# Solvela > Solana-native payment gateway for AI agents: an OpenAI-compatible LLM proxy at https://api.solvela.ai where every paid request is settled per call in USDC-SPL over the x402 protocol (HTTP 402 quote, signed payment, retry) with no API key and no account. 44 models from six upstream providers, 17 of them free; a trustless on-chain escrow scheme; a spend-down voucher channel; an A2A 0.3.0 agent card; a stdio MCP server; SDKs in TypeScript, Python, Go and Rust. Open source at github.com/solvela-ai/solvela. Generated by API Evangelist on 2026-09-19 from the provider's public surface (method: generated). The provider publishes no llms.txt: /llms.txt returned 404 on api.solvela.ai, and solvela.ai / docs.solvela.ai return HTTP 402 DEPLOYMENT_DISABLED on every path, so the documentation links below point at the public source of the docs site. ## How to call it - Free: POST https://api.solvela.ai/v1/chat/completions with {"model":"free","messages":[...]} — no header, no wallet; 5 requests/min per IP. - Paid: send the same request without PAYMENT-SIGNATURE, read the 402 body (accepts[].amount in atomic USDC, pay_to, max_timeout_seconds 300), sign a USDC-SPL transfer on Solana mainnet, resend the byte-identical request with the signed payload base64-encoded in PAYMENT-SIGNATURE. Keep the X-Solvela-Receipt header from the response. - Model ids are provider-prefixed (openai/gpt-4o, anthropic/claude-sonnet-4-5-20250929); aliases (sonnet, gpt5, haiku) and profiles (auto, eco, premium, free) are accepted in the model field. - Rate limit 60/min per payer wallet; headers x-ratelimit-limit / -remaining / -reset (seconds) and retry-after on 429. - Errors are {"error":{"type","message"}}; a 402 without a payment header is the x402 PaymentRequired object at the top level (detect by x402_version). ## APIs - [Solvela Gateway API](https://github.com/solvela-ai/solvela): base https://api.solvela.ai — createChatCompletion (POST /v1/chat/completions), listModels (GET /v1/models), getReceipt (GET /v1/receipts/{receipt_id}), health (GET /health) - [OpenAPI 3.1 (provider-hosted)](https://api.solvela.ai/openapi.json) - [OpenAPI 3.1 (catalog copy, verbatim)](https://raw.githubusercontent.com/api-evangelist/solvela-ai/refs/heads/main/openapi/solvela-ai-openapi.json) - [Model catalog with USDC pricing](https://api.solvela.ai/v1/models) - [Full price table](https://api.solvela.ai/pricing) - [x402 payment-method discovery](https://api.solvela.ai/v1/supported) - [x402 well-known discovery](https://api.solvela.ai/.well-known/x402) - [Marketplace tools (web search, Solana prices)](https://api.solvela.ai/v1/services) - [Escrow configuration](https://api.solvela.ai/v1/escrow/config) ## Agents - [A2A agent card](https://api.solvela.ai/.well-known/agent-card.json): JSON-RPC endpoint https://api.solvela.ai/a2a, protocolVersion 0.3.0, extensions AP2 (merchant) and a2a-x402, one skill chat-completion - [A2A protocol docs](https://github.com/solvela-ai/solvela/blob/main/dashboard/content/docs/concepts/a2a.mdx) - [MCP server (stdio)](https://www.npmjs.com/package/@solvela/mcp-server): npx -y @solvela/mcp-server; tools chat, smart_chat, web_search, solana_price, wallet_status, list_models, spending, deposit_escrow - [MCP server README](https://github.com/solvela-ai/solvela/blob/main/sdks/mcp/README.md) - [Claude Code drop-in sidecar @solvela/dropin](https://www.npmjs.com/package/@solvela/dropin) ## Docs (source of docs.solvela.ai) - [Documentation index](https://github.com/solvela-ai/solvela/tree/main/dashboard/content/docs) - [Quick start](https://github.com/solvela-ai/solvela#quick-start) - [x402 protocol](https://github.com/solvela-ai/solvela/blob/main/dashboard/content/docs/concepts/x402.mdx) - [Authentication](https://github.com/solvela-ai/solvela/blob/main/dashboard/content/docs/api/authentication.mdx) - [Errors](https://github.com/solvela-ai/solvela/blob/main/dashboard/content/docs/api/errors.mdx) - [Rate limits](https://github.com/solvela-ai/solvela/blob/main/dashboard/content/docs/api/rate-limits.mdx) - [Pricing](https://github.com/solvela-ai/solvela/blob/main/dashboard/content/docs/concepts/pricing.mdx) - [Free tier](https://github.com/solvela-ai/solvela/blob/main/dashboard/content/docs/concepts/free-tier.mdx) - [Escrow](https://github.com/solvela-ai/solvela/blob/main/dashboard/content/docs/concepts/escrow.mdx) - [Spend-down channel](https://github.com/solvela-ai/solvela/blob/main/dashboard/content/docs/concepts/spend-down-channel.mdx) - [Security](https://github.com/solvela-ai/solvela/blob/main/dashboard/content/docs/operations/security.mdx) - [SDKs](https://github.com/solvela-ai/solvela/blob/main/dashboard/content/docs/sdks/index.mdx) - [Commercial license](https://github.com/solvela-ai/solvela/blob/main/dashboard/content/docs/enterprise/commercial-license.mdx) - [Changelog](https://github.com/solvela-ai/solvela/blob/main/CHANGELOG.md) - [Security policy](https://github.com/solvela-ai/solvela/blob/main/SECURITY.md) ## SDKs - [@solvela/sdk (npm, 0.4.0)](https://www.npmjs.com/package/@solvela/sdk) - [solvela-sdk (PyPI, 0.4.0)](https://pypi.org/project/solvela-sdk/) - [github.com/solvela-ai/solvela/sdks/go (v0.5.0)](https://pkg.go.dev/github.com/solvela-ai/solvela/sdks/go) - [solvela-client (crates.io, 0.4.0)](https://crates.io/crates/solvela-client) - [solvela-cli (crates.io, 0.2.0)](https://crates.io/crates/solvela-cli) ## API Evangelist artifacts - [apis.yml](https://raw.githubusercontent.com/api-evangelist/solvela-ai/refs/heads/main/apis.yml) - [Agent card manifest](https://raw.githubusercontent.com/api-evangelist/solvela-ai/refs/heads/main/a2a/solvela-ai-a2a.yml) - [MCP manifest](https://raw.githubusercontent.com/api-evangelist/solvela-ai/refs/heads/main/mcp/solvela-ai-mcp.yml) - [Tool crosswalk](https://raw.githubusercontent.com/api-evangelist/solvela-ai/refs/heads/main/mcp/solvela-ai-tool-crosswalk.yml) - [Conventions (idempotency, dry run, reversibility)](https://raw.githubusercontent.com/api-evangelist/solvela-ai/refs/heads/main/conventions/solvela-ai-conventions.yml) - [Authentication](https://raw.githubusercontent.com/api-evangelist/solvela-ai/refs/heads/main/authentication/solvela-ai-authentication.yml) - [Errors](https://raw.githubusercontent.com/api-evangelist/solvela-ai/refs/heads/main/errors/solvela-ai-problem-types.yml) - [Rate limits](https://raw.githubusercontent.com/api-evangelist/solvela-ai/refs/heads/main/rate-limits/solvela-ai-rate-limits.yml) - [Plans and pricing](https://raw.githubusercontent.com/api-evangelist/solvela-ai/refs/heads/main/plans/solvela-ai-plans-pricing.yml) - [Conformance](https://raw.githubusercontent.com/api-evangelist/solvela-ai/refs/heads/main/conformance/solvela-ai-conformance.yml) - [Lifecycle](https://raw.githubusercontent.com/api-evangelist/solvela-ai/refs/heads/main/lifecycle/solvela-ai-lifecycle.yml) - [Packages](https://raw.githubusercontent.com/api-evangelist/solvela-ai/refs/heads/main/packages/solvela-ai-packages.yml) - [Agent skills](https://raw.githubusercontent.com/api-evangelist/solvela-ai/refs/heads/main/skills/_index.yml)