Nem Catapult REST Endpoints
65
AI ReadinessAI-Aware (B)65/100
Community OpenAPI document · agent-readyFinanceBankingnone81 EndpointsREST
Know of an official OpenAPI document? Contribute it →
For Agents
Read accounts, blocks, transactions, and chain state from a Symbol blockchain node, and broadcast signed transactions to the network.
Use for: Look up the balance of a Symbol account by address, Submit a signed Symbol transaction to a node, Get the latest block height on the Symbol chain, Retrieve the full transaction list for a given block height
Not supported: Does not handle wallet key management, transaction signing, or fiat conversion - use for Symbol blockchain node reads and signed transaction broadcast only.
The Catapult REST API is the public HTTP interface for nodes running the Symbol blockchain (the protocol born from the NEM ecosystem). It exposes 81 endpoints covering accounts, blocks, transactions, mosaics, namespaces, finalisation, and node and network metadata, so a client can query chain state, broadcast signed transactions, and watch finality progress without running its own node. The API is designed for wallets, explorers, and back-office services that need a read and submit interface to the Symbol chain.
Install Jentic One Beta
Connect the Catapult REST Endpoints to your agent
Jentic One is a self-hosted execution layer for AI agents. It lets your agent call the Catapult REST Endpoints, or any other public or private API you need. You set the rules, the agent never sees your credentials, and every call is logged.
Two steps, two machines. Install the instance in a safe environment, then register your agent from wherever it runs.
1
Step 1: Jentic One Host machine
# On the machine that will host your Jentic One instance:
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fnem.io%2Fnem" | sh2
Step 2: Agent machine
# On the machine where your agent runs (keep this separate from the instance):
curl -fsSL "https://jentic.com/install.sh?src=apis&api=%2Fapis%2Fnem.io%2Fnem" | sh
jentic register # connects your agent to your Jentic One instanceJentic One is in public beta. The setup above keeps your agent separate from the instance, which is what you want before using real credentials: an agent running as the same OS user as Jentic One can read its stored keys directly. Just evaluating? A single local install is fine to start. See the secure deployment guide for the tiers.
Capabilities
What an agent can do with Catapult REST Endpoints API.
Look up account state, including balances and supplemental keys, by address or public key
Submit signed transactions to a Symbol node through the transactions endpoint
Query block headers, full blocks, and merkle proofs for any block height
Read mosaic and namespace records to resolve token metadata and human-readable aliases
Track chain progression and finalisation through the chain info and finalization endpoints
Inspect node identity, peers, and network properties for health monitoring
Use Cases
Patterns agents use Catapult REST Endpoints API for, with concrete tasks.
★ Wallet Account Lookup
Wallet front-ends call /accounts/{accountId} to render a Symbol account: balance, mosaics held, and account type. The merkle variant under /accounts/{accountId}/merkle returns a proof, useful for light clients that want to verify state against a block hash rather than trusting the node outright.
Fetch the account state for address TBLOCKCHAINSAMPLEADDRESS and return the list of mosaics and balances.
Transaction Broadcast and Confirmation
Services that build and sign transactions off-node use the Catapult REST API to push them to the network. The transactions endpoints accept the signed payload, expose status lookups for unconfirmed and confirmed states, and the finalization endpoints confirm when a block is irreversible. This pattern keeps signing keys off the node host while still using the node for broadcast.
Submit a signed transfer transaction to the Symbol testnet and poll until it is confirmed in a block.
Block Explorer Backend
Block explorers fan out reads against /blocks, /blocks/{height}, and the merkle endpoints to build a full chain view. Combined with /chain/info for current height and /node for identity, an explorer can render block, transaction, and account pages without running its own indexer for primary data.
Get the current chain height, then fetch the block at that height and list every transaction it contains.
AI Agent Integration via Jentic
An AI agent uses Jentic to call Symbol nodes without needing a hand-coded SDK. Jentic exposes the Catapult REST operations by intent, so an agent asking to read a Symbol account or submit a transaction is routed to the correct endpoint with a typed schema, which is valuable when integrating chain reads into a wider workflow.
Use Jentic to search for read symbol blockchain account, load the schema for /accounts/{accountId}, and return the balance for a given address.
Key Endpoints
81 endpoints — the catapult rest api is the public http interface for nodes running the symbol blockchain (the protocol born from the nem ecosystem).
METHOD
PATH
DESCRIPTION
GET
/accounts/{accountId}
Get account state by address or public key
GET
/accounts/{accountId}/merkle
Get account state with merkle proof
GET
/blocks/{height}
Get a block by height
GET
/blocks/{height}/transactions/{hash}/merkle
Get a transaction merkle proof for a block
GET
/chain/info
Get current chain height and finalisation state
GET
/accounts/{accountId}
Get account state by address or public key
GET
/accounts/{accountId}/merkle
Get account state with merkle proof
GET
/blocks/{height}
Get a block by height
GET
/blocks/{height}/transactions/{hash}/merkle
Get a transaction merkle proof for a block
GET
/chain/info
Get current chain height and finalisation state
Jentic AI Readiness Score
This API is usable in Jentic One now. Its AI-readiness score against Jentic's framework shows where it stands today and where improvements would make it even easier for agents to use.
C
Catapult REST Endpoints
- AI-Aware (B)65/100
50
Foundational Compliance62
Developer Experience & Jentic Compatibility53
AI-Readiness & Agent Experience89
Agent Usability100
Security75
AI DiscoverabilityPowered by JenticScoring Framework 1.0.0 | Scoring Engine 0.4.0
Show dimension breakdown
50
Foundational Compliance
Base layer of spec validity and structural soundness.
Grade: C-Signals: 4
0%
Lint Results
Aggregated quality score from linter diagnostics, weighted by severity.
100%
Resolution Completeness
Percentage of `$ref` references that resolve successfully.
0%
Specification Validity
Checks whether the API description parses successfully and conforms to its declared specification (e.g., OpenAPI).
100%
Structural Integrity
Structural correctness score based on schema issues using logarithmic dampening.
62
Developer Experience & Jentic Compatibility
Clarity, completeness, and ingestion readiness for developers and tooling.
Grade: B-Signals: 4
3%
Example Density
How richly the API is illustrated with examples.
100%
Example Validity
Percentage of examples that conform to their schemas.
46%
Response Coverage
Percentage of operations with complete response definitions (success, client error, server error).
100%
Tooling Readiness
Health of API ingestion, bundling, and resolution within Jentic pipelines.
53
AI-Readiness & Agent Experience
Semantic breadth, depth, and agent comprehension for AI systems.
Grade: CSignals: 4
80%
Description Coverage
Coverage of descriptions across API elements.
0%
Error Standardization
Coverage of RFC 9457 Problem Details for error responses.
100%
OperationId Quality
Coverage, uniqueness, and casing consistency of operationIds for AI inference.
34%
Summary Coverage
Coverage of summaries across operations/tags/info.
89
Agent Usability
Functional utility, complexity comfort, and AI orchestration readiness.
Grade: ASignals: 1
89%
Complexity Comfort
Agent comfort level based on API operational and structural complexity.
100
Security
Trust, risk posture, and security compliance.
Grade: A+Signals: 1
100%
Authentication Strength
Average quality of security schemes based on authentication method strength (weakest link for OAuth2).
75
AI Discoverability
Findability, semantic richness, and reasoning readiness.
Grade: A-Signals: 1
75%
Descriptive Richness
Clarity and depth of descriptions across API elements.
Score it yourself
Every API in the directory is allowlisted, so you can re-score it with no key required.
npx @jentic/api-scorecard-cli score <openapi-url>Why Jentic?
What agents get from Jentic-routed access to this vendor.
Setup
Wiring the Catapult REST endpoints by hand means pointing calls at the correct Symbol node host and port, reading account and block data through their merkle variants, and broadcasting only pre-signed transactions yourself. Through Jentic you install once, import the Catapult endpoints from the API Directory, and your agent calls it, with any gateway credential stored once.
Permission scoping
Catapult puts the account id and block height in the URL path (/accounts/{accountId}, /blocks/{height}), so a rule can pin your agent to reads for one account or block and nothing else. You choose the operations it may call, so anything beyond the reads you list is not included unless you add it.
Credential isolation
Catapult REST is unauthenticated, so your Jentic One instance stores no node credential, and any gateway or proxy token is stored once, encrypted, and injected at execution time. No secret enters the agent's prompt, logs, or context.
Intent-based discovery
Agents search Jentic by intent such as 'read a Symbol account state' or 'fetch chain info', and Jentic returns the matching Catapult REST operation with its schema so the agent calls the right endpoint without browsing the reference docs.
Related APIs
Alternatives and complements available in the Jentic catalogue.
FAQs
Specific to using Catapult REST Endpoints API through Jentic.
What authentication does the Catapult REST API use?
Catapult REST endpoints are unauthenticated by default - a Symbol node serves public chain data and accepts pre-signed transactions. When fronting a node with a gateway that adds an API key, store that key in your Jentic One instance so it never reaches the agent context.
Can I submit signed transactions through the Catapult REST API?
Yes. Sign the transaction off-node, then PUT the signed payload to the transactions endpoint exposed by Catapult REST. The node validates and gossips it. Use the /chain/info and finalization endpoints to confirm inclusion and irreversibility.
What are the rate limits for the Catapult REST API?
Rate limits are not defined in the spec - they depend on which node operator is hosting the endpoint. For the public testnet at reference.symboltest.net, treat reads as moderate and avoid hammering /blocks for full chain scans; use /chain/info to drive incremental fetches.
How do I read a Symbol account balance with the Catapult REST API through Jentic?
Search Jentic for read symbol blockchain account, load the schema for GET /accounts/{accountId}, and execute with the address. The full flow is pip install jentic, search, load, execute.
Does the API include endpoints for finalisation?
Yes. The spec covers finalisation proof endpoints alongside /chain/info, so a client can verify when a block is irreversible rather than relying on confirmation depth heuristics.
Can I limit what my agent is allowed to do with the Symbol blockchain API?
Yes. Because you self-host Jentic One, your own rules decide which Catapult REST operations the agent may call, so you can allow account reads on GET /accounts/{accountId} and block reads on GET /blocks/{height} while withholding the transactions endpoint that broadcasts signed payloads. Since the account id and block height sit in the URL path, a rule can pin the agent to reads for a single account or block and nothing else. Any gateway or proxy token stays in your instance and is injected only for the operations you list, so anything you do not add is not available to the agent.
GET STARTED