majordomo/README.md

# majordomo

A clean-slate Go library for building LLM-backed agents: one canonical API
over many model providers, a parseable model naming / failover / tiering
system with built-in health tracking, capability-aware multimodality, tool
calls, structured output, and composable agents and skills.

> The [support matrix](#featureprovider-support-matrix) below is kept
> honest: *pending* means not built, and this README is updated in the
> same commit as the behavior it describes. Runnable programs for every
> feature live in [examples/](examples/README.md).

## Install

```bash
go get gitea.stevedudenhoeffer.com/steve/majordomo
```

Requires Go 1.26+.

## Quickstart

```go
package main

import (
    "context"
    "fmt"

    "gitea.stevedudenhoeffer.com/steve/majordomo"
)

func main() {
    reg := majordomo.New() // built-ins + LLM_* env providers

    m, err := reg.Parse("ollama-cloud/minimax-m3:cloud")
    if err != nil { panic(err) }

    resp, err := m.Generate(context.Background(), majordomo.Request{
        Messages: []majordomo.Message{majordomo.UserText("hello!")},
    })
    if err != nil { panic(err) }
    fmt.Println(resp.Text())
}
```

`majordomo.Parse(...)` (package level) uses a lazily-built default registry
if you don't need isolation.

## Model specs: targets, chains, tiers

A model spec is a comma-separated **failover chain**; each element is either
a `provider/model` target or a registered **alias** (tier):

```go
// Try minimax-m3 first; on failure kimi-k2.6; finally fall back to opus-4.8.
m, _ := reg.Parse("ollama-cloud/minimax-m3:cloud,ollama-cloud/kimi-k2.6:cloud,anthropic/opus-4.8")

// Identical, with the registered alias "thinking" appended and expanded
// in place as the tail of the chain:
m, _ = reg.Parse("ollama-cloud/minimax-m3:cloud,ollama-cloud/kimi-k2.6:cloud,anthropic/opus-4.8,thinking")
```

Everything after the **first `/`** (up to the next comma) is the model id,
passed to the provider **verbatim** — tags (`:cloud`, `:30b`) and ids with
extra slashes survive intact. majordomo never validates ids against a
catalog.

### Custom tiers (aliases)

```go
reg.RegisterAlias("thinking", "anthropic/opus-4.8,ollama-cloud/minimax-m3:cloud")
reg.RegisterAlias("workhorse", "ollama-cloud/minimax-m2.7:cloud,ollama-cloud/qwen3-coder:480b-cloud")

m, _ := reg.Parse("thinking") // a chain, same Model interface as a single target
```

Aliases may appear anywhere in a chain (head, middle, tail), may reference
other aliases, and expand inline and recursively; cycles are detected and
returned as errors.

### Failover & health

Chains are health-tracked per target:

- A **single transient error** (429/5xx, timeout, connection failure) is
  retried once on the same target.
- **Repeated transient errors** (default: 2 consecutive failed attempts)
  bench the target — chains skip it until its cooldown expires (exponential:
  5s, 10s, 20s, ... capped at 5m). Any success resets it.
- `model not found` advances down the chain without penalty; auth/malformed
  errors fail fast (failing over can't fix a bad key). All knobs are
  configurable via `WithChainConfig` / `WithHealthConfig`.
- If every element fails, you get one joined error naming each target and
  why it failed.

## Providers

### Built-in env vars

| Provider | Spec name | Key env var | Default endpoint |
|----------|-----------|-------------|------------------|
| OpenAI (+compatible) | `openai` | `OPENAI_API_KEY` | https://api.openai.com/v1 |
| Anthropic (+compatible) | `anthropic` | `ANTHROPIC_API_KEY` | https://api.anthropic.com |
| Google (Gemini) | `google` | `GOOGLE_API_KEY` / `GEMINI_API_KEY` | Gemini API (official SDK) |
| Ollama Cloud | `ollama-cloud` | `OLLAMA_API_KEY` | https://ollama.com |
| Ollama (local) | `ollama` | — | `OLLAMA_HOST` or http://localhost:11434 |
| foreman | `foreman` | — (token via DSN) | requires an LLM_* DSN or `ollama.Foreman(url, token)` |

OpenAI-compatible / Anthropic-compatible endpoints: construct the provider
with a name and base URL and register it —

```go
reg.RegisterProvider(openai.New(
    openai.WithName("groq"),
    openai.WithBaseURL("https://api.groq.com/openai/v1"),
    openai.WithAPIKey(key),
    // openai.WithLegacyMaxTokens(), // for servers that only honor max_tokens
))
// now "groq/llama-3.3-70b" works in Parse, chains, and aliases
```

### `LLM_*` env-DSN provider definitions

Define named providers entirely from the environment (go-llm parity):

```
LLM_M1=foreman://test-token-change-me@foreman-m1.orgrimmar.dudenhoeffer.casa
LLM_M5=foreman://test-token-change-me@foreman-m5.orgrimmar.dudenhoeffer.casa
```

defines providers `m1` and `m5` (foreman targets — native Ollama wire
protocol behind a bearer token). They are first-class in `Parse`, chains,
and aliases:

```go
m, _ := reg.Parse("m5/qwen3:30b,m1/qwen3:30b,thinking")
```

DSN format: `scheme://[token@]host[/path]`, scheme ∈ `foreman`, `ollama`,
`ollama-cloud`, `openai`, `anthropic`, `google`/`gemini`, or any scheme you
add with `RegisterScheme`. The token is the credential (bearer token / API
key); the base URL is always `https://host[/path]`. `New()` loads `LLM_*`
vars eagerly; unknown provider names also resolve lazily at Parse time
(`my-prov/x` → `LLM_MY_PROV`).

### Custom providers

Implement the two-method `Provider` interface and register it:

```go
reg.RegisterProvider(myProvider) // now "myprovider/model-x" parses, chains, aliases
```

## Multimodality

Attach images without knowing the target's limits. Before each attempt the
request is normalized against the **actual serving target's** declared
capabilities: the real format is sniffed from the bytes, oversize images
are downscaled (aspect preserved), disallowed formats are re-encoded, and
byte budgets are enforced by a quality ladder. What cannot be made to fit
is rejected with a clear `ErrUnsupported` error — and in a chain, the
request simply advances to the next (e.g. vision-capable) element.

```go
resp, err := m.Generate(ctx, majordomo.Request{
    Messages: []majordomo.Message{
        majordomo.UserParts(majordomo.Text("what's in this image?"),
            majordomo.Image("image/png", pngBytes)),
    },
})
```

## Tool calls

```go
weather := majordomo.Tool{
    Name:        "get_weather",
    Description: "Current weather for a city",
    Parameters:  json.RawMessage(`{"type":"object","properties":{"city":{"type":"string"}},"required":["city"]}`),
    Handler: func(ctx context.Context, args json.RawMessage) (any, error) {
        var p struct{ City string `json:"city"` }
        _ = json.Unmarshal(args, &p)
        return map[string]any{"city": p.City, "temp_c": 21}, nil
    },
}
resp, _ := m.Generate(ctx, req, majordomo.WithTools(weather))
// resp.ToolCalls → execute → append ToolResultsMessage → continue
```

Each provider maps this one shape to its native function-calling format
(OpenAI tools/tool_calls, Anthropic tool_use/tool_result, Ollama tools with
object arguments). Tool-call ids are synthesized when a backend omits them;
streaming buffers tool-call arguments until they parse.

## Structured output

```go
resp, _ := m.Generate(ctx, req, majordomo.WithSchema(schemaJSON, "answer"))
```

Maps to OpenAI `response_format: json_schema`, Anthropic
`output_config.format`, Ollama `format`, and Google `responseJsonSchema`.

The typed helper derives the schema from your struct (all fields required,
`additionalProperties:false`, pointers nullable; `description:"..."` and
`enum:"a,b,c"` tags supported) and unmarshals the result:

```go
type Verdict struct {
    Guilty bool   `json:"guilty"`
    Why    string `json:"why" description:"one-sentence rationale"`
}
v, err := majordomo.Generate[Verdict](ctx, m, req)
```

## Agents

An agent is a model + system prompt + toolboxes, run as a tool-dispatch
loop until the model answers (or `MaxSteps`):

```go
import "gitea.stevedudenhoeffer.com/steve/majordomo/agent"

a := agent.New(m, "You are a research assistant.",
    agent.WithToolbox(searchTools),
    agent.WithMaxSteps(8),
    agent.WithStepObserver(func(s agent.Step) { log.Printf("step %d", s.Index) }),
)
res, err := a.Run(ctx, "What changed in Go 1.26?")
// res.Output, res.Steps, res.Usage; res.Messages round-trips via
// agent.WithHistory for conversation continuation.
```

The loop never panics: tool handler errors and panics become error results
the model can react to; unknown tools likewise; duplicate tool names across
toolboxes fail loudly. On `agent.ErrMaxSteps` (and on model errors) the
partial result with the full transcript is still returned.

## Skills

Skills are reusable instruction+tool bundles attachable to **any** agent,
at construction or on demand. Instructions extend the system prompt;
tools extend the toolset — additively, in attachment order.

```go
import (
    "gitea.stevedudenhoeffer.com/steve/majordomo/skill"
    "gitea.stevedudenhoeffer.com/steve/majordomo/skill/calc"
    "gitea.stevedudenhoeffer.com/steve/majordomo/skill/clock"
)

research := skill.New("research",
    skill.WithInstructions("Cite a source for every claim."),
    skill.WithTools(searchTool, fetchTool),
)

a := agent.New(m, "You are helpful.", agent.WithSkill(research))
a.AddSkill(clock.New()) // ready-made: time awareness
a.AddSkill(calc.New())  // ready-made: exact arithmetic
```

Anything implementing the three-method `agent.Skill` interface (Name /
Instructions / Tools) is a skill — `skill.New` is just the convenient way
to build one.

## Feature/provider support matrix

| Provider | Resolve/Parse | Chat | Streaming | Tools | Structured | Images | Env DSN |
|----------------------|:---:|:---:|:---:|:---:|:---:|:---:|:---:|
| OpenAI (+compatible) | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
| Anthropic (+compat) | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
| Google (Gemini) | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
| Ollama Cloud | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
| Ollama (local) | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ |
| foreman | ✅ | ✅ | ✅¹ | ✅ | ✅ | ✅ | ✅ |
| fake (testing) | ✅ | ✅ | ✅ | ✅ | ✅ | ✅ | — |

¹ foreman's daemon currently buffers sync chat responses (no token-by-token
streaming); majordomo's stream API works against it and delivers the
response as a single delta plus final event.

Notes: Ollama has no native tool_choice — `"none"` drops the tools;
`"required"`/named choices are best-effort ignored there. Ollama Cloud
ignores the `format` field (verified live), so the provider also states
the schema as an explicit system instruction — constrained decoding on
local Ollama, instruction-guided JSON on cloud, one canonical API either
way.

Cross-cutting: Parse grammar ✅ · aliases/tiers ✅ · failover chains ✅ ·
health tracking/backoff ✅ · LLM_* env DSNs ✅ · media pipeline ✅
(per-target normalization in chains) · agent loop ✅ · `Generate[T]` +
schema derivation ✅ · skills ✅ (with clock + calc examples).

## Development

```bash
go build ./... && go vet ./... && go test -race -count=1 ./...
```

The default test suite is fully hermetic (no network, no credentials).
Live integration tests (Phase 8) are gated behind the `live` build tag and
read `.env` (see `.env.example`; never commit `.env`).

Design decisions are recorded in [docs/adr/](docs/adr/README.md);
conventions in [CLAUDE.md](CLAUDE.md); build history in
[progress.md](progress.md); the mort conversion plan in
[docs/mort-migration.md](docs/mort-migration.md).