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.

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.

string

Keyword search across title, description, and tags.

string

Filter by category slug.

string

Pricing tier: free, standard, premium, or enterprise.

string

Data modality: structured (tabular) or document (text/PDF).

string

File format: csv, tsv, json, jsonl, parquet, txt, md, or pdf.

number

Maximum per-access price in USDC. Excludes listings above this threshold.

string[]

Schema columns that must exist in the dataset.

string

default:"newest"

Sort order: newest, popular, price_asc, or price_desc.

number

default:"20"

Number of results to return. Accepts 1–100.

{
  "name": "search_datasets",
  "arguments": {
    "query": "sentiment",
    "required_fields": ["text", "label"],
    "max_price_usdc": 25
  }
}

list_market_apis

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

string

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

string

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

string

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

string

Preferred settlement chain: base, solana, or stellar.

boolean

When true, return only Sella-verified providers.

number

Maximum per-call price in USDC.

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.

string

required

The ID of the dataset to trial.

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.

string

required

The ID of the dataset to retrieve.

string

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

string

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

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.

string

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

string

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

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.

string

required

A valid MergeKit configuration in YAML format.

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