mcp server

excalibur-mcp

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

Description as published by the maintainer. Source

• version 0.37.0
• active

active — Registry entry last updated 2026-07-31.

What this server can do

77 functions, named and described by the server itself. Parameter names are shown because they say more about what a function does than its name usually does.

excalibur_account_statement(days, npub, dpop_token)

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. Args: npub: The patron's Nostr public key (npub1...). dpop_token: Raw JSON of a kind-27235 Nostr event signed by npub — not base64, not NIP-98 'Authorization: Nostr <b64>' framing. Its `u` tag must hold THIS tool's exact name (from tools/list), not the endpoint URL; content:"", created_at within 60s of now, and a random `nonce` tag recommended. Or a cached dpop_token phrase. days: Number of days of daily usage history to include (default 30). Required: npub, dpop_token.

excalibur_account_statement_infographic(days, npub, dpop_token)

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. Args: npub: The Nostr public key (npub1...) whose statement to render. dpop_token: Raw JSON of a kind-27235 Nostr event signed by npub — not base64, not NIP-98 'Authorization: Nostr <b64>' framing. Its `u` tag must hold THIS tool's exact name (from tools/list), not the endpoint URL; content:"", created_at within 60s of now, and a random `nonce` tag recommended. Or a cached dpop_token phrase. days: Number of days of daily usage history to include (default 30). Required: npub, dpop_token.

excalibur_adoption_status(dpop_token, authority_npub)

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). Required: authority_npub.

excalibur_begin_oauth(npub, dpop_token)

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. Args: npub: Your DPYC patron npub (npub1...). dpop_token: Raw JSON of a kind-27235 Nostr event signed by npub — not base64, not NIP-98 'Authorization: Nostr <b64>' framing. Its `u` tag must hold THIS tool's exact name (from tools/list), not the endpoint URL; content:"", created_at within 60s of now, and a random `nonce` tag recommended. Or a cached dpop_token phrase. Required: npub, dpop_token.

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(npub, dpop_token)

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. Args: npub: The Nostr public key (npub1...) whose balance to check. dpop_token: Raw JSON of a kind-27235 Nostr event signed by npub — not base64, not NIP-98 'Authorization: Nostr <b64>' framing. Its `u` tag must hold THIS tool's exact name (from tools/list), not the endpoint URL; content:"", created_at within 60s of now, and a random `nonce` tag recommended. Or a cached dpop_token phrase. Required: npub, dpop_token.

excalibur_check_oauth_status(npub, dpop_token)

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. Args: npub: The same Nostr public key (npub1...) used in begin_oauth. dpop_token: Raw JSON of a kind-27235 Nostr event signed by npub — not base64, not NIP-98 'Authorization: Nostr <b64>' framing. Its `u` tag must hold THIS tool's exact name (from tools/list), not the endpoint URL; content:"", created_at within 60s of now, and a random `nonce` tag recommended. Or a cached dpop_token phrase. Required: npub, dpop_token.

excalibur_check_payment(npub, dpop_token, invoice_id)

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. Args: invoice_id: The invoice ID returned by purchase_credits. npub: The Nostr public key (npub1...) that purchased the invoice. dpop_token: Raw JSON of a kind-27235 Nostr event signed by npub — not base64, not NIP-98 'Authorization: Nostr <b64>' framing. Its `u` tag must hold THIS tool's exact name (from tools/list), not the endpoint URL; content:"", created_at within 60s of now, and a random `nonce` tag recommended. Or a cached dpop_token phrase. Required: invoice_id, npub, dpop_token.

excalibur_check_price(npub, tool_id, dpop_token, tool_kwargs)

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. Args: tool_id: Either the tool's UUID (from the pricing model) or a bare capability string (e.g. ``"deal_scenario"``). FE callers usually have the capability name; this resolves both so the FE doesn't need to derive UUIDs locally. tool_kwargs: Optional JSON object with tool call parameters for ad valorem / categorical-multiplier pricing preview (e.g. '{"amount_sats": 5000}' or '{"difficulty": "sovereign", "mode": "live"}'). Required: tool_id.

excalibur_check_proof_status(dpop_token, patron_npub)

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. Args: patron_npub: Required. The patron's npub (npub1...). dpop_token: Required. The dpop_token phrase returned by ``request_npub_proof`` / ``receive_npub_proof``.

excalibur_create_post(doc, npub, title, status, cease_at, tweet_url, dpop_token, publish_at, recurrence, text_cache, client_req_id)

Store a new post (draft or scheduled). Returns its ``post_id``. Args: doc: The editable Doc — a JSON object whose consumed key is ``blocks``, a list of block objects. A minimal static post is one block: ``{"blocks": [{"text": "gm. stack sats.", "flags": []}]}``. Blocks are joined with a blank line between them to form ``text_cache``. Each block: - ``text`` (str): the block's copy (for a dynamic block, a prompt). - ``flags`` (list): editor highlight regions, each ``{"start": int, "end": int, "note": str, "colorIdx": int}`` (char offsets into ``text``) — pass ``[]`` when there are none. - ``dynamic`` (bool, optional): when true ``text`` is a prompt the server resolves with an LLM at post time; ``fallback`` (str) is posted if it fails, and ``domains``/``maxFetches``/``runtimeLimit`` bound its web access. Voice/bans live in your separate Voice profile and the schedule in ``publish_at``/``recurrence``/``cease_at`` — neither belongs in ``doc``. text_cache: Composed text (blocks joined) for scheduler + list excerpts. publish_at: ISO-8601 first/next publish time; required when status='scheduled'. recurrence: ``{"freq": "daily|weekly|monthly", "interval": n}`` or null. cease_at: ISO-8601 stop time for recurrence; null = open-ended. status: ``draft`` or ``scheduled``. client_req_id: Idempotency key — re-sending the same id returns the same post without a second charge. title: Optional human label for the post; the list falls back to the first body line when it is blank. npub: Your DPYC patron Nostr public key for credit attribution. Required: doc.

excalibur_delete_coupon(coupon_id, dpop_token)

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. Required: coupon_id.

excalibur_delete_patron_credential(npub, field, dpop_token)

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. Args: npub: The patron's Nostr public key (npub1...). dpop_token: Raw JSON of a kind-27235 Nostr event signed by npub — not base64, not NIP-98 'Authorization: Nostr <b64>' framing. Its `u` tag must hold THIS tool's exact name (from tools/list), not the endpoint URL; content:"", created_at within 60s of now, and a random `nonce` tag recommended. Or a cached dpop_token phrase. field: The credential field name to remove. Required: npub, dpop_token, field.

excalibur_delete_post(hard, npub, post_id, dpop_token)

Delete a stored post. Default is a soft delete (``status='archived'``); pass ``hard=True`` to remove the row permanently. Required: post_id.

excalibur_delete_snippet(npub, dpop_token, snippet_id)

Delete one of your saved snippets by id. Free and owner-scoped. Required: snippet_id.

excalibur_fetch_dynamic_block(npub, dpop_token, claim_check)

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. Required: claim_check.

excalibur_forget_coupon(npub, coupon_id, dpop_token)

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``. Required: npub, coupon_id.

excalibur_forget_credentials(npub, service, dpop_token)

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. Args: service: The credential service to forget. npub: The Nostr public key (npub1...) whose credentials to forget. dpop_token: Raw JSON of a kind-27235 Nostr event signed by npub — not base64, not NIP-98 'Authorization: Nostr <b64>' framing. Its `u` tag must hold THIS tool's exact name (from tools/list), not the endpoint URL; content:"", created_at within 60s of now, and a random `nonce` tag recommended. Or a cached dpop_token phrase. Free. Required: service, npub, dpop_token.

excalibur_get_nostr_profile(npub)

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(npub, notarization_id)

Generate a Merkle inclusion proof that a patron's balance was included in a Bitcoin-notarized snapshot. Args: notarization_id: The notarization record ID. npub: The patron's Nostr public key (npub1...). Required: notarization_id, npub.

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(npub, dpop_token)

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). Args: npub: The patron's Nostr public key (npub1...). dpop_token: Raw JSON of a kind-27235 Nostr event signed by npub — not base64, not NIP-98 'Authorization: Nostr <b64>' framing. Its `u` tag must hold THIS tool's exact name (from tools/list), not the endpoint URL; content:"", created_at within 60s of now, and a random `nonce` tag recommended. Or a cached dpop_token phrase. Required: npub, dpop_token.

excalibur_get_patron_onboarding_status(dpop_token, patron_npub)

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. Args: patron_npub: The patron's Nostr public key (npub1...). dpop_token: A kind-27235 Nostr event signed by patron_npub for this tool. Required: patron_npub, dpop_token.

excalibur_get_post(npub, post_id, dpop_token)

Read one stored post by id (owner-scoped). Required: post_id.

excalibur_get_post_metrics(npub, post_id, dpop_token)

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. Required: post_id.

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(npub, limit, dpop_token)

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(npub, dpop_token, snippet_id)

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``. Required: snippet_id.

excalibur_get_voice(npub, dpop_token)

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(npub, dpop_token)

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(npub, dpop_token, requeue_dead_id)

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(dpop_token)

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(npub, dpop_token)

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``. Required: npub.

excalibur_list_notarizations(limit, status)

List recent Bitcoin notarization records. Args: limit: Maximum records to return (default 20). status: Optional filter (e.g., 'submitted', 'confirmed').

excalibur_list_posts(npub, page, search, status, date_to, sort_col, sort_dir, date_from, page_size, date_field, dpop_token, template_id)

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. ``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(npub, page, search, date_to, sort_col, sort_dir, date_from, page_size, date_field, dpop_token)

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(name, dpop_token, total_uses, valid_from, valid_until, uses_per_patron, discount_percent)

Create a new operator-owned discount coupon. Args: name: The catchy code patrons type to redeem (operator-scoped uniqueness). discount_percent: Percentage off the base price (0-100). valid_from: ISO-8601 datetime when the coupon becomes active. valid_until: ISO-8601 datetime when the coupon expires. uses_per_patron: How many tool calls one patron can claim the discount on (default 1; pass null/None for unlimited within the window). total_uses: Aggregate cap across all patrons (default None = unlimited). Returns the new coupon row. RESTRICTED to operator — requires proof (nsec-signed kind-27235 or cached dpop_token token). Required: name, discount_percent, valid_from, valid_until.

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(npub)

Look up a DPYC community member by npub. Free. Required: npub.

excalibur_oracle_network_advisory

Get active network advisories from the Oracle. Free.

excalibur_post_nostr_message(npub, message, dpop_token)

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. Args: message: The note text to publish. npub: Your DPYC patron npub (npub1...) — proven, billed, and recorded as the note's author. Required: message.

excalibur_post_performance(npub, dpop_token)

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(npub, dpop_token)

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(npub, text, dpop_token)

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 Args: text: Tweet content with optional markdown formatting. npub: Your DPYC patron Nostr public key (npub1...) for credit attribution. Required: text.

excalibur_post_tweet_image(npub, text, image_url, banner_svg, dpop_token)

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. Args: text: Tweet content with optional markdown formatting. image_url: URL of an image to attach to the tweet. banner_svg: Self-contained SVG markup string, converted to PNG. npub: Your DPYC patron Nostr public key (npub1...) for credit attribution. Required: text.

excalibur_process_scheduled_posts(npub, dpop_token)

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(npub, signed_event)

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. Args: npub: The patron's Nostr public key the event must be signed by. signed_event: A JSON-encoded, client-signed kind-0 event.

excalibur_purchase_credits(npub, dpop_token, amount_sats)

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. Args: npub: The Nostr public key (npub1...) the credits will fund. dpop_token: Raw JSON of a kind-27235 Nostr event signed by npub — not base64, not NIP-98 'Authorization: Nostr <b64>' framing. Its `u` tag must hold THIS tool's exact name (from tools/list), not the endpoint URL; content:"", created_at within 60s of now, and a random `nonce` tag recommended. Or a cached dpop_token phrase. amount_sats: Satoshis to purchase (default 1000). Required: npub, dpop_token.

excalibur_receive_credentials(service, dpop_token, sender_npub, credential_card)

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. Args: sender_npub: Required. The npub that sent the credentials. service: Required. The credential service name (must match the service used in request_credential_channel). dpop_token: Required. The session phrase returned by request_credential_channel for this exact channel. credential_card: Optional. An ncred1... card to redeem directly (bypasses the relay drain; dpop_token not needed). Free.

excalibur_receive_npub_proof(dpop_token, patron_npub)

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. Args: patron_npub: Required. The patron's npub to receive proof from. dpop_token: Required. The dpop_token returned by request_npub_proof.

excalibur_redeem_coupon(code, npub, dpop_token)

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. Required: npub, code.

excalibur_refine_post_region(bans, npub, voice, region, full_text, dpop_token, instruction)

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. Args: region: The flagged span to rewrite. full_text: The whole tweet, for context. instruction: What the editor wants changed (optional). voice: Voice-profile text fed to the model (optional). bans: Banned constructions — JSON array or comma-separated (optional). npub: Your DPYC patron npub for credit billing. Required: region.

excalibur_report_issue(body, npub, title, tool_name, dpop_token)

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. Args: npub: Your Nostr public key (npub1...); the report's author of record. dpop_token: Raw JSON of a kind-27235 Nostr event signed by npub — not base64, not NIP-98 'Authorization: Nostr <b64>' framing. Its `u` tag must hold THIS tool's exact name (from tools/list), not the endpoint URL; content:"", created_at within 60s of now, and a random `nonce` tag recommended. Or a cached dpop_token phrase. title: One-line summary of the problem. body: The details — which tool, what was wrong, what you expected. tool_name: Optional: the specific tool the report is about (e.g. "schwab_get_option_chain"). Required: npub, dpop_token, title, body.

excalibur_request_adoption(note, dpop_token, service_url, authority_npub)

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. Args: authority_npub: npub of the Authority to request adoption from. dpop_token: operator-npub ownership proof (inline kind-27235 or cached token). service_url: this operator's MCP endpoint (advertised to the Authority). note: optional message for the Authority owner. Required: authority_npub.

excalibur_request_credential_channel(service, sender_npub)

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. Args: sender_npub: Required. The npub to send the template to. service: Required. The credential service name (e.g., from get_operator_onboarding_status or get_patron_onboarding_status). Free.

excalibur_request_npub_proof(reason, verify_at, patron_npub)

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. Args: patron_npub: Required. The patron's npub to request proof from. reason: 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 recipient sees *why* they are being asked — especially useful when the signer is unknown to them. verify_at: 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 Device Grant ``verification_uri``, generalized: the user approves only if the code in the DM matches the one you displayed there, so an unsolicited request they've never seen is refused. Signed into the attestation.

excalibur_reset_pricing_model(dpop_token)

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(bans, npub, voice, prompt, context, dpop_token, max_fetches, allowed_domains, runtime_limit_seconds)

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. Args: prompt: The dynamic block's prompt to run. context: The surrounding composed post (may contain the ⟨HERE⟩ marker). voice: Voice-profile text fed to the model (optional). bans: Banned constructions — JSON array or comma-separated (optional). allowed_domains: Author allowlist for web_fetch — JSON array or comma-separated. Blank = fetch any URL the prompt references. max_fetches: Author budget for web lookups (search + fetch), 1..25. runtime_limit_seconds: Author's time budget (clamped to the operator's configured block ceiling; see config.resolve_block_budget_max_s). Sets the job's runtime ceiling and the poll cadence (first poll ~75% of it), and is available to the operator's pricing model for ad-valorem fares. npub: Your DPYC patron npub for credit billing. Required: prompt.

excalibur_restore_credits(dpop_token, invoice_id, patron_npub)

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. Args: invoice_id: The BTCPay invoice ID to verify and credit. patron_npub: The patron's npub whose ledger receives the grant. dpop_token: A kind-27235 Nostr event signed by the OPERATOR's nsec for this tool. Patron proofs are rejected. Required: invoice_id, patron_npub, dpop_token.

excalibur_restore_neon_schema(dpop_token)

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(doc, name, npub, text, favorite, dpop_token, snippet_id)

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(bans, npub, profile, dpop_token)

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(npub, dpop_token)

Run one scheduler tick now (operator-only). Pokes the Worker's ``/tick`` — the same work the ~30-minute cron does: it claims a pending proof reply (completing your authorization) and fires any due posts. Use it right after approving in Studio so you don't wait for the next tick. 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(npub, dpop_token)

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_status(npub, dpop_token)

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(patron_npub)

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. Args: patron_npub: 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 reactively after a stale-token failure.

excalibur_set_pricing_model(dpop_token, model_json)

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. Required: model_json.

excalibur_update_coupon(name, coupon_id, dpop_token, total_uses, valid_from, valid_until, uses_per_patron, clear_total_uses, discount_percent, clear_uses_per_patron)

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. Required: coupon_id.

excalibur_update_operator_credential(field, value, dpop_token)

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. Args: field: The operator credential field to set. Must be declared in the operator's credential template. value: The value to store. dpop_token: Operator proof for this tool. Required: field, value, dpop_token.

excalibur_update_patron_credential(npub, field, value, dpop_token)

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. Args: npub: The patron's Nostr public key (npub1...). dpop_token: Raw JSON of a kind-27235 Nostr event signed by npub — not base64, not NIP-98 'Authorization: Nostr <b64>' framing. Its `u` tag must hold THIS tool's exact name (from tools/list), not the endpoint URL; content:"", created_at within 60s of now, and a random `nonce` tag recommended. Or a cached dpop_token phrase. field: The credential field name to set. value: The value to store. Required: npub, dpop_token, field, value.

excalibur_update_post(npub, patch, post_id, dpop_token, text_cache, client_req_id)

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. Required: post_id, patch.

Last successful function declaration observed on 2026-08-13. Source: https://excalibur-mcp.fastmcp.app/mcp. We list what the server declared; we do not call any of these functions.

Endpoint status observed on 2026-08-13. Source: https://excalibur-mcp.fastmcp.app/mcp.

Signals

These are separate measurements of different things. They are deliberately not combined into one score, because a popularity number that mixes website traffic with saves and stars cannot be checked or acted on.

Where to get it

• Repository — https://github.com/lonniev/excalibur-mcp
• Remote endpoint (streamable-http) — https://excalibur-mcp.fastmcp.app/mcp

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