statement. Returns the same data as account_statement, rendered as a dark-themed SVG graphic with balance hero, metrics cards, health gauge, tranche table, and tool usage breakdown. Costs 1 api_sat per call. Proof is verified by ``debit_or_deny`` before any cost is incurred.
excalibur_adoption_status
Check this operator's adoption-request status at a chosen Authority. Free. Polls the Authority MCP-to-MCP for the status of this operator's request (pending / approved / rejected / provisioned).
excalibur_begin_oauth
Start the OAuth2 authorization flow. Returns an authorization URL. Open it in a browser to log in and authorize. Then call ``check_oauth_status`` with the same npub to complete. Free. Proof of npub ownership is required so an observer cannot DOS your account by initiating OAuth flows in your name. Do NOT call this pre-emptively. If a session may still be valid, attempt the live tool call first and only begin OAuth when it fails with ``upstream_auth_refresh_needed``. A 'pending' ``check_oauth_status`` is not evidence that an existing session has lapsed.
excalibur_check_authority_balance
Check this operator's tax balance at the Authority. Returns the sats available for certifying patron credit purchases. When this balance reaches zero, patron top-ups cannot be certified and the operator must call purchase_credits on the Authority. This is the operator's own funding — not a patron balance. Free.
excalibur_check_balance
Check a patron's credit balance at this operator. This is the patron's spending balance — credits purchased via Lightning for tool calls at this operator. For the operator's own balance at the Authority (needed to certify patron purchases), use authority_check_balance instead. Free — no credits required. Proof of npub ownership is required to prevent anyone-with-the-registry from enumerating balances.
excalibur_check_oauth_status
Check whether the OAuth2 authorization flow has completed. Call after opening the authorization URL from ``begin_oauth`` and completing the login in your browser. Free. Proof of npub ownership is required: OAuth status exposes which upstream services a patron has connected. A 'pending' result here does NOT prove an existing session has lapsed — it only reports this authorization attempt. To find out whether a session still works, attempt the live call; fall back to ``begin_oauth`` only on an explicit ``upstream_auth_refresh_needed`` error.
excalibur_check_payment
Check the payment status of a Lightning invoice. Call after paying the invoice from purchase_credits. Free — no credits required. Proof of npub ownership is required to prevent credit-grant front-running by an observer of the invoice ID.
excalibur_check_price
Preview the effective cost of a tool call. Shows the base cost and any constraint effects (discounts, free trials, surge pricing). Free — no credits required.
excalibur_check_proof_status
Check whether a previously-cached dpop_token is still valid. Mirrors ``check_oauth_status`` for the npub-proof flow: a calling agent can ask "will my next paid call accept this dpop_token?" before burning credits on a guaranteed failure. Free, no side effects — does not evict the cache or touch relays.
excalibur_create_post
Store a new post (draft or scheduled). Returns its ``post_id``.
excalibur_delete_coupon
Delete a coupon. Cascades to all patron redemptions. Any chain step referencing the deleted coupon_id becomes a no-op (the constraint returns neutral on unknown ids) — the Studio surfaces orphan references as warnings. RESTRICTED to operator — requires proof.
excalibur_delete_operator_credential
Remove a single operator secret field. Deletes one key from the operator's encrypted credential blob without touching the others — the field-level counterpart to ``forget_credentials``, which wipes the whole row. Use it to retire a leftover after an SDK cutover (a Prefect key after Modal, or a stored but untemplated orphan like ``anthropic_api_key``) without taking the operator down for a full re-delivery. Stored-but-untemplated fields are first-class: the delete is keyed on what is vaulted, not on what the current template declares. Idempotent — already-absent fields report ``removed: false`` without rewriting the vault. RESTRICTED to the operator — requires proof (nsec-signed kind-27235 or a cached dpop_token phrase); patron proofs are rejected. A deletion is as destructive as a write.
excalibur_delete_patron_credential
Remove a single patron credential field. Deletes one field from stored credentials without affecting other fields. Free. Proof of npub ownership is required — this is a write to the patron's sensitive credential vault.
excalibur_delete_post
Delete a stored post. Default is a soft delete (``status='archived'``); pass ``hard=True`` to remove the row permanently.
excalibur_delete_snippet
Delete one of your saved snippets by id. Free and owner-scoped.
excalibur_fetch_dynamic_block
Redeem a ``resolve_dynamic_block`` claim check (free, proof-gated). Poll this with the ``claim_check`` from ``resolve_dynamic_block`` until ``status == "done"`` (the resolved fragment is ``result.text``). While the job runs it returns ``{"status": "running", "poll_after_seconds": N}``; on failure ``{"status": "error", ...}`` (the start fare is refunded); an unknown or aged-out claim returns ``{"status": "expired", ...}``. Owner-scoped — only the npub that started the job can redeem it. Also acts as the watchdog: a stalled job is re-kicked when polled.
excalibur_forget_coupon
Remove a coupon from this patron's redemption list. Cosmetic only — the coupon itself still exists at the operator, and the patron can re-redeem the same code later while the window allows. Free — requires proof of ``npub``.
excalibur_forget_credentials
Delete vaulted credentials for a specific service and npub. For operator credentials, pass the operator's own npub. For patron credentials, pass the patron's npub. Always requires proof of npub ownership — a deletion is as destructive as a write.
excalibur_get_nostr_profile
Read an npub's public Nostr profile (NIP-01 kind-0 metadata). Free, no proof — the data is already public on relays. Returns the latest metadata fields (name, display_name, about, picture, banner, nip05, website, lud16) or an empty profile if none is published.
excalibur_get_notarization_proof
Generate a Merkle inclusion proof that a patron's balance was included in a Bitcoin-notarized snapshot.
excalibur_get_operator_onboarding_status
Report this operator's configuration readiness. Shows which operator settings are configured, which are missing, and how to deliver each missing value. For patron-level credential status, use get_patron_onboarding_status instead. Free.
excalibur_get_patron_credential_fields
List stored patron credential field names (not values). Returns the names of fields stored for a patron, plus each field's ``delivered_at`` ISO-8601 timestamp when known (null for secrets vaulted before timestamps were recorded). Values are never exposed — use this to verify which fields are configured and how old each one is. Free. Proof of npub ownership is required: the list of configured fields is itself sensitive (reveals which integrations a patron has set up).
excalibur_get_patron_onboarding_status
Report a patron's credential readiness for this operator. For set-once services (eXcalibur, TheBrain), shows which patron secrets are configured and which are missing. For dynamic/OAuth2 services (Schwab), reports that no patron credentials are needed. Free. Proof of npub ownership is required because credential presence is sensitive information about the patron's setup.
excalibur_get_post
Read one stored post by id (owner-scoped).
excalibur_get_post_metrics
Patron: raw metrics snapshot series for one owned post. Returns the append-only ``post_metrics_snapshot`` rows (impressions, likes, clicks, cadence_key, t_offset, link_placement, snippet_ids) ordered by capture time. Empty when the post has not been harvested yet.
excalibur_get_pricing_model
Get the active pricing model for this operator. Free. If no model exists, self-initializes a scaffold with all registered tools at 0 sats. No economic data from code.
excalibur_get_scheduler_log
Read recent scheduler-tick outcomes. Each ``process_scheduled_posts`` run — fired by the Cloudflare cron Worker or a manual trigger — records its summary. This surfaces them so the FE debug log can show what the Worker is doing: the per-tick heartbeat (proof it ran) and per-post outcomes (posted / skip+error reasons like ``insufficient_balance`` or ``oauth_token_expired``). Owner-scoped: the operator sees every tick in full; any other proven patron sees the global heartbeat (``processed`` count + ``run_at``) plus only the per-post entries for THEIR OWN posts. Free; npub proof required. Returns ``{runs:[{run_at, summary}], scope}``.
excalibur_get_snippet
Read one of your saved snippets by id (full row incl. ``doc`` block document). Free and owner-scoped. Returns ``{"success": true, "snippet": …}`` or ``snippet_not_found``.
excalibur_get_voice
Read your saved writing Voice — a profile blurb plus a list of "banned construction" chips (``{text, on}``) the editor passes to ``refine_post_region``. Owner-scoped; priced by the operator's pricing model (use ``check_price``). When you have not saved a Voice yet this returns an empty one (``{"voice": {"profile": "", "bans": []}}``) so the editor can seed its own defaults, not an error.
excalibur_get_x_profile
Fetch the connected X account's handle and name for this patron (free). Uses the patron's vaulted X OAuth token to call X's ``/users/me``. Returns ``{connected: true, username, name, profile_image_url}`` when connected, or the OAuth situation (``connected`` absent) when X isn't linked yet. Used to show the real @handle on the editor's tweet-card preview.
excalibur_harvest_metrics
Operator-only: one cadence-aware metrics harvest sweep. Drains due ``metrics_harvest_job`` rows (t+15m … t+28d), fetches X ``non_public_metrics`` / ``organic_metrics`` under each patron's OAuth context, and appends ``post_metrics_snapshot`` rows. A missed cadence is permanent data loss — failed jobs retry up to 5 attempts then land in the dead-letter queue; pass ``requeue_dead_id`` to retry one. Also runs as phase 3 of every ``process_scheduled_posts`` tick.
excalibur_list_canonical_identities
Return canonical (tool_id, mcp_name, …) for every tool the wheel exposes. The authoritative source for any client (Studio, agents, FE) that needs to know how this MCP identifies its tools. Reconcile uses this output to UUID-join against the stored pricing model — no name-based UUID derivation, no guessing. Includes both ToolIdentity-seeded tools and any UUID recorded by ``@paid_tool`` that is missing from the registry. The latter appear with ``registered: false`` (and in the top-level ``unregistered`` array) so Reconcile can flag deploy drift instead of silently reporting clean when a live tool was never seeded (#174). If the operator renames a function or rebrands a slug, the mcp_name in this output changes but tool_id stays. That's the whole point of the canonical-UUID design. Also diffs the live FastMCP wire surface against the registry. Tools exposed on the wire but absent from the registry appear in ``unregistered`` so Reconcile can flag deploy drift instead of silently under-reporting (issue #175). Free, no side effects.
excalibur_list_constraint_types
List all available constraint types and their parameter schemas. Returns the type, category, description, and parameter specs for every constraint that can be used in a pricing pipeline. Free — no credits required.
excalibur_list_coupons
List every coupon this operator has minted (newest first). Each row carries the current ``times_redeemed`` counter — the Studio renders a progress bar from this against ``total_uses``. RESTRICTED to operator — requires proof.
excalibur_list_my_coupons
List the coupons this patron has redeemed on this operator. Returns both active and exhausted redemptions with a per-row ``status`` (``active`` / ``window_closed`` / ``patron_limit`` / ``total_limit``). Free — requires proof of ``npub``.
excalibur_list_notarizations
List recent Bitcoin notarization records.
excalibur_list_posts
List your stored posts, server-side sorted, filtered, and offset-paginated. Optional ``status`` filter — a single status or a comma-separated set (e.g. ``draft,scheduled``), matched as set membership. ``sort_col`` is one of ``created|updated|status|scheduled`` (default ``created``); ``sort_dir`` is ``asc|desc``. ``search`` is a case-insensitive regular expression matched against the post text. ``date_from``/``date_to`` accept bare ``YYYY-MM-DD`` (UTC-calendar day, end-inclusive) or an ISO instant (patron-local midnight from the FE — exclusive upper bound when instant). Bound the ``date_field`` column, one of ``created|updated|scheduled|sent`` (default ``created``). ``template_id`` filters to the sent occurrences a recurring template fired. ``sent_hour`` (0–23) with ``time_zone`` (IANA) keeps only posts whose ``last_sent_at`` local wall hour in that zone matches — used by the Performance time-of-day chart deep-link. ``page`` is 0-indexed; ``page_size`` is 1..100. Each row carries ``is_recurring``, ``has_dynamic``, and ``template_id`` (set on sent occurrences). Returns ``{posts:[…], total, page, page_size}`` reflecting the filtered set.
excalibur_list_snippets
List your saved post snippets, server-side sorted, filtered, and offset-paginated. ``sort_col`` is one of ``favorite|created|updated|name`` (default ``favorite``); ``sort_dir`` is ``asc|desc``. ``search`` is a case-insensitive regular expression matched against the snippet name or body. ``date_from``/``date_to`` accept bare ``YYYY-MM-DD`` (UTC-calendar day, end-inclusive) or an ISO instant (patron-local midnight from the FE). Bound the ``date_field`` column, one of ``created|updated`` (default ``created``). ``page`` is 0-indexed; ``page_size`` is 1..200. Free, owner-scoped. Returns ``{snippets:[…], total, page, page_size}`` reflecting the filtered set.
excalibur_mint_coupon
Create a new operator-owned discount coupon.
excalibur_notarize_ledger
Build a Merkle tree of all patron balances and submit the root to Bitcoin via OpenTimestamps. Operator-only background task. Bitcoin confirmation takes 1-6 hours. Free — no credits required.
excalibur_oracle_about
Describe the DPYC ecosystem via the Oracle. Free.
excalibur_oracle_get_tax_rate
Get the current DPYC certification tax rate. Free.
excalibur_oracle_how_to_join
Get DPYC onboarding instructions from the Oracle. Free.
excalibur_oracle_lookup_member
Look up a DPYC community member by npub. Free.
excalibur_oracle_network_advisory
Get active network advisories from the Oracle. Free.
excalibur_post_nostr_message
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.
excalibur_post_performance
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.
excalibur_post_performance_infographic
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.
excalibur_post_tweet
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
excalibur_post_tweet_image
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.
excalibur_process_scheduled_posts
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}``.
excalibur_publish_nostr_profile
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.
excalibur_purchase_credits
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.
excalibur_receive_credentials
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.
excalibur_receive_npub_proof
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 the ``dpop_token`` — the same token. The calling application MUST remember it and pass it as the ``dpop_token`` parameter on every subsequent paid tool call. The proof (a hash of the token) is stored in the vault keyed by that hash — the MCP never stores the raw token itself. Free.
excalibur_redeem_coupon
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.
excalibur_refine_post_region
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.
excalibur_report_issue
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.
excalibur_request_adoption
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.
excalibur_request_credential_channel
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.
excalibur_request_npub_proof
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 demonstrated-proof-of-possession token that the calling application MUST remember and pass as the ``dpop_token`` parameter on every subsequent paid tool call. The MCP does not retain this value across restarts. **Lifecycle:** The cached proof expires after the patron's chosen duration. When it expires, call ``request_npub_proof`` again for a fresh challenge, then wait for the user, then call ``receive_npub_proof``. Free.
excalibur_reset_pricing_model
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).
excalibur_resolve_dynamic_block
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.
excalibur_restore_credits
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.
excalibur_restore_neon_schema
Re-run ``ensure_schema()`` on every NeonVault this operator uses. Diagnostic / recovery tool for the case where the Neon HTTP SQL API is returning persistent 4xx errors and the operator suspects the schema isn't there or grants are wrong. Idempotent — uses ``CREATE TABLE IF NOT EXISTS`` so a successful re-run is harmless. Returns the per-step result. If any step raises, surfaces the Neon error message inline (0.31.0 reads the SQL error body that earlier wheels swallowed behind ``raise_for_status``). RESTRICTED to operator — requires proof (nsec-signed).
excalibur_save_snippet
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": …}``.
excalibur_save_voice
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": {...}}``.
excalibur_scheduler_check_now
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.
excalibur_scheduler_pending
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.
excalibur_scheduler_reissue
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}``.
excalibur_scheduler_status
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.
excalibur_service_status
Check the health and configuration of this service. Free.
excalibur_session_status
Check operator readiness. Returns the operator lifecycle state and clear guidance on what to do next. Free. Lifecycle states: - ready: Operator is warm and fully operational — vault AND pricing model verified. Proceed with tool calls. - warming_up: Operator is initializing (cold start). Try a tool call — it will warm up on demand. - 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.
excalibur_set_pricing_model
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.
excalibur_update_coupon
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). RESTRICTED to operator — requires proof.
excalibur_update_operator_credential
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 proof (nsec-signed kind-27235 or a cached dpop_token phrase); patron proofs are rejected.
excalibur_update_patron_credential
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.
excalibur_update_post
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.

Endpoints

URLTransportStateLatencyChecked
https://excalibur-mcp.fastmcp.app/mcp streamable-http answering 504 ms 15 min ago

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Excalibur MCP — questions

Answers built from our own checks of this server.

What can Excalibur MCP do?
It exposes 79 tools, read directly from the server on our last check. Among them: excalibur_account_statement, excalibur_account_statement_infographic, excalibur_adoption_status, excalibur_begin_oauth, excalibur_check_authority_balance, excalibur_check_balance and 73 more. The full list with descriptions is on this page — we take it from the server itself via tools/list, not from a README. How MCP servers expose tools in the first place →
Is Excalibur MCP working right now?
We send a real MCP handshake every 15 minutes. Over the last 24 hours 91 of 91 checks got a reply (100.0%), average response time 672 ms. The bar chart above shows every period we have measured.
How do I connect Excalibur MCP?
Copy the ready config from this page — we generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each with the file path that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.
Does Excalibur MCP need an API key?
No. Excalibur MCP completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 79 of them are readable on this page. This is what we observed, not what the docs claim.
How fast is Excalibur MCP?
It answers our handshake in 672 ms on average, which is faster than 18% of all working MCP servers we measure. That is on the slow side — worth knowing if the tool sits inside an interactive loop. The comparison comes from our own checks across the whole registry, every 15 minutes.
Is Excalibur MCP open source?
We cannot say either way: written in Python, 3 stars on GitHub and 3 open issues, but we could not determine the licence, and without one the code is not open source by default.