x402 is an open payment standard that lets an HTTP API charge for access using the 402 Payment Required status code. A caller pays in USDC, the server verifies the payment via a facilitator, then serves the request.

How do I pay for an endpoint on this API?

Send the request without payment first to receive a 402 response describing the price and payment details, then retry with a signed x402 payment header. USDC is paid on Base mainnet (eip155:8453), settled via the Coinbase CDP facilitator.

Is this API operated by a human or an autonomous agent?

The endpoint catalog is proposed and implemented by an autonomous agent, with every production deploy reviewed and approved by a human before it goes live.

Sovereign AI — x402 Paid API Catalog

An autonomous agent-operated API, monetized per-request in USDC on Base mainnet (eip155:8453) via the x402 payment protocol, settled through Coinbase's CDP facilitator.

Every endpoint below returns 402 Payment Required until a valid x402 payment is attached to the request. See /health for a free liveness check, or query a facilitator's /discovery/resources endpoint for machine-readable Bazaar discovery metadata.

Method	Path	Price	Description
POST	`/api/v1/chat/completions`	$0.005	AI chat completions API - pay per request with USDC on Base
POST	`/api/v1/code/exec`	$0.02	Execute Python code in a real, isolated E2B cloud sandbox (not a subprocess) and return stdout/stderr/results.
POST	`/api/v1/email/send`	$0.005	Send a plain-text or HTML email via Resend.
POST	`/api/v1/prime/check`	$0.001	Check if a number is prime.
POST	`/api/v1/qrcode`	$0.01	Generate a QR code SVG or Data URL from input text or URL without external third-party API keys.
POST	`/api/v1/repo/github/file`	$0.002	Fetch a file's contents from a GitHub repository at a given ref.
POST	`/api/v1/sequence/catalan`	$0.001	Calculate the nth Catalan number.
POST	`/api/v1/sequence/collatz_conjecture`	$0.001	Generate the Collatz sequence for a given number up to a specified limit.
POST	`/api/v1/sequence/even`	$0.001	Generate a list of even numbers up to a specified limit.
POST	`/api/v1/sequence/factorize`	$0.001	Factorize a given number into its prime factors.
POST	`/api/v1/sequence/fibonacci_pair`	$0.001	Generate the next Fibonacci pair (a, b) given a starting pair (a, b).
POST	`/api/v1/sequence/gcd`	$0.001	Compute the GCD of two integers.
POST	`/api/v1/sequence/hamming_weight`	$0.001	Calculate the Hamming weight (number of 1s) in the binary representation of a non-negative integer.
POST	`/api/v1/sequence/handshake`	$0.001	Generate a random handshake sequence (numbers and symbols) for secure connections.
POST	`/api/v1/sequence/harmonic`	$0.001	Generate a list of harmonic numbers (1 + 1/2 + ... + 1/n) up to a specified limit n.
POST	`/api/v1/sequence/hexadecimal`	$0.001	Convert a given non-negative integer to its hexadecimal string representation.
POST	`/api/v1/sequence/mersenne`	$0.001	Check if a given exponent p yields a Mersenne prime (2^p - 1).
POST	`/api/v1/sequence/odds`	$0.001	Generate a list of odd numbers up to a specified limit.
POST	`/api/v1/sequence/palindrome`	$0.001	Check if a given number is a palindrome.
POST	`/api/v1/sequence/permutations`	$0.002	Generate all permutations of a given sequence.
POST	`/api/v1/sequence/prime`	$0.001	Generate a list of prime numbers up to a specified limit.
POST	`/api/v1/sequence/prime_pairs`	$0.001	Generate twin prime pairs (p, p+2, both prime) up to a specified limit.
POST	`/api/v1/sequence/roman`	$0.001	Convert a given integer to its Roman numeral representation.
POST	`/api/v1/sequence/totient`	$0.001	Calculate Euler totient function phi(n) for a given positive integer n.
POST	`/api/v1/text/summarize`	$0.002	Generate a summary of a given text using the GLM chat model.
POST	`/api/v1/vector/pinecone/query`	$0.003	Query a Pinecone index for the nearest vectors to a given vector.
POST	`/api/v1/vector/pinecone/upsert`	$0.005	Upsert vectors into a Pinecone index (index must already exist in your Pinecone project -- 'test-index', dimension 2, is kept live for exactly this example).
POST	`/api/v1/vector/qdrant/query`	$0.003	Query a Qdrant collection for the nearest points to a given vector.
POST	`/api/v1/vector/qdrant/upsert`	$0.005	Upsert points into a Qdrant collection (collection is created automatically on first upsert if it doesn't exist).
POST	`/api/v1/web/scrape`	$0.01	Scrape a URL and return clean Markdown (via Firecrawl). Priced above Firecrawl's own per-scrape cost.
POST	`/calculate_fibonacci/:limit`	$0.001	Calculate the Fibonacci sequence up to N terms.