Read the card

The first command is:

canact probe --provider ollama --model llama3.2:3b --cheap --json

The built-in Ollama URL is http://127.0.0.1:11434/v1. That string is the crate constant OLLAMA_BASE_URL. Nothing reads an environment variable of that name. Pass --base-url to use a different URL.

Definitions

A host is the program that will call the model. That is the CLI user, Aider, Cline, or a ProbeClient. The card is for that host.

Host policy is the set of envelope fields a host branches on: how many tools to send, which edit format to pick, whether to fall back to XML, and whether to repair JSON. It is not a rank of the model.

The fixed probe tool set is what canact sends. tool_selection sends eight names: read_file, edit_file, doc_set, search, run_command, list_dir, md_replace_section, and write_file. parallel_tool_scale sends read_file only. That set is not the caller's schema. This page does not describe a host-supplied tool list.

The context ladder climbs 4096, then 8192, then 16384. --cheap and --suite=policy stop after 4096. --full and --suite=all continue through 8192 and 16384.

canact probe --json prints the host-policy envelope. The cache file is probes.json. Entries last 30 days. The cache key includes the suite version (currently 97). fromCache is true only when this print came from that file. cacheable means the result may be stored. A context-window rejection keeps the last passing ladder rung, and the card stays cacheable. A provider safety stop is not a score, so the card is not stored. A malformed tool call is a completed Weak. Do not paste the envelope over probes.json.

Envelope fields

The Getting started page and the README host-policy table list the fields a host branches on. The envelope also always includes these:

Field	Meaning
`model`	Model id that was probed
`provider`	Provider label
`overall`	Lowest measured level among tool calling, JSON output, and instruction following (`weak`, `medium`, or `strong`). `weak` when none of those three were measured.
`canUseTools`	Native or XML tool calling completed Medium or stronger
`supportsVision`	The vision probe completed Medium or stronger
`toolSelectionStatus`	`completed`, `skipped`, `unprobed`, or `error` for `tool_selection`. Read this before treating `maxTools` 10 as measured Weak.
`effectiveContextTokens`	Measured usable context, in tokens, or JSON `null` until a suite writes it
`probedContextFloor`	Highest passing ladder rung when the climb is incomplete, or JSON `null`
`skipExpensive`	True on the policy suite
`suite`	`policy`, `full`, or `all`
`advertisedContextTokens`	Catalog or flag prior, or JSON `null`
`probedAt`	Unix seconds when the card was stored
`scoreScale`	`min` 0.0, `max` 1.0, `strongMin` 0.8, `mediumMin` 0.4
`probes`	Policy dimensions. `multiTurnTaskSequencing` is present on policy with status `skipped`.
`diagnostics`	Empty on policy and full. Populated on `--suite=all`.

maxOutputTokens is inserted only when it was measured. It is omitted otherwise. constraintPlacement is inserted only on --suite=all, and only when a placement was measured. Both fields are already in the README host-policy table.

On a policy run, agentLoop is JSON null and probes.multiTurnTaskSequencing.status is skipped. A full suite that completes sequencing sets agentLoop to full, assisted, or single.

Exit code 2

When the model cannot use tools, canact prints the envelope on stdout first, then this line on stderr, then exits 2:

error: cannot use tools (native and XML both failed to complete)

JSON on stdout is still valid. A shell with set -e stops on that exit code.

Library

ProbeRunner stays on feature runtime. ProbeRunner::new is the full suite and paid concurrency (64). ProbeRunner::new_throttled is the policy suite and free concurrency (3). The README example uses new_throttled. .suite() changes the suite only. .throttled() changes concurrency only. .cheap() and .full() set both.

A snippet that constructs OpenAiCompatClient needs features runtime and openai. The key below is None because this URL is local Ollama. Do not put a raw key in the source.

canact = { version = "0.10", default-features = false, features = ["runtime", "openai"] }

#![allow(unused)]
fn main() {
use canact::{CatalogPriors, OpenAiCompatClient};

let _client = OpenAiCompatClient::new(
    "http://127.0.0.1:11434/v1",
    None,
    "llama3.2:3b",
    "ollama",
    CatalogPriors::default(),
)
.expect("client");
}

Matrix

canact matrix prints pretty JSON. Each cell is pass, degraded, fail, or skipped. There is no --json flag and no human table. --provider is optional. Omit it to include every cached provider. The command does not call a model.

MCP

canact mcp --api-key-env XAI_API_KEY --base-url http://127.0.0.1:11434/v1

--api-key-env is the name of an environment variable. The tool cannot name a different variable, and it must not receive a raw key. --base-url is the probe URL. The tool cannot replace it. --allow-base-url lets the tool pass a base URL that is not a loopback host. --allow-cache lets the tool pass a cache path outside the default cache directory.

Other commands

The credential table is in Getting started. canact probe --no-login skips stored Grok and Claude Code logins. Environment variables and --api-key still apply. See #288.

canact cache path prints the cache file. canact cache list prints the stored rows. This page does not copy that output. See #287.

canact export --all writes the Aider pair and cline.modelinfo.json and leaves stdout empty. The file list stays in the README. See #289.

canact probe --dry-run prints the provider, redacted base URL, suite, and probe names, then exits. It does not read a login, the cache, or the network. See #290.

canact probe --fail-on weak exits 2 when a finished row is Weak. --fail-on degraded also exits 2 for Medium. A skipped row or a probe error does not count. An unknown value exits 1.

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