Fine Structure MCP Server

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answering

Fine Structure is answering right now. Last checked 2 min ago. It exposes 99 tools.

Build and host full-stack apps from a prompt, with agents that reach you on WhatsApp and email.

Uptime history 91 days of history · worst day 92%

91 days agonow

100.0%

Uptime 24h

92 of 92 checks

Tools

read from the server

639 ms

Response time

average over 24h

open, no key

Access

streamable-http

What changed 158

Every tool that appeared, vanished or quietly changed what it asks for. Recorded since 9 August 2026. No other catalogue keeps this.

19 Oct 2 tools appeared preview_saved_version, set_agent_owner_relay

15 Oct a tool changed the parameters it asks for get_platform_guide

14 Oct a tool description was rewritten list_apps

13 Oct 4 tools appeared get_agent_conversation, get_agent_task, list_agent_conversations and 1 more

4 Oct 2 tools appeared get_app_metadata, set_app_metadata

26 Sep 7 tools appeared create_platform_request, get_platform_request, invoke_function and 4 more

26 Sep 3 tools changed the parameters they ask for4 times that day get_platform_guide, get_recommended_workflow, set_function_policy

26 Sep a tool description was rewritten get_app_security_context

25 Sep a tool description was rewritten set_entity_policy

25 Sep a tool changed the parameters it asks for set_entity_policy

and 135 more, back to 9 August 2026

Fine Structure missed 2 checks this week

Everything else answered, so this is steady rather than shaky. We check every 15 minutes, which is how a one-off gets told apart from the start of a pattern, and how you hear about the next one within the hour instead of from your users.

Connect this server

Endpoint below is the one we actually reach during checks — not the one copied from a README. Last verified 2 min ago.

Claude Code Claude Desktop Codex Cursor VS Code

run in your terminal

claude mcp add fine-structure --transport http https://finestructure.ai/api/mcp

Settings → Connectors → Add custom connector, then paste this address

https://finestructure.ai/api/mcp

~/.codex/config.toml

[mcp_servers.fine-structure]
url = "https://finestructure.ai/api/mcp"

.cursor/mcp.json

{
  "mcpServers": {
    "fine-structure": {
      "url": "https://finestructure.ai/api/mcp"
    }
  }
}

.vscode/mcp.json

{
  "servers": {
    "fine-structure": {
      "type": "http",
      "url": "https://finestructure.ai/api/mcp"
    }
  }
}

Available tools 99

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

app

create_app

Create a new application from a natural language prompt. The AI generates a complete web app with pages, components, styling, and data models. Returns a job_id - poll get_job_status to track progress. When the job is done, the app is ready.

get_app_analytics

Traffic analytics for an app's published site over a chosen window: total views, unique visitors, daily series, top pages, top referrer domains and device split.

get_app_detail

Deep introspection of an app: entities, pages, settings, integrations, environment variables, and file structure. Use this to understand what an app contains before updating it.

get_app_files

Get the file tree for an app with paths and byte sizes.

get_app_links

Return editor, preview, published path, subdomain, and custom-domain links plus whether each works for anonymous visitors, app users, or Studio users based on publish and auth settings.

get_app_metadata

Read the saved public HTML-shell identity: name, description, language and image URLs/dimensions. Same settings as Studio SEO/GEO.

get_app_security_audit

Read recent server-side security audit events for an app.

get_app_security_context

Return safe security context for one owned app: owner id/email, Studio collaborators, generated-app members, route policies, entity policies, function policies, and recent security audit entries. Does not return secrets and does not grant access to other apps.

get_app_status

Get app overview: files, published state, URL, active jobs.

list_app_domains

List an app's platform path, subdomain, and configured custom domain with verification, SSL, primary-domain, redirect, publish, and login-gating status.

list_app_members

List generated-app runtime users/members for an app. This is separate from Studio project collaborators.

read_app_file

Read one source file from an app's virtual filesystem. Paths follow the Fine Structure app file API, documented at https://finestructure.ai/api/mcp/docs.

read_app_files

Read several source files from an app's virtual filesystem. Paths follow the Fine Structure app file API, documented at https://finestructure.ai/api/mcp/docs.

remove_app_member

Remove a generated-app runtime member.

set_app_metadata

Update public HTML-shell metadata immediately, without AI, code edits, publishing or Saved Versions. Upload social_image/icon as base64 PNG/JPEG/WebP (max 5 MB, 4096px); null clears an image. Language sets HTML lang/dir and OG locale. For per-page cards, write optional seo.json and publish it; dynamic entries may read only explicitly public entity records.

set_app_subdomain

Set or clear the app platform subdomain - the '<subdomain>.<base domain>' host Fine Structure already serves the app on. Runs the same ownership, format, reserved-name and uniqueness checks as the Studio subdomain field because it calls the same model function. Replacing a subdomain takes effect immediately and creates NO redirect: the previous name stops resolving to this app and is released for anyone to claim. Pass an empty subdomain to clear it. For a domain the user owns, use add_custom_domain instead.

update_app

Update an existing application with a new prompt. The AI modifies the app based on your instructions. Creates a Saved Version before the update. Returns a job_id - poll get_job_status to track progress.

update_app_member_role

Update a generated-app runtime member role. This cannot assign owner and cannot change the Fine Structure account owner.

write_app_file

Create or replace one file in an app's virtual filesystem. Creates a Saved Version before changing content. Paths and file model follow the Fine Structure app file API, documented at https://finestructure.ai/api/mcp/docs.

entity

create_entity_records

Create/insert records in one app entity. Executes directly for the authenticated app owner and returns the created record ids.

create_entity_schema

Create an entity schema file in entities/<Entity>.json. Creates a Saved Version before writing.

delete_entity_records

Delete exact records by ID or exact-match filters. Executes directly for the authenticated app owner; pass expected_count as a safety check to abort on a mismatch.

query_entity

Query app data records for one entity with optional exact-match filters.

set_entity_policy

Replace server-side entity access policy. Optional action rules override read/write roles and can allow public create without public read, update, or delete. Omitting rules replaces any existing action rules with read/write role behavior.

update_entity_metadata

Set relationship/index metadata on an entity schema. This stores metadata in the schema file; DB index creation is automatic where supported by the platform.

update_entity_record

Compatibility tool that updates one record by ID. Executes directly for the authenticated app owner.

update_entity_records

Update exact records. Select explicit record_ids or exact-match filters and provide shared changes, or provide per-record updates. Executes directly for the authenticated app owner; expected_count aborts the write on a mismatch.

update_entity_schema

Replace or shallow-merge an existing entity schema file. Creates a Saved Version before writing.

agent

create_agent

Create an autonomous AI agent on the user's Fine Structure account: a standing worker, not a chat session. It gets the platform's default safe tool policy and its own email address, it can read and write the app database, and once the owner phone is verified (see get_agent_whatsapp) it can message its owner on WhatsApp and by email through the platform system channels. Pair it with schedule_agent_task for recurring work such as following up new leads on WhatsApp each morning, watching an app for runtime errors, or sending a weekly summary. Messaging anyone other than the verified owner requires a channel the owner connects in the Fine Structure Studio.

get_agent_conversation

Read visible messages, answers and result links in an owned agent's conversation. Returns the newest page in chronological order. For older history, pass next_before_id as before_id. For new replies, omit before_id.

get_agent_task

Check a durable task returned by send_agent_message or list_agent_tasks. Includes the latest execution status and pending approvals, including before a run starts. Task scheduling state is separate from run outcome. Read the conversation for the actual answer; accepted/queued is not completed. Approvals must still be decided by the owner in Fine Structure.

get_agent_whatsapp

Read the WhatsApp state of the connected account: whether the owner's phone is verified, which platform numbers they can connect, and which conversations already route to which agent. Call this first whenever the user asks to talk to an agent on WhatsApp, and repeat its next_step to them.

list_agent_conversations

List recent visible conversations belonging to one of your agents. Use get_agent_conversation to read replies and results.

list_agent_tasks

List scheduled tasks for one agent (or the whole account), including schedule, status and next_run_at.

set_agent_owner_relay

Set the owner's consent for one owned agent to relay reports from another owned agent (or all sources with '*'). Uses the same preference as the agent screen. Does not send a message or grant access to customer conversations.

agency

agency_create_claim_link

Agency mode only. Create a client claim link for an existing app owned by the agent. The client must log in with the invited email before ownership transfers.

agency_create_client

Agency mode only. Create or update a client record for an account-level agent. This does not create a verified Fine Structure user account and does not transfer ownership.

agency_create_client_app

Agency mode only. Create a new app owned by the agent, start generation, and create a claim link for the client. Ownership transfers only when the invited client logs in with the same email and accepts the claim link.

agency_get_claim_status

Agency mode only. Inspect one handoff status without exposing the raw claim token.

agency_list_clients

Agency mode only. List client records and app handoff status for the authenticated agent.

platform

create_platform_request

Open a request to the Fine Structure platform team: a bug, a feature request or a question about the platform itself (not about the user's app). Use it when something in the platform blocks you instead of working around it. Give a reproduction the team can run (invoke_function / curl / the exact tool call and result), what you expected, and how the team will know it is closed. Credential-looking values are redacted. Returns request_id and a Studio URL; the team's replies, status changes and deployments come back through get_platform_request / list_platform_requests. Limits: 20 per account per day, 32 KB.

get_platform_guide

Return a machine-readable Fine Structure / FSe2 guide for AI agents. Call this at the start of an MCP session to learn app files, entities, safe edit workflows, validation, publishing, A/B testing, secrets, and platform rules.

get_platform_request

list_platform_requests

Your account's platform requests, newest activity first. Call it at the start of a session with since=<the updated_date you last saw> to learn what changed: replies, needs_info questions to answer, deployments with their commit. Filters: app_id, status.

update_platform_request

test

create_ab_test

Create a native Fine Structure A/B test between existing app pages. Use update_app first if a variant page still needs to be generated. Creates a Saved Version before the change.

delete_ab_test

Delete a native A/B test from an app. Creates a Saved Version before the change.

get_ab_test_stats

Get views, unique visitors, conversions, and conversion rates for an A/B test.

update_ab_test

Update a native A/B test, including active state, variants, traffic, and conversion goal. Creates a Saved Version before the change.

domain

check_domain_verification

Check Fine Structure custom-domain verification and SSL status for the configured custom domain, then save the latest status.

get_domain_ssl_status

Return SSL/certificate status and pending certificate validation DNS records for the app custom domain.

get_domain_verification

Return the exact DNS records and instructions required to verify and route the app custom domain.

secret

delete_secret

Delete one app secret by key.

list_secret_keys

List secret key names for an app. Secret values are never returned.

set_secret

Create or update one encrypted app secret. The secret value is never returned.

validate

validate_app

Run deterministic app checks: syntax, imports, routes/pages, entity schemas, missing entities, and recorded runtime errors.

validate_change_set

Validate current app files plus staged change set files before applying.

validate_entity_relationships

Validate entity relationship metadata and *_id references against existing entity schemas.

compare

compare_current_to_version

Compare the current app files to a Saved Version and return compact per-file diffs.

compare_saved_versions

Compare two Saved Versions and return per-file additions, removals, modifications, and compact diffs.

configure

configure_domain_redirects

Configure custom-domain redirect policy: primary domain, optional www/root redirect, and HTTPS enforcement.

configure_integration

Store safe non-secret integration metadata for an app. Use set_secret for API keys/tokens.

custom

add_custom_domain

Attach or replace the app custom domain through the same Fine Structure Studio custom-domain flow. Returns exact DNS verification and routing records for the user to configure at their DNS provider.

remove_custom_domain

Remove the configured custom domain from the app and clean up the platform-side hostname registration when possible.

preview

get_preview_url

Return editor preview and published/public URLs for an app.

preview_saved_version

Prepare an isolated read-only Saved Version preview, if enabled by the deployment. Returns compiled files for an offline sandbox, never restores files or reads live records. Never execute the returned program with host credentials. Requires app access and versions:read.

agents

list_agents

List the AI agents on the user's account with id, name, role, status and FineMail address.

apply

apply_change_set

Apply a staged change set to the app. Creates a Saved Version before applying. Blocks on validation errors unless force=true.

apps

list_apps

List owned and accepted Studio-shared applications, newest activity first. Returns up to `limit` apps per call plus the total count; page with `offset` when the account has more. Accepted editors can edit shared source; viewers can read it. Publishing, records, domains and security administration remain owner-only.

attach

attach_agent_whatsapp

Connect a platform WhatsApp number to one of the account's agents, so the owner can message that number and reach that agent. Requires the owner to be verified first. Take phone_number_id from get_agent_whatsapp. A number already used by another account is still valid to connect: it answers only this owner's verified phone.

change

create_change_set

Create a staged file change set. Add multiple file changes, validate them as one app state, then apply atomically.

confirm

confirm_owner_phone_verification

Confirm the 6-digit code the owner received on WhatsApp from start_owner_phone_verification. On success the owner is verified: agents can message them, and platform numbers become connectable.

detach

detach_agent_whatsapp

Disconnect the owner's WhatsApp route from a platform number. Removes only this account's route; other accounts sharing the number keep theirs.

discard

discard_change_set

Discard a pending staged change set without changing app files.

entities

get_entities

Get all entity (data model) schemas for an app, with record counts. Each entity has fields, types, and relationships.

errors

get_errors

Get recent runtime errors for an app (last 20). Useful for diagnosing issues before updating.

file

add_file_change

Stage one file upsert or delete inside a change set. Does not modify the live app until apply_change_set. Paths follow the Fine Structure app file API, documented at https://finestructure.ai/api/mcp/docs.

function

set_function_policy

Create or update the server-owned access policy of a backend function (functions/<name>.js). Without a policy a function answers only to the app owner's Studio token (401 for app visitors and webhooks). Recipes: anonymous checkout step or inbound webhook/IPN -> require_auth=false; signed-in members -> require_auth=true + allowed_roles (e.g. ['authenticated'] or ['admin','staff']); webhook with a shared secret -> require_secret=true + secret_name (an app secret) that the caller sends in secret_header. allowed_hosts fences the function's outbound network to those hosts plus the platform backend; omit it for open egress.

inspect

inspect_preview

Return server-side preview context: URLs, persisted runtime/network errors, static clickable candidates, pages, and explicit live-browser availability.

integrations

list_integrations

List supported integrations and safe connected integration metadata for an app. Tokens/secrets are never returned.

invite

invite_app_member

Provision a generated-app runtime member with a role. This does not create a Studio collaborator, and the owner role cannot be assigned. password is required: ask the account owner which password the member should get. This tool never generates one, because a generated password would come back in the result and that is a live credential in the conversation transcript.

invoke

invoke_function

Run a backend function of an owned app exactly like the HTTP route and return its status and JSON. caller='owner' runs as the app owner; caller='anonymous' first evaluates the function policy as a public visitor and returns the 401/403 decision without running when access would be denied. Use it to verify a function (secrets, outbound calls, policy) before wiring it into the app.

job

get_job_status

Poll the status of an async generation job. Use this after create_app or update_app to know when the job is done. Returns status ('running' or 'done'), progress events, and result summary when complete.

pages

get_pages

Get all pages in an app with their file paths and sizes.

patch

patch_app_file

Patch one file by replacing exact text. Safer than full overwrite for targeted edits. Creates a Saved Version before changing content. Paths follow the Fine Structure app file API, documented at https://finestructure.ai/api/mcp/docs.

primary

set_primary_domain

Set which app host should be treated as primary for generated links and custom-domain redirects.

publish

publish_app

Publish an app - freeze current state and make it live at a URL. Also configures whether the public URL is open, app-login gated, private, or inferred from the app.

recommended

get_recommended_workflow

Return the recommended MCP tool sequence for a task type. Use this before creating apps, editing files, seeding data, publishing, setting up A/B tests, restoring versions, or configuring secrets/integrations.

rename

rename_app_file

Rename or move one app source file atomically. Internally stages an upsert at new_path and a delete at old_path, validates the resulting app state, and creates a Saved Version before applying.

reply_platform_request

Add a reply or a finding to one of your platform requests without opening a new one, e.g. to answer a needs_info question (that reopens it).

restore

restore_file_from_version

Restore one file from a Saved Version instead of restoring the entire app. Creates a Saved Version before changing the file. Paths follow the Fine Structure app file API, documented at https://finestructure.ai/api/mcp/docs.

route

set_route_policy

Create or update a server-owned route policy for a generated app route.

saved

list_saved_versions

List restorable Saved Versions for an app, including versions created by MCP writes.

schedule

schedule_agent_task

Create a scheduled task for one of the user's agents. Supported schedule types: once (run_at ISO local time + timezone), interval (interval_minutes 5-1440), hourly, daily (time HH:MM + timezone), weekly (time + timezone + days_of_week 0=Sunday..6), cron (5-field expression + timezone), manual (only runs on demand). Returns the normalized schedule and the computed next_run_at so you can read the fire time back to the user in their timezone.

seed

seed_entity

Compatibility tool for starter-record creation. Inserts directly for the authenticated app owner; by default it only seeds an empty entity (skip_if_not_empty).

send

send_agent_message

Talk to an existing agent or assign it work using its normal tools, memory, permissions and team. Omit conversation_id to start a new owner conversation; supply it to continue one. Returns acceptance and a durable task_id immediately, NOT a completed answer. Poll get_agent_task and read get_agent_conversation for the actual response. Work continues after MCP disconnects. A follow-up in a busy conversation uses the normal queue. Customer conversations are readable but cannot be impersonated by this tool.

start

start_owner_phone_verification

Send a 6-digit code over WhatsApp to the ACCOUNT OWNER's own phone. This is the one-time ownership proof required before a platform number can be connected, and it also unlocks agents messaging the owner. Ask the user for their own WhatsApp number first and send only to that. No WhatsApp Business account is involved.

subdomain

check_subdomain_available

Check whether a platform subdomain can be claimed before calling set_app_subdomain. Returns available plus a status of available, invalid, reserved, taken, current, or empty, with the exact reason. Pass app_id (an app you own) to have that app's own current subdomain reported as 'current' instead of 'taken'.

tests

list_ab_tests

List the platform A/B tests configured for an app.

Tools removed

Tools this server used to expose. Anything built against them stopped working on the day they went.

estimate_video_cost

removed 15 Aug 2026

generate_image

removed 15 Aug 2026

generate_slideshow

removed 15 Aug 2026

generate_video

removed 15 Aug 2026

get_slideshow

removed 15 Aug 2026

get_video_status

removed 15 Aug 2026

list_media_capabilities

removed 15 Aug 2026

list_slideshows

removed 15 Aug 2026

list_video_jobs

removed 15 Aug 2026

render_slideshow_images

removed 15 Aug 2026

restore_saved_version

removed 17 Aug 2026

email_marketing_app_configure

removed 17 Aug 2026

email_marketing_app_contact_profile

removed 17 Aug 2026

email_marketing_app_create_broadcast

removed 17 Aug 2026

email_marketing_app_create_event_trigger

removed 17 Aug 2026

email_marketing_app_create_segment

removed 17 Aug 2026

email_marketing_app_create_sequence

removed 17 Aug 2026

email_marketing_app_create_workflow

removed 17 Aug 2026

email_marketing_app_deliverability

removed 17 Aug 2026

email_marketing_app_process_queue

removed 17 Aug 2026

email_marketing_app_queue_status

removed 17 Aug 2026

email_marketing_app_record_event

removed 17 Aug 2026

email_marketing_app_report

removed 17 Aug 2026

email_marketing_app_status

removed 17 Aug 2026

email_marketing_app_suppress_contact

removed 17 Aug 2026

email_marketing_app_sync_contacts

removed 17 Aug 2026

email_marketing_configure_sender

removed 17 Aug 2026

email_marketing_create_broadcast

removed 17 Aug 2026

email_marketing_create_sequence

removed 17 Aug 2026

email_marketing_create_variable_trigger

removed 17 Aug 2026

email_marketing_status

removed 17 Aug 2026

email_marketing_trigger_variable

removed 17 Aug 2026

email_marketing_update_template

removed 17 Aug 2026

Endpoints

URL	Transport	State	Latency	Checked
https://finestructure.ai/api/mcp	streamable-http	answering	870 ms	2 min ago

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Fine Structure — questions

Answers built from our own checks of this server.

What can Fine Structure do?

It exposes 99 tools, read directly from the server on our last check. Among them: add_custom_domain, add_file_change, agency_create_claim_link, agency_create_client, agency_create_client_app, agency_get_claim_status and 93 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 →

What is Fine Structure mostly used for?

Its tools cluster around app, entity and agent. That is what this server is built to work with — the grouping comes from the actual tool names, not from a category we assigned.

Is Fine Structure working right now?

We send a real MCP handshake every 15 minutes. Over the last 24 hours 92 of 92 checks got a reply (100.0%), average response time 639 ms. The bar chart above shows every period we have measured.

Did Fine Structure ever remove tools?

Yes. estimate_video_cost, generate_image, generate_slideshow, generate_video and 29 more are no longer exposed — we recorded the date each one disappeared. A tool vanishing usually means a breaking change for anything that depended on it.

How do I connect Fine Structure?

Copy the ready config from this page. We generate it for Claude Code, Claude Desktop, Codex, Cursor and VS Code, each in the form that client actually reads. It is a remote server, so there is nothing to install — the client connects to the address.

Does Fine Structure need an API key?

No. Fine Structure completed a full MCP handshake with us as an anonymous client and listed its tools without asking for anything. All 99 of them are readable on this page. This is what we observed, not what the docs claim.

How fast is Fine Structure?

It answers our handshake in 639 ms on average, which is faster than 16% 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.