Content from a CMS or API

A collection can come from where your content already lives. Name a source in the collection’s schema, and mira build fetches it, turns each item into an entry, and checks it against the schema like a Markdown file in content/. Routes give entries URLs, templates render them, and agents read them over MCP, the same as local content.

{
  "collections": {
    "posts": {
      "fields": { "title": "string", "date": "date", "excerpt": "string?" },
      "source": {
        "sanity": {
          "project": "abc123",
          "dataset": "production",
          "query": "*[_type == \"post\" && defined(slug.current)]"
        },
        "map": { "date": "publishedAt" }
      }
    }
  }
}

A collection can have a source and files in content/<name>/ at once; their entries are sorted together. Without a schema, every top level field of each item is kept.

Fields, slugs, and bodies

Each schema field is read from the item field with the same name. map reads it from somewhere else, with a dotted path such as author.name or tags.0:

Key in map	What it sets
slug	The entry’s URL segment. Defaults to slug; a Sanity slug object works as is
body	The entry’s content. Defaults to body. Markdown text, Sanity Portable Text, and Contentful Rich Text are all converted to Markdown
any field	That field, read from the given path

Images in rich text are downloaded at build time and processed like local media: sized, encoded to AVIF, and served from your site rather than the CMS’s servers.

Sanity

Key	What it is
project	The project ID
dataset	The dataset, such as production
query	A GROQ query that returns a list of documents
token_env	Optional. An environment variable holding a read token, for private datasets

Only published documents are read. Without a token, Mira reads from Sanity’s CDN.

Contentful

"source": {
  "contentful": { "space": "abc123", "content_type": "blogPost", "token_env": "CONTENTFUL_TOKEN" },
  "map": { "date": "publishDate" }
}

Key	What it is
space	The space ID
content_type	The content type ID
token_env	The environment variable holding a Content Delivery API token
environment	Optional. Defaults to master
locale	Optional. Defaults to the space’s default locale

Every entry of the type is read, a thousand at a time. Linked assets become objects with their url, title, and description, and linked entries become their fields, two levels deep. Each item also has id, created, and updated from Contentful, so "map": { "slug": "id" } works for types without a slug field.

Supabase

"source": {
  "supabase": {
    "url": "https://abcd.supabase.co",
    "table": "events",
    "select": "title,slug,starts,venue(name)",
    "filter": { "published": "eq.true" },
    "key_env": "SUPABASE_ANON_KEY"
  }
}

Key	What it is
url	The project URL
table	The table or view
select	Optional. Columns, in PostgREST syntax. Defaults to *
filter	Optional. Column conditions, in PostgREST syntax, such as "eq.true" or "gte.2026-01-01"
key_env	The environment variable holding the key. The anon key reads what row level security allows

Rows are read a thousand at a time, so tables of any size load.

GraphQL

Any GraphQL API: Hygraph, Shopify’s Storefront API, WordPress with WPGraphQL, Strapi, Payload, and others.

"source": {
  "graphql": {
    "url": "https://shop.example.com/api/2026-07/graphql.json",
    "query": "{ products(first: 100) { nodes { handle title description } } }",
    "items": "data.products.nodes",
    "headers": { "X-Shopify-Storefront-Access-Token": "SHOPIFY_TOKEN" }
  },
  "map": { "slug": "handle" }
}

items is the path to the list in the response. token_env sends a bearer token, and headers sends other headers, each naming the environment variable that holds its value. A GraphQL error in the response fails the build with its message.

Any JSON endpoint

Any HTTPS endpoint that returns a list: a REST API such as Strapi, Directus, WordPress, or Ghost, or a function you write on AWS Lambda, Google Cloud Functions, Azure Functions, Supabase Edge Functions, or Cloudflare Workers that reads from DynamoDB, Firestore, Cosmos DB, or anything else.

"source": {
  "json": {
    "url": "https://api.example.com/v1/menu",
    "items": "data",
    "headers": { "x-api-key": "MENU_API_KEY" }
  }
}

Key	What it is
url	An https:// URL. Query strings are allowed; credentials are not
items	Optional. The path to the list in the response, when it is not the response itself
token_env	Optional. An environment variable holding a bearer token
headers	Optional. Headers, each naming the environment variable that holds its value

Tokens and secrets

Tokens are never written in mira.config.json. Each source names an environment variable, and the build stops with the variable’s name if it is not set. Set them in your shell for local builds and in your host’s settings for builds there. Tokens never reach the cache, the build output, or error messages.

Builds, caching, and failures

• mira build fetches every source on every build, so a deploy publishes current content. Deploy again when content changes, for example with your CMS’s webhook and your host’s deploy hook.
• mira dev reuses what it fetched for 10 minutes, so saving a file does not refetch.
• Responses are cached in .mira/cache/, separately for each set of credentials, so a copy fetched with one token is never used with another. If a source cannot be reached and a cached copy exists, the build uses it and warns, with the copy’s age. Without a cached copy, the build fails with the reason.
• A source that refuses the token (HTTP 401 or 403) fails the build and its cached copy is deleted, so revoking a token stops its content from being published.
• Requests go over HTTPS only, time out after 30 seconds, and are limited to 32 MB.
• An item that does not match the schema fails the build, naming the collection and the item, such as collections.posts.source item 4: missing required field date.