Ringfence is a budget firewall for Claude Code, Cursor, Aider, and every other AI coding agent. Dashboards tell you after the bill is gone. Ringfence stops the next API call when the cap hits.
Local install in 60 seconds. No card. No prompts ever leave your laptop.
When the daily or monthly cap hits, the proxy returns 429. The agent's retry loop stops. No more $3k weekend bills.
fence is a local CLI + proxy. Install with one curl, point your tool at it (ANTHROPIC_BASE_URL / OPENAI_BASE_URL / GENAI_API_BASE — same proxy port for all three). Every call gets priced and capped before it goes upstream.
Prompts and completions never leave your machine. The optional cloud receives token-count metadata only — never the contents.
Solo devs run fence locally for free, forever. Teams add the cloud for shared rollups, Slack alerts, and per-developer budgets — billed flat, no per-seat surprise.
Most AI cost tools tell you about the bill. Ringfence prevents the next dollar.
| Ringfence | Helicone / Portkey / Langfuse | Anthropic Console | ccusage / OSS dashboards | |
|---|---|---|---|---|
| Hard cutoff at the cap | ✓ | ✗ | partial | ✗ |
| Self-hosted (prompts never leave) | ✓ | ✗ | ✗ | ✓ |
| Per-developer attribution | ✓ | ✓ | ✗ | ✗ |
| Multi-provider | Claude (OpenAI v0.2) | ✓ | ✗ | ✗ |
| Single-binary install | ✓ | ✗ | ✗ | ✓ |
| Flat pricing, no per-seat | ✓ | ✗ | n/a | free |
Flat tiers. No per-seat checkout friction. Eng managers can expense the first three without procurement.
$0 /forever
£29 / ~$39 per month
Save £58/yr
£79 / ~$99 per month
Save £158/yr
£249 / ~$299 per month
Save £498/yr
Need SAML SSO or to run the cloud on your own infrastructure? Contact us about the enterprise plan — from $4,800/yr with audit log, SAML SSO, and support contract.
Install once, point your AI tool at the local proxy, you're done.
curl -sSL https://ringfence.dev/install.sh | bash fence enable-system-wide # sets all three base URLs at once # ANTHROPIC_BASE_URL → for Claude Code / Aider / Cursor # OPENAI_BASE_URL → for Codex CLI / OpenAI SDKs # GENAI_API_BASE → for Gemini SDKs
Or, manually for one tool at a time — see the per-provider list below.
fence-proxy intercepts each provider on a single port. Tell your tool to use the proxy by exporting the right base URL — that's the only step.
Claude Code · Aider · Cursor (when configured for Anthropic) · the official Anthropic Python / TypeScript SDKs
export ANTHROPIC_BASE_URL=http://localhost:9000
Routes: /v1/messages, /v1/complete
Codex CLI · the official OpenAI Python / TypeScript SDKs · Aider when configured for OpenAI · Cursor (OpenAI mode)
export OPENAI_BASE_URL=http://localhost:9000 # legacy SDKs use OPENAI_API_BASE — set both to be safe: export OPENAI_API_BASE=http://localhost:9000
Routes: /v1/chat/completions, /v1/responses, /v1/embeddings
Tools that use the @google/genai SDK with a configurable base URL · custom integrations using generativelanguage.googleapis.com
export GENAI_API_BASE=http://localhost:9000
Routes: /v1beta/models/<name>:generateContent, :streamGenerateContent
Tools that hard-code their upstream (e.g. the Claude Desktop app, some IDE-embedded Gemini integrations) can't be intercepted without TLS-MITM and aren't supported in v1. Run fence providers any time for the current canonical list.