This commit is contained in:
afjcjsbx 2026-03-13 18:16:19 +01:00
parent bb7202462a
commit b5adb2bb02
3 changed files with 195 additions and 65 deletions

View file

@ -19,30 +19,62 @@ The user's intent reaches the model **as soon as the current tool finishes**, no
```mermaid
graph TD
subgraph External Callers
CH[Channel Handler]
API[HTTP API]
WS[WebSocket]
TG[Telegram]
DC[Discord]
SL[Slack]
end
subgraph AgentLoop
BUS[MessageBus]
DRAIN[drainBusToSteering goroutine]
SQ[steeringQueue]
RLI[runLLMIteration]
TE[Tool Execution Loop]
LLM[LLM Call]
end
CH -->|Steer| SQ
API -->|Steer| SQ
WS -->|Steer| SQ
TG -->|PublishInbound| BUS
DC -->|PublishInbound| BUS
SL -->|PublishInbound| BUS
BUS -->|ConsumeInbound while busy| DRAIN
DRAIN -->|Steer| SQ
RLI -->|1. initial poll| SQ
TE -->|2. poll after each tool| SQ
TE -->|3. poll after last tool| SQ
SQ -->|pendingMessages| RLI
RLI -->|inject into context| LLM
```
### Bus drain mechanism
Channels (Telegram, Discord, etc.) publish messages to the `MessageBus` via `PublishInbound`. Without additional wiring, these messages would sit in the bus buffer until the current `processMessage` finishes — meaning steering would never work for real users.
The solution: when `Run()` starts processing a message, it spawns a **drain goroutine** (`drainBusToSteering`) that keeps consuming from the bus and calling `Steer()`. When `processMessage` returns, the drain is canceled and normal consumption resumes.
```mermaid
sequenceDiagram
participant Bus
participant Run
participant Drain
participant AgentLoop
Run->>Bus: ConsumeInbound() → msg
Run->>Drain: spawn drainBusToSteering(ctx)
Run->>Run: processMessage(msg)
Note over Drain: running concurrently
Bus-->>Drain: ConsumeInbound() → newMsg
Drain->>AgentLoop: al.transcribeAudioInMessage(ctx, newMsg)
Drain->>AgentLoop: Steer(providers.Message{Content: newMsg.Content})
Run->>Run: processMessage returns
Run->>Drain: cancel context
Note over Drain: exits
```
## Data Structures
### steeringQueue
@ -59,7 +91,7 @@ A thread-safe FIFO queue, private to the `agent` package.
| Method | Description |
|--------|-------------|
| `push(msg)` | Appends a message to the queue |
| `push(msg) error` | Appends a message to the queue. Returns an error if the queue is full (`MaxQueueSize`) |
| `dequeue() []Message` | Removes and returns messages according to `mode`. Returns `nil` if empty |
| `len() int` | Returns the current queue length |
| `setMode(mode)` | Updates the dequeue strategy |
@ -86,7 +118,7 @@ A new field was added to `processOptions`:
| Method | Signature | Description |
|--------|-----------|-------------|
| `Steer` | `Steer(msg providers.Message)` | Enqueues a steering message. Thread-safe, can be called from any goroutine. |
| `Steer` | `Steer(msg providers.Message) error` | Enqueues a steering message. Returns an error if the queue is full or not initialized. Thread-safe, can be called from any goroutine. |
| `SteeringMode` | `SteeringMode() SteeringMode` | Returns the current dequeue mode. |
| `SetSteeringMode` | `SetSteeringMode(mode SteeringMode)` | Changes the dequeue mode at runtime. |
| `Continue` | `Continue(ctx, sessionKey, channel, chatID) (string, error)` | Resumes an idle agent using pending steering messages. Returns `""` if queue is empty. |
@ -134,24 +166,18 @@ sequenceDiagram
LLM-->>runLLMIteration: response with toolCalls[0..N]
loop for each tool call (sequential)
alt i > 0
ToolExecution->>AgentLoop: dequeueSteeringMessages()
AgentLoop-->>ToolExecution: steeringMessages
alt steering found
Note over ToolExecution: Mark tool[i..N] as<br/>"Skipped due to queued user message."
ToolExecution-->>runLLMIteration: steeringAfterTools = steeringMessages
Note over ToolExecution: break out of tool loop
end
end
ToolExecution->>ToolExecution: execute tool[i]
ToolExecution->>ToolExecution: process result,<br/>append to messages[]
alt last tool (i == N-1)
ToolExecution->>AgentLoop: dequeueSteeringMessages()
AgentLoop-->>ToolExecution: steeringMessages (may be empty)
ToolExecution->>AgentLoop: dequeueSteeringMessages()
AgentLoop-->>ToolExecution: steeringMessages
alt steering found
opt remaining tools > 0
Note over ToolExecution: Mark tool[i+1..N-1] as<br/>"Skipped due to queued user message."
end
Note over ToolExecution: steeringAfterTools = steeringMessages
Note over ToolExecution: break out of tool loop
end
end
@ -168,12 +194,11 @@ sequenceDiagram
| # | Location | When | Purpose |
|---|----------|------|---------|
| 1 | Top of `runLLMIteration`, before first LLM call | Once, at loop entry | Catch messages enqueued while the agent was still setting up context |
| 2 | Between tool calls, before tool `[i]` where `i > 0` | After each tool finishes | Interrupt mid-batch if the user sent a steering message |
| 3 | After the last tool in the batch | After tool `[N-1]` finishes | Catch messages that arrived during the last tool's execution |
| 2 | After every tool completes (including the first and the last) | Immediately after each tool's result is processed | Interrupt the batch as early as possible — if steering is found and there are remaining tools, they are all skipped |
### What happens to skipped tools
When steering interrupts a tool batch at index `i`, all tools from `i` to `N-1` are **not executed**. Instead, a tool result message is generated for each:
When steering interrupts a tool batch after tool `[i]` completes, all tools from `[i+1]` to `[N-1]` are **not executed**. Instead, a tool result message is generated for each:
```json
{
@ -213,6 +238,27 @@ This allows **one extra iteration** when steering arrives right at the max itera
> **Trade-off:** This introduces latency when the LLM requests multiple independent tools in a single turn. In practice, most batches contain 1-2 tools, so the impact is minimal. The benefit of being able to interrupt outweighs the cost.
### Why skip remaining tools (instead of letting them finish)
Two strategies were considered when a steering message is detected mid-batch:
1. **Skip remaining tools** (chosen) — stop executing, mark the rest as skipped, inject steering
2. **Finish all tools, then inject** — let everything run, append steering afterwards
Strategy 2 was rejected for three reasons:
**Irreversible side effects.** Tools can send emails, write files, spawn subagents, or call external APIs. If the user says "stop" or "change direction", those actions have already happened and cannot be undone.
| Tool batch | Steering | Skip (1) | Finish (2) |
|---|---|---|---|
| `[search, send_email]` | "don't send it" | Email not sent | Email sent |
| `[query, write_file, spawn]` | "wrong database" | Only query runs | File + subagent wasted |
| `[fetch₁, fetch₂, fetch₃, write]` | topic change | 1 fetch | 3 fetches + write, all discarded |
**Wasted latency.** Tools like web fetches and API calls take seconds each. In a 3-tool batch averaging 3-4s per tool, the user would wait 10+ seconds for work that gets thrown away.
**The LLM retains full awareness.** Skipped tools receive an explicit `"Skipped due to queued user message."` result, so the model knows what was not done and can decide whether to re-execute with the new context or take a different path.
## The Continue() method
`Continue` handles the case where the agent is **idle** (its last message was from the assistant) and the user has enqueued steering messages in the meantime.
@ -255,3 +301,6 @@ flowchart TD
| Skipped tools get explicit error results | The LLM protocol requires a tool result for every tool call in the assistant message. Omitting them would cause API errors. The skip message also informs the model about what was not done. |
| `Continue()` uses `SkipInitialSteeringPoll` | Prevents race conditions and double-dequeuing when resuming an idle agent. |
| Queue stored on `AgentLoop`, not `AgentInstance` | Steering is a loop-level concern (it affects the iteration flow), not a per-agent concern. All agents share the same steering queue since `processMessage` is sequential. |
| Bus drain goroutine in `Run()` | Channels (Telegram, Discord, etc.) publish to the bus via `PublishInbound`. Without the drain, messages would queue in the bus channel buffer and only be consumed after `processMessage` returns — defeating the purpose of steering. The drain goroutine bridges the gap by consuming new bus messages and calling `Steer()` while the agent is busy. |
| Audio transcription before steering | The drain goroutine calls `al.transcribeAudioInMessage(ctx, msg)` before steering, so voice messages are converted to text before the agent sees them. If transcription fails, the error is silently discarded and the original message is steered as-is. |
| `MaxQueueSize = 10` | Prevents unbounded memory growth if a user sends many messages while the agent is busy. Excess messages are dropped with a warning. |

View file

@ -49,13 +49,16 @@ The environment variable `PICOCLAW_AGENTS_DEFAULTS_STEERING_MODE` can be used as
### Steer — Send a steering message
```go
agentLoop.Steer(providers.Message{
err := agentLoop.Steer(providers.Message{
Role: "user",
Content: "change direction, focus on X instead",
})
if err != nil {
// Queue is full (MaxQueueSize=10) or not initialized
}
```
The message is enqueued in a thread-safe manner. It will be picked up at the next polling point (after the current tool finishes).
The message is enqueued in a thread-safe manner. Returns an error if the queue is full or not initialized. It will be picked up at the next polling point (after the current tool finishes).
### SteeringMode / SetSteeringMode
@ -73,6 +76,9 @@ When the agent is idle (it has finished processing and its last message was from
```go
response, err := agentLoop.Continue(ctx, sessionKey, channel, chatID)
if err != nil {
// Error (e.g. "no default agent available")
}
if response == "" {
// No steering messages in queue, the agent stays idle
}
@ -82,21 +88,48 @@ if response == "" {
## Polling points in the loop
Steering is checked at **three points** in the agent cycle:
Steering is checked at **two points** in the agent cycle:
1. **At loop start** — before the first LLM call, to catch messages enqueued during setup
2. **After each tool** — between tool calls within the same batch
3. **After the last tool** — to catch messages that arrived while the last tool was executing
2. **After every tool completes** — including the first and the last. If steering is found and there are remaining tools, they are all skipped immediately
## Skipped tool behavior
## Why remaining tools are skipped
When steering interrupts a batch of tool calls, the tools that were not yet executed receive a `tool` result with:
When a steering message is detected, all remaining tools in the batch are skipped rather than executed. The alternative — let all tools finish and inject the steering message afterwards — was considered and rejected. Here is why.
### Preventing unwanted side effects
Tools can have **irreversible side effects**. If the user says "no, wait" while the agent is mid-batch, executing the remaining tools means those side effects happen anyway:
| Tool batch | Steering message | With skip | Without skip |
|---|---|---|---|
| `[web_search, send_email]` | "don't send it" | Email **not** sent | Email sent, damage done |
| `[query_db, write_file, spawn_agent]` | "use another database" | Only the query runs | File written + subagent spawned, all wasted |
| `[search₁, search₂, search₃, write_file]` | user changes topic entirely | 1 search | 3 searches + file write, all irrelevant |
### Avoiding wasted time
Tools that take seconds (web fetches, API calls, database queries) would all run to completion before the agent sees the user's correction. In a batch of 3 tools each taking 3-4 seconds, that's 10+ seconds of work that will be discarded.
With skipping, the agent reacts as soon as the current tool finishes — typically within a few seconds instead of waiting for the entire batch.
### The LLM gets full context
Skipped tools receive an explicit error result (`"Skipped due to queued user message."`), so the model knows exactly which actions were not performed. It can then decide whether to re-execute them with the new context, or take a different path entirely.
### Trade-off: sequential execution
Skipping requires tools to run **sequentially** (the previous implementation ran them in parallel). This introduces latency when the LLM requests multiple independent tools in a single turn. In practice, most batches contain 1-2 tools, so the impact is minimal compared to the benefit of being able to stop unwanted actions.
## Skipped tool result format
When steering interrupts a batch, each tool that was not executed receives a `tool` result with:
```
Content: "Skipped due to queued user message."
```
This is saved to the session and sent to the model, so it is aware that some requested actions were not performed.
This is saved to the session via `AddFullMessage` and sent to the model, so it is aware that some requested actions were not performed.
## Full flow example
@ -117,8 +150,17 @@ This is saved to the session and sent to the model, so it is aware that some req
7. LLM receives the full updated context and responds accordingly
```
## Automatic bus drain
When the agent loop (`Run()`) starts processing a message, it spawns a background goroutine that keeps consuming new inbound messages from the bus. These messages are automatically redirected into the steering queue via `Steer()`. This means:
- Users on any channel (Telegram, Discord, etc.) don't need to do anything special — their messages are automatically captured as steering when the agent is busy
- Audio messages are transcribed before being steered, so the agent receives text. If transcription fails, the original (non-transcribed) message is steered as-is
- When `processMessage` finishes, the drain goroutine is canceled and normal message consumption resumes
## Notes
- Steering **does not interrupt** a tool that is currently executing. It waits for the current tool to finish, then checks the queue.
- With `one-at-a-time` mode, if multiple messages are enqueued rapidly, they will be processed one per iteration. This gives the model the opportunity to react to each message individually.
- With `all` mode, all pending messages are combined into a single injection. Useful when you want the agent to receive all the context at once.
- The steering queue has a maximum capacity of 10 messages (`MaxQueueSize`). `Steer()` returns an error when the queue is full. In the bus drain path, the error is logged as a warning and the message is effectively dropped.

View file

@ -260,6 +260,13 @@ func (al *AgentLoop) Run(ctx context.Context) error {
continue
}
// Start a goroutine that drains the bus while processMessage is
// running. Any inbound messages that arrive during processing are
// redirected into the steering queue so the agent loop can pick
// them up between tool calls.
drainCtx, drainCancel := context.WithCancel(ctx)
go al.drainBusToSteering(drainCtx)
// Process message
func() {
// TODO: Re-enable media cleanup after inbound media is properly consumed by the agent.
@ -275,6 +282,8 @@ func (al *AgentLoop) Run(ctx context.Context) error {
// }
// }()
defer drainCancel()
response, err := al.processMessage(ctx, msg)
if err != nil {
response = fmt.Sprintf("Error processing message: %v", err)
@ -321,6 +330,39 @@ func (al *AgentLoop) Run(ctx context.Context) error {
return nil
}
// drainBusToSteering continuously consumes inbound messages and redirects
// them into the steering queue. It runs in a goroutine while processMessage
// is active and stops when drainCtx is canceled (i.e., processMessage returns).
func (al *AgentLoop) drainBusToSteering(ctx context.Context) {
for {
msg, ok := al.bus.ConsumeInbound(ctx)
if !ok {
return
}
// Transcribe audio if needed before steering, so the agent sees text.
msg, _ = al.transcribeAudioInMessage(ctx, msg)
logger.InfoCF("agent", "Redirecting inbound message to steering queue",
map[string]any{
"channel": msg.Channel,
"sender_id": msg.SenderID,
"content_len": len(msg.Content),
})
if err := al.Steer(providers.Message{
Role: "user",
Content: msg.Content,
}); err != nil {
logger.WarnCF("agent", "Failed to steer message, will be lost",
map[string]any{
"error": err.Error(),
"channel": msg.Channel,
})
}
}
}
func (al *AgentLoop) Stop() {
al.running.Store(false)
}
@ -1285,33 +1327,6 @@ func (al *AgentLoop) runLLMIteration(
var steeringAfterTools []providers.Message
for i, tc := range normalizedToolCalls {
// Check for steering before executing (except for the first tool)
if i > 0 {
if steerMsgs := al.dequeueSteeringMessages(); len(steerMsgs) > 0 {
steeringAfterTools = steerMsgs
logger.InfoCF("agent", "Steering interrupt: skipping remaining tools",
map[string]any{
"agent_id": agent.ID,
"skipped_from": i,
"total_tools": len(normalizedToolCalls),
"steering_count": len(steerMsgs),
})
// Mark remaining tool calls as skipped
for j := i; j < len(normalizedToolCalls); j++ {
skippedTC := normalizedToolCalls[j]
toolResultMsg := providers.Message{
Role: "tool",
Content: "Skipped due to queued user message.",
ToolCallID: skippedTC.ID,
}
messages = append(messages, toolResultMsg)
agent.Sessions.AddFullMessage(opts.SessionKey, toolResultMsg)
}
break
}
}
argsJSON, _ := json.Marshal(tc.Arguments)
argsPreview := utils.Truncate(string(argsJSON), 200)
logger.InfoCF("agent", fmt.Sprintf("Tool call: %s(%s)", tc.Name, argsPreview),
@ -1414,11 +1429,35 @@ func (al *AgentLoop) runLLMIteration(
messages = append(messages, toolResultMsg)
agent.Sessions.AddFullMessage(opts.SessionKey, toolResultMsg)
// After the last tool, also check for steering messages.
if i == len(normalizedToolCalls)-1 {
if steerMsgs := al.dequeueSteeringMessages(); len(steerMsgs) > 0 {
steeringAfterTools = steerMsgs
// After EVERY tool (including the first and last), check for
// steering messages. If found and there are remaining tools,
// skip them all.
if steerMsgs := al.dequeueSteeringMessages(); len(steerMsgs) > 0 {
remaining := len(normalizedToolCalls) - i - 1
if remaining > 0 {
logger.InfoCF("agent", "Steering interrupt: skipping remaining tools",
map[string]any{
"agent_id": agent.ID,
"completed": i + 1,
"skipped": remaining,
"total_tools": len(normalizedToolCalls),
"steering_count": len(steerMsgs),
})
// Mark remaining tool calls as skipped
for j := i + 1; j < len(normalizedToolCalls); j++ {
skippedTC := normalizedToolCalls[j]
toolResultMsg := providers.Message{
Role: "tool",
Content: "Skipped due to queued user message.",
ToolCallID: skippedTC.ID,
}
messages = append(messages, toolResultMsg)
agent.Sessions.AddFullMessage(opts.SessionKey, toolResultMsg)
}
}
steeringAfterTools = steerMsgs
break
}
}