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Hedera topics API

The topics object represents the information associated with a topic entity and returns topic messages information.

Hedera topics API is one of 10 APIs that Hedera publishes on the APIs.io network, described by a machine-readable OpenAPI specification.

Tagged areas include topics. The published artifact set on APIs.io includes an OpenAPI specification, API documentation, and rate-limit docs.

This API exposes 4 operations across 4 paths, and defines 15 schemas. It is described by OpenAPI 3.1.0, at version 0.156.0.

Requests are made against a single base URL, {scheme}://{network}.mirrornode.hedera.com.

4 operations 4 paths 15 schemas 4 GET

Metadata

The identity and technical contract details declared by the specification.

Specification
OpenAPI 3.1.0
API Version
0.156.0
Base URL
https://mainnet.mirrornode.hedera.com
License
Resource Areas
1

Paths & Operations 4

Across 4 paths, the API surfaces 4 operations — 4 GET. Each is listed below with its method, path, parameters, and response codes.

topics 4

The topics object represents the information associated with a topic entity and returns topic messages information.

GET
/api/v1/topics/{topicId}
Get topic by ID
getTopic 1 param → 200400404
GET
/api/v1/topics/{topicId}/messages
List topic messages by id
getTopicMessages 6 params → 200400404
GET
/api/v1/topics/{topicId}/messages/{sequenceNumber}
Get topic message by id and sequence number
getTopicMessageByIdAndSequenceNumber 2 params → 200400404
GET
/api/v1/topics/messages/{timestamp}
Get topic message by consensusTimestamp
getTopicMessageByTimestamp 1 param → 200400404

Schemas 15

The contract defines 15 schemas that model the data the API accepts and returns. The most detailed are Topic (12 properties), TopicMessage (8 properties), TransactionId (4 properties), ChunkInfo (3 properties). Each schema is shown below with its type and property counts.

FixedCustomFee
object
3 properties
ChunkInfo
objectnull
3 properties
Key
objectnull
The public key which controls access to various network entities.
2 properties
TopicMessages
array
TimestampRange
object
A timestamp range an entity is valid for
2 properties
TimestampNullable
stringnull
A Unix timestamp in seconds.nanoseconds format
TransactionId
object
4 properties
Links
object
1 property
EntityId
stringnull
Network entity ID in the format of shard.realm.num
TopicMessage
object
8 properties 7 required
ConsensusCustomFees
object
Custom fees assessed for each message submitted to the topic
2 properties
Timestamp
string
A Unix timestamp in seconds.nanoseconds format
TopicMessagesResponse
object
2 properties
Error
object
1 property
Topic
object
12 properties 12 required

Specification

The full machine-readable OpenAPI contract behind this narrative.

Source

hedera-topics-api-openapi.yml Raw ↑

Other APIs Hedera publishes across the network.

Hedera accounts API
Hedera airdrops API
Hedera balances API
Hedera blocks API
Hedera contracts API
Hedera network API
Hedera schedules API
Hedera tokens API
Hedera transactions API