Machine-readable reference
Every fixed URL an agent can read to learn what IndexZero is and how to call it, without rendering a page.
Everything an agent needs to call IndexZero is published at a fixed URL. The documents are generated from the same constants the product enforces, so they cannot advertise a plan, a tool, or a scope the server does not have.
Product-level documents
| Document | URL | What it is |
|---|---|---|
| llms.txt | https://indexzero.site/llms.txt | What IndexZero is for, when to use it and when not to, how to call it, cost and limits, and the tool groups. Per the llmstxt.org format. |
| OpenAPI 3.1 | https://indexzero.site/openapi.json | The MCP endpoint, the OAuth security schemes with named scopes, the API-key scheme, and the JSON error shape. |
| MCP manifest | https://indexzero.site/.well-known/mcp.json | Endpoint, transport, authentication schemes, scopes, tool groups, pricing, and links, in one JSON document. Also served from the app origin. |
| Tool catalog | https://app.indexzero.site/api/mcp/catalog | Every tool with name, description, and JSON Schema for its arguments, in the shape function-calling APIs expect. Unauthenticated. |
| Health | https://app.indexzero.site/api/health | { ok, service, env, database, timestamp }. Unauthenticated. |
| Sitemap | https://indexzero.site/sitemap.xml | Every public marketing page. |
The discovery documents are cacheable for five minutes with an hour of stale-while-revalidate, so a deploy that moves an endpoint propagates quickly.
OAuth discovery
On the app origin, because the issuer and the resource live there. The marketing origin redirects these two paths rather than serving copies.
| Document | URL |
|---|---|
| Authorization server metadata (RFC 8414) | https://app.indexzero.site/.well-known/oauth-authorization-server |
| Protected resource metadata (RFC 9728) | https://app.indexzero.site/.well-known/oauth-protected-resource |
This manual
| Document | URL | What it is |
|---|---|---|
| Page index | https://docs.indexzero.site/llms.txt | Every page of this manual with its description. |
| Whole manual | https://docs.indexzero.site/llms-full.txt | Every page, concatenated. |
| Any page as markdown | append .md | https://docs.indexzero.site/credits.md is the markdown for /credits. / is /index.md. |
| Content negotiation | Accept: text/markdown | The same URL without .md answers with markdown when asked for it, with Vary: Accept. |
| Sitemap | https://docs.indexzero.site/sitemap.xml | Every page here. |
Every marketing page on indexzero.site also answers to Accept: text/markdown.
Fetching the tool catalog
curl https://app.indexzero.site/api/mcp/catalogThe response is a JSON array. Each entry has name, description, and parameters (a JSON Schema object for the tool's arguments). Descriptions state whether the tool costs credits, and the catalog also flags costsCredits and readOnly per tool, so a planner can budget before it connects.
The MCP endpoint itself
https://app.indexzero.site/mcpStreamable HTTP. POST sends a JSON-RPC 2.0 message; GET opens the server-to-client stream for an existing session (Mcp-Session-Id required); DELETE ends a session. Authenticate with an OAuth bearer token or an iz_ API key. See Any other client for a request that works from curl.