Tamp for OpenClaw#

Save 3-50% on input tokens by routing API requests through Tamp — a local HTTP proxy that compresses tool_result blocks before they reach Anthropic.

Prerequisites#

• Node.js 18+
• Anthropic API key — Tamp proxies requests to Anthropic. Your ANTHROPIC_API_KEY must be set in your OpenClaw config. Tamp itself does not store or read this key — it forwards the x-api-key header from incoming requests unchanged.

1. Install & Run#

bash

# Install a pinned version (recommended)
npm i -g @sliday/tamp@0.3.8

# Or run without installing
npx @sliday/tamp@0.3.8 -y

Start with default stages:

bash

TAMP_STAGES=minify,toon,strip-lines,whitespace,dedup,diff,prune tamp -y

Verify:

bash

curl http://localhost:7778/health
# {"status":"ok","version":"0.3.8","stages":["minify","toon",...]}

Tamp is open source (MIT). Audit the source, build from git, or run from a local clone: git clone https://github.com/sliday/tamp && cd tamp && npm install && node bin/tamp.js -y

2. Run as systemd service#

Create ~/.config/systemd/user/tamp.service:

ini

[Unit]
Description=Tamp token compression proxy
After=network.target

[Service]
# Adjust path: node -e "console.log(require('child_process').execFileSync('which', ['tamp']).toString().trim())"
ExecStart=/usr/local/bin/tamp
Restart=always
RestartSec=5
Environment=TAMP_PORT=7778
Environment=TAMP_STAGES=minify,toon,strip-lines,whitespace,dedup,diff,prune
Environment=TAMP_LOG=true

[Install]
WantedBy=default.target

bash

systemctl --user daemon-reload
systemctl --user enable --now tamp.service
journalctl --user -u tamp -f  # live compression logs

3. Configure OpenClaw#

Add a provider in your OpenClaw config:

json5

{
  models: {
    providers: {
      "anthropic-tamp": {
        baseUrl: "http://localhost:7778",
        apiKey: "${ANTHROPIC_API_KEY}",  // Forwarded to upstream, not stored by Tamp
        api: "anthropic-messages",
        models: [
          { id: "claude-opus-4-6", name: "Claude Opus 4.6 (compressed)" },
          { id: "claude-sonnet-4-6", name: "Claude Sonnet 4.6 (compressed)" }
        ]
      }
    }
  }
}

Set as primary model:

json5

{
  agents: {
    defaults: {
      model: { primary: "anthropic-tamp/claude-opus-4-6" }
    }
  }
}

Restart the gateway. All requests now flow through Tamp.

How it works#

text

OpenClaw → POST /v1/messages → Tamp (localhost:7778) → compresses JSON body → Anthropic API
                                                     ← streams response back unchanged

Tamp intercepts the request body, finds tool_result blocks in messages[], and compresses their content. Headers (including x-api-key) are forwarded unchanged. The response streams back untouched.

7 Compression Stages#

StageWhat it doesLossy?minifyStrip JSON whitespaceNotoonColumnar encoding for arrays (file listings, deps, routes)Nostrip-linesRemove line-number prefixes from Read tool outputNowhitespaceCollapse blank lines, trim trailing spacesNodedupDeduplicate identical tool_results across turnsNodiffDelta-encode similar re-reads as unified diffsNopruneStrip lockfile hashes, registry URLs, npm metadataMetadata only*

\* Prune removes fields like integrity, resolved, shasum, _id, _from, _nodeVersion from JSON — npm registry metadata not needed by the LLM. To keep full provenance, remove prune from TAMP_STAGES.

What to expect#

ScenarioSavingsChat sessions (short turns)3-5%Coding sessions (file reads, JSON)30-50%Lockfilesup to 81%Subagent tasks20-40%

Security Notes#

• API key handling: Tamp forwards the x-api-key / Authorization header from the incoming request to upstream. It does not store, log, or read API keys.
• Local only: Tamp binds to localhost by default. It does not accept external connections unless you change the bind address.
• No telemetry: Tamp does not phone home, collect analytics, or make any outbound connections except to the configured upstream API.
• Fallback: Add Anthropic direct as a fallback model in OpenClaw. If Tamp is down, requests bypass it automatically.

Resources#

• ~70MB RAM, <5ms latency per request
• No Python needed — all 7 stages run in Node.js
• Source (MIT) · tamp.dev · white paper