Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx agentmods add agents/chdb-io/chdb/contractgit clone --depth 1 https://github.com/chdb-io/chdbWhat it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.00000 | $0.03500 |
| Opus 5 | $0.00000 | $0.01750 |
| Sonnet 5 | $0.00000 | $0.00700 |
| Haiku 4.5 | $0.00000 | $0.00350 |
Grade A, and why
CONTRACT scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured yesterday.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 233 lines — stays where its author put it; the contents beside it link to each section on GitHub.
chDB Agent Tool — cross-language contract
Status: beta / experimental (introduced in chdb 4.2.0). The surface may change in a minor release while it stabilizes across bindings; pin a version if you depend on it.
Contract version:
0.3.0— exposed asCONTRACT_VERSIONand viacapabilities()in every binding. Downstream consumers probe capabilities instead of guessing from a package version (see Versioning & capabilities).
One behavior, many bindings. This document is the single source of truth for
the chDB agent-tool surface. chdb.agents.ChDBTool (Python) is the reference
implementation; the TypeScript binding (chdb-node) and any future language
binding under chdb-io implement the same methods with the same
semantics and are verified against the same fixture (conformance/cases.jsonl).
The goal is explicit: stop each language re-inventing query + introspection + safety with subtly different behavior. If a binding needs to diverge, it must add a case to the shared fixture documenting the divergence — not silently differ.
Methods (names are canonical; per-language casing may adapt)
| Canonical tool name | Purpose |
|---|---|
run_select_query |
Run read SQL with bound params; return rows + truncation metadata |
list_databases |
List databases |
list_tables |
List tables in a database (current if omitted) |
describe_table |
Columns/types of a table or a table-function expression |
get_sample_data |
A few sample rows from a table or table function |
list_functions |
List available SQL functions |
attach_file |
Register a local file as a queryable named table (writable tools only) |
Bindings expose these as native tools (Python methods on ChDBTool; TS
chdbTools(); MCP tools in mcp-clickhouse) but the capability set, argument
meaning, error classification, and safety guarantees are identical.
descriptors.json — the model-visible surface (single source)
descriptors.json (next to this file; vendored byte-identical in every
binding) is the single source of truth for the model-visible surface: tool
names, description text, and argument schemas. Everything the model reads is
generated from it:
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- yesterday First seen · 233 lines · 0 tokens per session scan A edd5e306176d
CONTRACT is an agent published in the GitHub repository chdb-io/chdb (2,885 stars, last pushed 4d ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 3,500 tokens. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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