Sella MCP tools: all parameters and JSON-RPC examples

Every Sella capability is exposed as an MCP tool served from a single endpoint. Send a tools/call JSON-RPC 2.0 request to invoke any tool:

{
  "jsonrpc": "2.0",
  "id": 1,
  "method": "tools/call",
  "params": {
    "name": "<tool>",
    "arguments": {}
  }
}

Base URL: POST https://sellag.vercel.app/api/mcp

Tools at a glance

Tool	Category	Auth	Cost
`sella_auth_start`	Auth	None	Free
`sella_auth_complete`	Auth	None	Free
`list_datasets`	Discovery	Key / OAuth	Free
`search_datasets`	Discovery	Key / OAuth	Free
`list_market_apis`	Discovery	Key / OAuth	Free
`try_dataset`	Evaluate	Key / OAuth	Free
`get_dataset`	Purchase	Key / OAuth	x402 (varies)
`cradle_breed_agent`	Compute	Key / OAuth	$10 USDC
`merge_models`	Compute	Key / OAuth	$15 USDC

Authenticated tools accept Authorization: Bearer sk_live_… or an OAuth token with the mcp:tools scope. The two auth tools are unauthenticated so a fresh agent can bootstrap credentials before it has a key.

Authentication tools

These two tools are unauthenticated — a brand-new agent uses them to get a key before it can call anything else. See Authentication & wallets.

sella_auth_start

Sends a 6-digit one-time code to the provided email address. Call this first to begin the login flow.

string

required

The operator’s email address to send the code to.

{
  "name": "sella_auth_start",
  "arguments": {
    "email": "you@example.com"
  }
}

sella_auth_complete

Submits the 6-digit code and returns an apiKey, agentId, mcpServerUrl, and — on first login — a walletConfig for the newly provisioned wallet.

string

required

The same email address used in sella_auth_start.

otp_code

string

required

The 6-digit code received by email.

{
  "name": "sella_auth_complete",
  "arguments": {
    "email": "you@example.com",
    "otp_code": "123456"
  }
}

Discovery tools

All three discovery tools are read-only and free. They return listing metadata — never paid content.

list_datasets · search_datasets

Both tools accept identical filter parameters and return dataset listing metadata. Use search_datasets when you have a keyword query; use list_datasets to page through the catalogue with filters. See Discover.

query

string

Keyword search across title, description, and tags.

list_market_apis

Searches the 1,400+ provider API Data Market. Returns provider metadata, pricing, and chain availability.

query

string

Free-text search over provider name, description, and tags.

domain_type

string

Domain code A1–A22. For example, A7 for web search and A8 for scraping.

product_class

string

Product class B1–B6. For example, B1 for pay-per-call APIs and B2 for data products.

chain

string

Preferred settlement chain: base, solana, or stellar.

verified_only

boolean

When true, return only Sella-verified providers.

max_price_usdc

number

Maximum per-call price in USDC.

limit

number

default:"25"

Maximum results to return. Accepts up to 50.

{
  "name": "list_market_apis",
  "arguments": {
    "query": "web scraping",
    "domain_type": "A8",
    "verified_only": true,
    "max_price_usdc": 0.01
  }
}

Evaluation tool

try_dataset

Opens a dataset in a closed trial — returning a preview, schema coverage report, and full quality datacard — with no payment required. Use this before committing to a purchase. See Evaluate.

dataset_id

string

required

The ID of the dataset to trial.

required_fields

string[]

Fields to verify are present before you decide to purchase.

{
  "name": "try_dataset",
  "arguments": {
    "dataset_id": "<id>",
    "required_fields": ["text", "label"]
  }
}

Purchase tool

get_dataset

Returns the full content of a dataset. Free-tier datasets return content immediately. Paid tiers require a valid x402 payment signature. See Purchase & payments.

dataset_id

string

required

The ID of the dataset to retrieve.

payment_signature

string

Base64-encoded x402 PAYMENT-SIGNATURE (v2, preferred). Produce this by signing the 402 challenge with your wallet key.

payment_proof

string

Legacy fallback proof (historically X-PAYMENT-RESPONSE). Use payment_signature for new integrations.

x_payment

string

Legacy v1 X-PAYMENT header value. Use payment_signature for new integrations.

{
  "name": "get_dataset",
  "arguments": {
    "dataset_id": "<id>",
    "payment_signature": "<base64>"
  }
}

Compute tools

Compute tools enqueue real GPU jobs and charge immediately. Both are annotated destructive — confirm the payment signature is correct before calling.

cradle_breed_agent

Enqueues a Cradle fine-tuning job on GPU and returns a Job ID. Costs $10 USDC. See Compute.

target_task

string

The NLP task to optimise for, e.g. text-classification or summarization.

base_model

string

An optional base-model hint to guide the breeding run.

payment_signature

string

x402 payment signature covering exactly $10 USDC.

{
  "name": "cradle_breed_agent",
  "arguments": {
    "target_task": "text-classification",
    "payment_signature": "<base64>"
  }
}

merge_models

Enqueues a MergeKit model-fusion job and returns a Job ID. Costs $15 USDC.

config_yaml

string

required

A valid MergeKit configuration in YAML format.

payment_signature

string

x402 payment signature covering exactly $15 USDC.

{
  "name": "merge_models",
  "arguments": {
    "config_yaml": "merge_method: linear\nmodels:\n  - model: mistralai/Mistral-7B-v0.1\n  - model: HuggingFaceH4/zephyr-7b-beta\ndtype: bfloat16",
    "payment_signature": "<base64>"
  }
}

cradle_breed_agent and merge_models are annotated destructive — they start real GPU jobs. get_dataset charges on paid tiers. All discovery and evaluation tools are read-only and free.

Protocol & Tools

Resources

Sella MCP tools: all parameters and JSON-RPC examples

Tools at a glance

Authentication tools

sella_auth_start

sella_auth_complete

Discovery tools

list_datasets · search_datasets

list_market_apis

Evaluation tool

try_dataset

Purchase tool

get_dataset

Compute tools

cradle_breed_agent

merge_models

​Tools at a glance

​Authentication tools

​sella_auth_start

​sella_auth_complete

​Discovery tools

​list_datasets · search_datasets

​list_market_apis

​Evaluation tool

​try_dataset

​Purchase tool

​get_dataset

​Compute tools

​cradle_breed_agent

​merge_models

Tools at a glance

Authentication tools

sella_auth_start

sella_auth_complete

Discovery tools

list_datasets · search_datasets

list_market_apis

Evaluation tool

try_dataset

Purchase tool

get_dataset

Compute tools

cradle_breed_agent

merge_models