The full upstream README, mirrored here for reference. Install config, tool schemas, adoption signals, and an original overview live on the Attester Oracle listing page.
MCP server for attester.dev: verification and API-existence oracle tools for AI agents, callable from any MCP client (Claude Code, Cursor, Windsurf, LangChain, CrewAI).
Every result ships with a wallet-signed attestation you can verify without
trusting us: POST https://attester.dev/receipts/verify is free.
No install needed. Point your MCP client at the hosted endpoint:
Four oracle tools work immediately: no account, no API key, no wallet. You get 25 free calls per day per client IP, shared across the four tools, resetting 00:00 UTC. (This config block works for Claude Code, Claude Desktop, and Cursor; any MCP client that speaks streamable HTTP.)
| Tool | What it does | Price per call |
|---|---|---|
attester_package_exists | Does this PyPI/npm package name really exist? Typosquat-adjacency flags on misses. | Free (25/day keyless); $0.002 paid |
attester_symbol_exists | Does this function, class, or constant exist in the package? Closest-match suggestions on misses. | Free (25/day keyless); $0.005 paid |
attester_symbol_signature | Exact signature, structured params, docstring, deprecation status, resolved at a pinned version. | Free (25/day keyless); $0.01 paid |
attester_version_diff | Symbol-level diff between two pinned versions: added, removed, changed, breaking/additive/neutral. | Free (25/day keyless); $0.02 paid |
Run it locally instead (stdio): install from source with
pip install git+https://github.com/maminihds/attester-mcp.git, then use
"command": "attester-mcp" in the config above. A zero-install
uvx attester-mcp command lands once the package is published to PyPI.
| Tool | What it does | Price per call |
|---|---|---|
oracle_verify_work | Check another agent's work: citation support, code correctness, data/schema validation. Verdict plus signed attestation. | $0.15 USDC |
oracle_code_research | Cited coding research; citations are re-checked and the proof attached. | $0.10 USDC |
oracle_judge | Grade an output against your rubric; signed score with per-criterion evidence. | $0.10 USDC |
oracle_watchtower_report | Signed 24h report on whether an x402 service honors its advertised prices. | $0.05 USDC |
oracle_spend_check | Pre-payment counterparty check: should your agent pay this address? | $0.005 USDC |
Payment works two ways:
att_live_... key once at
https://attester.dev/credits/claim?session_id=cs_..., and set
ATTESTER_API_KEY=att_live_... in the server env. Every paid call
deducts from the balance. Check it at
GET https://attester.dev/credits/balance with the key.
(CREDITS_API_KEY still works as an alias.) The free oracle tools honor
the key too: the demo routes skip the daily quota for it and never
charge.BUYER_PRIVATE_KEY to a Base wallet
with USDC. The wrapper pays per call automatically (402, sign, retry)
and sends the wallet address as X-Payer, which keys the paid
endpoints' free quotas.Without any key, the paid endpoints answer HTTP 402 with payment terms in the body.
skills/attester)The same API, packaged as an Agent Skill so agent configs load it as a
default tool: when-to-use rules, exact curl per endpoint (the keyless
/demo/v1/* free path for oracle checks, X-Payer free quotas for the
rest), verdict reading, and receipt verification.
Install paths:
Or copy skills/attester/ into ~/.claude/skills/ manually. The bundle
has a helper (skills/attester/scripts/call.py, stdlib + httpx) and two
worked transcripts in skills/attester/examples/.
Environment variables:
SERVER_URL: API base URL, defaults to https://attester.dev.ATTESTER_API_KEY: prepaid credits key (att_live_...), optional.BUYER_PRIVATE_KEY: Base wallet for x402 payment, optional.examples/plain_python.py: direct x402-paid call with the official SDK.
examples/langchain_example.py: LangChain tool wrapper.