Elva vs flue: Features, Pricing & Which Is Better (2026)

A side-by-side comparison of Elva and flue — features, pricing, and ideal use cases — to help you decide which AI tool fits your workflow.

Elva

Theneo

Freemium

Reads your repositories to discover every API, scores and governs them, then exposes them to developers and AI agents via hosted MCP servers.

Spec-Free API Discovery: Elva scans repository code directly to find endpoints and generates OpenAPI 3.1 as output, so no existing spec is needed to start.
Endpoint Scoring: Every collection is graded on design, developer experience, AI readiness, security and performance, with the weakest collection surfaced first.
AI Fix Pass: A one-click agent writes missing descriptions from code, types response schemas and documents auth, then rescores the collection.
API Contracts: Per-audience contracts pin the exact endpoints and fields a partner, internal team, public developer or MCP client receives, excluding PII and internal fields.
Breaking Change Enforcement: Each commit is diffed against published contracts, showing the schema diff, affected consumers and tools, and blocking publish by policy.
Hosted MCP Servers: Contracts generate MCP servers hosted behind Elva's gateway with OAuth2, scoped keys, per-tool authorization and exportable call logs.
MCP Playground and Agent Feedback: Test the server with a live model, then read the complaints agents file about confusing or failing tools, scored back into the catalog.
Multi-Target Publishing: One approved contract ships as OpenAPI spec, Theneo docs, MCP server, Postman collection and a typed TypeScript SDK in sync.

API Inventory Audit: Discover undocumented or forgotten endpoints across a large codebase and get a ranked list of what to fix first.
Agent Enablement: Expose an internal service to Claude, Cursor or ChatGPT as a governed MCP server instead of hand-writing tool wrappers.
Partner Integration Safety: Publish a restricted contract to an external partner and have Elva block commits that would break their integration.
PII Scoping: Keep customer emails and internal ops annotations out of a public or agent-facing surface while the same endpoints serve them internally.
Zombie Endpoint Retirement: Prove no active consumer references an endpoint before deleting it, using contract and call-log evidence.
Enterprise Security Review: Satisfy SOC 2, ISO 27001 and GDPR questions and wire agent access into an existing SSO and SCIM identity provider.
Documentation Drift Control: Keep docs, SDKs and Postman collections regenerated from code on every merge instead of maintained by hand.

Astro

Free

Open-source TypeScript agent harness framework for building autonomous agents and AI workflows.

Agent Harness: A programmable TypeScript harness giving any model sessions, tools, skills, instructions, and filesystem access.
Autonomous Agents: Build agents that keep context across conversations and events while working toward a goal.
Workflows: Run structured automations where your code guides agent reasoning from input to finished result.
Secure Sandboxes: Give agents an isolated environment to use tools, modify files, and complete real work safely.
Durable Execution: Agents preserve progress and recover through failures and restarts.
Subagents and Tools: Delegate tasks to specialized subagents and give agents typed actions for APIs and data.
MCP and Observability: Connect tools via Model Context Protocol and monitor agents with OpenTelemetry and Braintrust.

Building Autonomous Agents: Create Claude Code or Codex-style agents that complete open-ended tasks independently.
Structured Workflows: Automate multi-step processes where code controls the agent's reasoning path.
Safe Tool Use: Run agents in a secure sandbox so they can take real actions without risk to your systems.
Local or Hosted Deployment: Run agents from the CLI during development, then deploy to a hosted runtime.
Tool Integration: Connect agents to authenticated services through MCP servers.