Availability API

Serves data recorded by the Tiramisu DA layer, such as committed blocks

The availability API is the place to get onchain data, like blocks and transactions. It is the primary interface for downstream components like rollups and end users.

The API is designed to be robust and pure. Robust means that if the node hosting the API misses some data, for example from being offline when a certain block was finalized, it will automatically fetch the missing data from a peer, and will eventually fetch and store all finalized data. Pure means that each endpoint is a pure function -- with the exception of occasionally returning 404 for missing data, each endpoint will always give the same response given the same parameters.

Due to purity, this API provides no aggregate queries, like block or transaction counts, which might change as missing data is fetched. Likewise, every endpoint takes some specification of the exact point in the chain the client is looking for, like a block height or hash. There is no "latest block" query. Thus, most real-world use cases will need to complement the availability API with use of the node API.

Organization

While this API has many endpoints, don't be intimidated -- there is a method to the madness. The API is organized around collections of different resources, each of which corresponds to blocks and can be indexed by block height or hash.

Resources

  • Leaves

  • Headers

  • Blocks

  • Block summaries

  • Payloads

  • VID common

Indices

Each of these resources can be addressed in the following ways:

  • <resource>/:height

  • <resource>/hash/:hash

  • <resource>/payload-hash/:payload-hash

Not all of the indices are implemented for all resources, although in principle they can be. The supported indices are documented below for each endpoint. Future releases will fill in the missing functionality.

Leaves are currently indexed slightly differently from other resources. See documentation on leaf endpoints. Future versions of this API will merge the concept of a leaf and a header, resolving this discrepancy.

In addition, there are endpoints to fetch a range of each resource (<resource>/:form/:until) and to subscribe to a WebSockets stream (/stream/<resource>/:from).

Types

BlockSummary

{
    "header": Header,
    "hash": tagged<BLOCK>,
    "size": integer,
    "num_transactions": integer
}

BlockResponse

{
    "header": Header,
    "payload": Payload,
    "hash": tagged<BLOCK>,
    "size": integer,
    "num_transactions": integer
}

LeafResponse

{
    "leaf": Leaf,
    "qc": QC,
}

PayloadResponse

{
    "data": Payload,
    "height": integer,
    "size": integer,
    "block_hash": tagged<BLOCK>,
    "hash": tagged<HASH>
}

VidCommonResponse

{
    "common": VidCommon,
    "block_hash": tagged<BLOCK>,
    "payload_hash": tagged<HASH>
}

Endpoints

GET /availability/leaf

Paths

  • /availability/leaf/:height

  • /availability/leaf/hash/:hash

Parameters

Returns LeafResponse

GET /availability/leaf/:from/:until

Retrieve a range of consecutive leaves.

Parameters

Returns [LeafResponse]

GET /availability/stream/leaves/:height

This is a WebSockets endpoint. The client must be prepared to upgrade the connection to a WebSockets connection, including the proper headers.

Subscribe to a stream of leaves, in order, starting from the given height.

Parameters

Yields LeafResponse

GET /availability/header

Paths

  • /availability/header/:height

  • /availability/header/hash/:hash

  • /availability/header/payload-hash/:payload-hash

Parameters

Returns Header

GET /availability/header/:from/:until

Retrieve a range of consecutive headers.

Parameters

Returns [Header]

GET /availability/stream/headers/:height

This is a WebSockets endpoint. The client must be prepared to upgrade the connection to a WebSockets connection, including the proper headers.

Subscribe to a stream of headers, in order, starting from the given height.

Parameters

Yields Header

GET /availability/block

Paths

  • /availability/block/:height

  • /availability/block/hash/:hash

  • /availability/block/payload-hash/:payload-hash

Parameters

Returns BlockResponse

GET /availability/block/:from/:until

Retrieve a range of consecutive blocks.

Parameters

Returns [BlockResponse]

GET /availability/stream/blocks/:height

This is a WebSockets endpoint. The client must be prepared to upgrade the connection to a WebSockets connection, including the proper headers.

Subscribe to a stream of blocks, in order, starting from the given height.

Parameters

Yields BlockResponse

GET /availability/block/summary

Paths

  • /availability/block/summary/:height

Parameters

Returns BlockSummary

GET /availability/block/summaries/:from/:until

Retrieve a range of consecutive block summaries.

Parameters

Returns [BlockSummary]

GET /availability/payload

Paths

  • /availability/payload/:height

  • /availability/payload/block-hash/:block-hash

  • /availability/payload/hash/:hash

Parameters

Returns PayloadResponse

GET /availability/payload/:from/:until

Retrieve a range of consecutive payloads.

Parameters

Returns [PayloadResponse]

GET /availability/stream/payloads/:height

This is a WebSockets endpoint. The client must be prepared to upgrade the connection to a WebSockets connection, including the proper headers.

Subscribe to a stream of payloads, in order, starting from the given height.

Parameters

Yields PayloadResponse

GET /availability/vid/common

Paths

  • /availability/vid/common/:height

  • /availability/vid/common/hash/:hash

  • /availability/vid/common/payload-hash/:payload-hash

Parameters

Returns VidCommonResponse

GET /availability/stream/vid/common/:height

This is a WebSockets endpoint. The client must be prepared to upgrade the connection to a WebSockets connection, including the proper headers.

Subscribe to a stream of VID common objects, in order, starting from the given height.

Parameters

Yields VidCommonResponse

GET /availability/block/:height/namespace/:namespace

Get the list of transactions in a block from a given namespace, along with a proof that these are only and all such transactions from that block. Note that the proof may be null if transactions is empty, in which case the caller should check the namespace table for the specified block to confirm that :namespace is not present.

Parameters

Returns

{
    "transactions": [Transaction],
    "proof": NsProof | null
}

GET /availability/transaction

Paths

  • /availability/transaction/:height/:index

  • /availability/transaction/hash/:hash

Parameters

Returns

{
    "transaction": Transaction,
    "hash": tagged<TX>,
    "index": integer,
    "proof": TransactionInclusionProof,
    "block_hash": tagged<BLOCK>,
    "block_height": integer
}

The response contains the hash of the transaction, the hash and height of the block that contains it, and its index within that block. It also contains a TransactionInclusionProof, which proves inclusion of this transaction in the block with block_hash. The specific format of this type is not currently specified, but it can be deserialized and interpreted in Rust using the TxInclusionProof type.

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