on-chain analytics for evm contract

---

name: onchain-analysis description: Analyze any EVM smart contract — auto-fetches ABI, discovers usage patterns, decodes function calls via Dune, generates AI-driven analytics (charts, stats, time series), and returns structured results. Supports Ethereum, Polygon, BSC, Arbitrum, Optimism, Base, Avalanche.

---

On-Chain Analysis Skill

Analyze any verified EVM smart contract by pasting its address. The skill runs a full analysis pipeline:

1. ABI Fetching — Retrieves the verified ABI from Etherscan (or accepts a manual ABI) 2. Usage Discovery — Queries Dune to find which methods are most called, by whom, and with what value 3. Decoded Data Tables — AI generates DuneSQL queries using decode_evm_function_call() to build raw decoded data tables on Dune 4. Analytics Generation — A second AI pass generates 6-10 visualization queries (stats, time series, bar charts, pie charts) from the decoded tables 5. Execution — All queries are executed on Dune and results returned as structured JSON

When to Use

User asks "analyze this contract" or "what does this contract do"

User wants on-chain analytics, usage stats, or dashboards for a smart contract

User provides a contract address and wants to understand its activity

User asks about transaction patterns, caller behavior, or function usage

User wants to compare function usage or identify top callers

User asks "who uses this contract" or "how popular is this contract"

How to Call

POST https://esraarlhpxraucslsdle.supabase.co/functions/v1/onchain-analysis

Request Body

{
  "contractAddress": "0x00000000009726632680FB29d3F7A9734E3010E2",
  "chain": "base",
  "abi": "(optional — raw ABI JSON string if contract is unverified)"
}

Parameters

| Field | Type | Required | Description | |-------|------|----------|-------------| | contractAddress | string | Yes | The EVM contract address (0x-prefixed, 42 chars including 0x) | | chain | string | Yes | One of: ethereum, polygon, bsc, arbitrum, optimism, base, avalanche | | abi | string/array | No | Manual ABI if contract is not verified on Etherscan |

Supported Chains

| Chain | Example Explorer | |-------|-----------------| | ethereum | etherscan.io | | polygon | polygonscan.com | | bsc | bscscan.com | | arbitrum | arbiscan.io | | optimism | optimistic.etherscan.io | | base | basescan.org | | avalanche | snowtrace.io |

Response

{
  "contractAddress": "0x...",
  "chain": "base",
  "tldr": "## TLDR\n\n- Key insight 1 ...\n- Key insight 2 ...",
  "abiSummary": "Events (5):\n  - Transfer(...)\nWrite Functions (8):\n  - swap(...)",
  "dashboardUrl": "https://onchainwizard.ai/shared/abc123-uuid",
  "topMethods": [
    {
      "function_name": "swap",
      "call_count": 142000,
      "unique_callers": 5200,
      "total_eth": 1234.5678
    }
  ],
  "rawTables": [
    {
      "function_name": "swap",
      "query_id": 12345,
      "dune_url": "https://dune.com/queries/12345",
      "execution_state": "QUERY_STATE_COMPLETED"
    }
  ],
  "queryResults": [
    {
      "id": "total_swaps",
      "title": "Total Swaps",
      "type": "stat",
      "sql": "SELECT COUNT(*) AS value FROM query_12345",
      "rows": [{ "value": 142000 }]
    },
    {
      "id": "daily_swaps",
      "title": "Daily Swap Volume",
      "type": "timeseries",
      "sql": "SELECT DATE_TRUNC('day', block_time) AS date, COUNT(*) AS value FROM query_12345 GROUP BY 1 ORDER BY 1",
      "rows": [
        { "date": "2026-01-01", "value": 500 },
        { "date": "2026-01-02", "value": 620 }
      ]
    }
  ]
}

Query Result Types

| Type | Description | Key Fields | |------|-------------|------------| | stat | Single metric | rows[0].value — the headline number | | timeseries | Data over time | rows[].date, rows[].value | | bar | Category comparison | rows[].label, rows[].value | | pie | Distribution | rows[].label, rows[].value | | scatter | Correlation | rows[].x, rows[].y |

How to Present Results

1. Start with the TLDR — display it as markdown to give the user a quick overview 2. Dashboard link — always include the dashboardUrl so the user can view the full interactive dashboard: "📊 View full dashboard" 3. Stat queries (type: "stat") — show as headline metrics (e.g., "Total Swaps: 142,000") 4. Time series (type: "timeseries") — describe trends ("Daily swaps peaked at X on date Y") 5. Bar/Pie charts (type: "bar" / type: "pie") — summarize distributions ("Top 5 callers account for 60% of swaps") 6. Link to Dune — provide dune_url links for raw tables so users can explore further 7. Failed queries — if a query has error instead of rows, mention it briefly but don't block the rest

Example Conversations

Basic: "Analyze this contract"

User: Analyze 0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D on ethereum Action: Call the skill with { "contractAddress": "0x7a250d5630B4cF539739dF2C5dAcb4c659F2488D", "chain": "ethereum" } Present: TLDR → Stats → Trends → Distributions → Dune links

Missing chain

User: What does 0xABC...DEF do? Action: Ask which chain before calling. "Which chain is this contract on? I support Ethereum, Polygon, BSC, Arbitrum, Optimism, Base, and Avalanche."

Unverified contract

User: Analyze 0xABC...DEF on base API returns: "Could not fetch ABI" Action: Ask user for the ABI JSON, then retry with { "contractAddress": "...", "chain": "base", "abi": "" }

Follow-ups after analysis

"Tell me more about the top callers" → Expand on bar/pie data from queryResults

"What does the swap function do?" → Use abiSummary to explain

"Can I see the raw data?" → Link to rawTables[].dune_url

Important Notes

The analysis takes 2-5 minutes due to Dune query execution and materialization — set user expectations

Only works for contracts with verified ABIs (unless a manual ABI is provided)

The AI selects the most interesting functions automatically based on usage data

Raw decoded tables are saved as named queries on Dune for future reference

Query results may be empty if the contract has very little on-chain activity

Error Handling

| Error | Meaning | Recommended Action | |-------|---------|-------------------| | "Could not fetch ABI" | Contract is not verified | Ask user for the ABI | | "No write functions found" | No state-changing functions | Inform user; contract may be read-only or a proxy | | "Unsupported chain" | Chain not in supported list | List supported chains and ask again | | "Missing required API keys" | Server-side config issue | Report as a service error | | Timeout / no response | Analysis exceeded time limit | Suggest retrying; Dune may be under load |