Skip to main content
Glama
ProjectMakersDE

horizOn MCP Server

Official
by ProjectMakersDE
OverviewSchemaSourceRelated ServersDiscussionsAdmin
TypeScript
Remote

Create Match

horizon_create_match
Idempotent

Creates a server-ID lobby for explicit asynchronous multiplayer actions, using the original player-ledger revision to prevent revision conflicts.

Instructions

Creates one server-ID lobby under the original player-ledger revision. Use when: explicit asynchronous multiplayer actions after reading horizon://docs/matches. Not for: automatic polling, page traversal, timeout progression, invented winners or automatic rewards. Reconcile with horizon_get_matches and horizon_get_match. Consent and game consensus do not validate honest gameplay. Requires: userId and the player's session: sign in with horizon_signin_email or horizon_signin_anonymous and pass its accessToken as sessionToken. Side effects: One HTTP attempt. Reserves active and settlement capacity plus bounded invite slots atomically. Completed detail history is separate; FREE defaults to zero. Lost response: reconcile horizon_get_matches with the original intent. Returns: {match,playerRevision,pollAfterSeconds,serverTime} Errors: 404 hides private/missing/expired matches. 409 REVISION_CONFLICT or STATE_CONFLICT: explicitly reread and reconcile the original intent, never replace the revision or automatically resubmit. RESULT_CONFLICT preserves the original report. RUN_EXPIRED/RUN_ALREADY_USED never allow replacement ranked runs. 501 FEATURE_NOT_SUPPORTED is explicit for simpleServer ranked mode. 401 means the session is missing or expired: sign in again and retry with the new accessToken. 403 for a session means the token belongs to another user: pass the userId that signed in. Needs HORIZON_API_KEY. Every failure returns an error result (isError) with the HTTP status and body: a 401 that horizon_test_connection also returns means HORIZON_API_KEY is wrong, 429 means the account's per-minute rate limit was reached (wait a minute, then retry).

Input Schema

NameRequiredDescriptionDefault
userIdYesActive player matching the session and project
settingsYesComplete immutable lobby settings; current tier state cap also applies
sessionTokenYesPlayer accessToken sent only as Bearer
expectedRevisionYesOriginal reviewed revision; never substitute a newer revision after an uncertain write

Schema Changelog

Changes observed during successful MCP inspections.

  1. Addedv1.9.1

TDQS

A4.6/5.0
Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Beyond annotations, the description discloses atomic capacity and invite-slot reservation, lost-response reconciliation, revision/state conflict handling, 404 privacy behavior, 401/403 auth distinctions, 429 rate limits, and error-result behavior. These are material operational traits for a create operation.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is front-loaded with purpose and organized into Use when, Not for, Requires, Side effects, Returns, and Errors sections. It is thorough for a high-stakes mutation, but the error block is long and somewhat repetitive, keeping it from being maximally concise.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Even without an output schema, the description states the return shape and covers prerequisites, side effects, conflict semantics, and error cases. Combined with the annotations and fully described schema, an agent has enough information to invoke and recover from this tool correctly.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is already 100%, so the baseline is 3, but the description adds useful meaning: sign in via horizon_signin_email or horizon_signin_anonymous and pass that accessToken as sessionToken. It also reinforces expectedRevision as the original reviewed revision, though it does not expand nested settings fields.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description states a specific verb and resource: 'Creates one server-ID lobby under the original player-ledger revision.' It also scopes the action against reconciliation tools and lists exclusions, so the agent can distinguish this from get/list/start/join siblings without opening the schema.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives explicit 'Use when' and 'Not for' guidance, including exclusions for polling, page traversal, timeout progression, and invented results. It also names horizon_get_matches and horizon_get_match for reconciliation, though it does not explicitly route creation versus start_match or join_match.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

Deploy Server

Other Tools